Merge branch 'main' into peer-acl-multi-source

# Conflicts:
#	client/firewall/nftables/router_linux.go
#	client/firewall/uspfilter/filter.go

.github/dependabot.yml

@@ -3,8 +3,8 @@ updates:
   - package-ecosystem: "github-actions"
     directory: "/"
     schedule:
-      interval: "daily"
-    open-pull-requests-limit: 15
+      interval: "weekly"
+    open-pull-requests-limit: 3
     groups:
       actions:
         patterns:
@@ -22,9 +22,12 @@ updates:
     directories:
       - "/"
     schedule:
-      interval: "daily"
+      interval: "weekly"
     open-pull-requests-limit: 15
     groups:
+      golang-x-packages:
+        patterns:
+          - "golang.org/x/*"
       aws-sdk:
         patterns:
           - "github.com/aws/aws-sdk-go-v2/*"

.github/pull_request_template.md

@@ -2,6 +2,12 @@
 
 ## Issue ticket number and link
 
+<!--
+Required for anything that changes behavior. Link the issue (or the validated
+discussion it came from) that the NetBird team already agreed on. See
+https://github.com/netbirdio/netbird/blob/main/CONTRIBUTING.md#ticket-first-pr-second
+-->
+
 ## Stack
 
 <!-- branch-stack -->
@@ -12,7 +18,9 @@
 - [ ] Is a feature enhancement
 - [ ] It is a refactor
 - [ ] Created tests that fail without the change (if possible)
-- [ ] This change does **not** modify the public API, gRPC protocols, functionality behavior, CLI / service flags, or introduce a new feature — **OR** I have discussed it with the NetBird team beforehand (link the issue / Slack thread in the description). See [CONTRIBUTING.md](https://github.com/netbirdio/netbird/blob/main/CONTRIBUTING.md#discuss-changes-with-the-netbird-team-first).
+- [ ] I ran and tested this change locally — I did not rely on CI to find out whether it works
+- [ ] This PR has a single purpose (not a fix + refactor + feature in one)
+- [ ] This change is a trivial fix, **OR** it links an issue the NetBird team agreed on beforehand. Changes to the public API, gRPC protocols, functionality behavior, CLI / service flags, or new features always need that agreement first. See [CONTRIBUTING.md](https://github.com/netbirdio/netbird/blob/main/CONTRIBUTING.md#ticket-first-pr-second).
 
 > By submitting this pull request, you confirm that you have read and agree to the terms of the [Contributor License Agreement](https://github.com/netbirdio/netbird/blob/main/CONTRIBUTOR_LICENSE_AGREEMENT.md).
 

.github/workflows/test-infrastructure-files.yml

@@ -249,78 +249,35 @@ jobs:
           docker compose exec management ls -l /var/lib/netbird/ | grep -i GeoLite2-City_[0-9]*.mmdb
           docker compose exec management ls -l /var/lib/netbird/ | grep -i geonames_[0-9]*.db
 
-  test-getting-started-script:
+  test-legacy-getting-started-scripts:
     runs-on: ubuntu-latest
     steps:
-      - name: Install jq
-        run: sudo apt-get install -y jq
-
       - name: Checkout code
         uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
         with:
           persist-credentials: false
 
-      - name: run script with Zitadel PostgreSQL
-        run: NETBIRD_DOMAIN=use-ip bash -x infrastructure_files/getting-started-with-zitadel.sh
-
-      - name: test Caddy file gen postgres
-        run: test -f Caddyfile
-
-      - name: test docker-compose file gen postgres
-        run: test -f docker-compose.yml
-
-      - name: test management.json file gen postgres
-        run: test -f management.json
-
-      - name: test turnserver.conf file gen postgres
+      - name: Verify Dex retirement notice
         run: |
-          set -x
-          test -f turnserver.conf
-          grep external-ip turnserver.conf
+          if infrastructure_files/getting-started-with-dex.sh >stdout.txt 2>stderr.txt; then
+            echo "Expected the retired Dex installer to fail"
+            exit 1
+          fi
+          test ! -s stdout.txt
+          grep -Fq "Dex support is not deprecated." stderr.txt
+          grep -Fq "https://docs.netbird.io/selfhosted/selfhosted-quickstart" stderr.txt
+          grep -Fq "https://docs.netbird.io/selfhosted/identity-providers/local" stderr.txt
+          grep -Fq "removed in NetBird v0.80" stderr.txt
 
-      - name: test zitadel.env file gen postgres
-        run: test -f zitadel.env
-
-      - name: test dashboard.env file gen postgres
-        run: test -f dashboard.env
-
-      - name: test relay.env file gen postgres
-        run: test -f relay.env
-
-      - name: test zdb.env file gen postgres
-        run: test -f zdb.env
-
-      - name: Postgres run cleanup
+      - name: Verify Zitadel retirement notice
         run: |
-          docker compose down --volumes --rmi all
-          rm -rf docker-compose.yml Caddyfile zitadel.env dashboard.env machinekey/zitadel-admin-sa.token turnserver.conf management.json zdb.env
-
-      - name: run script with Zitadel CockroachDB
-        run: bash -x infrastructure_files/getting-started-with-zitadel.sh
-        env:
-          NETBIRD_DOMAIN: use-ip
-          ZITADEL_DATABASE: cockroach
-
-      - name: test Caddy file gen CockroachDB
-        run: test -f Caddyfile
-
-      - name: test docker-compose file gen CockroachDB
-        run: test -f docker-compose.yml
-
-      - name: test management.json file gen CockroachDB
-        run: test -f management.json
-
-      - name: test turnserver.conf file gen CockroachDB
-        run: |
-          set -x
-          test -f turnserver.conf
-          grep external-ip turnserver.conf
-
-      - name: test zitadel.env file gen CockroachDB
-        run: test -f zitadel.env
-
-      - name: test dashboard.env file gen CockroachDB
-        run: test -f dashboard.env
-
-      - name: test relay.env file gen CockroachDB
-        run: test -f relay.env
+          if bash infrastructure_files/getting-started-with-zitadel.sh >stdout.txt 2>stderr.txt; then
+            echo "Expected the retired Zitadel installer to fail"
+            exit 1
+          fi
+          test ! -s stdout.txt
+          grep -Fq "Zitadel support and existing Zitadel deployments are not deprecated." stderr.txt
+          grep -Fq "https://docs.netbird.io/selfhosted/selfhosted-quickstart" stderr.txt
+          grep -Fq "https://docs.netbird.io/selfhosted/identity-providers/zitadel" stderr.txt
+          grep -Fq "https://docs.netbird.io/selfhosted/selfhosted-guide" stderr.txt
+          grep -Fq "removed in NetBird v0.80" stderr.txt

.goreleaser_ui.yaml

@@ -24,6 +24,8 @@ builds:
     ldflags:
       - -s -w -X github.com/netbirdio/netbird/version.version={{.Version}} -X main.commit={{.Commit}} -X main.date={{.CommitDate}} -X main.builtBy=goreleaser
     mod_timestamp: "{{ .CommitTimestamp }}"
+    tags:
+      - production
 
   - id: netbird-ui-windows-amd64
     dir: client/ui
@@ -39,6 +41,8 @@ builds:
       - -s -w -X github.com/netbirdio/netbird/version.version={{.Version}} -X main.commit={{.Commit}} -X main.date={{.CommitDate}} -X main.builtBy=goreleaser
       - -H windowsgui
     mod_timestamp: "{{ .CommitTimestamp }}"
+    tags:
+      - production
 
   - id: netbird-ui-windows-arm64
     dir: client/ui
@@ -55,6 +59,8 @@ builds:
       - -s -w -X github.com/netbirdio/netbird/version.version={{.Version}} -X main.commit={{.Commit}} -X main.date={{.CommitDate}} -X main.builtBy=goreleaser
       - -H windowsgui
     mod_timestamp: "{{ .CommitTimestamp }}"
+    tags:
+      - production
 
 archives:
   - id: linux-arch

.goreleaser_ui_darwin.yaml

@@ -29,6 +29,8 @@ builds:
     ldflags:
       - -s -w -X github.com/netbirdio/netbird/version.version={{.Version}} -X main.commit={{.Commit}} -X main.date={{.CommitDate}} -X main.builtBy=goreleaser
     mod_timestamp: "{{ .CommitTimestamp }}"
+    tags:
+      - production
 
 universal_binaries:
   - id: netbird-ui-darwin

CONTRIBUTING.md

@@ -1,6 +1,6 @@
 # Contributing to NetBird
 
-Thanks for your interest in contributing to NetBird. 
+Thanks for your interest in contributing to NetBird.
 
 There are many ways that you can contribute:
 - Reporting issues
@@ -10,12 +10,69 @@ There are many ways that you can contribute:
 
 If you haven't already, join our slack workspace [here](https://docs.netbird.io/slack-url), we would love to discuss topics that need community contribution and enhancements to existing features.
 
+## Ticket first, PR second
+
+**Open a ticket and wait for feedback before you open a pull request.** Every PR
+that changes behavior must link to an issue the NetBird team has agreed on. A PR
+that arrives without one may be closed and redirected to a discussion, no matter
+how good the code is.
+
+Issues in this repository are maintainer-curated work items, so the flow starts
+in [Discussions](https://github.com/netbirdio/netbird/discussions):
+
+1. **Open a discussion.** Use
+   [Issue Triage](https://github.com/netbirdio/netbird/discussions/new?category=issue-triage)
+   for a bug, regression, or unexpected behavior, and
+   [Ideas & Feature Requests](https://github.com/netbirdio/netbird/discussions/new?category=ideas-feature-requests)
+   for a feature, enhancement, or integration idea. Setup and usage questions
+   belong in
+   [Q&A / Support](https://github.com/netbirdio/netbird/discussions/new?category=q-a-support).
+   Never report a security vulnerability in public — follow the
+   [security policy](https://github.com/netbirdio/netbird/security/policy)
+   instead.
+2. **Wait for feedback.** DevRel validates and reproduces the report, and a
+   maintainer confirms the direction. We may ask for more detail or propose a
+   different approach. Validated discussions become issues.
+3. **Then write the code**, following the approach agreed in the issue, and open
+   the PR linking that issue.
+
+Trivial fixes — a typo, a broken link, a documentation correction, or a one-line
+fix that already has an issue — can go straight to a PR. Everything else starts
+with a ticket. When in doubt, ask in the discussion or on
+[Slack](https://docs.netbird.io/slack-url); an hour of conversation up front
+regularly saves a week of rework.
+
+### High-risk areas
+
+These always need the design discussed and agreed in the issue **before** you
+write code:
+
+- **Public API** — REST / management API, OpenAPI schema, dashboard-facing contracts
+- **gRPC protocols** — management, signal, relay, and client daemon protos
+- **Functionality behavior** — anything existing deployments would experience differently after an upgrade
+- **Peer connectivity** — ICE and NAT traversal, relay selection, WireGuard® and Rosenpass key handling
+- **Client system integration** — routing, firewall, DNS, and interface management
+- **Authentication and authorization** — IdP integration, tokens, permissions, cryptography
+- **CLI / service flags**, configuration file format, and daemon IPC
+- **Store and database schema** — models and migrations
+- **New features**
+
+These surfaces are NetBird's contract with operators, self-hosters, and
+downstream integrators, and changes to them have compatibility, security, and
+release-planning implications. Agreeing on the direction early lets the PR
+review focus on implementation rather than design.
+
+Typical bug fixes, internal refactors, documentation updates, and tests do not
+need a design discussion, but should still be tied to an issue so the work is
+visible and nobody duplicates it.
+
 ## Contents
 
 - [Contributing to NetBird](#contributing-to-netbird)
+    - [Ticket first, PR second](#ticket-first-pr-second)
+        - [High-risk areas](#high-risk-areas)
     - [Contents](#contents)
     - [Code of conduct](#code-of-conduct)
-    - [Discuss changes with the NetBird team first](#discuss-changes-with-the-netbird-team-first)
     - [Directory structure](#directory-structure)
     - [Development setup](#development-setup)
         - [Requirements](#requirements)
@@ -24,6 +81,7 @@ If you haven't already, join our slack workspace [here](https://docs.netbird.io/
         - [Build and start](#build-and-start)
         - [Test suite](#test-suite)
     - [Checklist before submitting a PR](#checklist-before-submitting-a-pr)
+    - [When we close a PR](#when-we-close-a-pr)
     - [Other project repositories](#other-project-repositories)
     - [Contributor License Agreement](#contributor-license-agreement)
 
@@ -34,42 +92,66 @@ Conduct which can be found in the file [CODE_OF_CONDUCT.md](CODE_OF_CONDUCT.md).
 By participating, you are expected to uphold this code. Please report
 unacceptable behavior to community@netbird.io.
 
-## Discuss changes with the NetBird team first
-
-Changes to the **public API**, **gRPC protocols**, **functionality behavior**, **CLI / service flags**, or **new features** should be discussed with the NetBird team before you start the work. These surfaces are part of NetBird's contract with operators, self-hosters, and downstream integrators, and changes to them have compatibility, security, and release-planning implications that benefit from an early conversation.
-
-Open an issue or reach out on [Slack](https://docs.netbird.io/slack-url) to talk through what you have in mind. We'll help shape the change, flag any constraints we know about, and confirm the direction so the PR review can focus on implementation rather than design.
-
-Typical bug fixes, internal refactors, documentation updates, and tests do not need pre-discussion — open the PR directly.
-
 ## Directory structure
 
-The NetBird project monorepo is organized to maintain most of its individual dependencies code within their directories, except for a few auxiliary or shared packages.
+The NetBird project monorepo keeps most of each component's code within its own
+directory, except for a few auxiliary or shared packages. Protocol definitions
+and the client-side service clients live under [/shared](/shared), because both
+the agent and the services import them.
 
-The most important directories are:
+**Agent**
 
-- [/.github](/.github) - Github actions workflow files and issue templates
 - [/client](/client) - NetBird agent code
-- [/client/cmd](/client/cmd) - NetBird agent cli code
+- [/client/cmd](/client/cmd) - NetBird agent CLI code
 - [/client/internal](/client/internal) - NetBird agent business logic code
-- [/client/proto](/client/proto) - NetBird agent daemon GRPC proto files
 - [/client/server](/client/server) - NetBird agent daemon code for background execution
-- [/client/ui](/client/ui) - NetBird agent UI code
-- [/encryption](/encryption) - Contain main encryption code for agent communication
-- [/iface](/iface) - Wireguard® interface code
-- [/infrastructure_files](/infrastructure_files) - Getting started files containing docker and template scripts
+- [/client/proto](/client/proto) - NetBird agent daemon gRPC proto files
+- [/client/iface](/client/iface) - WireGuard® interface code
+- [/client/firewall](/client/firewall) - Platform firewall backends (nftables, iptables, pf, WFP, userspace)
+- [/client/ssh](/client/ssh) - Built-in SSH server and client
+- [/client/ui](/client/ui) - NetBird agent UI code (Wails v3 + React)
+- [/client/android](/client/android), [/client/ios](/client/ios) - Mobile platform bindings
+- [/client/wasm](/client/wasm) - WebAssembly build of the agent
+- [/client/mdm](/client/mdm) - MDM-delivered policy handling
+- [/client/system](/client/system) - Host and system information collection
+
+**Control plane services**
+
 - [/management](/management) - Management service code
-- [/management/client](/management/client) - Management service client code which is imported by the agent code
-- [/management/proto](/management/proto) - Management service GRPC proto files
 - [/management/server](/management/server) - Management service server code
 - [/management/server/http](/management/server/http) - Management service REST API code
+- [/management/server/store](/management/server/store) - Persistence layer and migrations
 - [/management/server/idp](/management/server/idp) - Management service IDP management code
-- [/release_files](/release_files) - Files that goes into release packages
+- [/management/server/peer](/management/server/peer), [/management/server/groups](/management/server/groups), [/management/server/networks](/management/server/networks), [/management/server/posture](/management/server/posture), [/management/server/permissions](/management/server/permissions) - Core domain packages
 - [/signal](/signal) - Signal service code
-- [/signal/client](/signal/client) - Signal service client code which is imported by the agent code
 - [/signal/peer](/signal/peer) - Signal service peer message logic
-- [/signal/proto](/signal/proto) - Signal service GRPC proto files
 - [/signal/server](/signal/server) - Signal service server code
+- [/relay](/relay) - Relay service code
+- [/relay/protocol](/relay/protocol) - Relay wire protocol
+- [/proxy](/proxy) - Identity-aware proxy used by Agent Network (LLM routing, ACME, access logs)
+- [/agent-network](/agent-network) - Agent Network overview and documentation
+- [/upload-server](/upload-server) - Debug bundle upload service
+
+**Shared code**
+
+- [/shared/management/proto](/shared/management/proto) - Management service gRPC proto files
+- [/shared/management/client](/shared/management/client) - Management service client code which is imported by the agent code
+- [/shared/management/http/api](/shared/management/http/api) - OpenAPI specification and generated REST API types
+- [/shared/signal/proto](/shared/signal/proto) - Signal service gRPC proto files
+- [/shared/signal/client](/shared/signal/client) - Signal service client code which is imported by the agent code
+- [/shared/relay](/shared/relay) - Relay client and shared relay types
+- [/shared/auth](/shared/auth), [/shared/sshauth](/shared/sshauth) - Shared authentication primitives
+- [/encryption](/encryption) - Contain main encryption code for agent communication
+- [/dns](/dns), [/route](/route), [/stun](/stun), [/sharedsock](/sharedsock), [/util](/util) - Shared networking and utility primitives
+- [/flow](/flow) - Flow event protocol shared by the agent and Management
+
+**Build, test, and packaging**
+
+- [/.github](/.github) - Github actions workflow files, issue templates, and the pull request template
+- [/e2e](/e2e) - End-to-end test suites and harness
+- [/infrastructure_files](/infrastructure_files) - Getting started files containing docker and template scripts
+- [/release_files](/release_files) - Files that goes into release packages
+- [/tools](/tools) - Development and maintenance tooling
 
 
 ## Development setup
@@ -234,12 +316,22 @@ cd client/ui
 task dev
 ```
 
-Pass daemon flags after `--`:
+Pass daemon flags after `--`, pointing the UI at the socket the daemon serves:
 
 ```
-task dev -- --daemon-addr=tcp://127.0.0.1:41731
+task dev -- --daemon-addr=unix:///var/run/netbird.sock   # Linux, macOS
+task dev -- --daemon-addr=npipe://netbird                # Windows
 ```
 
+On Windows the daemon serves a named pipe (`npipe://netbird`). Which path that
+ends up being depends on what the daemon may create: as a service or elevated it
+serves `\\.\pipe\ProtectedPrefix\Administrators\netbird`, which no unprivileged
+process can take from it, and otherwise it falls back to `\\.\pipe\netbird`.
+Clients try both and check who owns the pipe before using the plain one. Avoid
+`tcp://127.0.0.1:41731`: loopback TCP carries no caller identity, so the daemon
+refuses the operations that require an administrator and you will not exercise
+those paths.
+
 Production build (frontend assets embedded into the binary, output in `client/ui/bin/`):
 
 ```
@@ -324,23 +416,172 @@ The installer `netbird-installer.exe` will be created in root directory.
 
 ### Test suite
 
-The tests can be started via:
+The host-safe unit tests run as a normal user and leave host networking
+untouched:
 
 ```
-cd netbird
-go test -exec sudo ./...
+make test-unit
 ```
+
+Tests that need root and mutate host networking (firewall, routing, interface
+management) carry the `privileged` build tag and run inside a
+`--privileged --cap-add=NET_ADMIN` Docker container:
+
+```
+make test-privileged
+```
+
+Narrow a privileged run with environment variables:
+
+```
+PRIV_RUN=TestNftablesManager PRIV_PKGS=./client/firewall/nftables/... make test-privileged
+```
+
+Single packages can be run directly, adding `-race` when the change touches
+shared state:
+
+```
+go test -race ./client/internal/dns/...
+```
+
 > On Windows use a powershell with administrator privileges
 
 ## Checklist before submitting a PR
-As a critical network service and open-source project, we must enforce a few things before submitting the pull-requests:
+
+As a critical network service and open-source project, we must enforce a few
+things before submitting a pull request. The
+[pull request template](/.github/pull_request_template.md) mirrors this list —
+fill it in rather than deleting it.
+
+### Link the issue
+
+The PR description must link the agreed issue (or the validated discussion it
+came from). See [Ticket first, PR second](#ticket-first-pr-second).
+
+### Run it locally
+
+**If you can't run it, you can't submit it.** Build the affected components and
+exercise the change on a real setup — see [Build and start](#build-and-start).
+"CI will tell me" is not acceptable for a VPN agent that runs as root on other
+people's machines.
+
+### Green CI, and answer the bots
+
+We do not start reviewing while CI is red. Get the pipeline green first — a
+failing build, lint, or test means the PR is not ready for review.
+
+Alongside the test workflows, your PR is reviewed by CodeRabbit and scanned by
+SonarCloud, Snyk, and Codecov. Read what they report and either fix it or reply
+with why it does not apply; please do not resolve the threads without a
+response. They are not always right — this codebase has privileged,
+platform-specific, and concurrency-heavy paths that static analysis reads poorly
+— so push back when a finding is wrong rather than changing correct code to
+silence it. Security and dependency findings are the exception: treat those as
+real until shown otherwise. Do not edit workflows, thresholds, or scanner
+configuration to make a check pass.
+
+### One PR, one purpose
+
+Bug fix, refactor, feature: separate PRs. Mixed PRs are slow to review, hard to
+revert, and may be closed with a request to split them.
+
+### Keep it small
+
+Size is the strongest predictor of how long a PR waits for review. Aim for under
+roughly 400 changed lines across under 20 files. Past about 1000 lines or 50
+files, expect to be asked to split the change — and large PRs from outside the
+core team may be blocked until the scope has been agreed in a ticket. This is
+not only about reviewer time: NetBird's agent runs as root on other people's
+machines, and a sprawling diff cannot be reviewed with the care that deserves.
+
+Measure by hand-written code, excluding generated output, `go.sum`, and
+fixtures. If a change genuinely cannot be small — a protocol migration, a
+cross-component rename — agree the split in the issue before you start, and land
+it as a series of PRs that each build and make sense on their own.
+
+### Avoid force-pushing during review
+
+Once a PR is open, push new commits instead of rewriting history. A force-push
+detaches existing review comments from their lines, throws away the
+"changes since your last review" diff, and loses the CI history that showed
+which commit broke what. Since we squash on merge, there is nothing to gain from
+a tidy branch history.
+
+Force-pushing is sometimes unavoidable — rebasing to clear a real conflict, or
+removing a secret or large binary committed by mistake. When that happens, leave
+a comment on the PR so reviewers know their anchors moved.
+
+### Quality checks
+
+Run these from the repository root before pushing:
+
+```shell
+go fmt ./...
+make lint        # golangci-lint on files changed against origin/main
+make lint-all    # full-repository lint, matches CI
+make test-unit   # host-safe unit tests
+```
+
+`make setup-hooks` wires `make lint` into a pre-push hook so the fast lint runs
+automatically. If your change touches privileged paths (firewall, routing,
+interface management), also run `make test-privileged`, which executes the
+`privileged`-tagged suite inside a Docker container with `NET_ADMIN`.
+
+### Code standards
+
 - Keep functions as simple as possible, with a single purpose
 - Use private functions and constants where possible
 - Comment on any new public functions
 - Add unit tests for any new public function
+- Comment the **why**, not the **what** — explain non-obvious decisions, invariants, and constraints, not the line below
+- Keep comments within 90 characters per line and roughly 250 characters per comment; when a block needs more explanation than that, extract a named function instead of writing a longer comment (see [AGENTS.md](AGENTS.md#length-budget))
+
+### PR title and commits
+
+PR titles must start with a bracketed tag, enforced by
+[pr-title-check.yml](/.github/workflows/pr-title-check.yml):
+
+```text
+[client] Authorize daemon IPC callers by their local identity
+[management,client] Add MDM policy support
+```
+
+Use a comma-separated list inside a single pair of brackets when a change spans
+components. The `allowedTags` array in
+[pr-title-check.yml](/.github/workflows/pr-title-check.yml) is the source of
+truth — at the time of writing it accepts `management`, `client`, `signal`,
+`proxy`, `relay`, `misc`, `infrastructure`, `self-hosted`, and `doc`.
+
+Commit subjects follow the same convention — keep them short and put the
+reasoning in the body, why before what, with no bullet list of files changed.
+
+Keep the PR description itself under 1000 words on top of the template text.
+Reviewers read the diff; the description explains what the diff cannot.
 
 > When pushing fixes to the PR comments, please push as separate commits; we will squash the PR before merging, so there is no need to squash it before pushing it, and we are more than okay with 10-100 commits in a single PR. This helps review the fixes to the requested changes.
 
+### Documentation
+
+User-facing changes need a matching PR in
+[netbirdio/docs](https://github.com/netbirdio/docs); link it in the PR
+description, or state why documentation is not needed.
+
+## When we close a PR
+
+We would rather redirect early than let a PR sit. We may close one if:
+
+- It changes behavior with no linked issue, or the approach was never agreed with a maintainer
+- The change was clearly never run or tested locally
+- CI has been red without a response
+- It mixes unrelated purposes, or the purpose is not clear
+- It is far too large to review and the scope was never agreed in a ticket
+- The author cannot answer questions about their own change — including PRs that read as unreviewed model output, where review turns into a relay between the maintainer and an LLM. Tooling is fine; unreviewed output is not, you are responsible for the code you sign your name to
+- There has been no activity for 14 days after we requested changes
+
+A closed PR is not a rejected idea. Take it back to the
+[discussion](https://github.com/netbirdio/netbird/discussions), settle the
+approach, and reopen the work from there.
+
 ## Other project repositories
 
 NetBird project is composed of 3 main repositories:

SECURITY.md

@@ -1,12 +1,70 @@
 # Security Policy
 
-NetBird's goal is to provide a secure network. If you find a vulnerability or bug, please report it by opening an issue [here](https://github.com/netbirdio/netbird/issues/new?assignees=&labels=&template=bug-issue-report.md&title=) or by contacting us by email.
-
-There has yet to be an official bug bounty program for the NetBird project.
-
-## Supported Versions
-- We currently support only the latest version
+NetBird's goal is to provide a secure network. The client runs as a privileged service on every machine it is installed on,
+so we take reports about it seriously and we publish what we fix.
 
 ## Reporting a Vulnerability
 
-Please report security issues to `security@netbird.io`
+**Please do not open a public issue for a security vulnerability.** Public issues are visible to everyone, including before
+a fix is available.
+
+Report security issues one of these two ways:
+
+- **GitHub private vulnerability reporting** — [open a private report](https://github.com/netbirdio/netbird/security/advisories/new)
+  on this repository. This is the preferred route: it keeps the discussion, the draft advisory, and the credit in one place.
+- **Email** — `security@netbird.io`.
+
+If the finding affects NetBird Cloud or our hosted infrastructure rather than the open-source code, email us rather than
+filing a repository report.
+
+### What to include
+
+A report is easier to act on when it contains:
+
+- The affected component (client, management, signal, relay, dashboard) and the version or commit you tested
+- The platform and configuration, where relevant — operating system, self-hosted or NetBird Cloud, container or host install
+- What an attacker needs before they can exploit it: network position, an account, local access, a specific privilege level
+- Steps to reproduce, and a proof of concept if you have one
+- The impact you believe it has
+
+Partial reports are still welcome. If you are unsure whether something is a security issue, send it to `security@netbird.io`
+and let us make that call.
+
+## What to expect from us
+
+- **We acknowledge your report** and tell you whether we can reproduce it.
+- **We work with you on severity and scope.** If we assess it differently than you do, we will explain why rather than
+  silently downgrade it.
+- **We fix and release**, then publish a [GitHub Security Advisory](https://github.com/netbirdio/netbird/security/advisories)
+  naming the affected version range and the patched version.
+- **We credit reporters who want to be credited.** Tell us the name or handle you would like used, or that you would rather
+  stay anonymous.
+- **We keep you in the loop** until the advisory is published.
+
+We ask that you give us a reasonable opportunity to ship a fix before disclosing the issue publicly, and that you avoid
+accessing, modifying, or exfiltrating data belonging to other people while testing. Testing against your own installation
+or your own account is always fine.
+
+## Supported Versions
+
+We support the latest release. Security fixes ship in the next version rather than as backports to older releases, so
+upgrading to the current release is how you get them.
+
+Release notifications are available by watching [releases](https://github.com/netbirdio/netbird/releases).
+
+## Published advisories
+
+Every vulnerability we fix is published as a GitHub Security Advisory on the
+[advisories page](https://github.com/netbirdio/netbird/security/advisories), including the affected version range, the
+patched version, and the reporter's credit. Advisories for the Go module are also distributed through the Go vulnerability
+database, so `govulncheck` will report them against your dependencies.
+
+## Bug bounty
+
+There is no official bug bounty program for the NetBird project. We credit reporters in advisories, and we are grateful for
+the work, but we cannot currently offer payment for reports.
+
+## Non-security bugs
+
+For bugs that are not security issues, please use the
+[issue tracker](https://github.com/netbirdio/netbird/discussions/new/choose).

client/android/client.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"os"
 	"slices"
+	"strings"
 	"sync"
 	"time"
 
@@ -75,6 +76,24 @@ type Client struct {
 	connectClient *internal.ConnectClient
 	config        *profilemanager.Config
 	cacheDir      string
+
+	stateChangeMu    sync.Mutex
+	stateChangeSubID string
+	eventSub         *peer.EventSubscription
+	// Closed to stop the watch goroutines from delivering buffered items to a
+	// listener that has been removed or replaced. See stopStateChangeWatchLocked.
+	stateChangeDone chan struct{}
+
+	// Latched "the server wants an interactive login": survives the engine
+	// restarts that replace the run loop's context state. See Client.Status.
+	// Guarded by loginRequiredMu together with loginCleared, which counts
+	// clears so a stale observation cannot re-latch over one.
+	loginRequiredMu sync.Mutex
+	loginRequired   bool
+	loginCleared    uint64
+
+	extendMu     sync.Mutex
+	extendCancel context.CancelFunc
 }
 
 func (c *Client) setState(cfg *profilemanager.Config, cacheDir string, cc *internal.ConnectClient) {
@@ -148,11 +167,16 @@ func (c *Client) Run(platformFiles PlatformFiles, urlOpener URLOpener, isAndroid
 	if err != nil {
 		return err
 	}
-
 	// todo do not throw error in case of cancelled context
 	ctx = internal.CtxInitState(ctx)
 	connectClient := internal.NewConnectClient(ctx, cfg, c.recorder)
 	c.setState(cfg, cacheDir, connectClient)
+	// This path runs the interactive SSO flow, so reaching here means the peer
+	// is authenticated again — release the latch Status() reports from. Clear
+	// only once the fresh connect client is installed: until then Status()
+	// still reads the previous run's context state, which holds the NeedsLogin
+	// that prompted this login, and would re-latch what was just cleared.
+	c.clearLoginRequired()
 	return connectClient.RunOnAndroid(c.tunAdapter, c.iFaceDiscover, c.networkChangeListener, slices.Clone(dns.items), dnsReadyListener, stateFile, cacheDir)
 }
 
@@ -277,7 +301,7 @@ func (c *Client) DebugBundle(platformFiles PlatformFiles, anonymize bool) (strin
 	uploadCtx, cancel := context.WithTimeout(context.Background(), 2*time.Minute)
 	defer cancel()
 
-	key, err := debug.UploadDebugBundle(uploadCtx, types.DefaultBundleURL, cfg.ManagementURL.String(), path)
+	key, err := debug.UploadDebugBundle(uploadCtx, types.DefaultBundleURL, cfg.ManagementURL.String(), path, false)
 	if err != nil {
 		return "", fmt.Errorf("upload debug bundle: %w", err)
 	}
@@ -299,6 +323,13 @@ func (c *Client) SetInfoLogLevel() {
 // PeersList return with the list of the PeerInfos
 func (c *Client) PeersList() *PeerInfoArray {
 
+	// The recorder only caches transfer counters and handshake times; nothing
+	// refreshes them on its own, so without this they read as zero. The desktop
+	// daemon does the same before serving a full peer status.
+	if err := c.recorder.RefreshWireGuardStats(); err != nil {
+		log.Debugf("failed to refresh WireGuard stats: %v", err)
+	}
+
 	fullStatus := c.recorder.GetFullStatus()
 
 	peerInfos := make([]PeerInfo, len(fullStatus.Peers))
@@ -309,6 +340,20 @@ func (c *Client) PeersList() *PeerInfoArray {
 			FQDN:       p.FQDN,
 			ConnStatus: int(p.ConnStatus),
 			Routes:     PeerRoutes{routes: maps.Keys(p.GetRoutes())},
+
+			PubKey:                     p.PubKey,
+			Latency:                    formatDuration(p.Latency),
+			LatencyMs:                  p.Latency.Milliseconds(),
+			BytesRx:                    p.BytesRx,
+			BytesTx:                    p.BytesTx,
+			ConnStatusUpdate:           formatTime(p.ConnStatusUpdate),
+			Relayed:                    p.Relayed,
+			RosenpassEnabled:           p.RosenpassEnabled,
+			LastWireguardHandshake:     formatTime(p.LastWireguardHandshake),
+			LocalIceCandidateType:      p.LocalIceCandidateType,
+			RemoteIceCandidateType:     p.RemoteIceCandidateType,
+			LocalIceCandidateEndpoint:  p.LocalIceCandidateEndpoint,
+			RemoteIceCandidateEndpoint: p.RemoteIceCandidateEndpoint,
 		}
 		peerInfos[n] = pi
 	}
@@ -439,10 +484,6 @@ func (c *Client) RemoveConnectionListener() {
 	c.recorder.RemoveConnectionListener()
 }
 
-func (c *Client) toggleRoute(command routeCommand) error {
-	return command.toggleRoute()
-}
-
 func (c *Client) getRouteManager() (routemanager.Manager, error) {
 	client := c.getConnectClient()
 	if client == nil {
@@ -462,22 +503,22 @@ func (c *Client) getRouteManager() (routemanager.Manager, error) {
 	return manager, nil
 }
 
-func (c *Client) SelectRoute(route string) error {
+func (c *Client) SelectRoute(id string) error {
 	manager, err := c.getRouteManager()
 	if err != nil {
 		return err
 	}
 
-	return c.toggleRoute(selectRouteCommand{route: route, manager: manager})
+	return manager.SelectRoutes([]route.NetID{route.NetID(id)}, true)
 }
 
-func (c *Client) DeselectRoute(route string) error {
+func (c *Client) DeselectRoute(id string) error {
 	manager, err := c.getRouteManager()
 	if err != nil {
 		return err
 	}
 
-	return c.toggleRoute(deselectRouteCommand{route: route, manager: manager})
+	return manager.DeselectRoutes([]route.NetID{route.NetID(id)})
 }
 
 // getNetworkDomainsFromRoute extracts domains from a route and enriches each domain
@@ -512,3 +553,28 @@ func exportEnvList(list *EnvList) {
 		}
 	}
 }
+
+// formatDuration renders a duration for display, trimming the fractional part
+// to two digits so latencies read as "12.34ms" rather than "12.345678ms".
+func formatDuration(d time.Duration) string {
+	ds := d.String()
+	dotIndex := strings.Index(ds, ".")
+	if dotIndex == -1 {
+		return ds
+	}
+
+	endIndex := min(dotIndex+3, len(ds))
+
+	// Skip the remaining digits so only the unit suffix is appended back.
+	unitStart := endIndex
+	for unitStart < len(ds) && ds[unitStart] >= '0' && ds[unitStart] <= '9' {
+		unitStart++
+	}
+	return ds[:endIndex] + ds[unitStart:]
+}
+
+// formatTime renders a timestamp in UTC using a fixed layout. The zero time is
+// passed through as-is so the UI can recognise it and show "never" instead.
+func formatTime(t time.Time) string {
+	return t.UTC().Format("2006-01-02 15:04:05")
+}

client/android/peer_notifier.go

@@ -12,12 +12,30 @@ const (
 )
 
 // PeerInfo describe information about the peers. It designed for the UI usage
+//
+// The fields below ConnStatus back the peer detail screen. Durations and times
+// are pre-formatted into strings so the UI does not have to know Go's layouts;
+// Latency is additionally exposed as LatencyMs for colour coding.
 type PeerInfo struct {
 	IP         string
 	IPv6       string
 	FQDN       string
 	ConnStatus int
 	Routes     PeerRoutes
+
+	PubKey                     string
+	Latency                    string
+	LatencyMs                  int64
+	BytesRx                    int64
+	BytesTx                    int64
+	ConnStatusUpdate           string
+	Relayed                    bool
+	RosenpassEnabled           bool
+	LastWireguardHandshake     string
+	LocalIceCandidateType      string
+	RemoteIceCandidateType     string
+	LocalIceCandidateEndpoint  string
+	RemoteIceCandidateEndpoint string
 }
 
 func (p *PeerInfo) GetPeerRoutes() *PeerRoutes {

client/android/profile_manager.go

@@ -189,6 +189,19 @@ func (pm *ProfileManager) LogoutProfile(id string) error {
 	return nil
 }
 
+// RenameProfile changes a profile's display name. The profile ID, and therefore
+// its on-disk filename, is left untouched: only the "name" field of the config
+// is rewritten. This works for the default profile too, whose config lives in
+// netbird.cfg rather than under profiles/.
+func (pm *ProfileManager) RenameProfile(id string, newName string) error {
+	if err := pm.serviceMgr.RenameProfile(profilemanager.ID(id), androidUsername, newName); err != nil {
+		return fmt.Errorf("failed to rename profile: %w", err)
+	}
+
+	log.Infof("renamed profile %s to: %s", id, newName)
+	return nil
+}
+
 // RemoveProfile deletes a profile
 func (pm *ProfileManager) RemoveProfile(id string) error {
 	// Use ServiceManager (removes profile from profiles/ directory)

client/android/route_command.go

@@ -1,70 +0,0 @@
-//go:build android
-
-package android
-
-import (
-	"fmt"
-
-	log "github.com/sirupsen/logrus"
-	"golang.org/x/exp/maps"
-
-	"github.com/netbirdio/netbird/client/internal/routemanager"
-	"github.com/netbirdio/netbird/route"
-)
-
-func executeRouteToggle(id string, manager routemanager.Manager,
-	operationName string,
-	routeOperation func(routes []route.NetID, allRoutes []route.NetID) error) error {
-	netID := route.NetID(id)
-	routes := []route.NetID{netID}
-
-	routesMap := manager.GetClientRoutesWithNetID()
-	routes = route.ExpandV6ExitPairs(routes, routesMap)
-
-	log.Debugf("%s with ids: %v", operationName, routes)
-
-	if err := routeOperation(routes, maps.Keys(routesMap)); err != nil {
-		log.Debugf("error when %s: %s", operationName, err)
-		return fmt.Errorf("error %s: %w", operationName, err)
-	}
-
-	manager.TriggerSelection(manager.GetClientRoutes())
-
-	return nil
-}
-
-type routeCommand interface {
-	toggleRoute() error
-}
-
-type selectRouteCommand struct {
-	route   string
-	manager routemanager.Manager
-}
-
-func (s selectRouteCommand) toggleRoute() error {
-	routeSelector := s.manager.GetRouteSelector()
-	if routeSelector == nil {
-		return fmt.Errorf("no route selector available")
-	}
-
-	routeOperation := func(routes []route.NetID, allRoutes []route.NetID) error {
-		return routeSelector.SelectRoutes(routes, true, allRoutes)
-	}
-
-	return executeRouteToggle(s.route, s.manager, "selecting route", routeOperation)
-}
-
-type deselectRouteCommand struct {
-	route   string
-	manager routemanager.Manager
-}
-
-func (d deselectRouteCommand) toggleRoute() error {
-	routeSelector := d.manager.GetRouteSelector()
-	if routeSelector == nil {
-		return fmt.Errorf("no route selector available")
-	}
-
-	return executeRouteToggle(d.route, d.manager, "deselecting route", routeSelector.DeselectRoutes)
-}

client/android/session.go

@@ -0,0 +1,309 @@
+//go:build android
+
+package android
+
+import (
+	"context"
+	"fmt"
+
+	log "github.com/sirupsen/logrus"
+
+	"github.com/netbirdio/netbird/client/internal"
+	"github.com/netbirdio/netbird/client/internal/auth"
+	"github.com/netbirdio/netbird/client/internal/auth/sessionwatch"
+	"github.com/netbirdio/netbird/client/internal/peer"
+	cProto "github.com/netbirdio/netbird/client/proto"
+)
+
+// StateChangeListener receives client state notifications.
+//
+// OnStateChanged is a payload-free wake-up whenever the state snapshot
+// changed: connection state, the run-loop status label (e.g. NeedsLogin) or
+// the session deadline. It mirrors the daemon's SubscribeStatus stream
+// trigger — on each signal the consumer pulls the fresh values via
+// Status() / SessionExpiresAtUnix().
+//
+// OnSessionExpiring forwards the engine's session-expiry warnings, fired at
+// sessionwatch.WarningLead before the deadline and again at FinalWarningLead
+// (finalWarning true). The second one is suppressed when the user dismissed
+// the first via DismissSessionWarning. The daemon turns the same events into
+// its tray notification.
+type StateChangeListener interface {
+	OnStateChanged()
+	OnSessionExpiring(expiresAtUnix int64, leadMinutes int64, finalWarning bool)
+}
+
+// Status returns the connect run-loop's status label — the same value the
+// desktop daemon serves in StatusResponse.Status. "NeedsLogin" means the
+// management server rejected the peer and an interactive login is required.
+//
+// The label is latched: the run loop keeps its status in a per-run context
+// state, which a restart replaces with a fresh Idle one, so an engine restart
+// (network change, always-on) would otherwise erase the fact that the peer
+// still needs to log in. Only a successful interactive login or extend clears
+// it — see clearLoginRequired.
+func (c *Client) Status() string {
+	latched, generation := c.loginRequiredState()
+	if latched {
+		return string(internal.StatusNeedsLogin)
+	}
+	cc := c.getConnectClient()
+	if cc == nil {
+		return string(internal.StatusIdle)
+	}
+	status := cc.Status()
+	if status == internal.StatusNeedsLogin {
+		c.latchLoginRequired(generation)
+	}
+	return string(status)
+}
+
+func (c *Client) loginRequiredState() (bool, uint64) {
+	c.loginRequiredMu.Lock()
+	defer c.loginRequiredMu.Unlock()
+	return c.loginRequired, c.loginCleared
+}
+
+// latchLoginRequired records a NeedsLogin observation, unless a clear landed
+// while the caller was reading the run loop's status: cc.Status() is read
+// outside the lock, so a login or extend completing in that window would
+// otherwise be undone by this stale observation, stranding the UI on
+// "login required" over a healthy session.
+func (c *Client) latchLoginRequired(observedGeneration uint64) {
+	c.loginRequiredMu.Lock()
+	defer c.loginRequiredMu.Unlock()
+	if c.loginCleared != observedGeneration {
+		return
+	}
+	c.loginRequired = true
+}
+
+// clearLoginRequired releases the latch after a successful interactive login
+// or session extend, and invalidates any observation already in flight.
+func (c *Client) clearLoginRequired() {
+	c.loginRequiredMu.Lock()
+	defer c.loginRequiredMu.Unlock()
+	c.loginRequired = false
+	c.loginCleared++
+}
+
+// SessionExpiresAtUnix returns the SSO session deadline as unix seconds, or 0
+// when no deadline is known (not SSO-registered, expiry disabled, or the
+// engine has not received one yet). A past value means the session expired.
+// Mirror of StatusResponse.sessionExpiresAt on the desktop daemon.
+func (c *Client) SessionExpiresAtUnix() int64 {
+	deadline := c.recorder.GetSessionExpiresAt()
+	if deadline.IsZero() {
+		return 0
+	}
+	return deadline.Unix()
+}
+
+// SetStateChangeListener registers the state notification listener.
+// Replaces any previously registered listener; remove it with
+// RemoveStateChangeListener.
+func (c *Client) SetStateChangeListener(listener StateChangeListener) {
+	c.stateChangeMu.Lock()
+	defer c.stateChangeMu.Unlock()
+	c.stopStateChangeWatchLocked()
+	if listener == nil {
+		return
+	}
+
+	// Both subscriptions are buffered (one pending tick, ten pending events),
+	// so unsubscribing is not enough to stop callbacks: the loops would drain
+	// what is already queued and deliver it to a listener the caller has
+	// already removed or replaced. Gate every callback on this registration's
+	// own signal, which is closed before unsubscribing.
+	done := make(chan struct{})
+	c.stateChangeDone = done
+
+	id, ch := c.recorder.SubscribeToStateChanges()
+	c.stateChangeSubID = id
+	// The channel is closed by UnsubscribeFromStateChanges, which ends the
+	// goroutine. Ticks are coalesced (buffer of one), so a burst of changes
+	// wakes the listener once.
+	go func() {
+		for range ch {
+			select {
+			case <-done:
+				return
+			default:
+			}
+			listener.OnStateChanged()
+		}
+	}()
+
+	c.eventSub = c.recorder.SubscribeToEvents()
+	go watchSessionWarnings(c.eventSub, listener, done)
+}
+
+// RemoveStateChangeListener unregisters the state notification listener.
+func (c *Client) RemoveStateChangeListener() {
+	c.stateChangeMu.Lock()
+	defer c.stateChangeMu.Unlock()
+	c.stopStateChangeWatchLocked()
+}
+
+// DismissSessionWarning records the user's "Dismiss" on the first expiry
+// warning and suppresses the final one for the current deadline. A refreshed
+// deadline re-arms both. No-op while the engine is not running.
+func (c *Client) DismissSessionWarning() {
+	cc := c.getConnectClient()
+	if cc == nil {
+		return
+	}
+	engine := cc.Engine()
+	if engine == nil {
+		return
+	}
+	engine.DismissSessionWarning()
+}
+
+// ExtendAuthSession runs the interactive SSO flow to obtain a fresh JWT and
+// asks the management server to extend the session deadline. The tunnel is
+// untouched: no resync, no reconnect. Async; the result arrives on the
+// listener. Mirror of the daemon's RequestExtendAuthSession /
+// WaitExtendAuthSession RPC pair, with URLOpener playing the "UI opens the
+// browser" role.
+//
+// Only one flow may be in flight: the PKCE step binds a fixed loopback port,
+// so a second concurrent flow would fail on that bind. Call
+// CancelExtendAuthSession when the user abandons the browser.
+func (c *Client) ExtendAuthSession(urlOpener URLOpener, isAndroidTV bool, resultListener ErrListener) {
+	ctx, err := c.beginExtend()
+	if err != nil {
+		resultListener.OnError(err)
+		return
+	}
+
+	go func() {
+		defer c.endExtend()
+		if err := c.extendAuthSession(ctx, urlOpener, isAndroidTV); err != nil {
+			resultListener.OnError(err)
+			return
+		}
+		resultListener.OnSuccess()
+	}()
+}
+
+// CancelExtendAuthSession aborts an in-flight ExtendAuthSession. The tunnel is
+// left alone — unlike the login flow, which cancels the whole client context
+// by stopping the engine. Without this the abandoned PKCE wait keeps its
+// loopback port for the full flow timeout and blocks every later attempt.
+// No-op when no flow is running.
+func (c *Client) CancelExtendAuthSession() {
+	c.extendMu.Lock()
+	defer c.extendMu.Unlock()
+	if c.extendCancel != nil {
+		c.extendCancel()
+	}
+}
+
+func (c *Client) stopStateChangeWatchLocked() {
+	// Signal first, unsubscribe second: closing the channels only stops new
+	// items, and the loops would still hand whatever is buffered to a listener
+	// that is no longer registered.
+	if c.stateChangeDone != nil {
+		close(c.stateChangeDone)
+		c.stateChangeDone = nil
+	}
+	if c.stateChangeSubID != "" {
+		c.recorder.UnsubscribeFromStateChanges(c.stateChangeSubID)
+		c.stateChangeSubID = ""
+	}
+	if c.eventSub != nil {
+		// Closes the channel, which ends watchSessionWarnings.
+		c.recorder.UnsubscribeFromEvents(c.eventSub)
+		c.eventSub = nil
+	}
+}
+
+// watchSessionWarnings forwards the engine's session-expiry warnings to the
+// listener. The event stream also carries unrelated traffic — network-map
+// updates on every sync, DNS and route errors — so everything but an
+// AUTHENTICATION event carrying the session-warning marker is dropped. Exits
+// when the subscription is closed by UnsubscribeFromEvents, or earlier when
+// done is closed — the stream buffers up to ten events, and a deregistered
+// listener must not receive the ones already queued.
+func watchSessionWarnings(sub *peer.EventSubscription, listener StateChangeListener, done <-chan struct{}) {
+	for ev := range sub.Events() {
+		select {
+		case <-done:
+			return
+		default:
+		}
+		if ev.GetCategory() != cProto.SystemEvent_AUTHENTICATION {
+			continue
+		}
+		meta := ev.GetMetadata()
+		if meta[sessionwatch.MetaSessionWarning] != "true" {
+			// Other AUTHENTICATION events exist (e.g. a deadline rejected as
+			// out of range); they carry no warning marker.
+			continue
+		}
+		deadline, err := sessionwatch.ParseExpiresAt(meta[sessionwatch.MetaSessionExpiresAt])
+		if err != nil {
+			log.Warnf("session warning event with unparsable deadline: %v", err)
+			continue
+		}
+		lead, err := sessionwatch.ParseLeadMinutes(meta[sessionwatch.MetaSessionLeadMinutes])
+		if err != nil {
+			// Informational only — the deadline above is what drives the UI.
+			lead = 0
+		}
+		listener.OnSessionExpiring(deadline.Unix(), int64(lead),
+			meta[sessionwatch.MetaSessionFinal] == "true")
+	}
+}
+
+func (c *Client) beginExtend() (context.Context, error) {
+	c.extendMu.Lock()
+	defer c.extendMu.Unlock()
+	if c.extendCancel != nil {
+		return nil, fmt.Errorf("session extend already in progress")
+	}
+	ctx, cancel := context.WithCancel(context.Background())
+	c.extendCancel = cancel
+	return ctx, nil
+}
+
+func (c *Client) endExtend() {
+	c.extendMu.Lock()
+	defer c.extendMu.Unlock()
+	if c.extendCancel != nil {
+		c.extendCancel()
+		c.extendCancel = nil
+	}
+}
+
+func (c *Client) extendAuthSession(ctx context.Context, urlOpener URLOpener, isAndroidTV bool) error {
+	cfg, _, cc := c.stateSnapshot()
+	if cfg == nil || cc == nil {
+		return fmt.Errorf("engine is not running")
+	}
+	engine := cc.Engine()
+	if engine == nil {
+		return fmt.Errorf("engine is not initialized")
+	}
+
+	authClient, err := auth.NewAuth(ctx, cfg.PrivateKey, cfg.ManagementURL, cfg)
+	if err != nil {
+		return fmt.Errorf("failed to create auth client: %v", err)
+	}
+	defer authClient.Close()
+
+	a := &Auth{ctx: ctx, config: cfg}
+	tokenInfo, err := a.foregroundGetTokenInfo(authClient, urlOpener, isAndroidTV)
+	if err != nil {
+		return fmt.Errorf("interactive sso login failed: %v", err)
+	}
+
+	if _, err := engine.ExtendAuthSession(ctx, tokenInfo.GetTokenToUse()); err != nil {
+		return err
+	}
+	c.clearLoginRequired()
+
+	go urlOpener.OnLoginSuccess()
+	return nil
+}

client/cmd/daemon_error.go

@@ -0,0 +1,66 @@
+package cmd
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+
+	"google.golang.org/genproto/googleapis/rpc/errdetails"
+	gstatus "google.golang.org/grpc/status"
+
+	"github.com/netbirdio/netbird/client/internal/ipcauth"
+)
+
+// daemonCallError prepares a daemon error for display. A refusal the daemon
+// raised because the operation needs root/administrator is already guidance
+// written for the user, so it is surfaced on its own instead of buried under the
+// gRPC envelope and the name of the RPC that hit it. Anything else is wrapped
+// with context as usual.
+func daemonCallError(context string, err error) error {
+	if guidance, ok := privilegeGuidance(err); ok {
+		return errors.New(guidance)
+	}
+	return fmt.Errorf("%s: %w", context, err)
+}
+
+// privilegeGuidance renders the daemon's privilege refusal as a summary and the
+// command that performs the operation with the privileges it needs. It reports
+// false for any other error.
+func privilegeGuidance(err error) (string, bool) {
+	info, ok := privilegeErrorInfo(err)
+	if !ok {
+		return "", false
+	}
+
+	summary := info.GetMetadata()[ipcauth.ErrorMetaSummary]
+	command := info.GetMetadata()[ipcauth.ErrorMetaCommand]
+	if summary == "" {
+		// Detail without a summary: fall back to the status message, which
+		// carries the same text.
+		summary = strings.TrimSpace(gstatus.Convert(err).Message())
+	}
+	if command == "" {
+		return summary, true
+	}
+
+	return fmt.Sprintf("%s\n\n    %s\n", summary, command), true
+}
+
+// privilegeErrorInfo returns the daemon's privilege-refusal detail, if the error
+// carries one.
+func privilegeErrorInfo(err error) (*errdetails.ErrorInfo, bool) {
+	if err == nil {
+		return nil, false
+	}
+
+	for _, detail := range gstatus.Convert(err).Details() {
+		info, ok := detail.(*errdetails.ErrorInfo)
+		if !ok {
+			continue
+		}
+		if info.GetReason() == ipcauth.ErrorReasonPrivilegeRequired && info.GetDomain() == ipcauth.ErrorDomain {
+			return info, true
+		}
+	}
+	return nil, false
+}

client/cmd/debug.go

@@ -29,8 +29,9 @@ const errCloseConnection = "Failed to close connection: %v"
 var (
 	logFileCount        uint32
 	systemInfoFlag      bool
-	uploadBundleFlag    bool
-	uploadBundleURLFlag string
+	uploadBundleFlag         bool
+	uploadBundleURLFlag      string
+	uploadBundleInsecureFlag bool
 )
 
 var debugCmd = &cobra.Command{
@@ -174,10 +175,11 @@ func debugBundle(cmd *cobra.Command, _ []string) error {
 	}
 	if uploadBundleFlag {
 		request.UploadURL = uploadBundleURLFlag
+		request.UploadInsecure = uploadBundleInsecureFlag
 	}
 	resp, err := client.DebugBundle(cmd.Context(), request)
 	if err != nil {
-		return fmt.Errorf("failed to bundle debug: %v", status.Convert(err).Message())
+		return daemonCallError("bundle debug", err)
 	}
 	cmd.Printf("Local file:\n%s\n", resp.GetPath())
 
@@ -373,10 +375,11 @@ func runForDuration(cmd *cobra.Command, args []string) error {
 	}
 	if uploadBundleFlag {
 		request.UploadURL = uploadBundleURLFlag
+		request.UploadInsecure = uploadBundleInsecureFlag
 	}
 	resp, err := client.DebugBundle(cmd.Context(), request)
 	if err != nil {
-		return fmt.Errorf("failed to bundle debug: %v", status.Convert(err).Message())
+		return daemonCallError("bundle debug", err)
 	}
 
 	if needsRestoreUp {
@@ -524,10 +527,12 @@ func init() {
 	debugBundleCmd.Flags().BoolVarP(&systemInfoFlag, "system-info", "S", true, "Adds system information to the debug bundle")
 	debugBundleCmd.Flags().BoolVarP(&uploadBundleFlag, "upload-bundle", "U", false, "Uploads the debug bundle to a server")
 	debugBundleCmd.Flags().StringVar(&uploadBundleURLFlag, "upload-bundle-url", types.DefaultBundleURL, "Service URL to get an URL to upload the debug bundle")
+	debugBundleCmd.Flags().BoolVar(&uploadBundleInsecureFlag, "upload-bundle-insecure", false, "Allow uploading to an http or untrusted-TLS upload server (self-hosted); requires root")
 
 	forCmd.Flags().Uint32VarP(&logFileCount, "log-file-count", "C", 1, "Number of rotated log files to include in debug bundle")
 	forCmd.Flags().BoolVarP(&systemInfoFlag, "system-info", "S", true, "Adds system information to the debug bundle")
 	forCmd.Flags().BoolVarP(&uploadBundleFlag, "upload-bundle", "U", false, "Uploads the debug bundle to a server")
 	forCmd.Flags().StringVar(&uploadBundleURLFlag, "upload-bundle-url", types.DefaultBundleURL, "Service URL to get an URL to upload the debug bundle")
+	forCmd.Flags().BoolVar(&uploadBundleInsecureFlag, "upload-bundle-insecure", false, "Allow uploading to an http or untrusted-TLS upload server (self-hosted); requires root")
 	forCmd.Flags().Bool("capture", false, "Capture packets during the debug duration and include in bundle")
 }

client/cmd/logout.go

@@ -46,7 +46,7 @@ var logoutCmd = &cobra.Command{
 		}
 
 		if _, err := daemonClient.Logout(ctx, req); err != nil {
-			return fmt.Errorf("deregister: %v", err)
+			return daemonCallError("deregister", err)
 		}
 
 		cmd.Println("Deregistered successfully")

client/cmd/root.go

@@ -20,7 +20,6 @@ import (
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
 	"google.golang.org/grpc"
-	"google.golang.org/grpc/credentials/insecure"
 
 	daddr "github.com/netbirdio/netbird/client/internal/daemonaddr"
 	"github.com/netbirdio/netbird/client/internal/profilemanager"
@@ -91,6 +90,7 @@ var (
 			// Don't resolve for service commands — they create the socket, not connect to it.
 			if !isServiceCmd(cmd) {
 				daemonAddr = daddr.ResolveUnixDaemonAddr(daemonAddr)
+				daemonAddr = daddr.ResolveDaemonAddr(daemonAddr)
 			}
 			return nil
 		},
@@ -143,10 +143,10 @@ func init() {
 
 	defaultDaemonAddr := "unix:///var/run/netbird.sock"
 	if runtime.GOOS == "windows" {
-		defaultDaemonAddr = "tcp://127.0.0.1:41731"
+		defaultDaemonAddr = daddr.WindowsPipeAddr
 	}
 
-	rootCmd.PersistentFlags().StringVar(&daemonAddr, "daemon-addr", defaultDaemonAddr, "Daemon service address to serve CLI requests [unix|tcp]://[path|host:port]")
+	rootCmd.PersistentFlags().StringVar(&daemonAddr, "daemon-addr", defaultDaemonAddr, "Daemon service address to serve CLI requests [unix|tcp|npipe]://[path|host:port|name]")
 	rootCmd.PersistentFlags().StringVarP(&managementURL, "management-url", "m", "", fmt.Sprintf("Management Service URL [http|https]://[host]:[port] (default \"%s\")", profilemanager.DefaultManagementURL))
 	rootCmd.PersistentFlags().StringVar(&adminURL, "admin-url", "", fmt.Sprintf("Admin Panel URL [http|https]://[host]:[port] (default \"%s\")", profilemanager.DefaultAdminURL))
 	rootCmd.PersistentFlags().StringVarP(&logLevel, "log-level", "l", "info", "sets NetBird log level")
@@ -269,12 +269,10 @@ func DialClientGRPCServer(ctx context.Context, addr string) (*grpc.ClientConn, e
 	ctx, cancel := context.WithTimeout(ctx, time.Second*10)
 	defer cancel()
 
-	return grpc.DialContext(
-		ctx,
-		strings.TrimPrefix(addr, "tcp://"),
-		grpc.WithTransportCredentials(insecure.NewCredentials()),
-		grpc.WithBlock(),
-	)
+	target, opts := daddr.DialTarget(addr)
+	opts = append(opts, grpc.WithBlock())
+
+	return grpc.DialContext(ctx, target, opts...)
 }
 
 // WithBackOff execute function in backoff cycle.

client/cmd/service.go

@@ -33,10 +33,15 @@ var (
 )
 
 type program struct {
-	ctx              context.Context
-	cancel           context.CancelFunc
-	serv             *grpc.Server
-	jsonServ         *http.Server
+	ctx      context.Context
+	cancel   context.CancelFunc
+	serv     *grpc.Server
+	jsonServ *http.Server
+	// jsonClient is the gateway's own connection to the daemon. It is held so
+	// shutting the gateway down also closes it: nothing else references it once
+	// the handlers are registered, so its transport goroutines would otherwise
+	// outlive the server.
+	jsonClient       *grpc.ClientConn
 	jsonServMu       sync.Mutex
 	serverInstance   *server.Server
 	serverInstanceMu sync.Mutex

client/cmd/service_controller.go

@@ -5,6 +5,7 @@ package cmd
 import (
 	"context"
 	"fmt"
+	"runtime"
 	"time"
 
 	"github.com/kardianos/service"
@@ -13,6 +14,8 @@ import (
 	"github.com/spf13/cobra"
 	"google.golang.org/grpc"
 
+	"github.com/netbirdio/netbird/client/internal/daemonaddr"
+	"github.com/netbirdio/netbird/client/internal/ipcauth"
 	"github.com/netbirdio/netbird/client/proto"
 	"github.com/netbirdio/netbird/client/server"
 	"github.com/netbirdio/netbird/client/system"
@@ -26,6 +29,31 @@ func validateJSONSocketFlags() error {
 	return nil
 }
 
+// daemonServerOptions installs the transport credentials that expose each
+// caller's kernel-authenticated identity to the handlers, which is what lets
+// the daemon require root/administrator for privileged operations.
+//
+// The handshake exchanges no bytes, so older CLI and UI binaries still
+// interoperate. Callers on a TCP socket carry no identity at all: the daemon
+// keeps serving them, and the privileged operations deny them, so a warning is
+// logged to make the loss of functionality visible.
+func daemonServerOptions(network string) []grpc.ServerOption {
+	if network == "tcp" {
+		log.Warnf("daemon is listening on TCP (%s): callers carry no verifiable identity over TCP, "+
+			"so privileged operations (SSH root login, SSH auth, enabling the SSH server, management URL changes, "+
+			"deregistration) will be denied. Use a unix socket, or npipe:// on Windows", daemonAddr)
+		return nil
+	}
+
+	creds := ipcauth.NewTransportCredentials()
+	if creds == nil {
+		log.Warnf("daemon IPC has no peer-identity primitive on %s: privileged operations will be denied", runtime.GOOS)
+		return nil
+	}
+
+	return []grpc.ServerOption{grpc.Creds(creds)}
+}
+
 func (p *program) Start(svc service.Service) error {
 	// Start should not block. Do the actual work async.
 	log.Info("starting NetBird service") //nolint
@@ -37,68 +65,106 @@ func (p *program) Start(svc service.Service) error {
 	// Collect static system and platform information
 	system.UpdateStaticInfoAsync()
 
-	// in any case, even if configuration does not exists we run daemon to serve CLI gRPC API.
-	p.serv = grpc.NewServer()
-
-	daemonListener, err := listenOnAddress(daemonAddr)
-	if err != nil {
-		return fmt.Errorf("listen daemon interface: %w", err)
+	// A daemon installed before named-pipe support has the loopback TCP address
+	// persisted. Move it to the named pipe so an upgraded daemon can identify
+	// its callers instead of silently serving an unauthenticated socket.
+	if migrated, ok := daemonaddr.MigrateLegacy(daemonAddr); ok {
+		log.Infof("daemon address %q predates named-pipe support, listening on %q so callers can be identified", daemonAddr, migrated)
+		daemonAddr = migrated
 	}
 
-	var jsonListener *socketListener
-	if enableJSONSocket {
-		jsonListener, err = listenOnAddress(jsonSocket)
-		if err != nil {
-			_ = daemonListener.Close()
-			return fmt.Errorf("listen daemon JSON interface: %w", err)
-		}
-	} else {
-		removeStaleUnixSocketForAddress(jsonSocket)
+	network, _, err := parseListenAddress(daemonAddr)
+	if err != nil {
+		return fmt.Errorf("parse daemon address: %w", err)
+	}
+
+	// in any case, even if configuration does not exists we run daemon to serve CLI gRPC API.
+	p.serv = grpc.NewServer(daemonServerOptions(network)...)
+
+	daemonListener, jsonListener, err := listenDaemonSockets()
+	if err != nil {
+		return err
 	}
 
 	go func() {
-		defer daemonListener.Close()
-		if jsonListener != nil {
-			defer jsonListener.Close()
-		}
-
-		if err := daemonListener.chmodUnixSocket("daemon"); err != nil {
-			log.Error(err)
-			return
-		}
-		if jsonListener != nil {
-			if err := jsonListener.chmodUnixSocket("daemon JSON"); err != nil {
-				log.Error(err)
-				return
-			}
-		}
-
-		serverInstance := server.New(p.ctx, util.FindFirstLogPath(logFiles), configPath, profilesDisabled, updateSettingsDisabled, captureEnabled, networksDisabled)
-		if err := serverInstance.Start(); err != nil {
-			log.Fatalf("failed to start daemon: %v", err)
-		}
-		proto.RegisterDaemonServiceServer(p.serv, serverInstance)
-
-		p.serverInstanceMu.Lock()
-		p.serverInstance = serverInstance
-		p.serverInstanceMu.Unlock()
-
-		if jsonListener != nil {
-			if err := p.startJSONGateway(jsonListener, daemonAddr); err != nil {
-				log.Fatalf("failed to start daemon JSON server: %v", err)
-			}
-		} else {
-			log.Debug("daemon JSON socket disabled")
-		}
-
-		log.Printf("started daemon server: %v", daemonListener.address)
-		if err := p.serv.Serve(daemonListener.Listener); err != nil {
-			log.Errorf("failed to serve daemon requests: %v", err)
+		// Fatal here rather than inside serve, so serve's deferred listener
+		// closes run before the process exits.
+		if err := p.serve(daemonListener, jsonListener); err != nil {
+			log.Fatalf("failed to %v", err)
 		}
 	}()
 	return nil
 }
 
+// listenDaemonSockets opens the daemon control socket and, when it is enabled, the
+// JSON gateway socket. The control socket is closed again if the second one fails,
+// so a failed start leaves nothing listening. The returned JSON listener is nil
+// when the socket is disabled.
+func listenDaemonSockets() (*socketListener, *socketListener, error) {
+	daemonListener, err := listenOnAddress(daemonAddr)
+	if err != nil {
+		return nil, nil, fmt.Errorf("listen daemon interface: %w", err)
+	}
+
+	if !enableJSONSocket {
+		removeStaleUnixSocketForAddress(jsonSocket)
+		return daemonListener, nil, nil
+	}
+
+	jsonListener, err := listenOnAddress(jsonSocket)
+	if err != nil {
+		if cerr := daemonListener.Close(); cerr != nil {
+			log.Debugf("close daemon listener: %v", cerr)
+		}
+		return nil, nil, fmt.Errorf("listen daemon JSON interface: %w", err)
+	}
+
+	return daemonListener, jsonListener, nil
+}
+
+// serve brings up the daemon server on an already-open control socket and blocks
+// until it stops. jsonListener is nil when the JSON socket is disabled. A returned
+// error means the daemon cannot run at all and the caller is expected to exit; the
+// failures it recovers from on its own are logged here.
+func (p *program) serve(daemonListener, jsonListener *socketListener) error {
+	defer daemonListener.Close()
+	if jsonListener != nil {
+		defer jsonListener.Close()
+	}
+
+	// chmodUnixSocket is a no-op for a nil listener and for a non-unix one.
+	if err := daemonListener.chmodUnixSocket("daemon"); err != nil {
+		log.Error(err)
+		return nil
+	}
+	if err := jsonListener.chmodUnixSocket("daemon JSON"); err != nil {
+		log.Error(err)
+		return nil
+	}
+
+	serverInstance := server.New(p.ctx, util.FindFirstLogPath(logFiles), configPath, profilesDisabled, updateSettingsDisabled, captureEnabled, networksDisabled)
+	if err := serverInstance.Start(); err != nil {
+		return fmt.Errorf("start daemon: %w", err)
+	}
+	proto.RegisterDaemonServiceServer(p.serv, serverInstance)
+
+	p.serverInstanceMu.Lock()
+	p.serverInstance = serverInstance
+	p.serverInstanceMu.Unlock()
+
+	if jsonListener == nil {
+		log.Debug("daemon JSON socket disabled")
+	} else if err := p.startJSONGateway(jsonListener, daemonAddr); err != nil {
+		return fmt.Errorf("start daemon JSON server: %w", err)
+	}
+
+	log.Printf("started daemon server: %v", daemonListener.address)
+	if err := p.serv.Serve(daemonListener.Listener); err != nil {
+		log.Errorf("failed to serve daemon requests: %v", err)
+	}
+	return nil
+}
+
 func (p *program) Stop(srv service.Service) error {
 	p.serverInstanceMu.Lock()
 	if p.serverInstance != nil {
@@ -113,8 +179,13 @@ func (p *program) Stop(srv service.Service) error {
 	p.cancel()
 
 	p.jsonServMu.Lock()
-	jsonServ := p.jsonServ
+	jsonServ, jsonClient := p.jsonServ, p.jsonClient
 	p.jsonServMu.Unlock()
+	if jsonClient != nil {
+		if err := jsonClient.Close(); err != nil {
+			log.Debugf("close daemon JSON gateway client: %v", err)
+		}
+	}
 	if jsonServ != nil {
 		shutdownCtx, shutdownCancel := context.WithTimeout(context.Background(), 2*time.Second)
 		if err := jsonServ.Shutdown(shutdownCtx); err != nil {

client/cmd/service_json_gateway.go

@@ -5,27 +5,123 @@ package cmd
 import (
 	"context"
 	"errors"
+	"fmt"
 	"net"
 	"net/http"
-	"strings"
+	"sync"
 	"time"
 
 	"github.com/grpc-ecosystem/grpc-gateway/v2/runtime"
 	log "github.com/sirupsen/logrus"
 	"google.golang.org/grpc"
-	"google.golang.org/grpc/credentials/insecure"
 
+	"github.com/netbirdio/netbird/client/internal/daemonaddr"
+	"github.com/netbirdio/netbird/client/internal/ipcauth"
 	"github.com/netbirdio/netbird/client/proto"
 )
 
-func grpcGatewayEndpoint(addr string) string {
-	return strings.TrimPrefix(addr, "tcp://")
+// jsonPeerIdentity is the context key under which the connecting HTTP client's
+// identity is stashed for the lifetime of its connection.
+type jsonPeerIdentity struct{}
+
+// jsonPeerIdentityValue pairs the identity with whether it could be read at
+// all, so an unreadable identity is forwarded as "unknown" rather than omitted.
+type jsonPeerIdentityValue struct {
+	id    ipcauth.Identity
+	known bool
+}
+
+// jsonConnContext reads the identity of the client connecting to the JSON
+// socket and stashes it on the connection's context. The gateway re-dials the
+// daemon in-process, so the daemon would otherwise see every JSON request as
+// coming from the daemon itself.
+func jsonConnContext(ctx context.Context, c net.Conn) context.Context {
+	value := jsonPeerIdentityValue{}
+	id, err := ipcauth.ConnIdentity(c)
+	if err != nil {
+		log.Warnf("json gateway: cannot read HTTP client identity, privileged operations will be denied for this connection: %v", err)
+	} else {
+		value.id = id
+		value.known = true
+	}
+	return context.WithValue(ctx, jsonPeerIdentity{}, value)
+}
+
+// forwardIdentity stamps the HTTP client's identity onto every call the gateway
+// makes to the daemon.
+//
+// It is an interceptor on the gateway's client connection rather than a
+// runtime.WithMetadata annotator because grpc-gateway skips annotators when no
+// request header maps to metadata, which an HTTP/1.0 request with no Host header
+// over a unix socket achieves. The daemon would then receive no marker, see its own
+// identity as the transport peer, and authorize the request as the daemon itself.
+// An interceptor runs for every RPC whatever the request looked like.
+func forwardIdentity(ctx context.Context) context.Context {
+	value, ok := ctx.Value(jsonPeerIdentity{}).(jsonPeerIdentityValue)
+	if !ok {
+		// No ConnContext ran for this request, so forward an unknown identity:
+		// the daemon must not mistake its own identity for the client's.
+		return ipcauth.WithForwardedIdentity(ctx, ipcauth.Identity{}, false)
+	}
+	return ipcauth.WithForwardedIdentity(ctx, value.id, value.known)
+}
+
+func forwardIdentityUnary(ctx context.Context, method string, req, reply any, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error {
+	return invoker(forwardIdentity(ctx), method, req, reply, cc, opts...)
+}
+
+func forwardIdentityStream(ctx context.Context, desc *grpc.StreamDesc, cc *grpc.ClientConn, method string, streamer grpc.Streamer, opts ...grpc.CallOption) (grpc.ClientStream, error) {
+	return streamer(forwardIdentity(ctx), desc, cc, method, opts...)
+}
+
+// reservedHeaderWarning limits the dropped-header warning to the first occurrence.
+var reservedHeaderWarning sync.Once
+
+// jsonIncomingHeaderMatcher keeps an HTTP client from supplying the metadata the
+// gateway uses to forward its identity. grpc-gateway turns "Grpc-Metadata-<key>"
+// headers into gRPC metadata and joins them ahead of what its annotators add, so
+// without this filter a JSON client could send its own x-netbird-fwd-uid and the
+// daemon would authorize that instead of the client's real identity.
+func jsonIncomingHeaderMatcher(key string) (string, bool) {
+	mapped, ok := runtime.DefaultHeaderMatcher(key)
+	if !ok {
+		return "", false
+	}
+	if ipcauth.IsReservedForwardKey(mapped) {
+		// Warn once: any client can send these on every request, so warning each
+		// time hands it a way to fill the log. The rest are debug-level.
+		reservedHeaderWarning.Do(func() {
+			log.Warnf("json gateway: dropping reserved header %q from a request: only the gateway may set the caller's identity", key)
+		})
+		log.Debugf("json gateway: dropping reserved header %q", key)
+		return "", false
+	}
+	return mapped, true
 }
 
 func (p *program) startJSONGateway(jsonListener *socketListener, daemonEndpoint string) error {
-	mux := runtime.NewServeMux()
-	opts := []grpc.DialOption{grpc.WithTransportCredentials(insecure.NewCredentials())}
-	if err := proto.RegisterDaemonServiceHandlerFromEndpoint(p.ctx, mux, grpcGatewayEndpoint(daemonEndpoint), opts); err != nil {
+	if jsonListener.network == "tcp" {
+		log.Warnf("daemon JSON socket is listening on TCP (%s): callers carry no verifiable identity over TCP, "+
+			"so privileged operations will be denied for JSON clients", jsonListener.address)
+	}
+
+	mux := runtime.NewServeMux(runtime.WithIncomingHeaderMatcher(jsonIncomingHeaderMatcher))
+
+	// grpc.NewClient does not connect until the first request, so registering
+	// the handler here cannot block daemon startup.
+	target, opts := daemonaddr.DialTarget(daemonEndpoint)
+	opts = append(opts,
+		grpc.WithChainUnaryInterceptor(forwardIdentityUnary),
+		grpc.WithChainStreamInterceptor(forwardIdentityStream),
+	)
+	conn, err := grpc.NewClient(target, opts...)
+	if err != nil {
+		return fmt.Errorf("create daemon client for JSON gateway: %w", err)
+	}
+	if err := proto.RegisterDaemonServiceHandler(p.ctx, mux, conn); err != nil {
+		if cerr := conn.Close(); cerr != nil {
+			log.Debugf("close daemon client after failed JSON gateway registration: %v", cerr)
+		}
 		return err
 	}
 
@@ -35,10 +131,12 @@ func (p *program) startJSONGateway(jsonListener *socketListener, daemonEndpoint
 		BaseContext: func(net.Listener) context.Context {
 			return p.ctx
 		},
+		ConnContext: jsonConnContext,
 	}
 
 	p.jsonServMu.Lock()
 	p.jsonServ = jsonServer
+	p.jsonClient = conn
 	p.jsonServMu.Unlock()
 
 	go func() {

client/cmd/service_json_gateway_test.go

@@ -0,0 +1,261 @@
+//go:build !windows && !ios && !android
+
+package cmd
+
+import (
+	"context"
+	"net"
+	"net/http"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"github.com/grpc-ecosystem/grpc-gateway/v2/runtime"
+	"google.golang.org/grpc/credentials"
+	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/peer"
+
+	"github.com/netbirdio/netbird/client/internal/ipcauth"
+)
+
+// The JSON gateway runs inside the daemon and re-dials it locally, so every JSON
+// request reaches a handler with the daemon's own identity as the transport peer.
+// The gateway therefore forwards its HTTP client's identity as metadata, and the
+// daemon authorizes that instead of itself. These tests drive the real wiring
+// (jsonConnContext, forwardIdentity, jsonIncomingHeaderMatcher) and check the
+// identity a handler would end up authorizing.
+
+// daemonSideCtx is what a handler sees for a gateway-relayed call. The transport
+// peer must be this process's own identity: the gateway is the daemon, so the two
+// cannot differ, and hardcoding root here instead would describe a state that
+// never occurs.
+func daemonSideCtx(t *testing.T, md metadata.MD) context.Context {
+	t.Helper()
+	self, err := ipcauth.CurrentProcessIdentity()
+	if err != nil {
+		t.Skipf("cannot read this process's identity: %v", err)
+	}
+	ctx := peer.NewContext(context.Background(), &peer.Peer{
+		AuthInfo: ipcauth.AuthInfo{
+			CommonAuthInfo: credentials.CommonAuthInfo{SecurityLevel: credentials.NoSecurity},
+			Identity:       self,
+		},
+	})
+	return metadata.NewIncomingContext(ctx, md)
+}
+
+// gatewayMetadata reproduces what the daemon receives for a JSON request: the
+// mux annotates the context from the request's headers, then the interceptor on the
+// gateway's client connection stamps the caller's identity. The order matters,
+// since the interceptor must win over anything a header put there.
+func gatewayMetadata(t *testing.T, req *http.Request, ctx context.Context) metadata.MD {
+	t.Helper()
+	mux := runtime.NewServeMux(runtime.WithIncomingHeaderMatcher(jsonIncomingHeaderMatcher))
+	annotated, err := runtime.AnnotateContext(ctx, mux, req,
+		"/daemon.DaemonService/SetConfig",
+		runtime.WithHTTPPathPattern("/daemon.DaemonService/SetConfig"))
+	if err != nil {
+		t.Fatalf("annotate: %v", err)
+	}
+
+	md, ok := metadata.FromOutgoingContext(forwardIdentity(annotated))
+	if !ok {
+		t.Fatal("the interceptor produced no metadata")
+	}
+	return md
+}
+
+// clientCtx is the connection context jsonConnContext would have produced for an
+// HTTP client whose identity the gateway could read.
+func clientCtx(id ipcauth.Identity, known bool) context.Context {
+	return context.WithValue(context.Background(), jsonPeerIdentity{},
+		jsonPeerIdentityValue{id: id, known: known})
+}
+
+// An HTTP client must not be able to name its own identity. grpc-gateway turns
+// Grpc-Metadata-<key> headers into gRPC metadata, so without the header filter and
+// the interceptor overwriting the reserved keys, this request would authorize as
+// uid 0.
+func TestJSONGateway_ForgedIdentityHeaderIsDropped(t *testing.T) {
+	req, err := http.NewRequest(http.MethodPost, "http://localhost/daemon.DaemonService/SetConfig", nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	req.Header.Set("Grpc-Metadata-X-Netbird-Fwd-Uid", "0")
+	req.Header.Set("Grpc-Metadata-X-Netbird-Fwd-Gid", "0")
+	req.Header.Set("Grpc-Metadata-X-Netbird-Fwd", "1")
+	req.Header.Set("Grpc-Metadata-X-Netbird-Fwd-Sid", "S-1-5-18")
+
+	caller := ipcauth.Identity{UID: 31000, GID: 31000}
+	md := gatewayMetadata(t, req, clientCtx(caller, true))
+
+	id, ok := ipcauth.CallerIdentity(daemonSideCtx(t, md))
+	if !ok {
+		t.Fatal("the forwarded identity should be usable")
+	}
+	if id.IsPrivileged() {
+		t.Errorf("forged header was believed: authorized as %v", id)
+	}
+	if id.UID != caller.UID {
+		t.Errorf("authorized as uid %d, want the real client %d", id.UID, caller.UID)
+	}
+}
+
+// A request with no headers at all (HTTP/1.0 needs no Host, and a unix socket
+// yields no host:port) makes grpc-gateway produce no metadata whatsoever and skip
+// its annotators: "if len(pairs) == 0 { return ctx, nil, nil }" in
+// runtime/context.go. That is why the identity is stamped by an interceptor
+// instead. This is the case that previously reached the gate as the daemon itself.
+func TestJSONGateway_HeaderlessRequestIsStillMarkedForwarded(t *testing.T) {
+	req, err := http.NewRequest(http.MethodPost, "http://localhost/daemon.DaemonService/SetConfig", nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	req.Header = http.Header{}
+	req.Host = ""
+
+	caller := ipcauth.Identity{UID: 31000, GID: 31000}
+	ctx := clientCtx(caller, true)
+
+	// Pin the skip path itself: if grpc-gateway ever produced a pair here, this
+	// test would still pass below while no longer covering what it was written for.
+	mux := runtime.NewServeMux(runtime.WithIncomingHeaderMatcher(jsonIncomingHeaderMatcher))
+	annotated, err := runtime.AnnotateContext(ctx, mux, req,
+		"/daemon.DaemonService/SetConfig",
+		runtime.WithHTTPPathPattern("/daemon.DaemonService/SetConfig"))
+	if err != nil {
+		t.Fatalf("annotate: %v", err)
+	}
+	if md, ok := metadata.FromOutgoingContext(annotated); ok {
+		t.Fatalf("grpc-gateway produced metadata %v for a headerless request; "+
+			"this test no longer covers the annotator-skip path", md)
+	}
+
+	md := gatewayMetadata(t, req, ctx)
+
+	id, ok := ipcauth.CallerIdentity(daemonSideCtx(t, md))
+	if !ok {
+		t.Fatal("the forwarded identity should be usable")
+	}
+	if id.UID != caller.UID || id.IsPrivileged() {
+		t.Errorf("authorized as %v, want the real client uid %d", id, caller.UID)
+	}
+}
+
+// When the gateway cannot read its client's identity (a TCP JSON socket, say) it
+// forwards the marker alone. The daemon must then report "unidentified" so the
+// privileged operations refuse, rather than falling back to the gateway's own
+// identity.
+func TestJSONGateway_UnreadableClientIdentityIsUnidentified(t *testing.T) {
+	req, err := http.NewRequest(http.MethodPost, "http://localhost/daemon.DaemonService/SetConfig", nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	md := gatewayMetadata(t, req, clientCtx(ipcauth.Identity{}, false))
+
+	if id, ok := ipcauth.CallerIdentity(daemonSideCtx(t, md)); ok {
+		t.Errorf("a request with no client identity was authorized as %v", id)
+	}
+}
+
+// A request that never passed through jsonConnContext (no stashed identity) must
+// also come out unidentified rather than as the daemon.
+func TestJSONGateway_MissingConnContextIsUnidentified(t *testing.T) {
+	req, err := http.NewRequest(http.MethodPost, "http://localhost/daemon.DaemonService/SetConfig", nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	md := gatewayMetadata(t, req, context.Background())
+
+	if id, ok := ipcauth.CallerIdentity(daemonSideCtx(t, md)); ok {
+		t.Errorf("a request with no connection context was authorized as %v", id)
+	}
+}
+
+// End to end over a real unix socket: the gateway reads the connecting client's
+// identity from the socket itself, so a client cannot present anything else.
+func TestJSONGateway_IdentityComesFromTheSocket(t *testing.T) {
+	mux := runtime.NewServeMux(runtime.WithIncomingHeaderMatcher(jsonIncomingHeaderMatcher))
+
+	type observed struct {
+		md metadata.MD
+	}
+	seen := make(chan observed, 1)
+
+	srv := &http.Server{
+		Handler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			ctx, err := runtime.AnnotateContext(r.Context(), mux, r,
+				"/daemon.DaemonService/SetConfig",
+				runtime.WithHTTPPathPattern("/daemon.DaemonService/SetConfig"))
+			if err != nil {
+				t.Errorf("annotate: %v", err)
+				return
+			}
+			md, _ := metadata.FromOutgoingContext(forwardIdentity(ctx))
+			seen <- observed{md: md}
+			w.WriteHeader(http.StatusOK)
+		}),
+		ReadHeaderTimeout: 5 * time.Second,
+		ConnContext:       jsonConnContext,
+	}
+
+	sock := filepath.Join(t.TempDir(), "http.sock")
+	ln, err := net.Listen("unix", sock)
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() {
+		if err := srv.Close(); err != nil {
+			t.Logf("close server: %v", err)
+		}
+	})
+	go func() {
+		if err := srv.Serve(ln); err != nil && err != http.ErrServerClosed {
+			t.Logf("serve: %v", err)
+		}
+	}()
+
+	conn, err := net.Dial("unix", sock)
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() {
+		if err := conn.Close(); err != nil {
+			t.Logf("close conn: %v", err)
+		}
+	})
+
+	// Forge the identity headers on the wire as well.
+	request := "POST /daemon.DaemonService/SetConfig HTTP/1.1\r\n" +
+		"Host: localhost\r\n" +
+		"Grpc-Metadata-X-Netbird-Fwd: 1\r\n" +
+		"Grpc-Metadata-X-Netbird-Fwd-Uid: 0\r\n" +
+		"Content-Length: 0\r\n\r\n"
+	if _, err := conn.Write([]byte(request)); err != nil {
+		t.Fatal(err)
+	}
+
+	select {
+	case got := <-seen:
+		self, err := ipcauth.CurrentProcessIdentity()
+		if err != nil {
+			t.Skipf("cannot read this process's identity: %v", err)
+		}
+		// The socket peer is this test process, so that is the identity the
+		// gateway must forward, not the uid 0 the request asked for.
+		if uids := got.md.Get("x-netbird-fwd-uid"); len(uids) != 1 {
+			t.Fatalf("x-netbird-fwd-uid = %v, want exactly the gateway's own value", uids)
+		}
+		id, ok := ipcauth.CallerIdentity(daemonSideCtx(t, got.md))
+		if !ok {
+			t.Fatal("the forwarded identity should be usable")
+		}
+		if id.UID != self.UID {
+			t.Errorf("authorized as uid %d, want the socket peer %d", id.UID, self.UID)
+		}
+	case <-time.After(5 * time.Second):
+		t.Fatal("the gateway never handled the request")
+	}
+}

client/cmd/service_params.go

@@ -13,6 +13,7 @@ import (
 	"github.com/spf13/cobra"
 
 	"github.com/netbirdio/netbird/client/configs"
+	"github.com/netbirdio/netbird/client/internal/daemonaddr"
 	"github.com/netbirdio/netbird/util"
 )
 
@@ -125,6 +126,13 @@ func applyServiceParams(cmd *cobra.Command, params *serviceParams) {
 
 	if !rootCmd.PersistentFlags().Changed("daemon-addr") && params.DaemonAddr != "" {
 		daemonAddr = params.DaemonAddr
+		// An install that predates named-pipe support has the loopback TCP
+		// address saved. Callers carry no identity over TCP, so move it to the
+		// pipe instead of restoring a socket the daemon cannot authorize on.
+		if migrated, ok := daemonaddr.MigrateLegacy(daemonAddr); ok {
+			cmd.Printf("Moving the saved daemon address from %s to %s so the daemon can identify its callers\n", daemonAddr, migrated)
+			daemonAddr = migrated
+		}
 	}
 
 	if !serviceCmd.PersistentFlags().Changed("json-socket") && params.JSONSocket != "" {

client/cmd/service_pipe_other.go

@@ -0,0 +1,14 @@
+//go:build !windows
+
+package cmd
+
+import (
+	"fmt"
+	"net"
+)
+
+// listenNamedPipe is Windows-only: no other platform serves the daemon on a
+// named pipe.
+func listenNamedPipe(string) (net.Listener, string, error) {
+	return nil, "", fmt.Errorf("named pipes are only supported on Windows")
+}

client/cmd/service_pipe_windows.go

@@ -0,0 +1,41 @@
+//go:build windows
+
+package cmd
+
+import (
+	"errors"
+	"fmt"
+	"net"
+
+	"github.com/Microsoft/go-winio"
+	log "github.com/sirupsen/logrus"
+
+	"github.com/netbirdio/netbird/client/internal/daemonaddr"
+	"github.com/netbirdio/netbird/client/internal/ipcauth"
+)
+
+// listenNamedPipe creates the daemon control pipe and reports the path it ended
+// up on. The security descriptor lets any local caller connect, as a Unix socket
+// at 0666 does, and the privileged operations are authorized separately from the
+// caller's token.
+//
+// The protected name comes first so that an unprivileged process cannot take the
+// name before the service does. Creating it requires being an administrator or
+// LocalSystem, so a daemon an ordinary user runs themselves, as in netstack mode,
+// falls back to the plain name; clients try both and check who serves them.
+func listenNamedPipe(name string) (net.Listener, string, error) {
+	var errs []error
+	for _, path := range daemonaddr.PipePaths(name) {
+		listener, err := winio.ListenPipe(path, &winio.PipeConfig{
+			SecurityDescriptor: ipcauth.DefaultPipeSDDL(),
+		})
+		if err != nil {
+			log.Debugf("not serving the daemon on %s: %v", path, err)
+			errs = append(errs, fmt.Errorf("%s: %w", path, err))
+			continue
+		}
+		return listener, path, nil
+	}
+
+	return nil, "", errors.Join(errs...)
+}

client/cmd/service_socket.go

@@ -26,6 +26,14 @@ func listenOnAddress(addr string) (*socketListener, error) {
 		return nil, err
 	}
 
+	if network == "npipe" {
+		listener, path, err := listenNamedPipe(address)
+		if err != nil {
+			return nil, err
+		}
+		return &socketListener{Listener: listener, network: network, address: path}, nil
+	}
+
 	if network == "unix" {
 		removeStaleUnixSocket(address)
 	}
@@ -41,11 +49,11 @@ func listenOnAddress(addr string) (*socketListener, error) {
 func parseListenAddress(addr string) (string, string, error) {
 	network, address, ok := strings.Cut(addr, "://")
 	if !ok || network == "" || address == "" {
-		return "", "", fmt.Errorf("address must be in [unix|tcp]://[path|host:port] format: %q", addr)
+		return "", "", fmt.Errorf("address must be in [unix|tcp|npipe]://[path|host:port|name] format: %q", addr)
 	}
 
 	switch network {
-	case "unix", "tcp":
+	case "unix", "tcp", "npipe":
 		return network, address, nil
 	default:
 		return "", "", fmt.Errorf("unsupported daemon address protocol: %v", network)

client/cmd/up.go

@@ -325,7 +325,7 @@ func runInDaemonMode(ctx context.Context, cmd *cobra.Command, pm *profilemanager
 		if st, ok := gstatus.FromError(err); ok && st.Code() == codes.Unavailable {
 			log.Warnf("setConfig method is not available in the daemon: %s", st.Message())
 		} else {
-			return fmt.Errorf("call service setConfig method: %v", err)
+			return daemonCallError("call service setConfig method", err)
 		}
 	}
 
@@ -379,7 +379,7 @@ func doDaemonUp(ctx context.Context, cmd *cobra.Command, client proto.DaemonServ
 	}
 
 	if loginErr != nil {
-		return fmt.Errorf("login failed: %v", loginErr)
+		return daemonCallError("login failed", loginErr)
 	}
 
 	if loginResp.NeedsSSOLogin {
@@ -392,7 +392,7 @@ func doDaemonUp(ctx context.Context, cmd *cobra.Command, client proto.DaemonServ
 		ProfileName: &profileID,
 		Username:    &username,
 	}); err != nil {
-		return fmt.Errorf("call service up method: %v", err)
+		return daemonCallError("call service up method", err)
 	}
 
 	return nil

client/configs/configs.go

@@ -6,6 +6,11 @@ import (
 	"runtime"
 )
 
+// UILogFile is the file name the desktop UI writes its log to. It is defined
+// here so the UI (writer), the daemon's RegisterUILog validation, and the debug
+// bundle collector all share one definition.
+const UILogFile = "gui-client.log"
+
 var StateDir string
 
 func init() {

client/firewall/allower_other.go

@@ -0,0 +1,11 @@
+//go:build android || (!linux && !windows)
+
+package firewall
+
+import "github.com/netbirdio/netbird/client/firewall/uspfilter"
+
+// interfaceAllower returns no allower: these platforms have no host firewall to
+// open for the interface.
+func interfaceAllower(IFaceMapper, uint16) uspfilter.InterfaceAllower {
+	return nil
+}

client/firewall/allower_windows.go

@@ -0,0 +1,10 @@
+//go:build windows
+
+package firewall
+
+import "github.com/netbirdio/netbird/client/firewall/uspfilter"
+
+// interfaceAllower returns the Windows netsh-based interface allower.
+func interfaceAllower(iface IFaceMapper, _ uint16) uspfilter.InterfaceAllower {
+	return uspfilter.NewWindowsInterfaceAllower(iface)
+}

client/firewall/create.go

@@ -6,8 +6,6 @@ import (
 	"fmt"
 	"runtime"
 
-	log "github.com/sirupsen/logrus"
-
 	firewall "github.com/netbirdio/netbird/client/firewall/manager"
 	"github.com/netbirdio/netbird/client/firewall/uspfilter"
 	nftypes "github.com/netbirdio/netbird/client/internal/netflow/types"
@@ -21,13 +19,11 @@ func NewFirewall(iface IFaceMapper, _ *statemanager.Manager, flowLogger nftypes.
 	}
 
 	// use userspace packet filtering firewall
-	fm, err := uspfilter.Create(iface, disableServerRoutes, flowLogger, mtu)
-	if err != nil {
-		return nil, err
-	}
-	err = fm.AllowNetbird()
-	if err != nil {
-		log.Warnf("failed to allow netbird interface traffic: %v", err)
-	}
-	return fm, nil
+	return uspfilter.Create(uspfilter.Config{
+		IFace:               iface,
+		DisableServerRoutes: disableServerRoutes,
+		FlowLogger:          flowLogger,
+		MTU:                 mtu,
+		InterfaceAllower:    interfaceAllower(iface, mtu),
+	})
 }

client/firewall/create_linux.go

@@ -16,6 +16,7 @@ import (
 	firewall "github.com/netbirdio/netbird/client/firewall/manager"
 	nbnftables "github.com/netbirdio/netbird/client/firewall/nftables"
 	"github.com/netbirdio/netbird/client/firewall/uspfilter"
+	"github.com/netbirdio/netbird/client/iface/netstack"
 	nftypes "github.com/netbirdio/netbird/client/internal/netflow/types"
 	"github.com/netbirdio/netbird/client/internal/statemanager"
 )
@@ -29,47 +30,107 @@ const (
 	NFTABLES
 )
 
-// SKIP_NFTABLES_ENV is the environment variable to skip nftables check
-const SKIP_NFTABLES_ENV = "NB_SKIP_NFTABLES_CHECK"
+// SkipNftablesEnv is the environment variable to skip nftables check
+const SkipNftablesEnv = "NB_SKIP_NFTABLES_CHECK"
+
+// errNoFirewallManager indicates no kernel firewall backend is present,
+// as opposed to a backend that exists but failed to create or initialize.
+var errNoFirewallManager = errors.New("no firewall manager found")
 
 // FWType is the type for the firewall type
 type FWType int
 
 func NewFirewall(iface IFaceMapper, stateManager *statemanager.Manager, flowLogger nftypes.FlowLogger, disableServerRoutes bool, mtu uint16) (firewall.Manager, error) {
-	// We run in userspace mode and force userspace firewall was requested. We don't attempt native firewall.
-	if iface.IsUserspaceBind() && forceUserspaceFirewall() {
-		log.Info("forcing userspace firewall")
-		return createUserspaceFirewall(iface, nil, disableServerRoutes, flowLogger, mtu)
+	// Userspace firewall without a native counterpart: routing is handled
+	// entirely in userspace. The interface is opened in the kernel's foreign
+	// filter chains via a table-less allower, except in netstack mode where no
+	// kernel interface exists.
+	if netstack.IsEnabled() || (iface.IsUserspaceBind() && forceUserspaceFirewall()) {
+		if netstack.IsEnabled() {
+			log.Info("netstack mode, using userspace firewall")
+		} else {
+			log.Info("forcing userspace firewall")
+		}
+		cfg := uspfilter.Config{
+			IFace:               iface,
+			DisableServerRoutes: disableServerRoutes,
+			FlowLogger:          flowLogger,
+			MTU:                 mtu,
+			InterfaceAllower:    interfaceAllower(iface, mtu),
+		}
+
+		return uspfilter.Create(cfg)
 	}
 
 	// Use native firewall for either kernel or userspace, the interface appears identical to netfilter
-	fm, err := createNativeFirewall(iface, stateManager, disableServerRoutes, mtu)
-
-	// Kernel cannot fall back to anything else, need to return error
-	if !iface.IsUserspaceBind() {
-		return fm, err
-	}
-
-	// Fall back to the userspace packet filter if native is unavailable
-	if err != nil {
-		log.Warnf("failed to create native firewall: %v. Proceeding with userspace", err)
-		return createUserspaceFirewall(iface, nil, disableServerRoutes, flowLogger, mtu)
-	}
-
-	// Native firewall handles packet filtering, but the userspace WireGuard bind
-	// needs a device filter for DNS interception hooks. Install a minimal
-	// hooks-only filter that passes all traffic through to the kernel firewall.
-	if err := iface.SetFilter(&uspfilter.HooksFilter{}); err != nil {
-		log.Warnf("failed to set hooks filter, DNS via memory hooks will not work: %v", err)
+	fm, err := createNativeFirewall(iface, stateManager, mtu)
+	switch {
+	case err == nil && !iface.IsUserspaceBind():
+		// Nothing to do, fall through
+	case err == nil && iface.IsUserspaceBind():
+		// Native firewall handles packet filtering, but the userspace WireGuard bind
+		// needs a device filter for DNS interception hooks. Install a minimal
+		// hooks-only filter that passes all traffic through to the kernel firewall.
+		if err := iface.SetFilter(&uspfilter.HooksFilter{}); err != nil {
+			log.Warnf("failed to set hooks filter, DNS via memory hooks will not work: %v", err)
+		}
+	case err != nil && !iface.IsUserspaceBind():
+		// Kernel cannot fall back to anything else, need to return error
+		return nil, err
+	case err != nil && iface.IsUserspaceBind():
+		// Fall back to the userspace packet filter if native is unavailable
+		logNativeFirewallUnavailable(err)
+		return uspfilter.Create(uspfilter.Config{
+			IFace:               iface,
+			DisableServerRoutes: disableServerRoutes,
+			FlowLogger:          flowLogger,
+			MTU:                 mtu,
+			InterfaceAllower:    interfaceAllower(iface, mtu),
+		})
 	}
 
 	return fm, nil
 }
 
-func createNativeFirewall(iface IFaceMapper, stateManager *statemanager.Manager, routes bool, mtu uint16) (firewall.Manager, error) {
+// interfaceAllower selects how the userspace firewall opens the interface in
+// foreign kernel chains: nftables when available (which also opens foreign nft
+// tables), else iptables (the legacy fallback, filter INPUT only), else nil.
+// firewalld trust is applied separately by the manager. Netstack has no kernel
+// interface to open.
+func interfaceAllower(iface IFaceMapper, mtu uint16) uspfilter.InterfaceAllower {
+	if netstack.IsEnabled() {
+		return nil
+	}
+
+	nftAllower, err := nbnftables.NewInterfaceAllower(iface, mtu)
+	if err == nil {
+		return nftAllower
+	}
+	log.Infof("no nftables interface allower: %v", err)
+
+	iptAllower, err := nbiptables.NewInterfaceAllower(iface)
+	if err == nil {
+		return iptAllower
+	}
+	log.Infof("no iptables interface allower: %v", err)
+
+	return nil
+}
+
+// logNativeFirewallUnavailable logs the fallback to userspace at info level
+// when no kernel firewall backend exists, and at warn level otherwise.
+func logNativeFirewallUnavailable(err error) {
+	if errors.Is(err, errNoFirewallManager) {
+		log.Infof("no native firewall backend available: %v. Proceeding with userspace", err)
+	} else {
+		log.Warnf("failed to create native firewall: %v. Proceeding with userspace", err)
+	}
+}
+
+func createNativeFirewall(iface IFaceMapper, stateManager *statemanager.Manager, mtu uint16) (firewall.Manager, error) {
 	fm, err := createFW(iface, mtu)
 	if err != nil {
-		return nil, fmt.Errorf("create firewall: %s", err)
+		return nil, fmt.Errorf("create firewall: %w", err)
 	}
 
 	if err = fm.Init(stateManager); err != nil {
@@ -88,29 +149,10 @@ func createFW(iface IFaceMapper, mtu uint16) (firewall.Manager, error) {
 		log.Info("creating an nftables firewall manager")
 		return nbnftables.Create(iface, mtu)
 	default:
-		log.Info("no firewall manager found, trying to use userspace packet filtering firewall")
-		return nil, errors.New("no firewall manager found")
+		return nil, errNoFirewallManager
 	}
 }
 
-func createUserspaceFirewall(iface IFaceMapper, fm firewall.Manager, disableServerRoutes bool, flowLogger nftypes.FlowLogger, mtu uint16) (firewall.Manager, error) {
-	var errUsp error
-	if fm != nil {
-		fm, errUsp = uspfilter.CreateWithNativeFirewall(iface, fm, disableServerRoutes, flowLogger, mtu)
-	} else {
-		fm, errUsp = uspfilter.Create(iface, disableServerRoutes, flowLogger, mtu)
-	}
-
-	if errUsp != nil {
-		return nil, fmt.Errorf("create userspace firewall: %s", errUsp)
-	}
-
-	if err := fm.AllowNetbird(); err != nil {
-		log.Errorf("failed to allow netbird interface traffic: %v", err)
-	}
-	return fm, nil
-}
-
 // check returns the firewall type based on common lib checks. It returns UNKNOWN if no firewall is found.
 func check() FWType {
 	useIPTABLES := false
@@ -132,35 +174,38 @@ func check() FWType {
 		}
 	}
 
-	nf := nftables.Conn{}
-	if chains, err := nf.ListChains(); err == nil && os.Getenv(SKIP_NFTABLES_ENV) != "true" {
-		if !useIPTABLES {
-			return NFTABLES
-		}
-
-		// search for chains where table is filter
-		// if we find one, we assume that nftables manager can be used with iptables
-		for _, chain := range chains {
-			if chain.Table.Name == "filter" {
+	// Honor the skip env before probing nftables at all.
+	if os.Getenv(SkipNftablesEnv) != "true" {
+		nf := nftables.Conn{}
+		if chains, err := nf.ListChains(); err == nil {
+			if !useIPTABLES {
 				return NFTABLES
 			}
-		}
 
-		// check tables for the following constraints:
-		// 1. there is no chain in nftables for the filter table and there is at least one chain in iptables, we assume that nftables manager can not be used
-		// 2. there is no tables or more than one table, we assume that nftables manager can be used
-		// 3. there is only one table and its name is filter, we assume that nftables manager can not be used, since there was no chain in it
-		// 4. if we find an error we log and continue with iptables check
-		nbTablesList, err := nf.ListTables()
-		switch {
-		case err == nil && len(iptablesChains) > 0:
-			return IPTABLES
-		case err == nil && len(nbTablesList) != 1:
-			return NFTABLES
-		case err == nil && len(nbTablesList) == 1 && nbTablesList[0].Name == "filter":
-			return IPTABLES
-		case err != nil:
-			log.Errorf("failed to list nftables tables on fw manager discovery: %s", err)
+			// search for chains where table is filter
+			// if we find one, we assume that nftables manager can be used with iptables
+			for _, chain := range chains {
+				if chain.Table.Name == "filter" {
+					return NFTABLES
+				}
+			}
+
+			// check tables for the following constraints:
+			// 1. there is no chain in nftables for the filter table and there is at least one chain in iptables, we assume that nftables manager can not be used
+			// 2. there is no tables or more than one table, we assume that nftables manager can be used
+			// 3. there is only one table and its name is filter, we assume that nftables manager can not be used, since there was no chain in it
+			// 4. if we find an error we log and continue with iptables check
+			nbTablesList, err := nf.ListTables()
+			switch {
+			case err == nil && len(iptablesChains) > 0:
+				return IPTABLES
+			case err == nil && len(nbTablesList) != 1:
+				return NFTABLES
+			case err == nil && len(nbTablesList) == 1 && nbTablesList[0].Name == "filter":
+				return IPTABLES
+			case err != nil:
+				log.Errorf("failed to list nftables tables on fw manager discovery: %s", err)
+			}
 		}
 	}
 
@@ -176,15 +221,21 @@ func isIptablesClientAvailable(client *iptables.IPTables) bool {
 	return err == nil
 }
 
+// forceUserspaceFirewall reports whether the userspace firewall is forced.
+// NB_FORCE_USERSPACE_ROUTER is an alias: forcing userspace routing implies the
+// userspace firewall, since the two are no longer separable.
 func forceUserspaceFirewall() bool {
-	val := os.Getenv(EnvForceUserspaceFirewall)
+	return envForceBool(EnvForceUserspaceFirewall) || envForceBool(uspfilter.EnvForceUserspaceRouter)
+}
+
+func envForceBool(name string) bool {
+	val := os.Getenv(name)
 	if val == "" {
 		return false
 	}
-
 	force, err := strconv.ParseBool(val)
 	if err != nil {
-		log.Warnf("failed to parse %s: %v", EnvForceUserspaceFirewall, err)
+		log.Warnf("failed to parse %s: %v", name, err)
 		return false
 	}
 	return force

client/firewall/iptables/acl_linux.go

@@ -1,560 +0,0 @@
-package iptables
-
-import (
-	"errors"
-	"fmt"
-	"maps"
-	"net"
-	"slices"
-
-	"github.com/coreos/go-iptables/iptables"
-	"github.com/google/uuid"
-	ipset "github.com/lrh3321/ipset-go"
-	log "github.com/sirupsen/logrus"
-
-	firewall "github.com/netbirdio/netbird/client/firewall/manager"
-	"github.com/netbirdio/netbird/client/internal/statemanager"
-	nbnet "github.com/netbirdio/netbird/client/net"
-)
-
-const (
-	tableName = "filter"
-
-	// rules chains contains the effective ACL rules
-	chainNameInputRules = "NETBIRD-ACL-INPUT"
-
-	// mangleFwdKey is the entries map key for mangle FORWARD guard rules that prevent
-	// external DNAT from bypassing ACL rules.
-	mangleFwdKey = "MANGLE-FORWARD"
-)
-
-type aclEntries map[string][][]string
-
-type entry struct {
-	spec     []string
-	position int
-}
-
-type aclManager struct {
-	iptablesClient  *iptables.IPTables
-	wgIface         iFaceMapper
-	entries         aclEntries
-	optionalEntries map[string][]entry
-	ipsetStore      *ipsetStore
-	v6              bool
-
-	stateManager *statemanager.Manager
-}
-
-func newAclManager(iptablesClient *iptables.IPTables, wgIface iFaceMapper) (*aclManager, error) {
-	return &aclManager{
-		iptablesClient:  iptablesClient,
-		wgIface:         wgIface,
-		entries:         make(map[string][][]string),
-		optionalEntries: make(map[string][]entry),
-		ipsetStore:      newIpsetStore(),
-		v6:              iptablesClient.Proto() == iptables.ProtocolIPv6,
-	}, nil
-}
-
-func (m *aclManager) init(stateManager *statemanager.Manager) error {
-	m.stateManager = stateManager
-
-	m.seedInitialEntries()
-	m.seedInitialOptionalEntries()
-
-	if err := m.cleanChains(); err != nil {
-		return fmt.Errorf("clean chains: %w", err)
-	}
-
-	if err := m.createDefaultChains(); err != nil {
-		return fmt.Errorf("create default chains: %w", err)
-	}
-
-	m.updateState()
-
-	return nil
-}
-
-func (m *aclManager) AddPeerFiltering(
-	id []byte,
-	ip net.IP,
-	protocol firewall.Protocol,
-	sPort *firewall.Port,
-	dPort *firewall.Port,
-	action firewall.Action,
-	ipsetName string,
-) ([]firewall.Rule, error) {
-	chain := chainNameInputRules
-
-	ipsetName = transformIPsetName(ipsetName, sPort, dPort, action)
-	if m.v6 && ipsetName != "" {
-		ipsetName += "-v6"
-	}
-	proto := protoForFamily(protocol, m.v6)
-	specs := filterRuleSpecs(ip, proto, sPort, dPort, action, ipsetName)
-
-	mangleSpecs := slices.Clone(specs)
-	mangleSpecs = append(mangleSpecs,
-		"-i", m.wgIface.Name(),
-		"-m", "addrtype", "--dst-type", "LOCAL",
-		"-j", "MARK", "--set-xmark", fmt.Sprintf("%#x", nbnet.PreroutingFwmarkRedirected),
-	)
-
-	specs = append(specs, "-j", actionToStr(action))
-	if ipsetName != "" {
-		if ipList, ipsetExists := m.ipsetStore.ipset(ipsetName); ipsetExists {
-			if err := m.addToIPSet(ipsetName, ip); err != nil {
-				return nil, fmt.Errorf("add IP to ipset: %w", err)
-			}
-			// if ruleset already exists it means we already have the firewall rule
-			// so we need to update IPs in the ruleset and return new fw.Rule object for ACL manager.
-			ipList.addIP(ip.String())
-			return []firewall.Rule{&Rule{
-				ruleID:    uuid.New().String(),
-				ipsetName: ipsetName,
-				ip:        ip.String(),
-				chain:     chain,
-				specs:     specs,
-				v6:        m.v6,
-			}}, nil
-		}
-
-		if err := m.flushIPSet(ipsetName); err != nil {
-			if errors.Is(err, ipset.ErrSetNotExist) {
-				log.Debugf("flush ipset %s before use: %v", ipsetName, err)
-			} else {
-				log.Errorf("flush ipset %s before use: %v", ipsetName, err)
-			}
-		}
-		if err := m.createIPSet(ipsetName); err != nil {
-			return nil, fmt.Errorf("create ipset: %w", err)
-		}
-		if err := m.addToIPSet(ipsetName, ip); err != nil {
-			return nil, fmt.Errorf("add IP to ipset: %w", err)
-		}
-
-		ipList := newIpList(ip.String())
-		m.ipsetStore.addIpList(ipsetName, ipList)
-	}
-
-	ok, err := m.iptablesClient.Exists(tableFilter, chain, specs...)
-	if err != nil {
-		return nil, fmt.Errorf("failed to check rule: %w", err)
-	}
-	if ok {
-		return nil, fmt.Errorf("rule already exists")
-	}
-
-	// Insert DROP rules at the beginning, append ACCEPT rules at the end
-	if action == firewall.ActionDrop {
-		// Insert at the beginning of the chain (position 1)
-		err = m.iptablesClient.Insert(tableFilter, chain, 1, specs...)
-	} else {
-		err = m.iptablesClient.Append(tableFilter, chain, specs...)
-	}
-	if err != nil {
-		return nil, err
-	}
-
-	if err := m.iptablesClient.Append(tableMangle, chainRTPRE, mangleSpecs...); err != nil {
-		log.Errorf("failed to add mangle rule: %v", err)
-		mangleSpecs = nil
-	}
-
-	rule := &Rule{
-		ruleID:      uuid.New().String(),
-		specs:       specs,
-		mangleSpecs: mangleSpecs,
-		ipsetName:   ipsetName,
-		ip:          ip.String(),
-		chain:       chain,
-		v6:          m.v6,
-	}
-
-	m.updateState()
-
-	return []firewall.Rule{rule}, nil
-}
-
-// DeletePeerRule from the firewall by rule definition
-func (m *aclManager) DeletePeerRule(rule firewall.Rule) error {
-	r, ok := rule.(*Rule)
-	if !ok {
-		return fmt.Errorf("invalid rule type")
-	}
-
-	shouldDestroyIpset := false
-	if ipsetList, ok := m.ipsetStore.ipset(r.ipsetName); ok {
-		// delete IP from ruleset IPs list and ipset
-		if _, ok := ipsetList.ips[r.ip]; ok {
-			ip := net.ParseIP(r.ip)
-			if ip == nil {
-				return fmt.Errorf("parse IP %s", r.ip)
-			}
-			if err := m.delFromIPSet(r.ipsetName, ip); err != nil {
-				return fmt.Errorf("delete ip from ipset: %w", err)
-			}
-			delete(ipsetList.ips, r.ip)
-		}
-
-		// if after delete, set still contains other IPs,
-		// no need to delete firewall rule and we should exit here
-		if len(ipsetList.ips) != 0 {
-			return nil
-		}
-
-		// we delete last IP from the set, that means we need to delete
-		// set itself and associated firewall rule too
-		m.ipsetStore.deleteIpset(r.ipsetName)
-		shouldDestroyIpset = true
-	}
-
-	if err := m.iptablesClient.Delete(tableName, r.chain, r.specs...); err != nil {
-		return fmt.Errorf("failed to delete rule: %s, %v: %w", r.chain, r.specs, err)
-	}
-
-	if r.mangleSpecs != nil {
-		if err := m.iptablesClient.Delete(tableMangle, chainRTPRE, r.mangleSpecs...); err != nil {
-			log.Errorf("failed to delete mangle rule: %v", err)
-		}
-	}
-
-	if shouldDestroyIpset {
-		if err := m.destroyIPSet(r.ipsetName); err != nil {
-			if errors.Is(err, ipset.ErrBusy) || errors.Is(err, ipset.ErrSetNotExist) {
-				log.Debugf("destroy empty ipset: %v", err)
-			} else {
-				log.Errorf("destroy empty ipset: %v", err)
-			}
-		}
-	}
-
-	m.updateState()
-
-	return nil
-}
-
-func (m *aclManager) Reset() error {
-	if err := m.cleanChains(); err != nil {
-		return fmt.Errorf("clean chains: %w", err)
-	}
-
-	m.updateState()
-
-	return nil
-}
-
-// todo write less destructive cleanup mechanism
-func (m *aclManager) cleanChains() error {
-	ok, err := m.iptablesClient.ChainExists(tableName, chainNameInputRules)
-	if err != nil {
-		log.Debugf("failed to list chains: %s", err)
-		return err
-	}
-	if ok {
-		for _, rule := range m.entries["INPUT"] {
-			err := m.iptablesClient.DeleteIfExists(tableName, "INPUT", rule...)
-			if err != nil {
-				log.Errorf("failed to delete rule: %v, %s", rule, err)
-			}
-		}
-
-		for _, rule := range m.entries["FORWARD"] {
-			err := m.iptablesClient.DeleteIfExists(tableName, "FORWARD", rule...)
-			if err != nil {
-				log.Errorf("failed to delete rule: %v, %s", rule, err)
-			}
-		}
-
-		err = m.iptablesClient.ClearAndDeleteChain(tableName, chainNameInputRules)
-		if err != nil {
-			log.Debugf("failed to clear and delete %s chain: %s", chainNameInputRules, err)
-			return err
-		}
-	}
-
-	ok, err = m.iptablesClient.ChainExists("mangle", "PREROUTING")
-	if err != nil {
-		return fmt.Errorf("list chains: %w", err)
-	}
-	if ok {
-		for _, rule := range m.entries["PREROUTING"] {
-			err := m.iptablesClient.DeleteIfExists("mangle", "PREROUTING", rule...)
-			if err != nil {
-				log.Errorf("failed to delete rule: %v, %s", rule, err)
-			}
-		}
-	}
-
-	for _, rule := range m.entries[mangleFwdKey] {
-		if err := m.iptablesClient.DeleteIfExists(tableMangle, chainFORWARD, rule...); err != nil {
-			log.Errorf("failed to delete mangle FORWARD guard rule: %v, %s", rule, err)
-		}
-	}
-
-	for _, ipsetName := range m.ipsetStore.ipsetNames() {
-		if err := m.flushIPSet(ipsetName); err != nil {
-			if errors.Is(err, ipset.ErrSetNotExist) {
-				log.Debugf("flush ipset %q during reset: %v", ipsetName, err)
-			} else {
-				log.Errorf("flush ipset %q during reset: %v", ipsetName, err)
-			}
-		}
-		if err := m.destroyIPSet(ipsetName); err != nil {
-			if errors.Is(err, ipset.ErrBusy) || errors.Is(err, ipset.ErrSetNotExist) {
-				log.Debugf("destroy ipset %q during reset: %v", ipsetName, err)
-			} else {
-				log.Errorf("destroy ipset %q during reset: %v", ipsetName, err)
-			}
-		}
-		m.ipsetStore.deleteIpset(ipsetName)
-	}
-
-	return nil
-}
-
-func (m *aclManager) createDefaultChains() error {
-	// chain netbird-acl-input-rules
-	if err := m.iptablesClient.NewChain(tableName, chainNameInputRules); err != nil {
-		log.Debugf("failed to create '%s' chain: %s", chainNameInputRules, err)
-		return err
-	}
-
-	for chainName, rules := range m.entries {
-		// mangle FORWARD guard rules are handled separately below
-		if chainName == mangleFwdKey {
-			continue
-		}
-		for _, rule := range rules {
-			if err := m.iptablesClient.InsertUnique(tableName, chainName, 1, rule...); err != nil {
-				log.Debugf("failed to create input chain jump rule: %s", err)
-				return err
-			}
-		}
-	}
-
-	for chainName, entries := range m.optionalEntries {
-		for _, entry := range entries {
-			if err := m.iptablesClient.InsertUnique(tableName, chainName, entry.position, entry.spec...); err != nil {
-				log.Errorf("failed to insert optional entry %v: %v", entry.spec, err)
-				continue
-			}
-			m.entries[chainName] = append(m.entries[chainName], entry.spec)
-		}
-	}
-	clear(m.optionalEntries)
-
-	// Insert mangle FORWARD guard rules to prevent external DNAT bypass.
-	for _, rule := range m.entries[mangleFwdKey] {
-		if err := m.iptablesClient.AppendUnique(tableMangle, chainFORWARD, rule...); err != nil {
-			log.Errorf("failed to add mangle FORWARD guard rule: %v", err)
-		}
-	}
-
-	return nil
-}
-
-// seedInitialEntries adds default rules to the entries map, rules are inserted on pos 1, hence the order is reversed.
-// We want to make sure our traffic is not dropped by existing rules.
-
-// The existing FORWARD rules/policies decide outbound traffic towards our interface.
-// In case the FORWARD policy is set to "drop", we add an established/related rule to allow return traffic for the inbound rule.
-func (m *aclManager) seedInitialEntries() {
-	established := getConntrackEstablished()
-
-	m.appendToEntries("INPUT", []string{"-i", m.wgIface.Name(), "-j", "DROP"})
-	m.appendToEntries("INPUT", []string{"-i", m.wgIface.Name(), "-j", chainNameInputRules})
-	m.appendToEntries("INPUT", append([]string{"-i", m.wgIface.Name()}, established...))
-
-	// Inbound is handled by our ACLs, the rest is dropped.
-	// For outbound we respect the FORWARD policy. However, we need to allow established/related traffic for inbound rules.
-	m.appendToEntries("FORWARD", []string{"-i", m.wgIface.Name(), "-j", "DROP"})
-
-	m.appendToEntries("FORWARD", []string{"-o", m.wgIface.Name(), "-j", chainRTFWDOUT})
-	m.appendToEntries("FORWARD", []string{"-i", m.wgIface.Name(), "-j", chainRTFWDIN})
-
-	// Mangle FORWARD guard: when external DNAT redirects traffic from the wg interface, it
-	// traverses FORWARD instead of INPUT, bypassing ACL rules. ACCEPT rules in filter FORWARD
-	// can be inserted above ours. Mangle runs before filter, so these guard rules enforce the
-	// ACL mark check where it cannot be overridden.
-	m.appendToEntries(mangleFwdKey, []string{
-		"-i", m.wgIface.Name(),
-		"-m", "conntrack", "--ctstate", "RELATED,ESTABLISHED",
-		"-j", "ACCEPT",
-	})
-	m.appendToEntries(mangleFwdKey, []string{
-		"-i", m.wgIface.Name(),
-		"-m", "conntrack", "--ctstate", "DNAT",
-		"-m", "mark", "!", "--mark", fmt.Sprintf("%#x", nbnet.PreroutingFwmarkRedirected),
-		"-j", "DROP",
-	})
-}
-
-func (m *aclManager) seedInitialOptionalEntries() {
-	m.optionalEntries["FORWARD"] = []entry{
-		{
-			spec:     []string{"-m", "mark", "--mark", fmt.Sprintf("%#x", nbnet.PreroutingFwmarkRedirected), "-j", "ACCEPT"},
-			position: 2,
-		},
-	}
-}
-
-func (m *aclManager) appendToEntries(chainName string, spec []string) {
-	m.entries[chainName] = append(m.entries[chainName], spec)
-}
-
-func (m *aclManager) updateState() {
-	if m.stateManager == nil {
-		return
-	}
-
-	var currentState *ShutdownState
-	if existing := m.stateManager.GetState(currentState); existing != nil {
-		if existingState, ok := existing.(*ShutdownState); ok {
-			currentState = existingState
-		}
-	}
-	if currentState == nil {
-		currentState = &ShutdownState{}
-	}
-
-	currentState.Lock()
-	defer currentState.Unlock()
-
-	// Clone the maps so the persisted state holds a private snapshot. The
-	// live maps keep being mutated by subsequent rule operations while the
-	// state manager marshals the state from its periodic-save goroutine.
-	// Sharing them by reference races the two and aborts the process with a
-	// concurrent map iteration and write.
-	if m.v6 {
-		currentState.ACLEntries6 = maps.Clone(m.entries)
-		currentState.ACLIPsetStore6 = m.ipsetStore.clone()
-	} else {
-		currentState.ACLEntries = maps.Clone(m.entries)
-		currentState.ACLIPsetStore = m.ipsetStore.clone()
-	}
-
-	if err := m.stateManager.UpdateState(currentState); err != nil {
-		log.Errorf("failed to update state: %v", err)
-	}
-}
-
-// filterRuleSpecs returns the specs of a filtering rule
-// protoForFamily translates ICMP to ICMPv6 for ip6tables.
-// ip6tables requires "ipv6-icmp" (or "icmpv6") instead of "icmp".
-func protoForFamily(protocol firewall.Protocol, v6 bool) string {
-	if v6 && protocol == firewall.ProtocolICMP {
-		return "ipv6-icmp"
-	}
-	return string(protocol)
-}
-
-func filterRuleSpecs(ip net.IP, protocol string, sPort, dPort *firewall.Port, action firewall.Action, ipsetName string) (specs []string) {
-	// don't use IP matching if IP is 0.0.0.0
-	matchByIP := !ip.IsUnspecified()
-
-	if matchByIP {
-		if ipsetName != "" {
-			specs = append(specs, "-m", "set", "--match-set", ipsetName, "src")
-		} else {
-			specs = append(specs, "-s", ip.String())
-		}
-	}
-	if protocol != "all" {
-		specs = append(specs, "-p", protocol)
-	}
-	specs = append(specs, applyPort("--sport", sPort)...)
-	specs = append(specs, applyPort("--dport", dPort)...)
-	return specs
-}
-
-func actionToStr(action firewall.Action) string {
-	if action == firewall.ActionAccept {
-		return "ACCEPT"
-	}
-	return "DROP"
-}
-
-func transformIPsetName(ipsetName string, sPort, dPort *firewall.Port, action firewall.Action) string {
-	if ipsetName == "" {
-		return ""
-	}
-
-	actionSuffix := ""
-	if action == firewall.ActionDrop {
-		actionSuffix = "-drop"
-	}
-
-	switch {
-	case sPort != nil && dPort != nil:
-		return ipsetName + "-sport-dport" + actionSuffix
-	case sPort != nil:
-		return ipsetName + "-sport" + actionSuffix
-	case dPort != nil:
-		return ipsetName + "-dport" + actionSuffix
-	default:
-		return ipsetName + actionSuffix
-	}
-}
-
-func (m *aclManager) createIPSet(name string) error {
-	opts := ipset.CreateOptions{
-		Replace: true,
-	}
-	if m.v6 {
-		opts.Family = ipset.FamilyIPV6
-	}
-
-	if err := ipset.Create(name, ipset.TypeHashNet, opts); err != nil {
-		return fmt.Errorf("create ipset %s: %w", name, err)
-	}
-
-	log.Debugf("created ipset %s with type hash:net", name)
-	return nil
-}
-
-func (m *aclManager) addToIPSet(name string, ip net.IP) error {
-	cidr := uint8(32)
-	if ip.To4() == nil {
-		cidr = 128
-	}
-
-	entry := &ipset.Entry{
-		IP:      ip,
-		CIDR:    cidr,
-		Replace: true,
-	}
-
-	if err := ipset.Add(name, entry); err != nil {
-		return fmt.Errorf("add IP to ipset %s: %w", name, err)
-	}
-
-	return nil
-}
-
-func (m *aclManager) delFromIPSet(name string, ip net.IP) error {
-	cidr := uint8(32)
-	if ip.To4() == nil {
-		cidr = 128
-	}
-
-	entry := &ipset.Entry{
-		IP:   ip,
-		CIDR: cidr,
-	}
-
-	if err := ipset.Del(name, entry); err != nil {
-		return fmt.Errorf("delete IP from ipset %s: %w", name, err)
-	}
-
-	return nil
-}
-
-func (m *aclManager) flushIPSet(name string) error {
-	return ipset.Flush(name)
-}
-
-func (m *aclManager) destroyIPSet(name string) error {
-	return ipset.Destroy(name)
-}

client/firewall/iptables/chains_linux.go

@@ -0,0 +1,346 @@
+//go:build !android
+
+package iptables
+
+import (
+	"fmt"
+
+	"github.com/hashicorp/go-multierror"
+	log "github.com/sirupsen/logrus"
+
+	nberrors "github.com/netbirdio/netbird/client/errors"
+	firewall "github.com/netbirdio/netbird/client/firewall/manager"
+	nbnet "github.com/netbirdio/netbird/client/net"
+)
+
+func (r *family) createContainers() error {
+	for _, chainInfo := range []struct {
+		chain string
+		table string
+	}{
+		{chainRTFwdIn, tableFilter},
+		{chainRTFwdOut, tableFilter},
+		{chainRTPre, tableMangle},
+		{chainRTNAT, tableNat},
+		{chainRTRdr, tableNat},
+		{chainRTMSSClamp, tableMangle},
+	} {
+		// Fallback: clear chains that survived an unclean shutdown.
+		if ok, _ := r.iptablesClient.ChainExists(chainInfo.table, chainInfo.chain); ok {
+			if err := r.iptablesClient.ClearAndDeleteChain(chainInfo.table, chainInfo.chain); err != nil {
+				log.Warnf("clear stale chain %s in %s: %v", chainInfo.chain, chainInfo.table, err)
+			}
+		}
+		if err := r.iptablesClient.NewChain(chainInfo.table, chainInfo.chain); err != nil {
+			return fmt.Errorf("create chain %s in table %s: %w", chainInfo.chain, chainInfo.table, err)
+		}
+	}
+
+	if err := r.insertEstablishedRule(chainRTFwdIn); err != nil {
+		return fmt.Errorf("insert established rule: %w", err)
+	}
+
+	if err := r.insertEstablishedRule(chainRTFwdOut); err != nil {
+		return fmt.Errorf("insert established rule: %w", err)
+	}
+
+	if err := r.addPostroutingRules(); err != nil {
+		return fmt.Errorf("add static nat rules: %w", err)
+	}
+
+	if err := r.addJumpRules(); err != nil {
+		return fmt.Errorf("add jump rules: %w", err)
+	}
+
+	if err := r.addMSSClampingRules(); err != nil {
+		log.Errorf("failed to add MSS clamping rules: %s", err)
+	}
+
+	return nil
+}
+
+func (r *family) addJumpRules() error {
+	// Jump to nat chain
+	natRule := jumpRuleSpec(chainRTNAT)
+	if err := r.iptablesClient.Insert(tableNat, chainPostrouting, 1, natRule...); err != nil {
+		return fmt.Errorf("add nat postrouting jump rule: %w", err)
+	}
+	r.rules[jumpNATPost] = natRule
+
+	// Jump to mangle prerouting chain
+	preRule := jumpRuleSpec(chainRTPre)
+	if err := r.iptablesClient.Insert(tableMangle, chainPrerouting, 1, preRule...); err != nil {
+		return fmt.Errorf("add mangle prerouting jump rule: %w", err)
+	}
+	r.rules[jumpManglePre] = preRule
+
+	// Jump to nat prerouting chain
+	rdrRule := jumpRuleSpec(chainRTRdr)
+	if err := r.iptablesClient.Insert(tableNat, chainPrerouting, 1, rdrRule...); err != nil {
+		return fmt.Errorf("add nat prerouting jump rule: %w", err)
+	}
+	r.rules[jumpNATPre] = rdrRule
+
+	return nil
+}
+
+func (r *family) setupDataPlaneMark() error {
+	var merr *multierror.Error
+	preRule := []string{
+		"-i", r.wgIface.Name(),
+		"-m", "conntrack", "--ctstate", "NEW",
+		"-j", "CONNMARK", "--set-mark", fmt.Sprintf("%#x", nbnet.DataPlaneMarkIn),
+	}
+
+	if err := r.iptablesClient.AppendUnique(tableMangle, chainPrerouting, preRule...); err != nil {
+		merr = multierror.Append(merr, fmt.Errorf("add mangle prerouting rule: %w", err))
+	} else {
+		r.rules[markManglePre] = preRule
+	}
+
+	postRule := []string{
+		"-o", r.wgIface.Name(),
+		"-m", "conntrack", "--ctstate", "NEW",
+		"-j", "CONNMARK", "--set-mark", fmt.Sprintf("%#x", nbnet.DataPlaneMarkOut),
+	}
+
+	if err := r.iptablesClient.AppendUnique(tableMangle, chainPostrouting, postRule...); err != nil {
+		merr = multierror.Append(merr, fmt.Errorf("add mangle postrouting rule: %w", err))
+	} else {
+		r.rules[markManglePost] = postRule
+	}
+
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+// seedInitialEntries adds default rules to the entries map. Rules are
+// inserted at position 1, so the order here is reversed.
+//
+// Existing FORWARD policy decides outbound traffic towards our
+// interface. If FORWARD policy is "drop", we add an
+// established/related rule to allow return traffic for inbound rules.
+func (r *family) seedInitialEntries() {
+	established := getConntrackEstablished()
+
+	r.appendToEntries(chainInput, []string{"-i", r.wgIface.Name(), "-j", "DROP"})
+	r.appendToEntries(chainInput, []string{"-i", r.wgIface.Name(), "-j", chainACLInput})
+	r.appendToEntries(chainInput, append([]string{"-i", r.wgIface.Name()}, established...))
+
+	r.appendToEntries(chainForward, []string{"-i", r.wgIface.Name(), "-j", "DROP"})
+	r.appendToEntries(chainForward, []string{"-o", r.wgIface.Name(), "-j", chainRTFwdOut})
+	r.appendToEntries(chainForward, []string{"-i", r.wgIface.Name(), "-j", chainRTFwdIn})
+
+	// Mangle FORWARD guard: when external DNAT redirects traffic from
+	// the wg interface, it traverses FORWARD instead of INPUT,
+	// bypassing ACL rules. ACCEPT rules in filter FORWARD can be
+	// inserted above ours. Mangle runs before filter, so these guard
+	// rules enforce the ACL mark check where it cannot be overridden.
+	r.appendToEntries(mangleForwardKey, []string{
+		"-i", r.wgIface.Name(),
+		"-m", "conntrack", "--ctstate", "RELATED,ESTABLISHED",
+		"-j", "ACCEPT",
+	})
+	r.appendToEntries(mangleForwardKey, []string{
+		"-i", r.wgIface.Name(),
+		"-m", "conntrack", "--ctstate", "DNAT",
+		"-m", "mark", "!", "--mark", fmt.Sprintf("%#x", nbnet.PreroutingFwmarkRedirected),
+		"-j", "DROP",
+	})
+}
+
+func (r *family) seedInitialOptionalEntries() {
+	r.optionalEntries[chainForward] = []entry{
+		{
+			spec:     []string{"-m", "mark", "--mark", fmt.Sprintf("%#x", nbnet.PreroutingFwmarkRedirected), "-j", "ACCEPT"},
+			position: 2,
+		},
+	}
+}
+
+func (r *family) appendToEntries(chain chainKey, spec ruleSpec) {
+	r.entries[chain] = append(r.entries[chain], spec)
+}
+
+func (r *family) createDefaultChains() error {
+	if err := r.iptablesClient.NewChain(tableFilter, chainACLInput); err != nil {
+		return fmt.Errorf("create %s chain: %w", chainACLInput, err)
+	}
+
+	for chain, rules := range r.entries {
+		// mangle FORWARD guard rules are handled separately below
+		if chain == mangleForwardKey {
+			continue
+		}
+		for _, rule := range rules {
+			if err := r.iptablesClient.InsertUnique(tableFilter, string(chain), 1, rule...); err != nil {
+				return fmt.Errorf("insert jump rule into %s: %w", chain, err)
+			}
+		}
+	}
+
+	for chain, entries := range r.optionalEntries {
+		for _, entry := range entries {
+			if err := r.iptablesClient.InsertUnique(tableFilter, string(chain), entry.position, entry.spec...); err != nil {
+				log.Errorf("failed to insert optional entry %v: %v", entry.spec, err)
+				continue
+			}
+			r.entries[chain] = append(r.entries[chain], entry.spec)
+		}
+	}
+	clear(r.optionalEntries)
+
+	// Insert mangle FORWARD guard rules to prevent external DNAT bypass.
+	for _, rule := range r.entries[mangleForwardKey] {
+		if err := r.iptablesClient.AppendUnique(tableMangle, chainForward, rule...); err != nil {
+			log.Errorf("failed to add mangle FORWARD guard rule: %v", err)
+		}
+	}
+
+	return nil
+}
+
+func (r *family) cleanUpDefaultForwardRules() error {
+	var merr *multierror.Error
+
+	// cleanJumpRules removes the OUTPUT jump to NETBIRD-NAT-OUTPUT among
+	// the others, so the chain below deletes cleanly instead of failing
+	// with "device or resource busy".
+	if err := r.cleanJumpRules(); err != nil {
+		merr = multierror.Append(merr, fmt.Errorf("clean jump rules: %w", err))
+	}
+
+	for _, chainInfo := range []struct {
+		chain string
+		table string
+	}{
+		{chainRTFwdIn, tableFilter},
+		{chainRTFwdOut, tableFilter},
+		{chainRTPre, tableMangle},
+		{chainRTNAT, tableNat},
+		{chainRTRdr, tableNat},
+		{chainNATOutput, tableNat},
+		{chainRTMSSClamp, tableMangle},
+	} {
+		ok, err := r.iptablesClient.ChainExists(chainInfo.table, chainInfo.chain)
+		if err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("check chain %s in table %s: %w", chainInfo.chain, chainInfo.table, err))
+			continue
+		}
+		if ok {
+			if err := r.iptablesClient.ClearAndDeleteChain(chainInfo.table, chainInfo.chain); err != nil {
+				merr = multierror.Append(merr, fmt.Errorf("clear and delete chain %s in table %s: %w", chainInfo.chain, chainInfo.table, err))
+			}
+		}
+	}
+
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+func (r *family) cleanJumpRules() error {
+	// locations maps each jump rule to the built-in table and chain it
+	// was inserted into, plus the netbird chain it targets.
+	locations := map[firewall.RuleID]struct{ table, chain, target string }{
+		jumpNATPost:   {tableNat, chainPostrouting, chainRTNAT},
+		jumpManglePre: {tableMangle, chainPrerouting, chainRTPre},
+		jumpNATPre:    {tableNat, chainPrerouting, chainRTRdr},
+		jumpMSSClamp:  {tableMangle, chainForward, chainRTMSSClamp},
+		jumpNATOutput: {tableNat, chainOutput, chainNATOutput},
+	}
+
+	var merr *multierror.Error
+	for ruleID, loc := range locations {
+		rule, exists := r.rules[ruleID]
+		if !exists {
+			// Untracked (e.g. fresh start after an unclean shutdown with no
+			// restored state): if the target chain survived, remove the stale
+			// jump to it so the chain can be deleted.
+			ok, err := r.iptablesClient.ChainExists(loc.table, loc.target)
+			if err != nil {
+				merr = multierror.Append(merr, fmt.Errorf("check chain %s in table %s: %w", loc.target, loc.table, err))
+				continue
+			}
+			if !ok {
+				continue
+			}
+			rule = jumpRuleSpec(loc.target)
+		}
+		if err := r.iptablesClient.DeleteIfExists(loc.table, loc.chain, rule...); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("delete rule from chain %s in table %s: %w", loc.chain, loc.table, err))
+			continue
+		}
+		delete(r.rules, ruleID)
+	}
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+// jumpRuleSpec builds the iptables rule spec that jumps to target. Create
+// and cleanup sites share it so the installed and deleted specs cannot drift.
+func jumpRuleSpec(target string) []string {
+	return []string{"-j", target}
+}
+
+func (r *family) cleanAclChains() error {
+	var merr *multierror.Error
+
+	if err := r.cleanInputAclChain(); err != nil {
+		merr = multierror.Append(merr, err)
+	}
+
+	for _, rule := range r.entries[mangleForwardKey] {
+		if err := r.iptablesClient.DeleteIfExists(tableMangle, chainForward, rule...); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("delete mangle %s guard rule %v: %w", chainForward, rule, err))
+		}
+	}
+
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+func (r *family) cleanInputAclChain() error {
+	ok, err := r.iptablesClient.ChainExists(tableFilter, chainACLInput)
+	if err != nil {
+		return fmt.Errorf("check chain %s: %w", chainACLInput, err)
+	}
+	if !ok {
+		return nil
+	}
+
+	var merr *multierror.Error
+	for _, rule := range r.entries[chainInput] {
+		if err := r.iptablesClient.DeleteIfExists(tableFilter, chainInput, rule...); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("delete %s rule %v: %w", chainInput, rule, err))
+		}
+	}
+
+	for _, rule := range r.entries[chainForward] {
+		if err := r.iptablesClient.DeleteIfExists(tableFilter, chainForward, rule...); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("delete %s rule %v: %w", chainForward, rule, err))
+		}
+	}
+
+	if err := r.iptablesClient.ClearAndDeleteChain(tableFilter, chainACLInput); err != nil {
+		merr = multierror.Append(merr, fmt.Errorf("clear and delete %s chain: %w", chainACLInput, err))
+	}
+
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+func (r *family) cleanupDataPlaneMark() error {
+	var merr *multierror.Error
+	if preRule, exists := r.rules[markManglePre]; exists {
+		if err := r.iptablesClient.DeleteIfExists(tableMangle, chainPrerouting, preRule...); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("remove mangle prerouting rule: %w", err))
+		} else {
+			delete(r.rules, markManglePre)
+		}
+	}
+
+	if postRule, exists := r.rules[markManglePost]; exists {
+		if err := r.iptablesClient.DeleteIfExists(tableMangle, chainPostrouting, postRule...); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("remove mangle postrouting rule: %w", err))
+		} else {
+			delete(r.rules, markManglePost)
+		}
+	}
+
+	return nberrors.FormatErrorOrNil(merr)
+}

client/firewall/iptables/dnat_linux.go

@@ -0,0 +1,285 @@
+//go:build !android
+
+package iptables
+
+import (
+	"fmt"
+	"net/netip"
+	"strconv"
+	"strings"
+
+	"github.com/hashicorp/go-multierror"
+	log "github.com/sirupsen/logrus"
+
+	nberrors "github.com/netbirdio/netbird/client/errors"
+	firewall "github.com/netbirdio/netbird/client/firewall/manager"
+)
+
+func (r *family) AddDNATRule(rule firewall.ForwardRule) (firewall.Rule, error) {
+	ruleID := rule.ID()
+	if _, exists := r.rules[ruleID+dnatSuffix]; exists {
+		return rule, nil
+	}
+
+	toDestination := rule.TranslatedAddress.String()
+	switch {
+	case len(rule.TranslatedPort.Values) == 0:
+		// no translated port, use original port
+	case len(rule.TranslatedPort.Values) == 1:
+		toDestination += fmt.Sprintf(":%d", rule.TranslatedPort.Values[0])
+	case rule.TranslatedPort.IsRange && len(rule.TranslatedPort.Values) == 2:
+		// need the "/originalport" suffix to avoid dnat port randomization
+		toDestination += fmt.Sprintf(":%d-%d/%d", rule.TranslatedPort.Values[0], rule.TranslatedPort.Values[1], rule.DestinationPort.Values[0])
+	default:
+		return nil, fmt.Errorf("invalid translated port: %v", rule.TranslatedPort)
+	}
+
+	proto := strings.ToLower(string(rule.Protocol))
+
+	rules := make(map[firewall.RuleID]ruleInfo, 3)
+
+	// DNAT rule
+	dnatRule := []string{
+		"!", "-i", r.wgIface.Name(),
+		"-p", proto,
+		"-j", "DNAT",
+		"--to-destination", toDestination,
+	}
+	dnatRule = append(dnatRule, applyPort("--dport", &rule.DestinationPort)...)
+	rules[ruleID+dnatSuffix] = ruleInfo{
+		table: tableNat,
+		chain: chainRTRdr,
+		rule:  dnatRule,
+	}
+
+	// SNAT rule
+	snatRule := []string{
+		"-o", r.wgIface.Name(),
+		"-p", proto,
+		"-d", rule.TranslatedAddress.String(),
+		"-j", "MASQUERADE",
+	}
+	snatRule = append(snatRule, applyPort("--dport", &rule.TranslatedPort)...)
+	rules[ruleID+snatSuffix] = ruleInfo{
+		table: tableNat,
+		chain: chainRTNAT,
+		rule:  snatRule,
+	}
+
+	// Forward filtering rule, if fwd policy is DROP
+	forwardRule := []string{
+		"-o", r.wgIface.Name(),
+		"-p", proto,
+		"-d", rule.TranslatedAddress.String(),
+		"-j", "ACCEPT",
+	}
+	forwardRule = append(forwardRule, applyPort("--dport", &rule.TranslatedPort)...)
+	rules[ruleID+fwdSuffix] = ruleInfo{
+		table: tableFilter,
+		chain: chainRTFwdOut,
+		rule:  forwardRule,
+	}
+
+	// Request forwarding once the rule is about to be installed, releasing
+	// it if installation fails so the refcount tracks the real rules.
+	if err := r.ipFwdState.RequestForwarding(); err != nil {
+		return nil, err
+	}
+
+	for key, ruleInfo := range rules {
+		if err := r.iptablesClient.Append(ruleInfo.table, ruleInfo.chain, ruleInfo.rule...); err != nil {
+			if rollbackErr := r.rollbackRules(rules); rollbackErr != nil {
+				log.Errorf("rollback failed: %v", rollbackErr)
+			}
+			r.releaseForwarding()
+			return nil, fmt.Errorf("add rule %s: %w", key, err)
+		}
+		r.rules[key] = ruleInfo.rule
+	}
+
+	r.updateState()
+	return rule, nil
+}
+
+func (r *family) rollbackRules(rules map[firewall.RuleID]ruleInfo) error {
+	var merr *multierror.Error
+	for key, ruleInfo := range rules {
+		if err := r.iptablesClient.DeleteIfExists(ruleInfo.table, ruleInfo.chain, ruleInfo.rule...); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("rollback rule %s: %w", key, err))
+			// On rollback error, add to rules map for next cleanup
+			r.rules[key] = ruleInfo.rule
+		}
+	}
+	if merr != nil {
+		r.updateState()
+	}
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+func (r *family) DeleteDNATRule(rule firewall.Rule) error {
+	ruleID := rule.ID()
+
+	var merr *multierror.Error
+	var found bool
+	if dnatRule, exists := r.rules[ruleID+dnatSuffix]; exists {
+		found = true
+		if err := r.iptablesClient.Delete(tableNat, chainRTRdr, dnatRule...); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("delete DNAT rule: %w", err))
+		}
+		delete(r.rules, ruleID+dnatSuffix)
+	}
+
+	if snatRule, exists := r.rules[ruleID+snatSuffix]; exists {
+		found = true
+		if err := r.iptablesClient.Delete(tableNat, chainRTNAT, snatRule...); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("delete SNAT rule: %w", err))
+		}
+		delete(r.rules, ruleID+snatSuffix)
+	}
+
+	if fwdRule, exists := r.rules[ruleID+fwdSuffix]; exists {
+		found = true
+		if err := r.iptablesClient.Delete(tableFilter, chainRTFwdOut, fwdRule...); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("delete forward rule: %w", err))
+		}
+		delete(r.rules, ruleID+fwdSuffix)
+	}
+
+	r.updateState()
+
+	// Release once, only if the rule was present and removed.
+	if merr == nil && found {
+		r.releaseForwarding()
+	}
+
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+// releaseForwarding drops one IP forwarding reference, logging any error.
+func (r *family) releaseForwarding() {
+	if err := r.ipFwdState.ReleaseForwarding(); err != nil {
+		log.Errorf("release IP forwarding: %v", err)
+	}
+}
+
+func (r *family) AddInboundDNAT(localAddr netip.Addr, protocol firewall.Protocol, originalPort, translatedPort uint16) error {
+	ruleID := firewall.RuleID(fmt.Sprintf("inbound-dnat-%s-%s-%d-%d", localAddr.String(), protocol, originalPort, translatedPort))
+
+	if _, exists := r.rules[ruleID]; exists {
+		return nil
+	}
+
+	dnatRule := []string{
+		"-i", r.wgIface.Name(),
+		"-p", strings.ToLower(protoForFamily(protocol, r.v6)),
+		"--dport", strconv.Itoa(int(originalPort)),
+		"-d", localAddr.String(),
+		"-m", "addrtype", "--dst-type", "LOCAL",
+		"-j", "DNAT",
+		"--to-destination", ":" + strconv.Itoa(int(translatedPort)),
+	}
+
+	info := ruleInfo{
+		table: tableNat,
+		chain: chainRTRdr,
+		rule:  dnatRule,
+	}
+
+	if err := r.iptablesClient.Append(info.table, info.chain, info.rule...); err != nil {
+		return fmt.Errorf("add inbound DNAT rule: %w", err)
+	}
+	r.rules[ruleID] = info.rule
+
+	r.updateState()
+	return nil
+}
+
+// RemoveInboundDNAT removes an inbound DNAT rule.
+func (r *family) RemoveInboundDNAT(localAddr netip.Addr, protocol firewall.Protocol, originalPort, translatedPort uint16) error {
+	ruleID := firewall.RuleID(fmt.Sprintf("inbound-dnat-%s-%s-%d-%d", localAddr.String(), protocol, originalPort, translatedPort))
+
+	if dnatRule, exists := r.rules[ruleID]; exists {
+		if err := r.iptablesClient.Delete(tableNat, chainRTRdr, dnatRule...); err != nil {
+			return fmt.Errorf("delete inbound DNAT rule: %w", err)
+		}
+		delete(r.rules, ruleID)
+	}
+
+	r.updateState()
+	return nil
+}
+
+// ensureNATOutputChain lazily creates the OUTPUT NAT chain and jump rule on first use.
+func (r *family) ensureNATOutputChain() error {
+	if _, exists := r.rules[jumpNATOutput]; exists {
+		return nil
+	}
+
+	chainExists, err := r.iptablesClient.ChainExists(tableNat, chainNATOutput)
+	if err != nil {
+		return fmt.Errorf("check chain %s: %w", chainNATOutput, err)
+	}
+	if !chainExists {
+		if err := r.iptablesClient.NewChain(tableNat, chainNATOutput); err != nil {
+			return fmt.Errorf("create chain %s: %w", chainNATOutput, err)
+		}
+	}
+
+	jumpRule := jumpRuleSpec(chainNATOutput)
+	if err := r.iptablesClient.Insert(tableNat, chainOutput, 1, jumpRule...); err != nil {
+		if !chainExists {
+			if delErr := r.iptablesClient.ClearAndDeleteChain(tableNat, chainNATOutput); delErr != nil {
+				log.Warnf("failed to rollback chain %s: %v", chainNATOutput, delErr)
+			}
+		}
+		return fmt.Errorf("add OUTPUT jump rule: %w", err)
+	}
+	r.rules[jumpNATOutput] = jumpRule
+
+	r.updateState()
+	return nil
+}
+
+// AddOutputDNAT adds an OUTPUT chain DNAT rule for locally-generated traffic.
+func (r *family) AddOutputDNAT(localAddr netip.Addr, protocol firewall.Protocol, originalPort, translatedPort uint16) error {
+	ruleID := firewall.RuleID(fmt.Sprintf("output-dnat-%s-%s-%d-%d", localAddr.String(), protocol, originalPort, translatedPort))
+
+	if _, exists := r.rules[ruleID]; exists {
+		return nil
+	}
+
+	if err := r.ensureNATOutputChain(); err != nil {
+		return err
+	}
+
+	dnatRule := []string{
+		"-p", strings.ToLower(protoForFamily(protocol, localAddr.Is6())),
+		"--dport", strconv.Itoa(int(originalPort)),
+		"-d", localAddr.String(),
+		"-j", "DNAT",
+		"--to-destination", ":" + strconv.Itoa(int(translatedPort)),
+	}
+
+	if err := r.iptablesClient.Append(tableNat, chainNATOutput, dnatRule...); err != nil {
+		return fmt.Errorf("add output DNAT rule: %w", err)
+	}
+	r.rules[ruleID] = dnatRule
+
+	r.updateState()
+	return nil
+}
+
+// RemoveOutputDNAT removes an OUTPUT chain DNAT rule.
+func (r *family) RemoveOutputDNAT(localAddr netip.Addr, protocol firewall.Protocol, originalPort, translatedPort uint16) error {
+	ruleID := firewall.RuleID(fmt.Sprintf("output-dnat-%s-%s-%d-%d", localAddr.String(), protocol, originalPort, translatedPort))
+
+	if dnatRule, exists := r.rules[ruleID]; exists {
+		if err := r.iptablesClient.Delete(tableNat, chainNATOutput, dnatRule...); err != nil {
+			return fmt.Errorf("delete output DNAT rule: %w", err)
+		}
+		delete(r.rules, ruleID)
+	}
+
+	r.updateState()
+	return nil
+}

client/firewall/iptables/family_linux.go

@@ -0,0 +1,252 @@
+//go:build !android
+
+package iptables
+
+import (
+	"fmt"
+	"maps"
+	"net/netip"
+
+	"github.com/coreos/go-iptables/iptables"
+	"github.com/hashicorp/go-multierror"
+	log "github.com/sirupsen/logrus"
+
+	nberrors "github.com/netbirdio/netbird/client/errors"
+	firewall "github.com/netbirdio/netbird/client/firewall/manager"
+	nbid "github.com/netbirdio/netbird/client/internal/acl/id"
+	"github.com/netbirdio/netbird/client/internal/routemanager/ipfwdstate"
+	"github.com/netbirdio/netbird/client/internal/routemanager/refcounter"
+	"github.com/netbirdio/netbird/client/internal/statemanager"
+)
+
+// constants needed to manage and create iptable rules
+const (
+	tableFilter = "filter"
+	tableNat    = "nat"
+	tableMangle = "mangle"
+
+	// chainACLInput is the peer ACL chain that holds installed
+	// peer-filtering rules.
+	chainACLInput = "NETBIRD-ACL-INPUT"
+
+	// mangleForwardKey is the entries map key for mangle FORWARD guard
+	// rules that prevent external DNAT from bypassing ACL rules.
+	mangleForwardKey chainKey = "MANGLE-FORWARD"
+
+	chainInput       = "INPUT"
+	chainPostrouting = "POSTROUTING"
+	chainPrerouting  = "PREROUTING"
+	chainForward     = "FORWARD"
+	chainRTNAT       = "NETBIRD-RT-NAT"
+	chainRTFwdIn     = "NETBIRD-RT-FWD-IN"
+	chainRTFwdOut    = "NETBIRD-RT-FWD-OUT"
+	chainRTPre       = "NETBIRD-RT-PRE"
+	chainRTRdr       = "NETBIRD-RT-RDR"
+	chainNATOutput   = "NETBIRD-NAT-OUTPUT"
+	chainRTMSSClamp  = "NETBIRD-RT-MSSCLAMP"
+
+	jumpManglePre  = "jump-mangle-pre"
+	jumpNATPre     = "jump-nat-pre"
+	jumpNATPost    = "jump-nat-post"
+	jumpNATOutput  = "jump-nat-output"
+	jumpMSSClamp   = "jump-mss-clamp"
+	markManglePre  = "mark-mangle-pre"
+	markManglePost = "mark-mangle-post"
+	matchSet       = "--match-set"
+
+	dnatSuffix firewall.RuleID = "_dnat"
+	snatSuffix firewall.RuleID = "_snat"
+	fwdSuffix  firewall.RuleID = "_fwd"
+
+	// ipv4TCPHeaderSize is the minimum IPv4 (20) + TCP (20) header size for MSS calculation.
+	ipv4TCPHeaderSize = 40
+	// ipv6TCPHeaderSize is the minimum IPv6 (40) + TCP (20) header size for MSS calculation.
+	ipv6TCPHeaderSize = 60
+)
+
+type ruleInfo struct {
+	chain string
+	table string
+	rule  []string
+}
+
+type routeRules map[firewall.RuleID][]string
+
+// ruleSpec is a single iptables rule expressed as its argument list
+// (e.g. {"-i", "wg0", "-j", "DROP"}).
+type ruleSpec []string
+
+// chainKey identifies the chain a seeded entry belongs to. It holds
+// built-in chain names ("INPUT", "FORWARD", "PREROUTING") plus the
+// synthetic mangleForwardKey bucket for the mangle FORWARD guard rules.
+type chainKey string
+
+// aclEntries maps a chain to the rules seeded into it to jump into or
+// guard the netbird ACL chains.
+type aclEntries map[chainKey][]ruleSpec
+
+type entry struct {
+	spec     ruleSpec
+	position int
+}
+
+// ipsetCounter is the shared hash:net refcounter used by peer and
+// route ACLs alike. The ipset library does not support comments, so
+// the key is just the set name (string).
+type ipsetCounter = refcounter.Counter[string, []netip.Prefix, struct{}]
+
+// family holds the per-address-family iptables state. One instance
+// handles route ACLs, peer ACLs, NAT, DNAT, and MSS clamping for a
+// single family; the top-level Manager owns one for v4 and another
+// for v6.
+type family struct {
+	iptablesClient *iptables.IPTables
+	wgIface        iFaceMapper
+	v6             bool
+
+	// Peer ACL chain bookkeeping.
+	entries         aclEntries
+	optionalEntries map[chainKey][]entry
+
+	// filters holds peer + route filter rules keyed by content hash.
+	// AddFilterRule writes here; DeleteFilterRule looks up by id.
+	filters      map[nbid.RuleID]*Rule
+	ipsetCounter *ipsetCounter
+
+	// rules holds NAT, jump, and MSS-clamping rules (auxiliary
+	// plumbing that isn't a filter rule).
+	rules routeRules
+
+	// Routing / NAT.
+	legacyManagement bool
+	mtu              uint16
+	ipFwdState       *ipfwdstate.IPForwardingState
+
+	stateManager *statemanager.Manager
+}
+
+func newFamily(iptablesClient *iptables.IPTables, wgIface iFaceMapper, mtu uint16) (*family, error) {
+	r := &family{
+		iptablesClient:  iptablesClient,
+		wgIface:         wgIface,
+		v6:              iptablesClient.Proto() == iptables.ProtocolIPv6,
+		entries:         make(aclEntries),
+		optionalEntries: make(map[chainKey][]entry),
+		filters:         make(map[nbid.RuleID]*Rule),
+		rules:           make(routeRules),
+		mtu:             mtu,
+		ipFwdState:      ipfwdstate.NewIPForwardingState(),
+	}
+
+	r.ipsetCounter = refcounter.New(
+		func(name string, sources []netip.Prefix) (struct{}, error) {
+			return struct{}{}, r.createIpSet(name, sources)
+		},
+		func(name string, _ struct{}) error {
+			return r.deleteIpSet(name)
+		},
+	)
+
+	return r, nil
+}
+
+// init wires the family to the state manager and installs both the
+// route ACL containers and the peer ACL chain skeleton.
+func (r *family) init(stateManager *statemanager.Manager) error {
+	r.stateManager = stateManager
+
+	if err := r.cleanUpDefaultForwardRules(); err != nil {
+		log.Errorf("failed to clean up rules from FORWARD chain: %s", err)
+	}
+
+	if err := r.createContainers(); err != nil {
+		return fmt.Errorf("create containers: %w", err)
+	}
+
+	if err := r.setupDataPlaneMark(); err != nil {
+		log.Errorf("failed to set up data plane mark: %v", err)
+	}
+
+	r.seedInitialEntries()
+	r.seedInitialOptionalEntries()
+
+	if err := r.cleanAclChains(); err != nil {
+		return fmt.Errorf("clean acl chains: %w", err)
+	}
+	if err := r.createDefaultChains(); err != nil {
+		return fmt.Errorf("create default chains: %w", err)
+	}
+
+	r.updateState()
+
+	return nil
+}
+
+// Reset tears down all firewall state owned by this family. ACL
+// chain cleanup runs before route-chain cleanup because the route
+// chains are still referenced by FORWARD jumps installed during
+// seedInitialEntries; deleting them first would trip EBUSY.
+func (r *family) Reset() error {
+	var merr *multierror.Error
+
+	if err := r.cleanAclChains(); err != nil {
+		merr = multierror.Append(merr, err)
+	}
+
+	if err := r.cleanUpDefaultForwardRules(); err != nil {
+		merr = multierror.Append(merr, err)
+	}
+
+	if err := r.ipsetCounter.Flush(); err != nil {
+		merr = multierror.Append(merr, err)
+	}
+
+	if err := r.cleanupDataPlaneMark(); err != nil {
+		merr = multierror.Append(merr, err)
+	}
+
+	clear(r.rules)
+	clear(r.filters)
+	r.updateState()
+
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+func (r *family) updateState() {
+	if r.stateManager == nil {
+		return
+	}
+
+	var currentState *ShutdownState
+	if existing := r.stateManager.GetState(currentState); existing != nil {
+		if existingState, ok := existing.(*ShutdownState); ok {
+			currentState = existingState
+		}
+	}
+	if currentState == nil {
+		currentState = &ShutdownState{}
+	}
+
+	currentState.Lock()
+	defer currentState.Unlock()
+
+	// Clone the rule maps so the persisted state holds a private snapshot.
+	// The live maps keep being mutated by subsequent rule operations while
+	// the state manager marshals the state from its periodic-save goroutine.
+	// Sharing the maps by reference races the two and aborts the process with
+	// a concurrent map iteration and write. The ipset counter guards itself
+	// during marshaling, so it can be shared directly.
+	if r.v6 {
+		currentState.RouteRules6 = maps.Clone(r.rules)
+		currentState.RouteIPsetCounter6 = r.ipsetCounter
+		currentState.ACLEntries6 = maps.Clone(r.entries)
+	} else {
+		currentState.RouteRules = maps.Clone(r.rules)
+		currentState.RouteIPsetCounter = r.ipsetCounter
+		currentState.ACLEntries = maps.Clone(r.entries)
+	}
+
+	if err := r.stateManager.UpdateState(currentState); err != nil {
+		log.Errorf("failed to update state: %v", err)
+	}
+}

client/firewall/iptables/filter_linux.go

@@ -0,0 +1,346 @@
+//go:build !android
+
+package iptables
+
+import (
+	"fmt"
+	"net/netip"
+	"slices"
+	"strconv"
+	"strings"
+
+	"github.com/hashicorp/go-multierror"
+	log "github.com/sirupsen/logrus"
+
+	nberrors "github.com/netbirdio/netbird/client/errors"
+	firewall "github.com/netbirdio/netbird/client/firewall/manager"
+	nbid "github.com/netbirdio/netbird/client/internal/acl/id"
+	nbnet "github.com/netbirdio/netbird/client/net"
+)
+
+// AddFilterRule installs a packet-filtering rule. With destination
+// empty, the rule goes to the peer ACL input chain plus a paired
+// mangle PREROUTING rule for the redirect mark. With destination set
+// (prefix or named set), it goes to the route ACL forward chain.
+// Multi-source rules collapse to one iptables rule via the shared
+// hash:net ipset.
+func (r *family) AddFilterRule(
+	id []byte,
+	sources []netip.Prefix,
+	destination firewall.Network,
+	proto firewall.Protocol,
+	sPort *firewall.Port,
+	dPort *firewall.Port,
+	action firewall.Action,
+) (firewall.Rule, error) {
+	ruleID := nbid.GenerateRuleID(sources, destination, proto, sPort, dPort, action)
+	if existing, ok := r.filters[ruleID]; ok {
+		return existing, nil
+	}
+
+	srcMatch, err := r.applySourceMatch(sourceNetwork(sources), sources)
+	if err != nil {
+		return nil, fmt.Errorf("apply source match: %w", err)
+	}
+
+	rule, err := r.installFilterRule(ruleID, srcMatch, destination, proto, sPort, dPort, action)
+	if err != nil {
+		r.dropSourceMatch(srcMatch)
+		return nil, err
+	}
+
+	r.filters[ruleID] = rule
+	r.updateState()
+	return rule, nil
+}
+
+func (r *family) hasRule(id nbid.RuleID) bool {
+	_, ok := r.filters[id]
+	return ok
+}
+
+// hasDNATRule reports whether this family owns the DNAT rule set for
+// the given user id. DNAT rules live in r.rules under the well-known
+// "<id>_dnat" key; the lookup here is used by Manager.DeleteDNATRule
+// to pick the right family.
+func (r *family) hasDNATRule(id firewall.RuleID) bool {
+	_, ok := r.rules[id+dnatSuffix]
+	return ok
+}
+
+// DeleteFilterRule removes a previously installed filter rule. The
+// rule's stored chain/table identify where to delete from; source set
+// references are recovered from the spec via findSets and dropped
+// from the shared ipset counter.
+func (r *family) DeleteFilterRule(rule firewall.Rule) error {
+	ruleID := rule.ID()
+	pr, ok := r.filters[ruleID]
+	if !ok {
+		log.Debugf("filter rule %s not found", ruleID)
+		return nil
+	}
+
+	// DeleteIfExists keeps both deletes idempotent so a retry after a
+	// partial failure does not error on the half that was already removed.
+	var merr *multierror.Error
+	if err := r.iptablesClient.DeleteIfExists(tableFilter, pr.chain, pr.specs...); err != nil {
+		merr = multierror.Append(merr, fmt.Errorf("delete rule from %s: %w", pr.chain, err))
+	}
+	if pr.mangleSpecs != nil {
+		if err := r.iptablesClient.DeleteIfExists(tableMangle, chainRTPre, pr.mangleSpecs...); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("delete mangle rule: %w", err))
+		}
+	}
+	if merr != nil {
+		// Leave the rule tracked so the caller retries the remaining half.
+		return nberrors.FormatErrorOrNil(merr)
+	}
+
+	// The rule is gone from iptables, so untrack it regardless of how the
+	// refcount decrement goes, but surface decrement failures so callers
+	// see the ipset desync.
+	delete(r.filters, ruleID)
+	r.updateState()
+	if err := r.decrementSetCounter(pr.specs); err != nil {
+		return fmt.Errorf("drop source set references: %w", err)
+	}
+	return nil
+}
+
+// findSets scans an iptables rule spec for "-m set --match-set <name>
+// <dir>" fragments and returns the named sets in occurrence order.
+// Used at delete time to drop ipsetCounter references.
+func findSets(rule []string) []string {
+	var sets []string
+	for i, arg := range rule {
+		if arg == "-m" && i+3 < len(rule) && rule[i+1] == "set" && rule[i+2] == matchSet {
+			sets = append(sets, rule[i+3])
+		}
+	}
+	return sets
+}
+
+// sourceNetwork classifies a source-prefix list into the firewall.Network
+// shape the rest of the spec-builder consumes: empty for match-any, a
+// single prefix inline, or an ipset for multiple sources.
+func sourceNetwork(sources []netip.Prefix) firewall.Network {
+	switch {
+	case len(sources) == 0:
+		return firewall.Network{}
+	case len(sources) == 1 && sources[0].Bits() == 0:
+		return firewall.Network{}
+	case len(sources) == 1:
+		return firewall.Network{Prefix: sources[0]}
+	default:
+		return firewall.Network{Set: firewall.NewPrefixSet(sources)}
+	}
+}
+
+// applySourceMatch returns the iptables match fragment for the rule's
+// source. For a Set it increments the shared ipset's refcount; for a
+// Prefix it emits a direct -s match; for the wildcard it returns nil.
+func (r *family) applySourceMatch(network firewall.Network, prefixes []netip.Prefix) ([]string, error) {
+	switch {
+	case network.IsSet():
+		if r.ipsetCounter == nil {
+			return nil, fmt.Errorf("multi-source peer rule requires shared ipset counter")
+		}
+		name := r.ipsetName(network.Set.HashedName())
+		if _, err := r.ipsetCounter.Increment(name, prefixes); err != nil {
+			return nil, fmt.Errorf("ipset increment %s: %w", name, err)
+		}
+		return []string{"-m", "set", matchSet, name, "src"}, nil
+	case network.IsPrefix():
+		return []string{"-s", network.Prefix.String()}, nil
+	default:
+		return nil, nil
+	}
+}
+
+// dropSourceMatch undoes whatever applySourceMatch reserved when
+// installing a rule fails. Safe to call when the spec is empty or holds
+// only inline matchers. Decrement errors are logged but not returned:
+// the install error is what the caller needs to see.
+func (r *family) dropSourceMatch(srcMatch []string) {
+	if r.ipsetCounter == nil {
+		return
+	}
+	for _, name := range findSets(srcMatch) {
+		if _, err := r.ipsetCounter.Decrement(name); err != nil {
+			log.Errorf("rollback ipset decrement %s: %v", name, err)
+		}
+	}
+}
+
+// decrementSetCounter drops ipset references owned by a raw rule spec
+// stored in r.rules (NAT / legacy route entries). It returns an error
+// aggregate so the caller surfaces decrement failures.
+func (r *family) decrementSetCounter(rule []string) error {
+	if r.ipsetCounter == nil {
+		return nil
+	}
+	var merr *multierror.Error
+	for _, name := range findSets(rule) {
+		if _, err := r.ipsetCounter.Decrement(name); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("decrement counter: %w", err))
+		}
+	}
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+// installFilterRule assembles and writes one iptables filter-chain
+// rule. With destination empty the rule lands in the peer ACL input
+// chain and a paired mangle PREROUTING rule is added for the redirect
+// mark. With destination set the rule lands in the route ACL forward
+// chain and there is no mangle pairing.
+func (r *family) installFilterRule(
+	ruleID nbid.RuleID,
+	srcMatch []string,
+	destination firewall.Network,
+	protocol firewall.Protocol,
+	sPort, dPort *firewall.Port,
+	action firewall.Action,
+) (*Rule, error) {
+	isRoute := !destination.IsZero()
+
+	proto := protoForFamily(protocol, r.v6)
+
+	specs := slices.Clone(srcMatch)
+	var destExp []string
+	if isRoute {
+		var err error
+		destExp, err = r.applyNetwork("-d", destination, nil)
+		if err != nil {
+			return nil, fmt.Errorf("apply network -d: %w", err)
+		}
+		specs = append(specs, destExp...)
+	}
+	specs = append(specs, filterMatchSpecs(proto, sPort, dPort)...)
+
+	var mangleSpecs []string
+	if !isRoute {
+		mangleSpecs = slices.Clone(specs)
+		mangleSpecs = append(mangleSpecs,
+			"-i", r.wgIface.Name(),
+			"-m", "addrtype", "--dst-type", "LOCAL",
+			"-j", "MARK", "--set-xmark", fmt.Sprintf("%#x", nbnet.PreroutingFwmarkRedirected),
+		)
+	}
+
+	specs = append(specs, "-j", actionToStr(action))
+
+	chain := chainACLInput
+	if isRoute {
+		chain = chainRTFwdIn
+	}
+
+	// Peer ACL drops are inserted at position 1 so they precede the
+	// chain's catch-all; route ACL drops are inserted at position 2
+	// to sit immediately after the established/related accept rule.
+	var err error
+	if action == firewall.ActionDrop {
+		pos := 1
+		if isRoute {
+			pos = 2
+		}
+		err = r.iptablesClient.Insert(tableFilter, chain, pos, specs...)
+	} else {
+		err = r.iptablesClient.Append(tableFilter, chain, specs...)
+	}
+	if err != nil {
+		r.dropSourceMatch(destExp)
+		return nil, fmt.Errorf("install filter rule on %s: %w", chain, err)
+	}
+
+	// The mangle redirect-mark rule is best effort: the filter rule itself
+	// is what enforces the ACL, so a mangle failure must not undo it. Drop
+	// the spec so teardown does not try to remove a rule that was not added.
+	if mangleSpecs != nil {
+		if err := r.iptablesClient.Append(tableMangle, chainRTPre, mangleSpecs...); err != nil {
+			log.Errorf("add mangle rule: %v", err)
+			mangleSpecs = nil
+		}
+	}
+
+	return &Rule{
+		id:          ruleID,
+		specs:       specs,
+		mangleSpecs: mangleSpecs,
+		chain:       chain,
+		v6:          r.v6,
+	}, nil
+}
+
+// applyNetwork resolves a firewall.Network into the iptables match
+// fragment for the given direction flag (-s or -d). Set networks
+// increment the shared ipset refcount; prefixes emit a direct match;
+// an empty network returns no spec ("match any").
+func (r *family) applyNetwork(flag string, network firewall.Network, prefixes []netip.Prefix) ([]string, error) {
+	direction := "src"
+	if flag == "-d" {
+		direction = "dst"
+	}
+
+	if network.IsSet() {
+		name := r.ipsetName(network.Set.HashedName())
+		if _, err := r.ipsetCounter.Increment(name, prefixes); err != nil {
+			return nil, fmt.Errorf("create or get ipset: %w", err)
+		}
+
+		return []string{"-m", "set", matchSet, name, direction}, nil
+	}
+	if network.IsPrefix() {
+		return []string{flag, network.Prefix.String()}, nil
+	}
+
+	// nolint:nilnil
+	return nil, nil
+}
+
+// protoForFamily translates ICMP to ICMPv6 for ip6tables.
+// ip6tables requires "ipv6-icmp" (or "icmpv6") instead of "icmp".
+func protoForFamily(protocol firewall.Protocol, v6 bool) string {
+	if v6 && protocol == firewall.ProtocolICMP {
+		return "ipv6-icmp"
+	}
+	return string(protocol)
+}
+
+// filterMatchSpecs returns the proto/port match fragment for a
+// filtering rule. The source match (-s or -m set) is built by the
+// caller and prepended.
+func filterMatchSpecs(protocol string, sPort, dPort *firewall.Port) (specs []string) {
+	if protocol != "all" {
+		specs = append(specs, "-p", protocol)
+	}
+	specs = append(specs, applyPort("--sport", sPort)...)
+	specs = append(specs, applyPort("--dport", dPort)...)
+	return specs
+}
+
+func actionToStr(action firewall.Action) string {
+	if action == firewall.ActionAccept {
+		return "ACCEPT"
+	}
+	return "DROP"
+}
+
+func applyPort(flag string, port *firewall.Port) []string {
+	if port == nil {
+		return nil
+	}
+
+	if port.IsRange && len(port.Values) == 2 {
+		return []string{flag, fmt.Sprintf("%d:%d", port.Values[0], port.Values[1])}
+	}
+
+	if len(port.Values) > 1 {
+		portList := make([]string, len(port.Values))
+		for i, p := range port.Values {
+			portList[i] = strconv.Itoa(int(p))
+		}
+		return []string{"-m", "multiport", flag, strings.Join(portList, ",")}
+	}
+
+	return []string{flag, strconv.Itoa(int(port.Values[0]))}
+}

client/firewall/iptables/interface_allower_linux.go

@@ -0,0 +1,93 @@
+package iptables
+
+import (
+	"fmt"
+
+	"github.com/coreos/go-iptables/iptables"
+	"github.com/hashicorp/go-multierror"
+	log "github.com/sirupsen/logrus"
+
+	nberrors "github.com/netbirdio/netbird/client/errors"
+)
+
+// InterfaceAllower opens the NetBird interface on the iptables filter INPUT
+// chain so the host firewall doesn't drop traffic the userspace firewall
+// handles. It is the fallback used when nftables is unavailable (an
+// iptables-legacy host).
+//
+// It opens INPUT only: the userspace router never forwards in the kernel.
+// firewalld trust is handled by the uspfilter manager, not here.
+type InterfaceAllower struct {
+	ifaceName string
+	ipt4      *iptables.IPTables
+	// ipt6 is nil when the interface has no IPv6 overlay address.
+	ipt6 *iptables.IPTables
+}
+
+// NewInterfaceAllower builds an iptables allower for the interface. It returns
+// an error when iptables is unavailable, so the caller can fall back to
+// firewalld trust.
+func NewInterfaceAllower(wgIface iFaceMapper) (*InterfaceAllower, error) {
+	ipt4, err := iptables.NewWithProtocol(iptables.ProtocolIPv4)
+	if err != nil {
+		return nil, fmt.Errorf("iptables not available: %w", err)
+	}
+	if _, err := ipt4.ListChains(tableFilter); err != nil {
+		return nil, fmt.Errorf("iptables filter table not available: %w", err)
+	}
+
+	a := &InterfaceAllower{ifaceName: wgIface.Name(), ipt4: ipt4}
+
+	// Missing v6 must not break the v4 path: open v4 only and continue.
+	if wgIface.Address().HasIPv6() {
+		ipt6, err := iptables.NewWithProtocol(iptables.ProtocolIPv6)
+		if err != nil {
+			log.Warnf("ip6tables not available, opening interface on v4 only: %v", err)
+		} else if _, err := ipt6.ListChains(tableFilter); err != nil {
+			log.Warnf("ip6tables filter table not available, opening interface on v4 only: %v", err)
+		} else {
+			a.ipt6 = ipt6
+		}
+	}
+
+	return a, nil
+}
+
+// Apply inserts the interface accept rule on the filter INPUT chain. It removes
+// any stale rule first so an unclean exit (e.g. SIGKILL, where Close never ran)
+// is recovered deterministically rather than accumulating duplicates.
+func (a *InterfaceAllower) Apply() error {
+	var merr *multierror.Error
+	for _, ipt := range a.clients() {
+		if err := ipt.DeleteIfExists(tableFilter, chainInput, a.inputRule()...); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("clean stale interface accept rule: %w", err))
+		}
+		if err := ipt.Insert(tableFilter, chainInput, 1, a.inputRule()...); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("add interface accept rule: %w", err))
+		}
+	}
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+// Close removes the interface accept rule.
+func (a *InterfaceAllower) Close() error {
+	var merr *multierror.Error
+	for _, ipt := range a.clients() {
+		if err := ipt.DeleteIfExists(tableFilter, chainInput, a.inputRule()...); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("remove interface accept rule: %w", err))
+		}
+	}
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+func (a *InterfaceAllower) inputRule() []string {
+	return []string{"-i", a.ifaceName, "-j", "ACCEPT"}
+}
+
+func (a *InterfaceAllower) clients() []*iptables.IPTables {
+	clients := []*iptables.IPTables{a.ipt4}
+	if a.ipt6 != nil {
+		clients = append(clients, a.ipt6)
+	}
+	return clients
+}

client/firewall/iptables/ipset_linux.go

@@ -0,0 +1,104 @@
+//go:build !android
+
+package iptables
+
+import (
+	"fmt"
+	"net/netip"
+
+	"github.com/hashicorp/go-multierror"
+	"github.com/lrh3321/ipset-go"
+	log "github.com/sirupsen/logrus"
+
+	nberrors "github.com/netbirdio/netbird/client/errors"
+	firewall "github.com/netbirdio/netbird/client/firewall/manager"
+)
+
+func (r *family) createIpSet(setName string, sources []netip.Prefix) error {
+	if err := r.createIPSet(setName); err != nil {
+		return fmt.Errorf("create set %s: %w", setName, err)
+	}
+
+	for _, prefix := range sources {
+		if err := r.addPrefixToIPSet(setName, prefix); err != nil {
+			// The refcounter records nothing when this callback errors,
+			// so destroy the set or it leaks in the kernel. A partial
+			// source set would also fail-open for deny rules, so the
+			// rule must fail rather than install with a missing source.
+			if derr := r.destroyIPSet(setName); derr != nil {
+				log.Warnf("rollback ipset %s after add failure: %v", setName, derr)
+			}
+			return fmt.Errorf("add element to set %s: %w", setName, err)
+		}
+	}
+
+	return nil
+}
+
+func (r *family) deleteIpSet(setName string) error {
+	if err := r.destroyIPSet(setName); err != nil {
+		return fmt.Errorf("destroy set %s: %w", setName, err)
+	}
+
+	log.Debugf("deleted unused ipset %s", setName)
+	return nil
+}
+
+func (r *family) UpdateSet(set firewall.Set, prefixes []netip.Prefix) error {
+	name := r.ipsetName(set.HashedName())
+	var merr *multierror.Error
+	for _, prefix := range prefixes {
+		if err := r.addPrefixToIPSet(name, prefix); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("add prefix to ipset: %w", err))
+		}
+	}
+	if merr == nil {
+		log.Debugf("updated set %s with prefixes %v", name, prefixes)
+	}
+
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+func (r *family) ipsetName(name string) string {
+	if r.v6 {
+		return name + "-v6"
+	}
+	return name
+}
+
+func (r *family) createIPSet(name string) error {
+	opts := ipset.CreateOptions{
+		Replace: true,
+	}
+	if r.v6 {
+		opts.Family = ipset.FamilyIPV6
+	}
+
+	if err := ipset.Create(name, ipset.TypeHashNet, opts); err != nil {
+		return fmt.Errorf("create ipset %s: %w", name, err)
+	}
+
+	log.Debugf("created ipset %s with type hash:net", name)
+	return nil
+}
+
+func (r *family) addPrefixToIPSet(name string, prefix netip.Prefix) error {
+	addr := prefix.Addr()
+	ip := addr.AsSlice()
+
+	entry := &ipset.Entry{
+		IP:      ip,
+		CIDR:    uint8(prefix.Bits()),
+		Replace: true,
+	}
+
+	if err := ipset.Add(name, entry); err != nil {
+		return fmt.Errorf("add prefix to ipset %s: %w", name, err)
+	}
+
+	return nil
+}
+
+func (r *family) destroyIPSet(name string) error {
+	return ipset.Destroy(name)
+}

client/firewall/iptables/manager_linux.go

@@ -3,7 +3,6 @@ package iptables
 import (
 	"context"
 	"fmt"
-	"net"
 	"net/netip"
 	"sync"
 
@@ -18,25 +17,21 @@ import (
 	"github.com/netbirdio/netbird/client/internal/statemanager"
 )
 
-type resetter interface {
-	Reset() error
-}
-
-// Manager of iptables firewall
+// Manager of iptables firewall. Per-family state (peer ACLs, route
+// ACLs, NAT, DNAT, MSS clamping) lives on family; Manager dispatches
+// by family and provides the public firewall.Manager surface.
 type Manager struct {
 	mutex sync.Mutex
 
 	wgIface iFaceMapper
 
 	ipv4Client   *iptables.IPTables
-	aclMgr       *aclManager
-	router       *router
+	family4      *family
 	rawSupported bool
 
 	// IPv6 counterparts, nil when no v6 overlay
 	ipv6Client *iptables.IPTables
-	aclMgr6    *aclManager
-	router6    *router
+	family6    *family
 }
 
 // iFaceMapper defines subset methods of interface required for manager
@@ -57,14 +52,9 @@ func Create(wgIface iFaceMapper, mtu uint16) (*Manager, error) {
 		ipv4Client: iptablesClient,
 	}
 
-	m.router, err = newRouter(iptablesClient, wgIface, mtu)
+	m.family4, err = newFamily(iptablesClient, wgIface, mtu)
 	if err != nil {
-		return nil, fmt.Errorf("create router: %w", err)
-	}
-
-	m.aclMgr, err = newAclManager(iptablesClient, wgIface)
-	if err != nil {
-		return nil, fmt.Errorf("create acl manager: %w", err)
+		return nil, fmt.Errorf("create family: %w", err)
 	}
 
 	if wgIface.Address().HasIPv6() {
@@ -81,21 +71,18 @@ func (m *Manager) createIPv6Components(wgIface iFaceMapper, mtu uint16) error {
 	if err != nil {
 		return fmt.Errorf("init ip6tables: %w", err)
 	}
-	m.ipv6Client = ip6Client
 
-	m.router6, err = newRouter(ip6Client, wgIface, mtu)
+	family6, err := newFamily(ip6Client, wgIface, mtu)
 	if err != nil {
-		return fmt.Errorf("create v6 router: %w", err)
+		return fmt.Errorf("create v6 family: %w", err)
 	}
 
-	// Share the same IP forwarding state with the v4 router, since
+	// Share the same IP forwarding state with the v4 family, since
 	// EnableIPForwarding controls both v4 and v6 sysctls.
-	m.router6.ipFwdState = m.router.ipFwdState
+	family6.ipFwdState = m.family4.ipFwdState
 
-	m.aclMgr6, err = newAclManager(ip6Client, wgIface)
-	if err != nil {
-		return fmt.Errorf("create v6 acl manager: %w", err)
-	}
+	m.ipv6Client = ip6Client
+	m.family6 = family6
 
 	return nil
 }
@@ -109,7 +96,7 @@ func (m *Manager) Init(stateManager *statemanager.Manager) error {
 		InterfaceState: &InterfaceState{
 			NameStr:   m.wgIface.Name(),
 			WGAddress: m.wgIface.Address(),
-			MTU:       m.router.mtu,
+			MTU:       m.family4.mtu,
 		},
 	}
 	stateManager.RegisterState(state)
@@ -141,31 +128,24 @@ func (m *Manager) Init(stateManager *statemanager.Manager) error {
 	return nil
 }
 
-// initChains initializes router and ACL chains for both address families,
-// rolling back on failure.
+// initChains initializes the per-family firewall state for both
+// address families, rolling back on failure.
 func (m *Manager) initChains(stateManager *statemanager.Manager) error {
 	type initStep struct {
 		name string
-		init func(*statemanager.Manager) error
-		mgr  resetter
+		r    *family
 	}
 
-	steps := []initStep{
-		{"router", m.router.init, m.router},
-		{"acl manager", m.aclMgr.init, m.aclMgr},
-	}
+	steps := []initStep{{"v4", m.family4}}
 	if m.hasIPv6() {
-		steps = append(steps,
-			initStep{"v6 router", m.router6.init, m.router6},
-			initStep{"v6 acl manager", m.aclMgr6.init, m.aclMgr6},
-		)
+		steps = append(steps, initStep{"v6", m.family6})
 	}
 
 	var initialized []initStep
 	for _, s := range steps {
-		if err := s.init(stateManager); err != nil {
+		if err := s.r.init(stateManager); err != nil {
 			for i := len(initialized) - 1; i >= 0; i-- {
-				if rerr := initialized[i].mgr.Reset(); rerr != nil {
+				if rerr := initialized[i].r.Reset(); rerr != nil {
 					log.Warnf("rollback %s: %v", initialized[i].name, rerr)
 				}
 			}
@@ -176,84 +156,50 @@ func (m *Manager) initChains(stateManager *statemanager.Manager) error {
 	return nil
 }
 
-// AddPeerFiltering adds a rule to the firewall
-//
-// Comment will be ignored because some system this feature is not supported
-func (m *Manager) AddPeerFiltering(
-	id []byte,
-	ip net.IP,
-	proto firewall.Protocol,
-	sPort *firewall.Port,
-	dPort *firewall.Port,
-	action firewall.Action,
-	ipsetName string,
-) ([]firewall.Rule, error) {
-	m.mutex.Lock()
-	defer m.mutex.Unlock()
-
-	if ip.To4() != nil {
-		return m.aclMgr.AddPeerFiltering(id, ip, proto, sPort, dPort, action, ipsetName)
-	}
-	if !m.hasIPv6() {
-		return nil, fmt.Errorf("add peer filtering for %s: %w", ip, firewall.ErrIPv6NotInitialized)
-	}
-	return m.aclMgr6.AddPeerFiltering(id, ip, proto, sPort, dPort, action, ipsetName)
-}
-
-func (m *Manager) AddRouteFiltering(
+// AddFilterRule installs a packet-filtering rule. See firewall.Manager
+// docs for destination semantics. Sources are a single address family;
+// the rule is dispatched to the matching v4 / v6 backend.
+func (m *Manager) AddFilterRule(
 	id []byte,
 	sources []netip.Prefix,
 	destination firewall.Network,
 	proto firewall.Protocol,
-	sPort, dPort *firewall.Port,
+	sPort *firewall.Port,
+	dPort *firewall.Port,
 	action firewall.Action,
 ) (firewall.Rule, error) {
+	if len(sources) == 0 {
+		return nil, firewall.ErrNoSources
+	}
+
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
 
-	if isIPv6RouteRule(sources, destination) {
+	fam := m.family4
+	if isIPv6Rule(sources, destination) {
 		if !m.hasIPv6() {
-			return nil, fmt.Errorf("add route filtering: %w", firewall.ErrIPv6NotInitialized)
+			return nil, fmt.Errorf("add filtering: %w", firewall.ErrIPv6NotInitialized)
 		}
-		return m.router6.AddRouteFiltering(id, sources, destination, proto, sPort, dPort, action)
+		fam = m.family6
 	}
-
-	return m.router.AddRouteFiltering(id, sources, destination, proto, sPort, dPort, action)
+	return fam.AddFilterRule(id, sources, destination, proto, sPort, dPort, action)
 }
 
-func isIPv6RouteRule(sources []netip.Prefix, destination firewall.Network) bool {
-	if destination.IsPrefix() {
-		return destination.Prefix.Addr().Is6()
-	}
-	return len(sources) > 0 && sources[0].Addr().Is6()
-}
-
-// DeletePeerRule from the firewall by rule definition
-func (m *Manager) DeletePeerRule(rule firewall.Rule) error {
+// DeleteFilterRule removes a rule previously added via AddFilterRule.
+// The rule is looked up by id in each family's filter cache.
+func (m *Manager) DeleteFilterRule(rule firewall.Rule) error {
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
 
-	if m.hasIPv6() && isIPv6IptRule(rule) {
-		return m.aclMgr6.DeletePeerRule(rule)
+	id := rule.ID()
+	if m.family4.hasRule(id) {
+		return m.family4.DeleteFilterRule(rule)
 	}
-	return m.aclMgr.DeletePeerRule(rule)
-}
-
-func isIPv6IptRule(rule firewall.Rule) bool {
-	r, ok := rule.(*Rule)
-	return ok && r.v6
-}
-
-// DeleteRouteRule deletes a routing rule.
-// Route rules are keyed by content hash. Check v4 first, try v6 if not found.
-func (m *Manager) DeleteRouteRule(rule firewall.Rule) error {
-	m.mutex.Lock()
-	defer m.mutex.Unlock()
-
-	if m.hasIPv6() && !m.router.hasRule(rule.ID()) {
-		return m.router6.DeleteRouteRule(rule)
+	if m.hasIPv6() && m.family6.hasRule(id) {
+		return m.family6.DeleteFilterRule(rule)
 	}
-	return m.router.DeleteRouteRule(rule)
+	log.Debugf("filter rule %s not found in any family", id)
+	return nil
 }
 
 func (m *Manager) IsServerRouteSupported() bool {
@@ -272,10 +218,10 @@ func (m *Manager) AddNatRule(pair firewall.RouterPair) error {
 		if !m.hasIPv6() {
 			return fmt.Errorf("add NAT rule: %w", firewall.ErrIPv6NotInitialized)
 		}
-		return m.router6.AddNatRule(pair)
+		return m.family6.AddNatRule(pair)
 	}
 
-	if err := m.router.AddNatRule(pair); err != nil {
+	if err := m.family4.AddNatRule(pair); err != nil {
 		return err
 	}
 
@@ -284,7 +230,7 @@ func (m *Manager) AddNatRule(pair firewall.RouterPair) error {
 	// wildcard 0.0.0.0/0 destination where the client resolves DNS.
 	if m.hasIPv6() && pair.Dynamic {
 		v6Pair := firewall.ToV6NatPair(pair)
-		if err := m.router6.AddNatRule(v6Pair); err != nil {
+		if err := m.family6.AddNatRule(v6Pair); err != nil {
 			return fmt.Errorf("add v6 NAT rule: %w", err)
 		}
 	}
@@ -300,18 +246,18 @@ func (m *Manager) RemoveNatRule(pair firewall.RouterPair) error {
 		if !m.hasIPv6() {
 			return nil
 		}
-		return m.router6.RemoveNatRule(pair)
+		return m.family6.RemoveNatRule(pair)
 	}
 
 	var merr *multierror.Error
 
-	if err := m.router.RemoveNatRule(pair); err != nil {
+	if err := m.family4.RemoveNatRule(pair); err != nil {
 		merr = multierror.Append(merr, fmt.Errorf("remove v4 NAT rule: %w", err))
 	}
 
 	if m.hasIPv6() && pair.Dynamic {
 		v6Pair := firewall.ToV6NatPair(pair)
-		if err := m.router6.RemoveNatRule(v6Pair); err != nil {
+		if err := m.family6.RemoveNatRule(v6Pair); err != nil {
 			merr = multierror.Append(merr, fmt.Errorf("remove v6 NAT rule: %w", err))
 		}
 	}
@@ -320,11 +266,14 @@ func (m *Manager) RemoveNatRule(pair firewall.RouterPair) error {
 }
 
 func (m *Manager) SetLegacyManagement(isLegacy bool) error {
-	if err := firewall.SetLegacyManagement(m.router, isLegacy); err != nil {
+	m.mutex.Lock()
+	defer m.mutex.Unlock()
+
+	if err := firewall.SetLegacyManagement(m.family4, isLegacy); err != nil {
 		return err
 	}
 	if m.hasIPv6() {
-		return firewall.SetLegacyManagement(m.router6, isLegacy)
+		return firewall.SetLegacyManagement(m.family6, isLegacy)
 	}
 	return nil
 }
@@ -341,19 +290,13 @@ func (m *Manager) Close(stateManager *statemanager.Manager) error {
 	}
 
 	if m.hasIPv6() {
-		if err := m.aclMgr6.Reset(); err != nil {
-			merr = multierror.Append(merr, fmt.Errorf("reset v6 acl manager: %w", err))
-		}
-		if err := m.router6.Reset(); err != nil {
-			merr = multierror.Append(merr, fmt.Errorf("reset v6 router: %w", err))
+		if err := m.family6.Reset(); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("reset v6 family: %w", err))
 		}
 	}
 
-	if err := m.aclMgr.Reset(); err != nil {
-		merr = multierror.Append(merr, fmt.Errorf("reset acl manager: %w", err))
-	}
-	if err := m.router.Reset(); err != nil {
-		merr = multierror.Append(merr, fmt.Errorf("reset router: %w", err))
+	if err := m.family4.Reset(); err != nil {
+		merr = multierror.Append(merr, fmt.Errorf("reset family: %w", err))
 	}
 
 	// Appending to merr intentionally blocks DeleteState below so ShutdownState
@@ -372,27 +315,6 @@ func (m *Manager) Close(stateManager *statemanager.Manager) error {
 	return nberrors.FormatErrorOrNil(merr)
 }
 
-// AllowNetbird allows netbird interface traffic.
-// This is called when USPFilter wraps the native firewall, adding blanket accept
-// rules so that packet filtering is handled in userspace instead of by netfilter.
-func (m *Manager) AllowNetbird() error {
-	var merr *multierror.Error
-	if _, err := m.AddPeerFiltering(nil, net.IP{0, 0, 0, 0}, firewall.ProtocolALL, nil, nil, firewall.ActionAccept, ""); err != nil {
-		merr = multierror.Append(merr, fmt.Errorf("allow netbird v4 interface traffic: %w", err))
-	}
-	if m.hasIPv6() {
-		if _, err := m.AddPeerFiltering(nil, net.IPv6zero, firewall.ProtocolALL, nil, nil, firewall.ActionAccept, ""); err != nil {
-			merr = multierror.Append(merr, fmt.Errorf("allow netbird v6 interface traffic: %w", err))
-		}
-	}
-
-	if err := firewalld.TrustInterface(m.wgIface.Name()); err != nil {
-		log.Warnf("failed to trust interface in firewalld: %v", err)
-	}
-
-	return nberrors.FormatErrorOrNil(merr)
-}
-
 // Flush doesn't need to be implemented for this manager
 func (m *Manager) Flush() error { return nil }
 
@@ -402,14 +324,14 @@ func (m *Manager) SetLogLevel(log.Level) {
 }
 
 func (m *Manager) EnableRouting() error {
-	if err := m.router.ipFwdState.RequestForwarding(); err != nil {
+	if err := m.family4.ipFwdState.RequestForwarding(); err != nil {
 		return fmt.Errorf("enable IP forwarding: %w", err)
 	}
 	return nil
 }
 
 func (m *Manager) DisableRouting() error {
-	if err := m.router.ipFwdState.ReleaseForwarding(); err != nil {
+	if err := m.family4.ipFwdState.ReleaseForwarding(); err != nil {
 		return fmt.Errorf("disable IP forwarding: %w", err)
 	}
 	return nil
@@ -424,9 +346,9 @@ func (m *Manager) AddDNATRule(rule firewall.ForwardRule) (firewall.Rule, error)
 		if !m.hasIPv6() {
 			return nil, fmt.Errorf("add DNAT rule: %w", firewall.ErrIPv6NotInitialized)
 		}
-		return m.router6.AddDNATRule(rule)
+		return m.family6.AddDNATRule(rule)
 	}
-	return m.router.AddDNATRule(rule)
+	return m.family4.AddDNATRule(rule)
 }
 
 // DeleteDNATRule deletes a DNAT rule
@@ -434,10 +356,10 @@ func (m *Manager) DeleteDNATRule(rule firewall.Rule) error {
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
 
-	if m.hasIPv6() && !m.router.hasRule(rule.ID()+dnatSuffix) {
-		return m.router6.DeleteDNATRule(rule)
+	if m.hasIPv6() && !m.family4.hasDNATRule(rule.ID()) {
+		return m.family6.DeleteDNATRule(rule)
 	}
-	return m.router.DeleteDNATRule(rule)
+	return m.family4.DeleteDNATRule(rule)
 }
 
 // UpdateSet updates the set with the given prefixes
@@ -454,12 +376,12 @@ func (m *Manager) UpdateSet(set firewall.Set, prefixes []netip.Prefix) error {
 		}
 	}
 
-	if err := m.router.UpdateSet(set, v4Prefixes); err != nil {
+	if err := m.family4.UpdateSet(set, v4Prefixes); err != nil {
 		return err
 	}
 
 	if m.hasIPv6() && len(v6Prefixes) > 0 {
-		if err := m.router6.UpdateSet(set, v6Prefixes); err != nil {
+		if err := m.family6.UpdateSet(set, v6Prefixes); err != nil {
 			return fmt.Errorf("update v6 set: %w", err)
 		}
 	}
@@ -476,9 +398,9 @@ func (m *Manager) AddInboundDNAT(localAddr netip.Addr, protocol firewall.Protoco
 		if !m.hasIPv6() {
 			return fmt.Errorf("add inbound DNAT: %w", firewall.ErrIPv6NotInitialized)
 		}
-		return m.router6.AddInboundDNAT(localAddr, protocol, originalPort, translatedPort)
+		return m.family6.AddInboundDNAT(localAddr, protocol, originalPort, translatedPort)
 	}
-	return m.router.AddInboundDNAT(localAddr, protocol, originalPort, translatedPort)
+	return m.family4.AddInboundDNAT(localAddr, protocol, originalPort, translatedPort)
 }
 
 // RemoveInboundDNAT removes an inbound DNAT rule.
@@ -490,9 +412,9 @@ func (m *Manager) RemoveInboundDNAT(localAddr netip.Addr, protocol firewall.Prot
 		if !m.hasIPv6() {
 			return fmt.Errorf("remove inbound DNAT: %w", firewall.ErrIPv6NotInitialized)
 		}
-		return m.router6.RemoveInboundDNAT(localAddr, protocol, originalPort, translatedPort)
+		return m.family6.RemoveInboundDNAT(localAddr, protocol, originalPort, translatedPort)
 	}
-	return m.router.RemoveInboundDNAT(localAddr, protocol, originalPort, translatedPort)
+	return m.family4.RemoveInboundDNAT(localAddr, protocol, originalPort, translatedPort)
 }
 
 // AddOutputDNAT adds an OUTPUT chain DNAT rule for locally-generated traffic.
@@ -504,9 +426,9 @@ func (m *Manager) AddOutputDNAT(localAddr netip.Addr, protocol firewall.Protocol
 		if !m.hasIPv6() {
 			return fmt.Errorf("add output DNAT: %w", firewall.ErrIPv6NotInitialized)
 		}
-		return m.router6.AddOutputDNAT(localAddr, protocol, originalPort, translatedPort)
+		return m.family6.AddOutputDNAT(localAddr, protocol, originalPort, translatedPort)
 	}
-	return m.router.AddOutputDNAT(localAddr, protocol, originalPort, translatedPort)
+	return m.family4.AddOutputDNAT(localAddr, protocol, originalPort, translatedPort)
 }
 
 // RemoveOutputDNAT removes an OUTPUT chain DNAT rule.
@@ -518,14 +440,14 @@ func (m *Manager) RemoveOutputDNAT(localAddr netip.Addr, protocol firewall.Proto
 		if !m.hasIPv6() {
 			return fmt.Errorf("remove output DNAT: %w", firewall.ErrIPv6NotInitialized)
 		}
-		return m.router6.RemoveOutputDNAT(localAddr, protocol, originalPort, translatedPort)
+		return m.family6.RemoveOutputDNAT(localAddr, protocol, originalPort, translatedPort)
 	}
-	return m.router.RemoveOutputDNAT(localAddr, protocol, originalPort, translatedPort)
+	return m.family4.RemoveOutputDNAT(localAddr, protocol, originalPort, translatedPort)
 }
 
 const (
 	chainNameRaw = "NETBIRD-RAW"
-	chainOUTPUT  = "OUTPUT"
+	chainOutput  = "OUTPUT"
 	tableRaw     = "raw"
 )
 
@@ -600,15 +522,15 @@ func (m *Manager) initNoTrackChain() error {
 
 	jumpRule := []string{"-j", chainNameRaw}
 
-	if err := m.ipv4Client.InsertUnique(tableRaw, chainOUTPUT, 1, jumpRule...); err != nil {
+	if err := m.ipv4Client.InsertUnique(tableRaw, chainOutput, 1, jumpRule...); err != nil {
 		if delErr := m.ipv4Client.DeleteChain(tableRaw, chainNameRaw); delErr != nil {
 			log.Debugf("delete orphan chain: %v", delErr)
 		}
 		return fmt.Errorf("add output jump rule: %w", err)
 	}
 
-	if err := m.ipv4Client.InsertUnique(tableRaw, chainPREROUTING, 1, jumpRule...); err != nil {
-		if delErr := m.ipv4Client.DeleteIfExists(tableRaw, chainOUTPUT, jumpRule...); delErr != nil {
+	if err := m.ipv4Client.InsertUnique(tableRaw, chainPrerouting, 1, jumpRule...); err != nil {
+		if delErr := m.ipv4Client.DeleteIfExists(tableRaw, chainOutput, jumpRule...); delErr != nil {
 			log.Debugf("delete output jump rule: %v", delErr)
 		}
 		if delErr := m.ipv4Client.DeleteChain(tableRaw, chainNameRaw); delErr != nil {
@@ -635,11 +557,11 @@ func (m *Manager) cleanupNoTrackChain() error {
 
 	jumpRule := []string{"-j", chainNameRaw}
 
-	if err := m.ipv4Client.DeleteIfExists(tableRaw, chainOUTPUT, jumpRule...); err != nil {
+	if err := m.ipv4Client.DeleteIfExists(tableRaw, chainOutput, jumpRule...); err != nil {
 		return fmt.Errorf("remove output jump rule: %w", err)
 	}
 
-	if err := m.ipv4Client.DeleteIfExists(tableRaw, chainPREROUTING, jumpRule...); err != nil {
+	if err := m.ipv4Client.DeleteIfExists(tableRaw, chainPrerouting, jumpRule...); err != nil {
 		return fmt.Errorf("remove prerouting jump rule: %w", err)
 	}
 
@@ -654,3 +576,13 @@ func (m *Manager) cleanupNoTrackChain() error {
 func getConntrackEstablished() []string {
 	return []string{"-m", "conntrack", "--ctstate", "RELATED,ESTABLISHED", "-j", "ACCEPT"}
 }
+
+// isIPv6Rule reports whether the rule belongs to the IPv6 family, from
+// the destination prefix when set, otherwise from the (single-family)
+// sources.
+func isIPv6Rule(sources []netip.Prefix, destination firewall.Network) bool {
+	if destination.IsPrefix() {
+		return destination.Prefix.Addr().Is6()
+	}
+	return len(sources) > 0 && sources[0].Addr().Is6()
+}

client/firewall/iptables/manager_linux_test.go

@@ -67,46 +67,39 @@ func TestIptablesManager(t *testing.T) {
 		time.Sleep(time.Second)
 	}()
 
-	var rule2 []fw.Rule
+	var rule2 fw.Rule
 	t.Run("add second rule", func(t *testing.T) {
 		ip := netip.MustParseAddr("10.20.0.3")
 		port := &fw.Port{
 			IsRange: true,
 			Values:  []uint16{8043, 8046},
 		}
-		rule2, err = manager.AddPeerFiltering(nil, ip.AsSlice(), "tcp", port, nil, fw.ActionAccept, "")
+		rule2, err = manager.AddFilterRule(nil, pfx(ip.AsSlice()), fw.Network{}, "tcp", port, nil, fw.ActionAccept)
 		require.NoError(t, err, "failed to add rule")
 
-		for _, r := range rule2 {
-			rr := r.(*Rule)
-			checkRuleSpecs(t, ipv4Client, rr.chain, true, rr.specs...)
-		}
+		rr := rule2.(*Rule)
+		checkRuleSpecs(t, ipv4Client, rr.chain, true, rr.specs...)
 	})
 
 	t.Run("delete second rule", func(t *testing.T) {
-		for _, r := range rule2 {
-			err := manager.DeletePeerRule(r)
-			require.NoError(t, err, "failed to delete rule")
-		}
-
-		require.Empty(t, manager.aclMgr.ipsetStore.ipsets, "rulesets index after removed second rule must be empty")
+		require.NoError(t, manager.DeleteFilterRule(rule2), "failed to delete rule")
 	})
 
 	t.Run("reset check", func(t *testing.T) {
 		// add second rule
 		ip := netip.MustParseAddr("10.20.0.3")
 		port := &fw.Port{Values: []uint16{5353}}
-		_, err = manager.AddPeerFiltering(nil, ip.AsSlice(), "udp", nil, port, fw.ActionAccept, "")
+		_, err = manager.AddFilterRule(nil, pfx(ip.AsSlice()), fw.Network{}, "udp", nil, port, fw.ActionAccept)
 		require.NoError(t, err, "failed to add rule")
 
 		err = manager.Close(nil)
 		require.NoError(t, err, "failed to reset")
 
-		ok, err := ipv4Client.ChainExists("filter", chainNameInputRules)
+		ok, err := ipv4Client.ChainExists("filter", chainACLInput)
 		require.NoError(t, err, "failed check chain exists")
 
 		if ok {
-			require.NoErrorf(t, err, "chain '%v' still exists after Close", chainNameInputRules)
+			require.NoErrorf(t, err, "chain '%v' still exists after Close", chainACLInput)
 		}
 	})
 }
@@ -128,15 +121,13 @@ func TestIptablesManagerDenyRules(t *testing.T) {
 		ip := netip.MustParseAddr("10.20.0.3")
 		port := &fw.Port{Values: []uint16{22}}
 
-		rule, err := manager.AddPeerFiltering(nil, ip.AsSlice(), "tcp", nil, port, fw.ActionDrop, "deny-ssh")
+		rule, err := manager.AddFilterRule(nil, pfx(ip.AsSlice()), fw.Network{}, "tcp", nil, port, fw.ActionDrop)
 		require.NoError(t, err, "failed to add deny rule")
-		require.NotEmpty(t, rule, "deny rule should not be empty")
+		require.NotNil(t, rule, "deny rule should not be nil")
 
 		// Verify the rule was added by checking iptables
-		for _, r := range rule {
-			rr := r.(*Rule)
-			checkRuleSpecs(t, ipv4Client, rr.chain, true, rr.specs...)
-		}
+		rr := rule.(*Rule)
+		checkRuleSpecs(t, ipv4Client, rr.chain, true, rr.specs...)
 	})
 
 	t.Run("deny rule precedence test", func(t *testing.T) {
@@ -144,36 +135,40 @@ func TestIptablesManagerDenyRules(t *testing.T) {
 		port := &fw.Port{Values: []uint16{80}}
 
 		// Add accept rule first
-		_, err := manager.AddPeerFiltering(nil, ip.AsSlice(), "tcp", nil, port, fw.ActionAccept, "accept-http")
+		_, err := manager.AddFilterRule(nil, pfx(ip.AsSlice()), fw.Network{}, "tcp", nil, port, fw.ActionAccept)
 		require.NoError(t, err, "failed to add accept rule")
 
 		// Add deny rule second for same IP/port - this should take precedence
-		_, err = manager.AddPeerFiltering(nil, ip.AsSlice(), "tcp", nil, port, fw.ActionDrop, "deny-http")
+		_, err = manager.AddFilterRule(nil, pfx(ip.AsSlice()), fw.Network{}, "tcp", nil, port, fw.ActionDrop)
 		require.NoError(t, err, "failed to add deny rule")
 
 		// Inspect the actual iptables rules to verify deny rule comes before accept rule
-		rules, err := ipv4Client.List("filter", chainNameInputRules)
+		rules, err := ipv4Client.List("filter", chainACLInput)
 		require.NoError(t, err, "failed to list iptables rules")
 
 		// Debug: print all rules
-		t.Logf("All iptables rules in chain %s:", chainNameInputRules)
+		t.Logf("All iptables rules in chain %s:", chainACLInput)
 		for i, rule := range rules {
 			t.Logf("  [%d] %s", i, rule)
 		}
 
+		// Single-source rules emit a direct `-s <ip>/32 ... --dport 80`
+		// match. Match on that shape instead of the legacy
+		// per-(action,port) ipset names ("deny-http"/"accept-http")
+		// that this test predates.
+		srcMatch := fmt.Sprintf("-s %s/32", ip)
 		var denyRuleIndex, acceptRuleIndex = -1, -1
 		for i, rule := range rules {
-			if strings.Contains(rule, "DROP") {
-				t.Logf("Found DROP rule at index %d: %s", i, rule)
-				if strings.Contains(rule, "deny-http") && strings.Contains(rule, "80") {
-					denyRuleIndex = i
-				}
+			if !strings.Contains(rule, srcMatch) || !strings.Contains(rule, "--dport 80") {
+				continue
 			}
-			if strings.Contains(rule, "ACCEPT") {
+			if strings.Contains(rule, "-j DROP") {
+				t.Logf("Found DROP rule at index %d: %s", i, rule)
+				denyRuleIndex = i
+			}
+			if strings.Contains(rule, "-j ACCEPT") {
 				t.Logf("Found ACCEPT rule at index %d: %s", i, rule)
-				if strings.Contains(rule, "accept-http") && strings.Contains(rule, "80") {
-					acceptRuleIndex = i
-				}
+				acceptRuleIndex = i
 			}
 		}
 
@@ -198,7 +193,6 @@ func TestIptablesManagerIPSet(t *testing.T) {
 		},
 	}
 
-	// just check on the local interface
 	manager, err := Create(mock, iface.DefaultMTU)
 	require.NoError(t, err)
 	require.NoError(t, manager.Init(nil))
@@ -212,27 +206,39 @@ func TestIptablesManagerIPSet(t *testing.T) {
 		time.Sleep(time.Second)
 	}()
 
-	var rule2 []fw.Rule
-	t.Run("add second rule", func(t *testing.T) {
+	var rule2 fw.Rule
+	t.Run("single source uses direct -s match (no ipset)", func(t *testing.T) {
 		ip := netip.MustParseAddr("10.20.0.3")
 		port := &fw.Port{
 			Values: []uint16{443},
 		}
-		rule2, err = manager.AddPeerFiltering(nil, ip.AsSlice(), "tcp", port, nil, fw.ActionAccept, "default")
-		for _, r := range rule2 {
-			require.NoError(t, err, "failed to add rule")
-			require.Equal(t, r.(*Rule).ipsetName, "default-sport", "ipset name must be set")
-			require.Equal(t, r.(*Rule).ip, "10.20.0.3", "ipset IP must be set")
-		}
+		rule2, err = manager.AddFilterRule(nil, pfx(ip.AsSlice()), fw.Network{}, "tcp", port, nil, fw.ActionAccept)
+		require.NoError(t, err, "failed to add rule")
+		require.NotNil(t, rule2)
+		require.Contains(t, rule2.(*Rule).specs, "-s",
+			"single-source rule should use direct -s match, not an ipset")
+		require.Empty(t, findSets(rule2.(*Rule).specs),
+			"single-source rule should not allocate a shared ipset")
 	})
 
-	t.Run("delete second rule", func(t *testing.T) {
-		for _, r := range rule2 {
-			err := manager.DeletePeerRule(r)
-			require.NoError(t, err, "failed to delete rule")
+	t.Run("delete single-source rule", func(t *testing.T) {
+		require.NoError(t, manager.DeleteFilterRule(rule2), "failed to delete rule")
+	})
 
-			require.Empty(t, manager.aclMgr.ipsetStore.ipsets, "rulesets index after removed second rule must be empty")
+	t.Run("multi-source uses shared ipset", func(t *testing.T) {
+		sources := []netip.Prefix{
+			netip.PrefixFrom(netip.MustParseAddr("10.20.0.3"), 32),
+			netip.PrefixFrom(netip.MustParseAddr("10.20.0.4"), 32),
+			netip.PrefixFrom(netip.MustParseAddr("10.20.0.5"), 32),
 		}
+		port := &fw.Port{Values: []uint16{8080}}
+		multi, err := manager.AddFilterRule(nil, sources, fw.Network{}, "tcp", nil, port, fw.ActionAccept)
+		require.NoError(t, err, "failed to add multi-source rule")
+		require.NotNil(t, multi, "multi-source rule must produce one iptables rule")
+		sets := findSets(multi.(*Rule).specs)
+		require.Len(t, sets, 1, "multi-source rule must reference exactly one ipset")
+
+		require.NoError(t, manager.DeleteFilterRule(multi))
 	})
 
 	t.Run("reset check", func(t *testing.T) {
@@ -283,7 +289,7 @@ func TestIptablesCreatePerformance(t *testing.T) {
 			start := time.Now()
 			for i := 0; i < testMax; i++ {
 				port := &fw.Port{Values: []uint16{uint16(1000 + i)}}
-				_, err = manager.AddPeerFiltering(nil, ip.AsSlice(), "tcp", nil, port, fw.ActionAccept, "")
+				_, err = manager.AddFilterRule(nil, pfx(ip.AsSlice()), fw.Network{}, "tcp", nil, port, fw.ActionAccept)
 
 				require.NoError(t, err, "failed to add rule")
 			}

client/firewall/iptables/router_linux_test.go

@@ -31,7 +31,7 @@ func TestIptablesManager_RestoreOrCreateContainers(t *testing.T) {
 	iptablesClient, err := iptables.NewWithProtocol(iptables.ProtocolIPv4)
 	require.NoError(t, err, "failed to init iptables client")
 
-	manager, err := newRouter(iptablesClient, ifaceMock, iface.DefaultMTU)
+	manager, err := newFamily(iptablesClient, ifaceMock, iface.DefaultMTU)
 	require.NoError(t, err, "should return a valid iptables manager")
 	require.NoError(t, manager.init(nil))
 
@@ -52,12 +52,12 @@ func TestIptablesManager_RestoreOrCreateContainers(t *testing.T) {
 	// 11. MSS clamping rule for outbound traffic
 	require.Len(t, manager.rules, 11, "should have created rules map")
 
-	exists, err := manager.iptablesClient.Exists(tableNat, chainPOSTROUTING, "-j", chainRTNAT)
-	require.NoError(t, err, "should be able to query the iptables %s table and %s chain", tableNat, chainPOSTROUTING)
+	exists, err := manager.iptablesClient.Exists(tableNat, chainPostrouting, "-j", chainRTNAT)
+	require.NoError(t, err, "should be able to query the iptables %s table and %s chain", tableNat, chainPostrouting)
 	require.True(t, exists, "postrouting jump rule should exist")
 
-	exists, err = manager.iptablesClient.Exists(tableMangle, chainPREROUTING, "-j", chainRTPRE)
-	require.NoError(t, err, "should be able to query the iptables %s table and %s chain", tableMangle, chainPREROUTING)
+	exists, err = manager.iptablesClient.Exists(tableMangle, chainPrerouting, "-j", chainRTPre)
+	require.NoError(t, err, "should be able to query the iptables %s table and %s chain", tableMangle, chainPrerouting)
 	require.True(t, exists, "prerouting jump rule should exist")
 
 	pair := firewall.RouterPair{
@@ -84,7 +84,7 @@ func TestIptablesManager_AddNatRule(t *testing.T) {
 			iptablesClient, err := iptables.NewWithProtocol(iptables.ProtocolIPv4)
 			require.NoError(t, err, "failed to init iptables client")
 
-			manager, err := newRouter(iptablesClient, ifaceMock, iface.DefaultMTU)
+			manager, err := newFamily(iptablesClient, ifaceMock, iface.DefaultMTU)
 			require.NoError(t, err, "shouldn't return error")
 			require.NoError(t, manager.init(nil))
 
@@ -95,7 +95,7 @@ func TestIptablesManager_AddNatRule(t *testing.T) {
 			err = manager.AddNatRule(testCase.InputPair)
 			require.NoError(t, err, "marking rule should be inserted")
 
-			natRuleKey := firewall.GenKey(firewall.NatFormat, testCase.InputPair)
+			natRuleKey := testCase.InputPair.GenKey(firewall.NatFormat)
 			markingRule := []string{
 				"-i", ifaceMock.Name(),
 				"-m", "conntrack",
@@ -106,8 +106,8 @@ func TestIptablesManager_AddNatRule(t *testing.T) {
 				fmt.Sprintf("%#x", nbnet.PreroutingFwmarkMasquerade),
 			}
 
-			exists, err := iptablesClient.Exists(tableMangle, chainRTPRE, markingRule...)
-			require.NoError(t, err, "should be able to query the iptables %s table and %s chain", tableMangle, chainRTPRE)
+			exists, err := iptablesClient.Exists(tableMangle, chainRTPre, markingRule...)
+			require.NoError(t, err, "should be able to query the iptables %s table and %s chain", tableMangle, chainRTPre)
 			if testCase.InputPair.Masquerade {
 				require.True(t, exists, "marking rule should be created")
 				foundRule, found := manager.rules[natRuleKey]
@@ -121,7 +121,7 @@ func TestIptablesManager_AddNatRule(t *testing.T) {
 
 			// Check inverse rule
 			inversePair := firewall.GetInversePair(testCase.InputPair)
-			inverseRuleKey := firewall.GenKey(firewall.NatFormat, inversePair)
+			inverseRuleKey := inversePair.GenKey(firewall.NatFormat)
 			inverseMarkingRule := []string{
 				"!", "-i", ifaceMock.Name(),
 				"-m", "conntrack",
@@ -132,8 +132,8 @@ func TestIptablesManager_AddNatRule(t *testing.T) {
 				fmt.Sprintf("%#x", nbnet.PreroutingFwmarkMasqueradeReturn),
 			}
 
-			exists, err = iptablesClient.Exists(tableMangle, chainRTPRE, inverseMarkingRule...)
-			require.NoError(t, err, "should be able to query the iptables %s table and %s chain", tableMangle, chainRTPRE)
+			exists, err = iptablesClient.Exists(tableMangle, chainRTPre, inverseMarkingRule...)
+			require.NoError(t, err, "should be able to query the iptables %s table and %s chain", tableMangle, chainRTPre)
 			if testCase.InputPair.Masquerade {
 				require.True(t, exists, "inverse marking rule should be created")
 				foundRule, found := manager.rules[inverseRuleKey]
@@ -157,7 +157,7 @@ func TestIptablesManager_RemoveNatRule(t *testing.T) {
 		t.Run(testCase.Name, func(t *testing.T) {
 			iptablesClient, _ := iptables.NewWithProtocol(iptables.ProtocolIPv4)
 
-			manager, err := newRouter(iptablesClient, ifaceMock, iface.DefaultMTU)
+			manager, err := newFamily(iptablesClient, ifaceMock, iface.DefaultMTU)
 			require.NoError(t, err, "shouldn't return error")
 			require.NoError(t, manager.init(nil))
 			defer func() {
@@ -170,7 +170,7 @@ func TestIptablesManager_RemoveNatRule(t *testing.T) {
 			err = manager.RemoveNatRule(testCase.InputPair)
 			require.NoError(t, err, "shouldn't return error")
 
-			natRuleKey := firewall.GenKey(firewall.NatFormat, testCase.InputPair)
+			natRuleKey := testCase.InputPair.GenKey(firewall.NatFormat)
 			markingRule := []string{
 				"-i", ifaceMock.Name(),
 				"-m", "conntrack",
@@ -181,8 +181,8 @@ func TestIptablesManager_RemoveNatRule(t *testing.T) {
 				fmt.Sprintf("%#x", nbnet.PreroutingFwmarkMasquerade),
 			}
 
-			exists, err := iptablesClient.Exists(tableMangle, chainRTPRE, markingRule...)
-			require.NoError(t, err, "should be able to query the iptables %s table and %s chain", tableMangle, chainRTPRE)
+			exists, err := iptablesClient.Exists(tableMangle, chainRTPre, markingRule...)
+			require.NoError(t, err, "should be able to query the iptables %s table and %s chain", tableMangle, chainRTPre)
 			require.False(t, exists, "marking rule should not exist")
 
 			_, found := manager.rules[natRuleKey]
@@ -190,7 +190,7 @@ func TestIptablesManager_RemoveNatRule(t *testing.T) {
 
 			// Check inverse rule removal
 			inversePair := firewall.GetInversePair(testCase.InputPair)
-			inverseRuleKey := firewall.GenKey(firewall.NatFormat, inversePair)
+			inverseRuleKey := inversePair.GenKey(firewall.NatFormat)
 			inverseMarkingRule := []string{
 				"!", "-i", ifaceMock.Name(),
 				"-m", "conntrack",
@@ -201,8 +201,8 @@ func TestIptablesManager_RemoveNatRule(t *testing.T) {
 				fmt.Sprintf("%#x", nbnet.PreroutingFwmarkMasqueradeReturn),
 			}
 
-			exists, err = iptablesClient.Exists(tableMangle, chainRTPRE, inverseMarkingRule...)
-			require.NoError(t, err, "should be able to query the iptables %s table and %s chain", tableMangle, chainRTPRE)
+			exists, err = iptablesClient.Exists(tableMangle, chainRTPre, inverseMarkingRule...)
+			require.NoError(t, err, "should be able to query the iptables %s table and %s chain", tableMangle, chainRTPre)
 			require.False(t, exists, "inverse marking rule should not exist")
 
 			_, found = manager.rules[inverseRuleKey]
@@ -219,13 +219,13 @@ func TestRouter_AddRouteFiltering(t *testing.T) {
 	iptablesClient, err := iptables.NewWithProtocol(iptables.ProtocolIPv4)
 	require.NoError(t, err, "Failed to create iptables client")
 
-	r, err := newRouter(iptablesClient, ifaceMock, iface.DefaultMTU)
-	require.NoError(t, err, "Failed to create router manager")
+	r, err := newFamily(iptablesClient, ifaceMock, iface.DefaultMTU)
+	require.NoError(t, err, "Failed to create family manager")
 	require.NoError(t, r.init(nil))
 
 	defer func() {
 		err := r.Reset()
-		require.NoError(t, err, "Failed to reset router")
+		require.NoError(t, err, "Failed to reset family")
 	}()
 
 	tests := []struct {
@@ -334,62 +334,30 @@ func TestRouter_AddRouteFiltering(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			ruleKey, err := r.AddRouteFiltering(nil, tt.sources, firewall.Network{Prefix: tt.destination}, tt.proto, tt.sPort, tt.dPort, tt.action)
-			require.NoError(t, err, "AddRouteFiltering failed")
+			ruleKey, err := r.AddFilterRule(nil, tt.sources, firewall.Network{Prefix: tt.destination}, tt.proto, tt.sPort, tt.dPort, tt.action)
+			require.NoError(t, err, "AddFilterRule failed")
 
-			// Check if the rule is in the internal map
-			rule, ok := r.rules[ruleKey.ID()]
-			assert.True(t, ok, "Rule not found in internal map")
+			stored, ok := r.filters[ruleKey.ID()]
+			require.True(t, ok, "rule not stored in filters")
+			t.Logf("Internal rule: %v", stored.specs)
 
-			// Log the internal rule
-			t.Logf("Internal rule: %v", rule)
-
-			// Check if the rule exists in iptables
-			exists, err := iptablesClient.Exists(tableFilter, chainRTFWDIN, rule...)
+			exists, err := iptablesClient.Exists(tableFilter, chainRTFwdIn, stored.specs...)
 			assert.NoError(t, err, "Failed to check rule existence")
 			assert.True(t, exists, "Rule not found in iptables")
 
-			var source firewall.Network
-			if len(tt.sources) > 1 {
-				source.Set = firewall.NewPrefixSet(tt.sources)
-			} else if len(tt.sources) > 0 {
-				source.Prefix = tt.sources[0]
-			}
-			// Verify rule content
-			params := routeFilteringRuleParams{
-				Source:      source,
-				Destination: firewall.Network{Prefix: tt.destination},
-				Proto:       tt.proto,
-				SPort:       tt.sPort,
-				DPort:       tt.dPort,
-				Action:      tt.action,
-			}
-
-			expectedRule, err := r.genRouteRuleSpec(params, nil)
-			require.NoError(t, err, "Failed to generate expected rule spec")
-
 			if tt.expectSet {
 				setName := firewall.NewPrefixSet(tt.sources).HashedName()
-				expectedRule, err = r.genRouteRuleSpec(params, nil)
-				require.NoError(t, err, "Failed to generate expected rule spec with set")
-
-				// Check if the set was created
 				_, exists := r.ipsetCounter.Get(setName)
 				assert.True(t, exists, "IPSet not created")
+				assert.NotEmpty(t, findSets(stored.specs), "Rule should reference an ipset")
 			}
 
-			assert.Equal(t, expectedRule, rule, "Rule content mismatch")
-
-			// Clean up
-			err = r.DeleteRouteRule(ruleKey)
-			require.NoError(t, err, "Failed to delete rule")
+			require.NoError(t, r.DeleteFilterRule(ruleKey), "Failed to delete rule")
 		})
 	}
 }
 
 func TestFindSetNameInRule(t *testing.T) {
-	r := &router{}
-
 	testCases := []struct {
 		name     string
 		rule     []string
@@ -430,7 +398,7 @@ func TestFindSetNameInRule(t *testing.T) {
 
 	for _, tc := range testCases {
 		t.Run(tc.name, func(t *testing.T) {
-			result := r.findSets(tc.rule)
+			result := findSets(tc.rule)
 
 			if len(result) != len(tc.expected) {
 				t.Errorf("Expected %d sets, got %d. Sets found: %v", len(tc.expected), len(result), result)

client/firewall/iptables/routing_linux.go

@@ -0,0 +1,263 @@
+//go:build !android
+
+package iptables
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/hashicorp/go-multierror"
+	log "github.com/sirupsen/logrus"
+
+	nberrors "github.com/netbirdio/netbird/client/errors"
+	firewall "github.com/netbirdio/netbird/client/firewall/manager"
+	nbnet "github.com/netbirdio/netbird/client/net"
+)
+
+func (r *family) AddNatRule(pair firewall.RouterPair) error {
+	if r.legacyManagement {
+		log.Warnf("This peer is connected to a NetBird Management service with an older version. Allowing all traffic for %s", pair.Destination)
+		if err := r.addLegacyRouteRule(pair); err != nil {
+			return fmt.Errorf("add legacy routing rule: %w", err)
+		}
+	}
+
+	if pair.Masquerade {
+		if err := r.addNatRule(pair); err != nil {
+			return fmt.Errorf("add nat rule: %w", err)
+		}
+
+		if err := r.addNatRule(firewall.GetInversePair(pair)); err != nil {
+			return fmt.Errorf("add inverse nat rule: %w", err)
+		}
+	}
+
+	r.updateState()
+
+	return nil
+}
+
+// RemoveNatRule removes an iptables rule pair from forwarding and nat chains
+func (r *family) RemoveNatRule(pair firewall.RouterPair) error {
+	if pair.Masquerade {
+		if err := r.removeNatRule(pair); err != nil {
+			return fmt.Errorf("remove nat rule: %w", err)
+		}
+
+		if err := r.removeNatRule(firewall.GetInversePair(pair)); err != nil {
+			return fmt.Errorf("remove inverse nat rule: %w", err)
+		}
+	}
+
+	if err := r.removeLegacyRouteRule(pair); err != nil {
+		return fmt.Errorf("remove legacy routing rule: %w", err)
+	}
+
+	r.updateState()
+
+	return nil
+}
+
+// addLegacyRouteRule adds a legacy routing rule for mgmt servers pre route acls
+func (r *family) addLegacyRouteRule(pair firewall.RouterPair) error {
+	ruleID := pair.GenKey(firewall.ForwardingFormat)
+
+	if err := r.removeLegacyRouteRule(pair); err != nil {
+		return err
+	}
+
+	rule := []string{"-s", pair.Source.String(), "-d", pair.Destination.String(), "-j", "ACCEPT"}
+	if err := r.iptablesClient.Append(tableFilter, chainRTFwdIn, rule...); err != nil {
+		return fmt.Errorf("add legacy forwarding rule %s -> %s: %w", pair.Source, pair.Destination, err)
+	}
+
+	r.rules[ruleID] = rule
+
+	return nil
+}
+
+func (r *family) removeLegacyRouteRule(pair firewall.RouterPair) error {
+	ruleID := pair.GenKey(firewall.ForwardingFormat)
+
+	if rule, exists := r.rules[ruleID]; exists {
+		if err := r.iptablesClient.DeleteIfExists(tableFilter, chainRTFwdIn, rule...); err != nil {
+			return fmt.Errorf("remove legacy forwarding rule %s -> %s: %w", pair.Source, pair.Destination, err)
+		}
+		delete(r.rules, ruleID)
+
+		if err := r.decrementSetCounter(rule); err != nil {
+			return fmt.Errorf("decrement ipset counter: %w", err)
+		}
+	}
+
+	return nil
+}
+
+// GetLegacyManagement returns the current legacy management mode
+func (r *family) GetLegacyManagement() bool {
+	return r.legacyManagement
+}
+
+// SetLegacyManagement sets the route manager to use legacy management mode
+func (r *family) SetLegacyManagement(isLegacy bool) {
+	r.legacyManagement = isLegacy
+}
+
+// RemoveAllLegacyRouteRules removes all legacy routing rules for mgmt servers pre route acls
+func (r *family) RemoveAllLegacyRouteRules() error {
+	var merr *multierror.Error
+	for k, rule := range r.rules {
+		if !strings.HasPrefix(string(k), firewall.ForwardingFormatPrefix) {
+			continue
+		}
+		if err := r.iptablesClient.DeleteIfExists(tableFilter, chainRTFwdIn, rule...); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("remove legacy forwarding rule: %w", err))
+		} else {
+			delete(r.rules, k)
+		}
+	}
+
+	r.updateState()
+
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+func (r *family) addPostroutingRules() error {
+	// First rule for outbound masquerade
+	rule1 := []string{
+		"-m", "mark", "--mark", fmt.Sprintf("%#x", nbnet.PreroutingFwmarkMasquerade),
+		"!", "-o", "lo",
+		"-j", "MASQUERADE",
+	}
+	if err := r.iptablesClient.Append(tableNat, chainRTNAT, rule1...); err != nil {
+		return fmt.Errorf("add outbound masquerade rule: %w", err)
+	}
+	r.rules["static-nat-outbound"] = rule1
+
+	// Second rule for return traffic masquerade
+	rule2 := []string{
+		"-m", "mark", "--mark", fmt.Sprintf("%#x", nbnet.PreroutingFwmarkMasqueradeReturn),
+		"-o", r.wgIface.Name(),
+		"-j", "MASQUERADE",
+	}
+	if err := r.iptablesClient.Append(tableNat, chainRTNAT, rule2...); err != nil {
+		return fmt.Errorf("add return masquerade rule: %w", err)
+	}
+	r.rules["static-nat-return"] = rule2
+
+	return nil
+}
+
+// addMSSClampingRules adds MSS clamping rules to prevent fragmentation for forwarded traffic.
+func (r *family) addMSSClampingRules() error {
+	overhead := uint16(ipv4TCPHeaderSize)
+	if r.v6 {
+		overhead = ipv6TCPHeaderSize
+	}
+	mss := r.mtu - overhead
+
+	// Add jump rule from FORWARD chain in mangle table to our custom chain
+	jumpRule := jumpRuleSpec(chainRTMSSClamp)
+	if err := r.iptablesClient.Insert(tableMangle, chainForward, 1, jumpRule...); err != nil {
+		return fmt.Errorf("add jump to MSS clamp chain: %w", err)
+	}
+	r.rules[jumpMSSClamp] = jumpRule
+
+	ruleOut := []string{
+		"-o", r.wgIface.Name(),
+		"-p", "tcp",
+		"--tcp-flags", "SYN,RST", "SYN",
+		"-j", "TCPMSS",
+		"--set-mss", fmt.Sprintf("%d", mss),
+	}
+	if err := r.iptablesClient.Append(tableMangle, chainRTMSSClamp, ruleOut...); err != nil {
+		return fmt.Errorf("add outbound MSS clamp rule: %w", err)
+	}
+	r.rules["mss-clamp-out"] = ruleOut
+
+	return nil
+}
+
+func (r *family) insertEstablishedRule(chain string) error {
+	establishedRule := getConntrackEstablished()
+
+	err := r.iptablesClient.Insert(tableFilter, chain, 1, establishedRule...)
+	if err != nil {
+		return fmt.Errorf("insert established rule: %w", err)
+	}
+
+	ruleID := firewall.RuleID("established-" + chain)
+	r.rules[ruleID] = establishedRule
+
+	return nil
+}
+
+func (r *family) addNatRule(pair firewall.RouterPair) error {
+	ruleID := pair.GenKey(firewall.NatFormat)
+
+	if rule, exists := r.rules[ruleID]; exists {
+		if err := r.iptablesClient.DeleteIfExists(tableMangle, chainRTPre, rule...); err != nil {
+			return fmt.Errorf("remove existing marking rule for %s: %w", pair.Destination, err)
+		}
+		delete(r.rules, ruleID)
+	}
+
+	markValue := nbnet.PreroutingFwmarkMasquerade
+	if pair.Inverse {
+		markValue = nbnet.PreroutingFwmarkMasqueradeReturn
+	}
+
+	rule := []string{"-i", r.wgIface.Name()}
+	if pair.Inverse {
+		rule = []string{"!", "-i", r.wgIface.Name()}
+	}
+
+	rule = append(rule,
+		"-m", "conntrack",
+		"--ctstate", "NEW",
+	)
+	sourceExp, err := r.applyNetwork("-s", pair.Source, nil)
+	if err != nil {
+		return fmt.Errorf("apply network -s: %w", err)
+	}
+	destExp, err := r.applyNetwork("-d", pair.Destination, nil)
+	if err != nil {
+		return fmt.Errorf("apply network -d: %w", err)
+	}
+
+	rule = append(rule, sourceExp...)
+	rule = append(rule, destExp...)
+	rule = append(rule,
+		"-j", "MARK", "--set-mark", fmt.Sprintf("%#x", markValue),
+	)
+
+	// Ensure nat rules come first, so the mark can be overwritten.
+	// Currently overwritten by the dst-type LOCAL rules for redirected traffic.
+	if err := r.iptablesClient.Insert(tableMangle, chainRTPre, 1, rule...); err != nil {
+		r.dropSourceMatch(rule)
+		return fmt.Errorf("add marking rule for %s: %w", pair.Destination, err)
+	}
+
+	r.rules[ruleID] = rule
+
+	return nil
+}
+
+func (r *family) removeNatRule(pair firewall.RouterPair) error {
+	ruleID := pair.GenKey(firewall.NatFormat)
+
+	if rule, exists := r.rules[ruleID]; exists {
+		if err := r.iptablesClient.DeleteIfExists(tableMangle, chainRTPre, rule...); err != nil {
+			return fmt.Errorf("remove marking rule for %s: %w", pair.Destination, err)
+		}
+		delete(r.rules, ruleID)
+
+		if err := r.decrementSetCounter(rule); err != nil {
+			return fmt.Errorf("decrement ipset counter: %w", err)
+		}
+	} else {
+		log.Debugf("marking rule %s not found", ruleID)
+	}
+
+	return nil
+}

client/firewall/iptables/rule.go

@@ -1,18 +1,20 @@
 package iptables
 
-// Rule to handle management of rules
-type Rule struct {
-	ruleID    string
-	ipsetName string
+import "github.com/netbirdio/netbird/client/firewall/manager"
 
+// Rule to handle management of rules. Source set membership (when the
+// rule was built against a shared hash:net ipset) is encoded in specs;
+// DeleteFilterRule recovers it via findSets so the refcounter can drop
+// the right reference.
+type Rule struct {
+	id          manager.RuleID
 	specs       []string
 	mangleSpecs []string
-	ip          string
 	chain       string
 	v6          bool
 }
 
-// GetRuleID returns the rule id
-func (r *Rule) ID() string {
-	return r.ruleID
+// ID returns the rule id
+func (r *Rule) ID() manager.RuleID {
+	return r.id
 }

client/firewall/iptables/rulestore_linux.go

@@ -1,127 +0,0 @@
-package iptables
-
-import (
-	"encoding/json"
-	"maps"
-)
-
-type ipList struct {
-	ips map[string]struct{}
-}
-
-func newIpList(ip string) *ipList {
-	ips := make(map[string]struct{})
-	ips[ip] = struct{}{}
-
-	return &ipList{
-		ips: ips,
-	}
-}
-
-func (s *ipList) addIP(ip string) {
-	s.ips[ip] = struct{}{}
-}
-
-// clone returns a deep copy of the ipList with its own ips map.
-func (s *ipList) clone() *ipList {
-	if s == nil {
-		return nil
-	}
-	return &ipList{ips: maps.Clone(s.ips)}
-}
-
-// MarshalJSON implements json.Marshaler
-func (s *ipList) MarshalJSON() ([]byte, error) {
-	return json.Marshal(struct {
-		IPs map[string]struct{} `json:"ips"`
-	}{
-		IPs: s.ips,
-	})
-}
-
-// UnmarshalJSON implements json.Unmarshaler
-func (s *ipList) UnmarshalJSON(data []byte) error {
-	temp := struct {
-		IPs map[string]struct{} `json:"ips"`
-	}{}
-	if err := json.Unmarshal(data, &temp); err != nil {
-		return err
-	}
-	s.ips = temp.IPs
-
-	if temp.IPs == nil {
-		temp.IPs = make(map[string]struct{})
-	}
-
-	return nil
-}
-
-type ipsetStore struct {
-	ipsets map[string]*ipList
-}
-
-func newIpsetStore() *ipsetStore {
-	return &ipsetStore{
-		ipsets: make(map[string]*ipList),
-	}
-}
-
-// clone returns a deep copy of the ipsetStore with its own ipsets map and
-// independent ipList entries.
-func (s *ipsetStore) clone() *ipsetStore {
-	if s == nil {
-		return nil
-	}
-	cloned := &ipsetStore{ipsets: make(map[string]*ipList, len(s.ipsets))}
-	for name, list := range s.ipsets {
-		cloned.ipsets[name] = list.clone()
-	}
-	return cloned
-}
-
-func (s *ipsetStore) ipset(ipsetName string) (*ipList, bool) {
-	r, ok := s.ipsets[ipsetName]
-	return r, ok
-}
-
-func (s *ipsetStore) addIpList(ipsetName string, list *ipList) {
-	s.ipsets[ipsetName] = list
-}
-
-func (s *ipsetStore) deleteIpset(ipsetName string) {
-	delete(s.ipsets, ipsetName)
-}
-
-func (s *ipsetStore) ipsetNames() []string {
-	names := make([]string, 0, len(s.ipsets))
-	for name := range s.ipsets {
-		names = append(names, name)
-	}
-	return names
-}
-
-// MarshalJSON implements json.Marshaler
-func (s *ipsetStore) MarshalJSON() ([]byte, error) {
-	return json.Marshal(struct {
-		IPSets map[string]*ipList `json:"ipsets"`
-	}{
-		IPSets: s.ipsets,
-	})
-}
-
-// UnmarshalJSON implements json.Unmarshaler
-func (s *ipsetStore) UnmarshalJSON(data []byte) error {
-	temp := struct {
-		IPSets map[string]*ipList `json:"ipsets"`
-	}{}
-	if err := json.Unmarshal(data, &temp); err != nil {
-		return err
-	}
-	s.ipsets = temp.IPSets
-
-	if temp.IPSets == nil {
-		temp.IPSets = make(map[string]*ipList)
-	}
-
-	return nil
-}

client/firewall/iptables/state_linux.go

@@ -29,17 +29,13 @@ type ShutdownState struct {
 
 	InterfaceState *InterfaceState `json:"interface_state,omitempty"`
 
-	RouteRules        routeRules    `json:"route_rules,omitempty"`
-	RouteIPsetCounter *ipsetCounter `json:"route_ipset_counter,omitempty"`
-
-	ACLEntries    aclEntries  `json:"acl_entries,omitempty"`
-	ACLIPsetStore *ipsetStore `json:"acl_ipset_store,omitempty"`
-
-	// IPv6 counterparts
+	RouteRules         routeRules    `json:"route_rules,omitempty"`
 	RouteRules6        routeRules    `json:"route_rules_v6,omitempty"`
+	RouteIPsetCounter  *ipsetCounter `json:"route_ipset_counter,omitempty"`
 	RouteIPsetCounter6 *ipsetCounter `json:"route_ipset_counter_v6,omitempty"`
-	ACLEntries6        aclEntries    `json:"acl_entries_v6,omitempty"`
-	ACLIPsetStore6     *ipsetStore   `json:"acl_ipset_store_v6,omitempty"`
+
+	ACLEntries  aclEntries `json:"acl_entries,omitempty"`
+	ACLEntries6 aclEntries `json:"acl_entries_v6,omitempty"`
 }
 
 func (s *ShutdownState) Name() string {
@@ -57,17 +53,14 @@ func (s *ShutdownState) Cleanup() error {
 	}
 
 	if s.RouteRules != nil {
-		ipt.router.rules = s.RouteRules
+		ipt.family4.rules = s.RouteRules
 	}
 	if s.RouteIPsetCounter != nil {
-		ipt.router.ipsetCounter.LoadData(s.RouteIPsetCounter)
+		ipt.family4.ipsetCounter.LoadData(s.RouteIPsetCounter)
 	}
 
 	if s.ACLEntries != nil {
-		ipt.aclMgr.entries = s.ACLEntries
-	}
-	if s.ACLIPsetStore != nil {
-		ipt.aclMgr.ipsetStore = s.ACLIPsetStore
+		ipt.family4.entries = s.ACLEntries
 	}
 
 	// Clean up v6 state even if the current run has no IPv6.
@@ -79,16 +72,13 @@ func (s *ShutdownState) Cleanup() error {
 	}
 	if ipt.hasIPv6() {
 		if s.RouteRules6 != nil {
-			ipt.router6.rules = s.RouteRules6
+			ipt.family6.rules = s.RouteRules6
 		}
 		if s.RouteIPsetCounter6 != nil {
-			ipt.router6.ipsetCounter.LoadData(s.RouteIPsetCounter6)
+			ipt.family6.ipsetCounter.LoadData(s.RouteIPsetCounter6)
 		}
 		if s.ACLEntries6 != nil {
-			ipt.aclMgr6.entries = s.ACLEntries6
-		}
-		if s.ACLIPsetStore6 != nil {
-			ipt.aclMgr6.ipsetStore = s.ACLIPsetStore6
+			ipt.family6.entries = s.ACLEntries6
 		}
 	}
 

client/firewall/iptables/testhelpers_linux_test.go

@@ -0,0 +1,27 @@
+//go:build privileged
+
+package iptables
+
+import (
+	"fmt"
+	"net"
+	"net/netip"
+)
+
+func pfx(ip net.IP) []netip.Prefix {
+	if ip == nil {
+		return []netip.Prefix{netip.PrefixFrom(netip.IPv4Unspecified(), 0)}
+	}
+	if ip.IsUnspecified() {
+		if ip.To4() != nil {
+			return []netip.Prefix{netip.PrefixFrom(netip.IPv4Unspecified(), 0)}
+		}
+		return []netip.Prefix{netip.PrefixFrom(netip.IPv6Unspecified(), 0)}
+	}
+	a, ok := netip.AddrFromSlice(ip)
+	if !ok {
+		panic(fmt.Sprintf("invalid IP length: %d", len(ip)))
+	}
+	a = a.Unmap()
+	return []netip.Prefix{netip.PrefixFrom(a, a.BitLen())}
+}

client/firewall/manager/firewall.go

@@ -3,7 +3,6 @@ package manager
 import (
 	"errors"
 	"fmt"
-	"net"
 	"net/netip"
 	"sort"
 
@@ -16,6 +15,12 @@ import (
 // method but the IPv6 firewall components were not initialized.
 var ErrIPv6NotInitialized = errors.New("IPv6 firewall not initialized")
 
+// ErrNoSources is returned when AddFilterRule is called with an empty
+// source list. "Match any source" must be expressed explicitly with a
+// /0 prefix; an empty list is a caller error and is rejected rather
+// than silently widening the rule to every source.
+var ErrNoSources = errors.New("rule has no sources")
+
 const (
 	ForwardingFormatPrefix = "netbird-fwd-"
 	ForwardingFormat       = "netbird-fwd-%s-%t"
@@ -23,13 +28,18 @@ const (
 	NatFormat              = "netbird-nat-%s-%t"
 )
 
+// RuleID identifies a firewall rule. It is a typed string so the
+// compiler catches accidental mixing with arbitrary string keys. It is
+// only an identifier and does not implement Rule.
+type RuleID string
+
 // Rule abstraction should be implemented by each firewall manager
 //
 // Each firewall type for different OS can use different type
 // of the properties to hold data of the created rule
 type Rule interface {
 	// ID returns the rule id
-	ID() string
+	ID() RuleID
 }
 
 // RuleDirection is the traffic direction which a rule is applied
@@ -91,6 +101,13 @@ func (d Network) IsPrefix() bool {
 	return d.Prefix.IsValid()
 }
 
+// IsZero returns true if the network designates no destination, i.e. it
+// is the zero value. A zero Network is the peer-rule sentinel; a non-zero
+// one carries a prefix or set destination.
+func (d Network) IsZero() bool {
+	return !d.IsPrefix() && !d.IsSet()
+}
+
 // Manager is the high level abstraction of a firewall manager
 //
 // It declares methods which handle actions required by the
@@ -98,46 +115,42 @@ func (d Network) IsPrefix() bool {
 type Manager interface {
 	Init(stateManager *statemanager.Manager) error
 
-	// AllowNetbird allows netbird interface traffic
-	AllowNetbird() error
-
-	// AddPeerFiltering adds a rule to the firewall
+	// AddFilterRule adds a packet-filtering rule to the firewall.
 	//
-	// If comment argument is empty firewall manager should set
-	// rule ID as comment for the rule
+	// If destination is the zero Network, the rule applies to traffic
+	// inbound to this node, i.e. peer ACL semantics, installed in
+	// the kernel's input chain. If destination is set (prefix or
+	// set), the rule applies to forwarded traffic with that
+	// destination, route ACL semantics, installed in the forward
+	// chain.
 	//
-	// Note: Callers should call Flush() after adding rules to ensure
-	// they are applied to the kernel and rule handles are refreshed.
-	AddPeerFiltering(
+	// sources must be a single address family; the caller splits mixed
+	// families and calls once per family. "Match any source" must be
+	// expressed with an explicit /0 prefix; an empty sources list is
+	// rejected with ErrNoSources so a zeroed list can never widen a
+	// rule to every source.
+	//
+	// Note: callers should call Flush() after adding rules.
+	AddFilterRule(
 		id []byte,
-		ip net.IP,
+		sources []netip.Prefix,
+		destination Network,
 		proto Protocol,
 		sPort *Port,
 		dPort *Port,
 		action Action,
-		ipsetName string,
-	) ([]Rule, error)
+	) (Rule, error)
 
-	// DeletePeerRule from the firewall by rule definition
-	DeletePeerRule(rule Rule) error
+	// DeleteFilterRule removes a filtering rule previously added via
+	// AddFilterRule. The rule's own type identifies whether it lives
+	// in the peer (input) or route (forward) path.
+	DeleteFilterRule(rule Rule) error
 
 	// IsServerRouteSupported returns true if the firewall supports server side routing operations
 	IsServerRouteSupported() bool
 
 	IsStateful() bool
 
-	AddRouteFiltering(
-		id []byte,
-		sources []netip.Prefix,
-		destination Network,
-		proto Protocol,
-		sPort, dPort *Port,
-		action Action,
-	) (Rule, error)
-
-	// DeleteRouteRule deletes a routing rule
-	DeleteRouteRule(rule Rule) error
-
 	// AddNatRule inserts a routing NAT rule
 	AddNatRule(pair RouterPair) error
 
@@ -185,8 +198,9 @@ type Manager interface {
 	SetupEBPFProxyNoTrack(proxyPort, wgPort uint16) error
 }
 
-func GenKey(format string, pair RouterPair) string {
-	return fmt.Sprintf(format, pair.ID, pair.Inverse)
+// GenKey builds the rule id for this pair from the given format.
+func (p RouterPair) GenKey(format string) RuleID {
+	return RuleID(fmt.Sprintf(format, p.ID, p.Inverse))
 }
 
 // LegacyManager defines the interface for legacy management operations
@@ -242,6 +256,20 @@ func MergeIPRanges(prefixes []netip.Prefix) []netip.Prefix {
 	return merged
 }
 
+// UnmapPrefix normalizes a v4-mapped v6 prefix (::ffff:a.b.c.d) to its
+// plain v4 form, shifting the prefix length out of the 96-bit mapped
+// range. Other prefixes are returned unchanged. Keeping prefixes
+// unmapped ensures v4 rules match consistently and the match builders
+// read the correct address length.
+func UnmapPrefix(p netip.Prefix) netip.Prefix {
+	addr := p.Addr()
+	if !addr.Is4In6() {
+		return p
+	}
+	bits := max(p.Bits()-96, 0)
+	return netip.PrefixFrom(addr.Unmap(), bits)
+}
+
 // SortPrefixes sorts the given slice of netip.Prefix in place.
 // It sorts first by IP address, then by prefix length (most specific to least specific).
 func SortPrefixes(prefixes []netip.Prefix) {

client/firewall/manager/forward_rule.go

@@ -13,13 +13,13 @@ type ForwardRule struct {
 	TranslatedPort    Port
 }
 
-func (r ForwardRule) ID() string {
+func (r ForwardRule) ID() RuleID {
 	id := fmt.Sprintf("%s;%s;%s;%s",
 		r.Protocol,
 		r.DestinationPort.String(),
 		r.TranslatedAddress.String(),
 		r.TranslatedPort.String())
-	return id
+	return RuleID(id)
 }
 
 func (r ForwardRule) String() string {

client/firewall/manager/set.go

@@ -40,7 +40,7 @@ func (h Set) Comment() string {
 
 // NewPrefixSet generates a unique name for an ipset based on the given prefixes.
 func NewPrefixSet(prefixes []netip.Prefix) Set {
-	// sort for consistent naming
+	prefixes = slices.Clone(prefixes)
 	SortPrefixes(prefixes)
 
 	hash := sha256.New()

client/firewall/nftables/acl_linux.go

@@ -1,713 +0,0 @@
-package nftables
-
-import (
-	"bytes"
-	"fmt"
-	"net"
-	"slices"
-	"strconv"
-	"strings"
-	"time"
-
-	"github.com/google/nftables"
-	"github.com/google/nftables/binaryutil"
-	"github.com/google/nftables/expr"
-	log "github.com/sirupsen/logrus"
-	"golang.org/x/sys/unix"
-
-	firewall "github.com/netbirdio/netbird/client/firewall/manager"
-	nbnet "github.com/netbirdio/netbird/client/net"
-)
-
-const (
-
-	// rules chains contains the effective ACL rules
-	chainNameInputRules = "netbird-acl-input-rules"
-
-	// filter chains contains the rules that jump to the rules chains
-	chainNameInputFilter       = "netbird-acl-input-filter"
-	chainNameForwardFilter     = "netbird-acl-forward-filter"
-	chainNameManglePrerouting  = "netbird-mangle-prerouting"
-	chainNameManglePostrouting = "netbird-mangle-postrouting"
-)
-
-const flushError = "flush: %w"
-
-type AclManager struct {
-	rConn              *nftables.Conn
-	sConn              *nftables.Conn
-	wgIface            iFaceMapper
-	routingFwChainName string
-	af                 addrFamily
-
-	workTable       *nftables.Table
-	chainInputRules *nftables.Chain
-	chainPrerouting *nftables.Chain
-
-	ipsetStore *ipsetStore
-	rules      map[string]*Rule
-}
-
-func newAclManager(table *nftables.Table, wgIface iFaceMapper, routingFwChainName string) (*AclManager, error) {
-	// sConn is used for creating sets and adding/removing elements from them
-	// it's differ then rConn (which does create new conn for each flush operation)
-	// and is permanent. Using same connection for both type of operations
-	// overloads netlink with high amount of rules ( > 10000)
-	sConn, err := nftables.New(nftables.AsLasting())
-	if err != nil {
-		return nil, fmt.Errorf("create nf conn: %w", err)
-	}
-
-	return &AclManager{
-		rConn:              &nftables.Conn{},
-		sConn:              sConn,
-		wgIface:            wgIface,
-		workTable:          table,
-		routingFwChainName: routingFwChainName,
-		af:                 familyForAddr(table.Family == nftables.TableFamilyIPv4),
-
-		ipsetStore: newIpsetStore(),
-		rules:      make(map[string]*Rule),
-	}, nil
-}
-
-func (m *AclManager) init(workTable *nftables.Table) error {
-	m.workTable = workTable
-	return m.createDefaultChains()
-}
-
-// AddPeerFiltering rule to the firewall
-//
-// If comment argument is empty firewall manager should set
-// rule ID as comment for the rule
-func (m *AclManager) AddPeerFiltering(
-	id []byte,
-	ip net.IP,
-	proto firewall.Protocol,
-	sPort *firewall.Port,
-	dPort *firewall.Port,
-	action firewall.Action,
-	ipsetName string,
-) ([]firewall.Rule, error) {
-	var ipset *nftables.Set
-	if ipsetName != "" {
-		var err error
-		ipset, err = m.addIpToSet(ipsetName, ip)
-		if err != nil {
-			return nil, err
-		}
-	}
-
-	newRules := make([]firewall.Rule, 0, 2)
-	ioRule, err := m.addIOFiltering(ip, proto, sPort, dPort, action, ipset)
-	if err != nil {
-		return nil, err
-	}
-
-	newRules = append(newRules, ioRule)
-	return newRules, nil
-}
-
-// DeletePeerRule from the firewall by rule definition
-func (m *AclManager) DeletePeerRule(rule firewall.Rule) error {
-	r, ok := rule.(*Rule)
-	if !ok {
-		return fmt.Errorf("invalid rule type")
-	}
-
-	if r.nftSet == nil {
-		if err := m.rConn.DelRule(r.nftRule); err != nil {
-			log.Errorf("failed to delete rule: %v", err)
-		}
-		if r.mangleRule != nil {
-			if err := m.rConn.DelRule(r.mangleRule); err != nil {
-				log.Errorf("failed to delete mangle rule: %v", err)
-			}
-		}
-		delete(m.rules, r.ID())
-		return m.rConn.Flush()
-	}
-
-	ips, ok := m.ipsetStore.ips(r.nftSet.Name)
-	if !ok {
-		if err := m.rConn.DelRule(r.nftRule); err != nil {
-			log.Errorf("failed to delete rule: %v", err)
-		}
-		if r.mangleRule != nil {
-			if err := m.rConn.DelRule(r.mangleRule); err != nil {
-				log.Errorf("failed to delete mangle rule: %v", err)
-			}
-		}
-		delete(m.rules, r.ID())
-		return m.rConn.Flush()
-	}
-
-	if _, ok := ips[r.ip.String()]; ok {
-		err := m.sConn.SetDeleteElements(r.nftSet, []nftables.SetElement{{Key: ipToBytes(r.ip, m.af)}})
-		if err != nil {
-			log.Errorf("delete elements for set %q: %v", r.nftSet.Name, err)
-		}
-		if err := m.sConn.Flush(); err != nil {
-			log.Debugf("flush error of set delete element, %s", r.nftSet.Name)
-			return err
-		}
-		m.ipsetStore.DeleteIpFromSet(r.nftSet.Name, r.ip)
-	}
-
-	// if after delete, set still contains other IPs,
-	// no need to delete firewall rule and we should exit here
-	if len(ips) > 0 {
-		return nil
-	}
-
-	if err := m.rConn.DelRule(r.nftRule); err != nil {
-		log.Errorf("failed to delete rule: %v", err)
-	}
-	if r.mangleRule != nil {
-		if err := m.rConn.DelRule(r.mangleRule); err != nil {
-			log.Errorf("failed to delete mangle rule: %v", err)
-		}
-	}
-
-	if err := m.rConn.Flush(); err != nil {
-		return err
-	}
-
-	delete(m.rules, r.ID())
-	m.ipsetStore.DeleteReferenceFromIpSet(r.nftSet.Name)
-
-	if m.ipsetStore.HasReferenceToSet(r.nftSet.Name) {
-		return nil
-	}
-
-	// we delete last IP from the set, that means we need to delete
-	// set itself and associated firewall rule too
-	m.rConn.FlushSet(r.nftSet)
-	m.rConn.DelSet(r.nftSet)
-	m.ipsetStore.deleteIpset(r.nftSet.Name)
-	return nil
-}
-
-// createDefaultAllowRules creates default allow rules for the input and output chains
-func (m *AclManager) createDefaultAllowRules() error {
-	expIn := []expr.Any{
-		&expr.Verdict{
-			Kind: expr.VerdictAccept,
-		},
-	}
-
-	_ = m.rConn.InsertRule(&nftables.Rule{
-		Table:    m.workTable,
-		Chain:    m.chainInputRules,
-		Position: 0,
-		Exprs:    expIn,
-	})
-
-	if err := m.rConn.Flush(); err != nil {
-		return fmt.Errorf(flushError, err)
-	}
-	return nil
-}
-
-// Flush rule/chain/set operations from the buffer
-//
-// Method also get all rules after flush and refreshes handle values in the rulesets
-func (m *AclManager) Flush() error {
-	if err := m.flushWithBackoff(); err != nil {
-		return err
-	}
-
-	if err := m.refreshRuleHandles(m.chainInputRules, false); err != nil {
-		log.Errorf("failed to refresh rule handles ipv4 input chain: %v", err)
-	}
-	if err := m.refreshRuleHandles(m.chainPrerouting, true); err != nil {
-		log.Errorf("failed to refresh rule handles prerouting chain: %v", err)
-	}
-
-	return nil
-}
-
-func (m *AclManager) addIOFiltering(
-	ip net.IP,
-	proto firewall.Protocol,
-	sPort *firewall.Port,
-	dPort *firewall.Port,
-	action firewall.Action,
-	ipset *nftables.Set,
-) (*Rule, error) {
-	ruleId := generatePeerRuleId(ip, proto, sPort, dPort, action, ipset)
-	if r, ok := m.rules[ruleId]; ok {
-		return &Rule{
-			nftRule:    r.nftRule,
-			mangleRule: r.mangleRule,
-			nftSet:     r.nftSet,
-			ruleID:     r.ruleID,
-			ip:         ip,
-		}, nil
-	}
-
-	var expressions []expr.Any
-
-	if proto != firewall.ProtocolALL {
-		expressions = append(expressions, &expr.Payload{
-			DestRegister: 1,
-			Base:         expr.PayloadBaseNetworkHeader,
-			Offset:       m.af.protoOffset,
-			Len:          uint32(1),
-		})
-
-		protoData, err := m.af.protoNum(proto)
-		if err != nil {
-			return nil, fmt.Errorf("convert protocol to number: %v", err)
-		}
-
-		expressions = append(expressions, &expr.Cmp{
-			Register: 1,
-			Op:       expr.CmpOpEq,
-			Data:     []byte{protoData},
-		})
-	}
-
-	rawIP := ipToBytes(ip, m.af)
-	// check if rawIP contains zeroed IPv4 0.0.0.0 value
-	// in that case not add IP match expression into the rule definition
-	if slices.ContainsFunc(rawIP, func(v byte) bool { return v != 0 }) {
-		expressions = append(expressions,
-			&expr.Payload{
-				DestRegister: 1,
-				Base:         expr.PayloadBaseNetworkHeader,
-				Offset:       m.af.srcAddrOffset,
-				Len:          m.af.addrLen,
-			},
-		)
-		// add individual IP for match if no ipset defined
-		if ipset == nil {
-			expressions = append(expressions,
-				&expr.Cmp{
-					Op:       expr.CmpOpEq,
-					Register: 1,
-					Data:     rawIP,
-				},
-			)
-		} else {
-			expressions = append(expressions,
-				&expr.Lookup{
-					SourceRegister: 1,
-					SetName:        ipset.Name,
-					SetID:          ipset.ID,
-				},
-			)
-		}
-	}
-
-	expressions = append(expressions, applyPort(sPort, true)...)
-	expressions = append(expressions, applyPort(dPort, false)...)
-
-	mainExpressions := slices.Clone(expressions)
-
-	switch action {
-	case firewall.ActionAccept:
-		mainExpressions = append(mainExpressions, &expr.Verdict{Kind: expr.VerdictAccept})
-	case firewall.ActionDrop:
-		mainExpressions = append(mainExpressions, &expr.Verdict{Kind: expr.VerdictDrop})
-	}
-
-	userData := []byte(ruleId)
-
-	chain := m.chainInputRules
-	rule := &nftables.Rule{
-		Table:    m.workTable,
-		Chain:    chain,
-		Exprs:    mainExpressions,
-		UserData: userData,
-	}
-
-	// Insert DROP rules at the beginning, append ACCEPT rules at the end
-	var nftRule *nftables.Rule
-	if action == firewall.ActionDrop {
-		nftRule = m.rConn.InsertRule(rule)
-	} else {
-		nftRule = m.rConn.AddRule(rule)
-	}
-
-	if err := m.rConn.Flush(); err != nil {
-		return nil, fmt.Errorf("flush input rule %s: %v", ruleId, err)
-	}
-
-	ruleStruct := &Rule{
-		nftRule: nftRule,
-		// best effort mangle rule
-		mangleRule: m.createPreroutingRule(expressions, userData),
-		nftSet:     ipset,
-		ruleID:     ruleId,
-		ip:         ip,
-	}
-	m.rules[ruleId] = ruleStruct
-	if ipset != nil {
-		m.ipsetStore.AddReferenceToIpset(ipset.Name)
-	}
-
-	return ruleStruct, nil
-}
-
-func (m *AclManager) createPreroutingRule(expressions []expr.Any, userData []byte) *nftables.Rule {
-	if m.chainPrerouting == nil {
-		log.Warn("prerouting chain is not created")
-		return nil
-	}
-
-	preroutingExprs := slices.Clone(expressions)
-
-	// interface
-	preroutingExprs = append([]expr.Any{
-		&expr.Meta{
-			Key:      expr.MetaKeyIIFNAME,
-			Register: 1,
-		},
-		&expr.Cmp{
-			Op:       expr.CmpOpEq,
-			Register: 1,
-			Data:     ifname(m.wgIface.Name()),
-		},
-	}, preroutingExprs...)
-
-	// local destination and mark
-	preroutingExprs = append(preroutingExprs,
-		&expr.Fib{
-			Register:       1,
-			ResultADDRTYPE: true,
-			FlagDADDR:      true,
-		},
-		&expr.Cmp{
-			Op:       expr.CmpOpEq,
-			Register: 1,
-			Data:     binaryutil.NativeEndian.PutUint32(unix.RTN_LOCAL),
-		},
-
-		&expr.Immediate{
-			Register: 1,
-			Data:     binaryutil.NativeEndian.PutUint32(nbnet.PreroutingFwmarkRedirected),
-		},
-		&expr.Meta{
-			Key:            expr.MetaKeyMARK,
-			Register:       1,
-			SourceRegister: true,
-		},
-	)
-
-	nfRule := m.rConn.AddRule(&nftables.Rule{
-		Table:    m.workTable,
-		Chain:    m.chainPrerouting,
-		Exprs:    preroutingExprs,
-		UserData: userData,
-	})
-
-	if err := m.rConn.Flush(); err != nil {
-		log.Errorf("failed to flush mangle rule %s: %v", string(userData), err)
-		return nil
-	}
-
-	return nfRule
-}
-
-func (m *AclManager) createDefaultChains() (err error) {
-	// chainNameInputRules
-	chain := m.createChain(chainNameInputRules)
-	err = m.rConn.Flush()
-	if err != nil {
-		log.Debugf("failed to create chain (%s): %s", chain.Name, err)
-		return fmt.Errorf(flushError, err)
-	}
-	m.chainInputRules = chain
-
-	// netbird-acl-input-filter
-	// type filter hook input priority filter; policy accept;
-	chain = m.createFilterChainWithHook(chainNameInputFilter, nftables.ChainHookInput)
-	m.addJumpRule(chain, m.chainInputRules.Name, expr.MetaKeyIIFNAME) // to netbird-acl-input-rules
-	m.addDropExpressions(chain, expr.MetaKeyIIFNAME)
-	err = m.rConn.Flush()
-	if err != nil {
-		log.Debugf("failed to create chain (%s): %s", chain.Name, err)
-		return err
-	}
-
-	// netbird-acl-forward-filter
-	chainFwFilter := m.createFilterChainWithHook(chainNameForwardFilter, nftables.ChainHookForward)
-	m.addJumpRulesToRtForward(chainFwFilter) // to netbird-rt-fwd
-	m.addDropExpressions(chainFwFilter, expr.MetaKeyIIFNAME)
-
-	err = m.rConn.Flush()
-	if err != nil {
-		log.Debugf("failed to create chain (%s): %s", chainNameForwardFilter, err)
-		return fmt.Errorf(flushError, err)
-	}
-
-	if err := m.allowRedirectedTraffic(chainFwFilter); err != nil {
-		log.Errorf("failed to allow redirected traffic: %s", err)
-	}
-
-	return nil
-}
-
-// Makes redirected traffic originally destined for the host itself (now subject to the forward filter)
-// go through the input filter as well. This will enable e.g. Docker services to keep working by accessing the
-// netbird peer IP.
-func (m *AclManager) allowRedirectedTraffic(chainFwFilter *nftables.Chain) error {
-	// Chain is created by route manager
-	// TODO: move creation to a common place
-	m.chainPrerouting = &nftables.Chain{
-		Name:     chainNameManglePrerouting,
-		Table:    m.workTable,
-		Type:     nftables.ChainTypeFilter,
-		Hooknum:  nftables.ChainHookPrerouting,
-		Priority: nftables.ChainPriorityMangle,
-	}
-
-	m.addFwmarkToForward(chainFwFilter)
-
-	if err := m.rConn.Flush(); err != nil {
-		return fmt.Errorf(flushError, err)
-	}
-
-	return nil
-}
-
-func (m *AclManager) addFwmarkToForward(chainFwFilter *nftables.Chain) {
-	m.rConn.InsertRule(&nftables.Rule{
-		Table: m.workTable,
-		Chain: chainFwFilter,
-		Exprs: []expr.Any{
-			&expr.Meta{
-				Key:      expr.MetaKeyMARK,
-				Register: 1,
-			},
-			&expr.Cmp{
-				Op:       expr.CmpOpEq,
-				Register: 1,
-				Data:     binaryutil.NativeEndian.PutUint32(nbnet.PreroutingFwmarkRedirected),
-			},
-			&expr.Verdict{
-				Kind: expr.VerdictAccept,
-			},
-		},
-	})
-}
-
-func (m *AclManager) addJumpRulesToRtForward(chainFwFilter *nftables.Chain) {
-	expressions := []expr.Any{
-		&expr.Meta{Key: expr.MetaKeyIIFNAME, Register: 1},
-		&expr.Cmp{
-			Op:       expr.CmpOpEq,
-			Register: 1,
-			Data:     ifname(m.wgIface.Name()),
-		},
-		&expr.Verdict{
-			Kind:  expr.VerdictJump,
-			Chain: m.routingFwChainName,
-		},
-	}
-
-	_ = m.rConn.AddRule(&nftables.Rule{
-		Table: m.workTable,
-		Chain: chainFwFilter,
-		Exprs: expressions,
-	})
-}
-
-func (m *AclManager) createChain(name string) *nftables.Chain {
-	chain := &nftables.Chain{
-		Name:  name,
-		Table: m.workTable,
-	}
-
-	chain = m.rConn.AddChain(chain)
-
-	insertReturnTrafficRule(m.rConn, m.workTable, chain)
-
-	return chain
-}
-
-func (m *AclManager) createFilterChainWithHook(name string, hookNum *nftables.ChainHook) *nftables.Chain {
-	polAccept := nftables.ChainPolicyAccept
-	chain := &nftables.Chain{
-		Name:     name,
-		Table:    m.workTable,
-		Hooknum:  hookNum,
-		Priority: nftables.ChainPriorityFilter,
-		Type:     nftables.ChainTypeFilter,
-		Policy:   &polAccept,
-	}
-
-	return m.rConn.AddChain(chain)
-}
-
-func (m *AclManager) addDropExpressions(chain *nftables.Chain, ifaceKey expr.MetaKey) []expr.Any {
-	expressions := []expr.Any{
-		&expr.Meta{Key: ifaceKey, Register: 1},
-		&expr.Cmp{
-			Op:       expr.CmpOpEq,
-			Register: 1,
-			Data:     ifname(m.wgIface.Name()),
-		},
-		&expr.Verdict{Kind: expr.VerdictDrop},
-	}
-	_ = m.rConn.AddRule(&nftables.Rule{
-		Table: m.workTable,
-		Chain: chain,
-		Exprs: expressions,
-	})
-	return nil
-}
-
-func (m *AclManager) addJumpRule(chain *nftables.Chain, to string, ifaceKey expr.MetaKey) {
-	expressions := []expr.Any{
-		&expr.Meta{Key: ifaceKey, Register: 1},
-		&expr.Cmp{
-			Op:       expr.CmpOpEq,
-			Register: 1,
-			Data:     ifname(m.wgIface.Name()),
-		},
-		&expr.Verdict{
-			Kind:  expr.VerdictJump,
-			Chain: to,
-		},
-	}
-
-	_ = m.rConn.AddRule(&nftables.Rule{
-		Table: chain.Table,
-		Chain: chain,
-		Exprs: expressions,
-	})
-}
-
-func (m *AclManager) addIpToSet(ipsetName string, ip net.IP) (*nftables.Set, error) {
-	ipset, err := m.rConn.GetSetByName(m.workTable, ipsetName)
-	rawIP := ipToBytes(ip, m.af)
-	if err != nil {
-		if ipset, err = m.createSet(m.workTable, ipsetName); err != nil {
-			return nil, fmt.Errorf("get set name: %v", err)
-		}
-
-		m.ipsetStore.newIpset(ipset.Name)
-	}
-
-	if m.ipsetStore.IsIpInSet(ipset.Name, ip) {
-		return ipset, nil
-	}
-
-	if err := m.sConn.SetAddElements(ipset, []nftables.SetElement{{Key: rawIP}}); err != nil {
-		return nil, fmt.Errorf("add set element for the first time: %v", err)
-	}
-
-	m.ipsetStore.AddIpToSet(ipset.Name, ip)
-
-	if err := m.sConn.Flush(); err != nil {
-		return nil, fmt.Errorf("flush add elements: %v", err)
-	}
-
-	return ipset, nil
-}
-
-// createSet in given table by name
-func (m *AclManager) createSet(table *nftables.Table, name string) (*nftables.Set, error) {
-	ipset := &nftables.Set{
-		Name:    name,
-		Table:   table,
-		Dynamic: true,
-		KeyType: m.af.setKeyType,
-	}
-
-	if err := m.rConn.AddSet(ipset, nil); err != nil {
-		return nil, fmt.Errorf("create set: %v", err)
-	}
-
-	if err := m.rConn.Flush(); err != nil {
-		return nil, fmt.Errorf("flush created set: %v", err)
-	}
-
-	return ipset, nil
-}
-
-func (m *AclManager) flushWithBackoff() (err error) {
-	backoff := 4
-	backoffTime := 1000 * time.Millisecond
-	for i := 0; ; i++ {
-		err = m.rConn.Flush()
-		if err != nil {
-			log.Debugf("failed to flush nftables: %v", err)
-			if !strings.Contains(err.Error(), "busy") {
-				return
-			}
-			log.Error("failed to flush nftables, retrying...")
-			if i == backoff-1 {
-				return err
-			}
-			time.Sleep(backoffTime)
-			backoffTime *= 2
-			continue
-		}
-		break
-	}
-	return
-}
-
-func (m *AclManager) refreshRuleHandles(chain *nftables.Chain, mangle bool) error {
-	if m.workTable == nil || chain == nil {
-		return nil
-	}
-
-	list, err := m.rConn.GetRules(m.workTable, chain)
-	if err != nil {
-		return err
-	}
-
-	for _, rule := range list {
-		if len(rule.UserData) == 0 {
-			continue
-		}
-		split := bytes.Split(rule.UserData, []byte(" "))
-		r, ok := m.rules[string(split[0])]
-		if ok {
-			if mangle {
-				*r.mangleRule = *rule
-			} else {
-				*r.nftRule = *rule
-			}
-		}
-	}
-
-	return nil
-}
-
-func generatePeerRuleId(ip net.IP, proto firewall.Protocol, sPort *firewall.Port, dPort *firewall.Port, action firewall.Action, ipset *nftables.Set) string {
-	rulesetID := ":" + string(proto) + ":"
-	if sPort != nil {
-		rulesetID += sPort.String()
-	}
-	rulesetID += ":"
-	if dPort != nil {
-		rulesetID += dPort.String()
-	}
-	rulesetID += ":"
-	rulesetID += strconv.Itoa(int(action))
-	if ipset == nil {
-		return "ip:" + ip.String() + rulesetID
-	}
-	return "set:" + ipset.Name + rulesetID
-}
-
-func ifname(n string) []byte {
-	b := make([]byte, 16)
-	copy(b, n+"\x00")
-	return b
-}
-
-
-// ipToBytes converts net.IP to the correct byte length for the address family.
-func ipToBytes(ip net.IP, af addrFamily) []byte {
-	if af.addrLen == 4 {
-		return ip.To4()
-	}
-	return ip.To16()
-}
-

client/firewall/nftables/chains_linux.go

@@ -0,0 +1,880 @@
+//go:build !android
+
+package nftables
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"slices"
+	"strings"
+	"time"
+
+	"github.com/coreos/go-iptables/iptables"
+	"github.com/google/nftables"
+	"github.com/google/nftables/binaryutil"
+	"github.com/google/nftables/expr"
+	"github.com/hashicorp/go-multierror"
+	log "github.com/sirupsen/logrus"
+	"golang.org/x/sys/unix"
+
+	nberrors "github.com/netbirdio/netbird/client/errors"
+	"github.com/netbirdio/netbird/client/firewall/firewalld"
+	firewall "github.com/netbirdio/netbird/client/firewall/manager"
+	nbnet "github.com/netbirdio/netbird/client/net"
+)
+
+func (r *family) createContainers() error {
+	r.chains[chainNameRoutingFw] = r.conn.AddChain(&nftables.Chain{
+		Name:  chainNameRoutingFw,
+		Table: r.workTable,
+	})
+
+	prio := *nftables.ChainPriorityNATSource - 1
+	r.chains[chainNameRoutingNat] = r.conn.AddChain(&nftables.Chain{
+		Name:     chainNameRoutingNat,
+		Table:    r.workTable,
+		Hooknum:  nftables.ChainHookPostrouting,
+		Priority: &prio,
+		Type:     nftables.ChainTypeNAT,
+	})
+
+	r.chains[chainNameRoutingRdr] = r.conn.AddChain(&nftables.Chain{
+		Name:     chainNameRoutingRdr,
+		Table:    r.workTable,
+		Hooknum:  nftables.ChainHookPrerouting,
+		Priority: nftables.ChainPriorityNATDest,
+		Type:     nftables.ChainTypeNAT,
+	})
+
+	r.chains[chainNameManglePostrouting] = r.conn.AddChain(&nftables.Chain{
+		Name:     chainNameManglePostrouting,
+		Table:    r.workTable,
+		Hooknum:  nftables.ChainHookPostrouting,
+		Priority: nftables.ChainPriorityMangle,
+		Type:     nftables.ChainTypeFilter,
+	})
+
+	r.chains[chainNameManglePrerouting] = r.conn.AddChain(&nftables.Chain{
+		Name:     chainNameManglePrerouting,
+		Table:    r.workTable,
+		Hooknum:  nftables.ChainHookPrerouting,
+		Priority: nftables.ChainPriorityMangle,
+		Type:     nftables.ChainTypeFilter,
+	})
+
+	r.chains[chainNameMangleForward] = r.conn.AddChain(&nftables.Chain{
+		Name:     chainNameMangleForward,
+		Table:    r.workTable,
+		Hooknum:  nftables.ChainHookForward,
+		Priority: nftables.ChainPriorityMangle,
+		Type:     nftables.ChainTypeFilter,
+	})
+
+	insertReturnTrafficRule(r.conn, r.workTable, r.chains[chainNameRoutingFw])
+
+	r.addPostroutingRules()
+
+	if err := r.conn.Flush(); err != nil {
+		return fmt.Errorf("initialize tables: %v", err)
+	}
+
+	if err := r.addMSSClampingRules(); err != nil {
+		log.Errorf("failed to add MSS clamping rules: %s", err)
+	}
+
+	// Kernel routing opens both INPUT and FORWARD.
+	if err := r.openInterface(true); err != nil {
+		log.Errorf("failed to open interface in foreign chains: %s", err)
+	}
+
+	if err := firewalld.TrustInterface(r.wgIface.Name()); err != nil {
+		log.Warnf("failed to trust interface in firewalld: %v", err)
+	}
+
+	if err := r.refreshRulesMap(); err != nil {
+		log.Errorf("failed to refresh rules: %s", err)
+	}
+
+	return nil
+}
+
+// setupDataPlaneMark configures the fwmark for the data plane
+func (r *family) setupDataPlaneMark() error {
+	if r.chains[chainNameManglePrerouting] == nil || r.chains[chainNameManglePostrouting] == nil {
+		return errors.New("no mangle chains found")
+	}
+
+	ctNew := getCtNewExprs()
+	preExprs := []expr.Any{
+		&expr.Meta{
+			Key:      expr.MetaKeyIIFNAME,
+			Register: 1,
+		},
+		&expr.Cmp{
+			Op:       expr.CmpOpEq,
+			Register: 1,
+			Data:     ifname(r.wgIface.Name()),
+		},
+	}
+	preExprs = append(preExprs, ctNew...)
+	preExprs = append(preExprs,
+		&expr.Immediate{
+			Register: 1,
+			Data:     binaryutil.NativeEndian.PutUint32(nbnet.DataPlaneMarkIn),
+		},
+		&expr.Ct{
+			Key:            expr.CtKeyMARK,
+			Register:       1,
+			SourceRegister: true,
+		},
+	)
+
+	preNftRule := &nftables.Rule{
+		Table: r.workTable,
+		Chain: r.chains[chainNameManglePrerouting],
+		Exprs: preExprs,
+	}
+	r.conn.AddRule(preNftRule)
+
+	postExprs := []expr.Any{
+		&expr.Meta{
+			Key:      expr.MetaKeyOIFNAME,
+			Register: 1,
+		},
+		&expr.Cmp{
+			Op:       expr.CmpOpEq,
+			Register: 1,
+			Data:     ifname(r.wgIface.Name()),
+		},
+	}
+	postExprs = append(postExprs, ctNew...)
+	postExprs = append(postExprs,
+		&expr.Immediate{
+			Register: 1,
+			Data:     binaryutil.NativeEndian.PutUint32(nbnet.DataPlaneMarkOut),
+		},
+		&expr.Ct{
+			Key:            expr.CtKeyMARK,
+			Register:       1,
+			SourceRegister: true,
+		},
+	)
+
+	postNftRule := &nftables.Rule{
+		Table: r.workTable,
+		Chain: r.chains[chainNameManglePostrouting],
+		Exprs: postExprs,
+	}
+	r.conn.AddRule(postNftRule)
+
+	if err := r.conn.Flush(); err != nil {
+		return fmt.Errorf("flush: %w", err)
+	}
+
+	return nil
+}
+
+// openInterface adds passthrough accept rules for the NetBird interface to the
+// kernel's filter table and external chains so they don't drop our traffic.
+// includeForward also opens the FORWARD chains (kernel routing); when false only
+// INPUT is opened, which is all the userspace router needs since it never
+// forwards in the kernel.
+func (r *family) openInterface(includeForward bool) error {
+	var merr *multierror.Error
+
+	if err := r.acceptFilterTableRules(includeForward); err != nil {
+		merr = multierror.Append(merr, err)
+	}
+
+	if err := r.acceptExternalChainsRules(includeForward); err != nil {
+		merr = multierror.Append(merr, fmt.Errorf("add accept rules to external chains: %w", err))
+	}
+
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+func (r *family) acceptFilterTableRules(includeForward bool) error {
+	if r.filterTable == nil {
+		return nil
+	}
+
+	fw := "iptables"
+
+	defer func() {
+		log.Debugf("Used %s to add accept input/forward rules", fw)
+	}()
+
+	// Try iptables first and fallback to nftables if iptables is not available.
+	// Use the correct protocol (iptables vs ip6tables) for the address family.
+	ipt, err := iptables.NewWithProtocol(r.iptablesProto())
+	if err != nil {
+		log.Warnf("Will use nftables to manipulate the filter table because iptables is not available: %v", err)
+
+		fw = "nftables"
+		return r.acceptFilterRulesNftables(r.filterTable, includeForward)
+	}
+
+	if err := r.acceptFilterRulesIptables(ipt, includeForward); err != nil {
+		log.Warnf("iptables failed (table may be incompatible), falling back to nftables: %v", err)
+		fw = "nftables"
+		return r.acceptFilterRulesNftables(r.filterTable, includeForward)
+	}
+	return nil
+}
+
+func (r *family) acceptFilterRulesIptables(ipt *iptables.IPTables, includeForward bool) error {
+	var merr *multierror.Error
+
+	if includeForward {
+		for _, rule := range r.getAcceptForwardRules() {
+			if err := ipt.Insert("filter", chainNameForward, 1, rule...); err != nil {
+				merr = multierror.Append(merr, fmt.Errorf("add iptables forward rule: %v", err))
+			} else {
+				log.Debugf("added iptables forward rule: %v", rule)
+			}
+		}
+	}
+
+	inputRule := r.getAcceptInputRule()
+	if err := ipt.Insert("filter", chainNameInput, 1, inputRule...); err != nil {
+		merr = multierror.Append(merr, fmt.Errorf("add iptables input rule: %v", err))
+	} else {
+		log.Debugf("added iptables input rule: %v", inputRule)
+	}
+
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+func (r *family) getAcceptForwardRules() [][]string {
+	intf := r.wgIface.Name()
+	return [][]string{
+		{"-i", intf, "-j", "ACCEPT"},
+		{"-o", intf, "-m", "conntrack", "--ctstate", "RELATED,ESTABLISHED", "-j", "ACCEPT"},
+	}
+}
+
+func (r *family) getAcceptInputRule() []string {
+	return []string{"-i", r.wgIface.Name(), "-j", "ACCEPT"}
+}
+
+// acceptFilterRulesNftables adds accept rules to the ip filter table using nftables.
+// This is used when iptables is not available.
+func (r *family) acceptFilterRulesNftables(table *nftables.Table, includeForward bool) error {
+	intf := ifname(r.wgIface.Name())
+
+	if includeForward {
+		forwardChain := &nftables.Chain{
+			Name:     chainNameForward,
+			Table:    table,
+			Type:     nftables.ChainTypeFilter,
+			Hooknum:  nftables.ChainHookForward,
+			Priority: nftables.ChainPriorityFilter,
+		}
+		r.insertForwardAcceptRules(forwardChain, intf)
+	}
+
+	inputChain := &nftables.Chain{
+		Name:     chainNameInput,
+		Table:    table,
+		Type:     nftables.ChainTypeFilter,
+		Hooknum:  nftables.ChainHookInput,
+		Priority: nftables.ChainPriorityFilter,
+	}
+	r.insertInputAcceptRule(inputChain, intf)
+
+	return r.conn.Flush()
+}
+
+// acceptExternalChainsRules adds accept rules to external chains (non-netbird, non-iptables tables).
+// It dynamically finds chains at call time to handle chains that may have been created after startup.
+func (r *family) acceptExternalChainsRules(includeForward bool) error {
+	chains := r.findExternalChains()
+	if len(chains) == 0 {
+		return nil
+	}
+
+	intf := ifname(r.wgIface.Name())
+	for _, chain := range chains {
+		r.applyExternalChainAccept(chain, intf, includeForward)
+	}
+
+	if err := r.conn.Flush(); err != nil {
+		return fmt.Errorf("flush external chain rules: %w", err)
+	}
+	return nil
+}
+
+func (r *family) applyExternalChainAccept(chain *nftables.Chain, intf []byte, includeForward bool) {
+	if chain.Hooknum == nil {
+		log.Debugf("skipping external chain %s/%s: hooknum is nil", chain.Table.Name, chain.Name)
+		return
+	}
+
+	log.Debugf("adding accept rules to external %s chain: %s %s/%s",
+		hookName(chain.Hooknum), familyName(chain.Table.Family), chain.Table.Name, chain.Name)
+
+	switch *chain.Hooknum {
+	case *nftables.ChainHookForward:
+		if includeForward {
+			r.insertForwardAcceptRules(chain, intf)
+		}
+	case *nftables.ChainHookInput:
+		r.insertInputAcceptRule(chain, intf)
+	}
+}
+
+func (r *family) insertForwardAcceptRules(chain *nftables.Chain, intf []byte) {
+	existing, err := r.existingNetbirdRulesInChain(chain)
+	if err != nil {
+		log.Warnf("skip forward accept rules in %s/%s: %v", chain.Table.Name, chain.Name, err)
+		return
+	}
+	r.insertForwardIifRule(chain, intf, existing)
+	r.insertForwardOifEstablishedRule(chain, intf, existing)
+}
+
+func (r *family) insertForwardIifRule(chain *nftables.Chain, intf []byte, existing map[string]bool) {
+	if existing[userDataAcceptForwardRuleIif] {
+		return
+	}
+	r.conn.InsertRule(&nftables.Rule{
+		Table: chain.Table,
+		Chain: chain,
+		Exprs: []expr.Any{
+			&expr.Meta{Key: expr.MetaKeyIIFNAME, Register: 1},
+			&expr.Cmp{Op: expr.CmpOpEq, Register: 1, Data: intf},
+			&expr.Counter{},
+			&expr.Verdict{Kind: expr.VerdictAccept},
+		},
+		UserData: []byte(userDataAcceptForwardRuleIif),
+	})
+}
+
+func (r *family) insertForwardOifEstablishedRule(chain *nftables.Chain, intf []byte, existing map[string]bool) {
+	if existing[userDataAcceptForwardRuleOif] {
+		return
+	}
+	exprs := []expr.Any{
+		&expr.Meta{Key: expr.MetaKeyOIFNAME, Register: 1},
+		&expr.Cmp{Op: expr.CmpOpEq, Register: 1, Data: intf},
+	}
+	r.conn.InsertRule(&nftables.Rule{
+		Table:    chain.Table,
+		Chain:    chain,
+		Exprs:    append(exprs, getEstablishedExprs(2)...),
+		UserData: []byte(userDataAcceptForwardRuleOif),
+	})
+}
+
+func (r *family) insertInputAcceptRule(chain *nftables.Chain, intf []byte) {
+	existing, err := r.existingNetbirdRulesInChain(chain)
+	if err != nil {
+		log.Warnf("skip input accept rule in %s/%s: %v", chain.Table.Name, chain.Name, err)
+		return
+	}
+	if existing[userDataAcceptInputRule] {
+		return
+	}
+	r.conn.InsertRule(&nftables.Rule{
+		Table: chain.Table,
+		Chain: chain,
+		Exprs: []expr.Any{
+			&expr.Meta{Key: expr.MetaKeyIIFNAME, Register: 1},
+			&expr.Cmp{Op: expr.CmpOpEq, Register: 1, Data: intf},
+			&expr.Counter{},
+			&expr.Verdict{Kind: expr.VerdictAccept},
+		},
+		UserData: []byte(userDataAcceptInputRule),
+	})
+}
+
+// existingNetbirdRulesInChain returns the set of netbird-owned UserData tags present in a chain; callers must bail on error since InsertRule is additive.
+func (r *family) existingNetbirdRulesInChain(chain *nftables.Chain) (map[string]bool, error) {
+	rules, err := r.conn.GetRules(chain.Table, chain)
+	if err != nil {
+		return nil, fmt.Errorf("list rules: %w", err)
+	}
+	present := map[string]bool{}
+	for _, rule := range rules {
+		if !isNetbirdAcceptRuleTag(rule.UserData) {
+			continue
+		}
+		present[string(rule.UserData)] = true
+	}
+	return present, nil
+}
+
+func isNetbirdAcceptRuleTag(userData []byte) bool {
+	switch string(userData) {
+	case userDataAcceptForwardRuleIif,
+		userDataAcceptForwardRuleOif,
+		userDataAcceptInputRule:
+		return true
+	}
+	return false
+}
+
+func (r *family) removeAcceptFilterRules() error {
+	var merr *multierror.Error
+
+	if err := r.removeFilterTableRules(); err != nil {
+		merr = multierror.Append(merr, err)
+	}
+
+	if err := r.removeExternalChainsRules(); err != nil {
+		merr = multierror.Append(merr, fmt.Errorf("remove external chain rules: %w", err))
+	}
+
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+func (r *family) removeFilterTableRules() error {
+	if r.filterTable == nil {
+		return nil
+	}
+
+	ipt, err := iptables.NewWithProtocol(r.iptablesProto())
+	if err != nil {
+		log.Debugf("iptables not available, using nftables to remove filter rules: %v", err)
+		return r.removeAcceptRulesFromTable(r.filterTable)
+	}
+
+	if err := r.removeAcceptFilterRulesIptables(ipt); err != nil {
+		log.Debugf("iptables removal failed (table may be incompatible), falling back to nftables: %v", err)
+		return r.removeAcceptRulesFromTable(r.filterTable)
+	}
+	return nil
+}
+
+func (r *family) removeAcceptRulesFromTable(table *nftables.Table) error {
+	chains, err := r.conn.ListChainsOfTableFamily(table.Family)
+	if err != nil {
+		return fmt.Errorf("list chains: %v", err)
+	}
+
+	for _, chain := range chains {
+		if chain.Table.Name != table.Name {
+			continue
+		}
+
+		if chain.Name != chainNameForward && chain.Name != chainNameInput {
+			continue
+		}
+
+		if err := r.removeAcceptRulesFromChain(table, chain); err != nil {
+			return err
+		}
+	}
+
+	return r.conn.Flush()
+}
+
+func (r *family) removeAcceptRulesFromChain(table *nftables.Table, chain *nftables.Chain) error {
+	rules, err := r.conn.GetRules(table, chain)
+	if err != nil {
+		return fmt.Errorf("get rules from %s/%s: %v", table.Name, chain.Name, err)
+	}
+
+	for _, rule := range rules {
+		if bytes.Equal(rule.UserData, []byte(userDataAcceptForwardRuleIif)) ||
+			bytes.Equal(rule.UserData, []byte(userDataAcceptForwardRuleOif)) ||
+			bytes.Equal(rule.UserData, []byte(userDataAcceptInputRule)) {
+			if err := r.conn.DelRule(rule); err != nil {
+				return fmt.Errorf("delete rule from %s/%s: %v", table.Name, chain.Name, err)
+			}
+		}
+	}
+	return nil
+}
+
+// removeExternalChainsRules removes our accept rules from all external chains.
+// This is deterministic - it scans for chains at removal time rather than relying on saved state,
+// ensuring cleanup works even after a crash or if chains changed.
+func (r *family) removeExternalChainsRules() error {
+	chains := r.findExternalChains()
+	if len(chains) == 0 {
+		return nil
+	}
+
+	var merr *multierror.Error
+	for _, chain := range chains {
+		if err := r.removeAcceptRulesFromChain(chain.Table, chain); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("remove rules from external chain %s/%s: %w", chain.Table.Name, chain.Name, err))
+			continue
+		}
+		if err := r.conn.Flush(); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("flush external chain %s/%s: %w", chain.Table.Name, chain.Name, err))
+		}
+	}
+
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+// findExternalChains scans for chains from non-netbird tables that have FORWARD or INPUT hooks.
+// This is used both at startup (to know where to add rules) and at cleanup (to ensure deterministic removal).
+func (r *family) findExternalChains() []*nftables.Chain {
+	var chains []*nftables.Chain
+
+	families := []nftables.TableFamily{r.af.tableFamily, nftables.TableFamilyINet}
+
+	for _, family := range families {
+		allChains, err := r.conn.ListChainsOfTableFamily(family)
+		if err != nil {
+			log.Debugf("list chains for family %d: %v", family, err)
+			continue
+		}
+
+		for _, chain := range allChains {
+			if r.isExternalChain(chain) {
+				chains = append(chains, chain)
+			}
+		}
+	}
+
+	return chains
+}
+
+func (r *family) isExternalChain(chain *nftables.Chain) bool {
+	if r.workTable != nil && chain.Table.Name == r.workTable.Name {
+		return false
+	}
+
+	// Skip firewalld-owned chains. Firewalld creates its chains with the
+	// NFT_CHAIN_OWNER flag, so inserting rules into them returns EPERM.
+	// We delegate acceptance to firewalld by trusting the interface instead.
+	if chain.Table.Name == firewalldTableName {
+		return false
+	}
+
+	// Skip iptables/ip6tables-managed tables (adding nft-native rules breaks iptables-save compat)
+	if (chain.Table.Family == nftables.TableFamilyIPv4 || chain.Table.Family == nftables.TableFamilyIPv6) && isIptablesTable(chain.Table.Name) {
+		return false
+	}
+
+	if chain.Type != nftables.ChainTypeFilter {
+		return false
+	}
+
+	if chain.Hooknum == nil {
+		return false
+	}
+
+	return *chain.Hooknum == *nftables.ChainHookForward || *chain.Hooknum == *nftables.ChainHookInput
+}
+
+func isIptablesTable(name string) bool {
+	switch name {
+	case tableNameFilter, tableNat, tableMangle, tableRaw, tableSecurity:
+		return true
+	}
+	return false
+}
+
+func (r *family) removeAcceptFilterRulesIptables(ipt *iptables.IPTables) error {
+	var merr *multierror.Error
+
+	for _, rule := range r.getAcceptForwardRules() {
+		if err := ipt.DeleteIfExists("filter", chainNameForward, rule...); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("remove iptables forward rule: %v", err))
+		}
+	}
+
+	inputRule := r.getAcceptInputRule()
+	if err := ipt.DeleteIfExists("filter", chainNameInput, inputRule...); err != nil {
+		merr = multierror.Append(merr, fmt.Errorf("remove iptables input rule: %v", err))
+	}
+
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+// Flush rule/chain/set operations from the buffer
+//
+// Method also get all rules after flush and refreshes handle values in the rulesets
+func (r *family) Flush() error {
+	if err := r.flushWithBackoff(); err != nil {
+		return err
+	}
+
+	if err := r.refreshRuleHandles(r.chainInputRules, false); err != nil {
+		log.Errorf("failed to refresh rule handles ipv4 input chain: %v", err)
+	}
+	if err := r.refreshRuleHandles(r.chainPrerouting, true); err != nil {
+		log.Errorf("failed to refresh rule handles prerouting chain: %v", err)
+	}
+
+	return nil
+}
+
+// queuePreroutingRule builds the prerouting mangle rule that marks
+// redirected traffic and queues it on the connection without flushing,
+// so the caller can commit it in the same transaction as the rule it
+// pairs with. Returns nil when the prerouting chain is absent, in which
+// case nothing is queued.
+func (r *family) queuePreroutingRule(expressions []expr.Any, userData []byte) *nftables.Rule {
+	if r.chainPrerouting == nil {
+		log.Warn("prerouting chain is not created")
+		return nil
+	}
+
+	preroutingExprs := slices.Clone(expressions)
+
+	// interface
+	preroutingExprs = append([]expr.Any{
+		&expr.Meta{
+			Key:      expr.MetaKeyIIFNAME,
+			Register: 1,
+		},
+		&expr.Cmp{
+			Op:       expr.CmpOpEq,
+			Register: 1,
+			Data:     ifname(r.wgIface.Name()),
+		},
+	}, preroutingExprs...)
+
+	// local destination and mark
+	preroutingExprs = append(preroutingExprs,
+		&expr.Fib{
+			Register:       1,
+			ResultADDRTYPE: true,
+			FlagDADDR:      true,
+		},
+		&expr.Cmp{
+			Op:       expr.CmpOpEq,
+			Register: 1,
+			Data:     binaryutil.NativeEndian.PutUint32(unix.RTN_LOCAL),
+		},
+
+		&expr.Immediate{
+			Register: 1,
+			Data:     binaryutil.NativeEndian.PutUint32(nbnet.PreroutingFwmarkRedirected),
+		},
+		&expr.Meta{
+			Key:            expr.MetaKeyMARK,
+			Register:       1,
+			SourceRegister: true,
+		},
+	)
+
+	return r.conn.AddRule(&nftables.Rule{
+		Table:    r.workTable,
+		Chain:    r.chainPrerouting,
+		Exprs:    preroutingExprs,
+		UserData: userData,
+	})
+}
+
+func (r *family) createDefaultChains() (err error) {
+	// chainNameInputRules
+	chain := r.createChain(chainNameInputRules)
+	err = r.conn.Flush()
+	if err != nil {
+		log.Debugf("failed to create chain (%s): %s", chain.Name, err)
+		return fmt.Errorf(flushError, err)
+	}
+	r.chainInputRules = chain
+
+	// netbird-acl-input-filter
+	// type filter hook input priority filter; policy accept;
+	chain = r.createFilterChainWithHook(chainNameInputFilter, nftables.ChainHookInput)
+	r.addJumpRule(chain, r.chainInputRules.Name, expr.MetaKeyIIFNAME) // to netbird-acl-input-rules
+	r.addDropExpressions(chain, expr.MetaKeyIIFNAME)
+	err = r.conn.Flush()
+	if err != nil {
+		log.Debugf("failed to create chain (%s): %s", chain.Name, err)
+		return err
+	}
+
+	// netbird-acl-forward-filter
+	chainFwFilter := r.createFilterChainWithHook(chainNameForwardFilter, nftables.ChainHookForward)
+	r.addJumpRulesToRtForward(chainFwFilter) // to netbird-rt-fwd
+	r.addDropExpressions(chainFwFilter, expr.MetaKeyIIFNAME)
+
+	err = r.conn.Flush()
+	if err != nil {
+		log.Debugf("failed to create chain (%s): %s", chainNameForwardFilter, err)
+		return fmt.Errorf(flushError, err)
+	}
+
+	if err := r.allowRedirectedTraffic(chainFwFilter); err != nil {
+		log.Errorf("failed to allow redirected traffic: %s", err)
+	}
+
+	return nil
+}
+
+// Makes redirected traffic originally destined for the host itself (now subject to the forward filter)
+// go through the input filter as well. This will enable e.g. Docker services to keep working by accessing the
+// netbird peer IP.
+func (r *family) allowRedirectedTraffic(chainFwFilter *nftables.Chain) error {
+	r.chainPrerouting = r.chains[chainNameManglePrerouting]
+
+	r.addFwmarkToForward(chainFwFilter)
+
+	if err := r.conn.Flush(); err != nil {
+		return fmt.Errorf(flushError, err)
+	}
+
+	return nil
+}
+
+func (r *family) addFwmarkToForward(chainFwFilter *nftables.Chain) {
+	r.conn.InsertRule(&nftables.Rule{
+		Table: r.workTable,
+		Chain: chainFwFilter,
+		Exprs: []expr.Any{
+			&expr.Meta{
+				Key:      expr.MetaKeyMARK,
+				Register: 1,
+			},
+			&expr.Cmp{
+				Op:       expr.CmpOpEq,
+				Register: 1,
+				Data:     binaryutil.NativeEndian.PutUint32(nbnet.PreroutingFwmarkRedirected),
+			},
+			&expr.Verdict{
+				Kind: expr.VerdictAccept,
+			},
+		},
+	})
+}
+
+func (r *family) addJumpRulesToRtForward(chainFwFilter *nftables.Chain) {
+	expressions := []expr.Any{
+		&expr.Meta{Key: expr.MetaKeyIIFNAME, Register: 1},
+		&expr.Cmp{
+			Op:       expr.CmpOpEq,
+			Register: 1,
+			Data:     ifname(r.wgIface.Name()),
+		},
+		&expr.Verdict{
+			Kind:  expr.VerdictJump,
+			Chain: r.routingFwChainName,
+		},
+	}
+
+	_ = r.conn.AddRule(&nftables.Rule{
+		Table: r.workTable,
+		Chain: chainFwFilter,
+		Exprs: expressions,
+	})
+}
+
+func (r *family) createChain(name string) *nftables.Chain {
+	chain := &nftables.Chain{
+		Name:  name,
+		Table: r.workTable,
+	}
+
+	chain = r.conn.AddChain(chain)
+
+	insertReturnTrafficRule(r.conn, r.workTable, chain)
+
+	return chain
+}
+
+func (r *family) createFilterChainWithHook(name string, hookNum *nftables.ChainHook) *nftables.Chain {
+	polAccept := nftables.ChainPolicyAccept
+	chain := &nftables.Chain{
+		Name:     name,
+		Table:    r.workTable,
+		Hooknum:  hookNum,
+		Priority: nftables.ChainPriorityFilter,
+		Type:     nftables.ChainTypeFilter,
+		Policy:   &polAccept,
+	}
+
+	return r.conn.AddChain(chain)
+}
+
+func (r *family) addDropExpressions(chain *nftables.Chain, ifaceKey expr.MetaKey) []expr.Any {
+	expressions := []expr.Any{
+		&expr.Meta{Key: ifaceKey, Register: 1},
+		&expr.Cmp{
+			Op:       expr.CmpOpEq,
+			Register: 1,
+			Data:     ifname(r.wgIface.Name()),
+		},
+		&expr.Verdict{Kind: expr.VerdictDrop},
+	}
+	_ = r.conn.AddRule(&nftables.Rule{
+		Table: r.workTable,
+		Chain: chain,
+		Exprs: expressions,
+	})
+	return nil
+}
+
+func (r *family) addJumpRule(chain *nftables.Chain, to string, ifaceKey expr.MetaKey) {
+	expressions := []expr.Any{
+		&expr.Meta{Key: ifaceKey, Register: 1},
+		&expr.Cmp{
+			Op:       expr.CmpOpEq,
+			Register: 1,
+			Data:     ifname(r.wgIface.Name()),
+		},
+		&expr.Verdict{
+			Kind:  expr.VerdictJump,
+			Chain: to,
+		},
+	}
+
+	_ = r.conn.AddRule(&nftables.Rule{
+		Table: chain.Table,
+		Chain: chain,
+		Exprs: expressions,
+	})
+}
+
+func (r *family) flushWithBackoff() (err error) {
+	backoff := 4
+	backoffTime := 1000 * time.Millisecond
+	for i := 0; ; i++ {
+		err = r.conn.Flush()
+		if err != nil {
+			log.Debugf("failed to flush nftables: %v", err)
+			if !strings.Contains(err.Error(), "busy") {
+				return
+			}
+			log.Error("failed to flush nftables, retrying...")
+			if i == backoff-1 {
+				return err
+			}
+			time.Sleep(backoffTime)
+			backoffTime *= 2
+			continue
+		}
+		break
+	}
+	return
+}
+
+func (r *family) refreshRuleHandles(chain *nftables.Chain, mangle bool) error {
+	if r.workTable == nil || chain == nil {
+		return nil
+	}
+
+	list, err := r.conn.GetRules(r.workTable, chain)
+	if err != nil {
+		return err
+	}
+
+	for _, rule := range list {
+		if len(rule.UserData) == 0 {
+			continue
+		}
+		pr, ok := r.filters[firewall.RuleID(rule.UserData)]
+		if !ok {
+			continue
+		}
+		if mangle {
+			if pr.mangleRule != nil {
+				*pr.mangleRule = *rule
+			}
+		} else {
+			*pr.nftRule = *rule
+		}
+	}
+
+	return nil
+}

client/firewall/nftables/dnat_linux.go

@@ -0,0 +1,565 @@
+//go:build !android
+
+package nftables
+
+import (
+	"fmt"
+	"net/netip"
+
+	"github.com/google/nftables"
+	"github.com/google/nftables/binaryutil"
+	"github.com/google/nftables/expr"
+	"github.com/google/nftables/xt"
+	"github.com/hashicorp/go-multierror"
+	log "github.com/sirupsen/logrus"
+
+	nberrors "github.com/netbirdio/netbird/client/errors"
+	firewall "github.com/netbirdio/netbird/client/firewall/manager"
+)
+
+func (r *family) AddDNATRule(rule firewall.ForwardRule) (firewall.Rule, error) {
+	ruleID := rule.ID()
+	if _, exists := r.rules[ruleID+dnatSuffix]; exists {
+		return rule, nil
+	}
+
+	protoNum, err := r.af.protoNum(rule.Protocol)
+	if err != nil {
+		return nil, fmt.Errorf("convert protocol to number: %w", err)
+	}
+
+	// Request forwarding once the rule is about to be installed, releasing
+	// it if a later step fails so the refcount tracks the real rules.
+	if err := r.ipFwdState.RequestForwarding(); err != nil {
+		return nil, err
+	}
+
+	if err := r.addDnatRedirect(rule, protoNum, ruleID); err != nil {
+		r.releaseForwarding()
+		return nil, err
+	}
+
+	if err := r.addDnatMasq(rule, protoNum, ruleID); err != nil {
+		r.releaseForwarding()
+		delete(r.rules, ruleID+dnatSuffix)
+		return nil, err
+	}
+
+	// Unlike iptables, there's no point in adding "out" rules in the forward chain here as our policy is ACCEPT.
+	// To overcome DROP policies in other chains, we'd have to add rules to the chains there.
+	// We also cannot just add "oif <iface> accept" there and filter in our own table as we don't know what is supposed to be allowed.
+	// TODO: find chains with drop policies and add rules there
+
+	if err := r.conn.Flush(); err != nil {
+		r.releaseForwarding()
+		return nil, fmt.Errorf("flush rules: %w", err)
+	}
+
+	return &rule, nil
+}
+
+func (r *family) addDnatRedirect(rule firewall.ForwardRule, protoNum uint8, ruleID firewall.RuleID) error {
+	dnatExprs := []expr.Any{
+		&expr.Meta{Key: expr.MetaKeyIIFNAME, Register: 1},
+		&expr.Cmp{
+			Op:       expr.CmpOpNeq,
+			Register: 1,
+			Data:     ifname(r.wgIface.Name()),
+		},
+		&expr.Meta{Key: expr.MetaKeyL4PROTO, Register: 1},
+		&expr.Cmp{
+			Op:       expr.CmpOpEq,
+			Register: 1,
+			Data:     []byte{protoNum},
+		},
+		&expr.Payload{
+			DestRegister: 1,
+			Base:         expr.PayloadBaseTransportHeader,
+			Offset:       2,
+			Len:          2,
+		},
+	}
+	portExprs, err := r.applyPort(&rule.DestinationPort, false)
+	if err != nil {
+		return fmt.Errorf("apply destination port: %w", err)
+	}
+	dnatExprs = append(dnatExprs, portExprs...)
+
+	// shifted translated port is not supported in nftables, so we hand this over to xtables
+	if rule.TranslatedPort.IsRange && len(rule.TranslatedPort.Values) == 2 {
+		if rule.TranslatedPort.Values[0] != rule.DestinationPort.Values[0] ||
+			rule.TranslatedPort.Values[1] != rule.DestinationPort.Values[1] {
+			return r.addXTablesRedirect(dnatExprs, ruleID, rule)
+		}
+	}
+
+	additionalExprs, regProtoMin, regProtoMax, err := r.handleTranslatedPort(rule)
+	if err != nil {
+		return err
+	}
+	dnatExprs = append(dnatExprs, additionalExprs...)
+
+	dnatExprs = append(dnatExprs,
+		&expr.NAT{
+			Type:        expr.NATTypeDestNAT,
+			Family:      uint32(r.af.tableFamily),
+			RegAddrMin:  1,
+			RegProtoMin: regProtoMin,
+			RegProtoMax: regProtoMax,
+		},
+	)
+
+	dnatRule := &nftables.Rule{
+		Table:    r.workTable,
+		Chain:    r.chains[chainNameRoutingRdr],
+		Exprs:    dnatExprs,
+		UserData: []byte(ruleID + dnatSuffix),
+	}
+	r.conn.AddRule(dnatRule)
+	r.rules[ruleID+dnatSuffix] = dnatRule
+
+	return nil
+}
+
+func (r *family) handleTranslatedPort(rule firewall.ForwardRule) ([]expr.Any, uint32, uint32, error) {
+	switch {
+	case rule.TranslatedPort.IsRange && len(rule.TranslatedPort.Values) == 2:
+		return r.handlePortRange(rule)
+	case len(rule.TranslatedPort.Values) == 0:
+		return r.handleAddressOnly(rule)
+	case len(rule.TranslatedPort.Values) == 1:
+		return r.handleSinglePort(rule)
+	default:
+		return nil, 0, 0, fmt.Errorf("invalid translated port: %v", rule.TranslatedPort)
+	}
+}
+
+func (r *family) handlePortRange(rule firewall.ForwardRule) ([]expr.Any, uint32, uint32, error) {
+	exprs := []expr.Any{
+		&expr.Immediate{
+			Register: 1,
+			Data:     rule.TranslatedAddress.AsSlice(),
+		},
+		&expr.Immediate{
+			Register: 2,
+			Data:     binaryutil.BigEndian.PutUint16(rule.TranslatedPort.Values[0]),
+		},
+		&expr.Immediate{
+			Register: 3,
+			Data:     binaryutil.BigEndian.PutUint16(rule.TranslatedPort.Values[1]),
+		},
+	}
+	return exprs, 2, 3, nil
+}
+
+func (r *family) handleAddressOnly(rule firewall.ForwardRule) ([]expr.Any, uint32, uint32, error) {
+	exprs := []expr.Any{
+		&expr.Immediate{
+			Register: 1,
+			Data:     rule.TranslatedAddress.AsSlice(),
+		},
+	}
+	return exprs, 0, 0, nil
+}
+
+func (r *family) handleSinglePort(rule firewall.ForwardRule) ([]expr.Any, uint32, uint32, error) {
+	exprs := []expr.Any{
+		&expr.Immediate{
+			Register: 1,
+			Data:     rule.TranslatedAddress.AsSlice(),
+		},
+		&expr.Immediate{
+			Register: 2,
+			Data:     binaryutil.BigEndian.PutUint16(rule.TranslatedPort.Values[0]),
+		},
+	}
+	return exprs, 2, 0, nil
+}
+
+func (r *family) addXTablesRedirect(dnatExprs []expr.Any, ruleID firewall.RuleID, rule firewall.ForwardRule) error {
+	dnatExprs = append(dnatExprs,
+		&expr.Counter{},
+		&expr.Target{
+			Name: "DNAT",
+			Rev:  2,
+			Info: &xt.NatRange2{
+				NatRange: xt.NatRange{
+					Flags:   uint(xt.NatRangeMapIPs | xt.NatRangeProtoSpecified | xt.NatRangeProtoOffset),
+					MinIP:   rule.TranslatedAddress.AsSlice(),
+					MaxIP:   rule.TranslatedAddress.AsSlice(),
+					MinPort: rule.TranslatedPort.Values[0],
+					MaxPort: rule.TranslatedPort.Values[1],
+				},
+				BasePort: rule.DestinationPort.Values[0],
+			},
+		},
+	)
+
+	natTable := &nftables.Table{
+		Name:   tableNat,
+		Family: r.af.tableFamily,
+	}
+	dnatRule := &nftables.Rule{
+		Table: natTable,
+		Chain: &nftables.Chain{
+			Name:     chainNameNatPrerouting,
+			Table:    natTable,
+			Type:     nftables.ChainTypeNAT,
+			Hooknum:  nftables.ChainHookPrerouting,
+			Priority: nftables.ChainPriorityNATDest,
+		},
+		Exprs:    dnatExprs,
+		UserData: []byte(ruleID + dnatSuffix),
+	}
+	r.conn.AddRule(dnatRule)
+	r.rules[ruleID+dnatSuffix] = dnatRule
+
+	return nil
+}
+
+func (r *family) addDnatMasq(rule firewall.ForwardRule, protoNum uint8, ruleID firewall.RuleID) error {
+	portExprs, err := r.applyPort(&rule.TranslatedPort, false)
+	if err != nil {
+		return fmt.Errorf("apply translated port: %w", err)
+	}
+
+	masqExprs := []expr.Any{
+		&expr.Meta{Key: expr.MetaKeyOIFNAME, Register: 1},
+		&expr.Cmp{
+			Op:       expr.CmpOpEq,
+			Register: 1,
+			Data:     ifname(r.wgIface.Name()),
+		},
+		&expr.Meta{Key: expr.MetaKeyL4PROTO, Register: 1},
+		&expr.Cmp{
+			Op:       expr.CmpOpEq,
+			Register: 1,
+			Data:     []byte{protoNum},
+		},
+		&expr.Payload{
+			DestRegister: 1,
+			Base:         expr.PayloadBaseNetworkHeader,
+			Offset:       r.af.dstAddrOffset,
+			Len:          r.af.addrLen,
+		},
+		&expr.Cmp{
+			Op:       expr.CmpOpEq,
+			Register: 1,
+			Data:     rule.TranslatedAddress.AsSlice(),
+		},
+	}
+
+	masqExprs = append(masqExprs, portExprs...)
+	masqExprs = append(masqExprs, &expr.Masq{})
+
+	masqRule := &nftables.Rule{
+		Table:    r.workTable,
+		Chain:    r.chains[chainNameRoutingNat],
+		Exprs:    masqExprs,
+		UserData: []byte(ruleID + snatSuffix),
+	}
+	r.conn.AddRule(masqRule)
+	r.rules[ruleID+snatSuffix] = masqRule
+
+	return nil
+}
+
+func (r *family) DeleteDNATRule(rule firewall.Rule) error {
+	ruleID := rule.ID()
+
+	if err := r.refreshRulesMap(); err != nil {
+		return fmt.Errorf(refreshRulesMapError, err)
+	}
+
+	var merr *multierror.Error
+	var needsFlush bool
+	var found bool
+
+	if dnatRule, exists := r.rules[ruleID+dnatSuffix]; exists {
+		found = true
+		if dnatRule.Handle == 0 {
+			log.Warnf("dnat rule %s has no handle, removing stale entry", ruleID+dnatSuffix)
+			delete(r.rules, ruleID+dnatSuffix)
+		} else if err := r.conn.DelRule(dnatRule); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("delete dnat rule: %w", err))
+		} else {
+			needsFlush = true
+		}
+	}
+
+	if masqRule, exists := r.rules[ruleID+snatSuffix]; exists {
+		found = true
+		if masqRule.Handle == 0 {
+			log.Warnf("snat rule %s has no handle, removing stale entry", ruleID+snatSuffix)
+			delete(r.rules, ruleID+snatSuffix)
+		} else if err := r.conn.DelRule(masqRule); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("delete snat rule: %w", err))
+		} else {
+			needsFlush = true
+		}
+	}
+
+	if needsFlush {
+		if err := r.conn.Flush(); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf(flushError, err))
+		}
+	}
+
+	if merr != nil {
+		return nberrors.FormatErrorOrNil(merr)
+	}
+
+	delete(r.rules, ruleID+dnatSuffix)
+	delete(r.rules, ruleID+snatSuffix)
+
+	// Release once, only if the rule was present and removed.
+	if found {
+		r.releaseForwarding()
+	}
+
+	return nil
+}
+
+// releaseForwarding drops one IP forwarding reference, logging any error.
+func (r *family) releaseForwarding() {
+	if err := r.ipFwdState.ReleaseForwarding(); err != nil {
+		log.Errorf("release IP forwarding: %v", err)
+	}
+}
+
+func (r *family) AddInboundDNAT(localAddr netip.Addr, protocol firewall.Protocol, originalPort, translatedPort uint16) error {
+	ruleID := firewall.RuleID(fmt.Sprintf("inbound-dnat-%s-%s-%d-%d", localAddr.String(), protocol, originalPort, translatedPort))
+
+	if _, exists := r.rules[ruleID]; exists {
+		return nil
+	}
+
+	protoNum, err := r.af.protoNum(protocol)
+	if err != nil {
+		return fmt.Errorf("convert protocol to number: %w", err)
+	}
+
+	exprs := []expr.Any{
+		&expr.Meta{Key: expr.MetaKeyIIFNAME, Register: 1},
+		&expr.Cmp{
+			Op:       expr.CmpOpEq,
+			Register: 1,
+			Data:     ifname(r.wgIface.Name()),
+		},
+		&expr.Meta{Key: expr.MetaKeyL4PROTO, Register: 2},
+		&expr.Cmp{
+			Op:       expr.CmpOpEq,
+			Register: 2,
+			Data:     []byte{protoNum},
+		},
+		&expr.Payload{
+			DestRegister: 3,
+			Base:         expr.PayloadBaseTransportHeader,
+			Offset:       2,
+			Len:          2,
+		},
+		&expr.Cmp{
+			Op:       expr.CmpOpEq,
+			Register: 3,
+			Data:     binaryutil.BigEndian.PutUint16(originalPort),
+		},
+	}
+
+	bits := 32
+	if localAddr.Is6() {
+		bits = 128
+	}
+	exprs = append(exprs, prefixMatchExprs(r.af, netip.PrefixFrom(localAddr, bits), false)...)
+
+	exprs = append(exprs,
+		&expr.Immediate{
+			Register: 1,
+			Data:     localAddr.AsSlice(),
+		},
+		&expr.Immediate{
+			Register: 2,
+			Data:     binaryutil.BigEndian.PutUint16(translatedPort),
+		},
+		&expr.NAT{
+			Type:        expr.NATTypeDestNAT,
+			Family:      uint32(r.af.tableFamily),
+			RegAddrMin:  1,
+			RegProtoMin: 2,
+			RegProtoMax: 0,
+		},
+	)
+
+	dnatRule := &nftables.Rule{
+		Table:    r.workTable,
+		Chain:    r.chains[chainNameRoutingRdr],
+		Exprs:    exprs,
+		UserData: []byte(ruleID),
+	}
+	r.conn.AddRule(dnatRule)
+
+	if err := r.conn.Flush(); err != nil {
+		return fmt.Errorf("add inbound DNAT rule: %w", err)
+	}
+
+	r.rules[ruleID] = dnatRule
+
+	return nil
+}
+
+// RemoveInboundDNAT removes an inbound DNAT rule.
+func (r *family) RemoveInboundDNAT(localAddr netip.Addr, protocol firewall.Protocol, originalPort, translatedPort uint16) error {
+	if err := r.refreshRulesMap(); err != nil {
+		return fmt.Errorf(refreshRulesMapError, err)
+	}
+
+	ruleID := firewall.RuleID(fmt.Sprintf("inbound-dnat-%s-%s-%d-%d", localAddr.String(), protocol, originalPort, translatedPort))
+
+	rule, exists := r.rules[ruleID]
+	if !exists {
+		return nil
+	}
+
+	if rule.Handle == 0 {
+		log.Warnf("inbound DNAT rule %s has no handle, removing stale entry", ruleID)
+		delete(r.rules, ruleID)
+		return nil
+	}
+
+	if err := r.conn.DelRule(rule); err != nil {
+		return fmt.Errorf("delete inbound DNAT rule %s: %w", ruleID, err)
+	}
+	if err := r.conn.Flush(); err != nil {
+		return fmt.Errorf("flush delete inbound DNAT rule: %w", err)
+	}
+	delete(r.rules, ruleID)
+
+	return nil
+}
+
+// ensureNATOutputChain lazily creates the OUTPUT NAT chain on first use.
+func (r *family) ensureNATOutputChain() error {
+	if _, exists := r.chains[chainNameNATOutput]; exists {
+		return nil
+	}
+
+	r.chains[chainNameNATOutput] = r.conn.AddChain(&nftables.Chain{
+		Name:     chainNameNATOutput,
+		Table:    r.workTable,
+		Hooknum:  nftables.ChainHookOutput,
+		Priority: nftables.ChainPriorityNATDest,
+		Type:     nftables.ChainTypeNAT,
+	})
+
+	if err := r.conn.Flush(); err != nil {
+		delete(r.chains, chainNameNATOutput)
+		return fmt.Errorf("create NAT output chain: %w", err)
+	}
+	return nil
+}
+
+// AddOutputDNAT adds an OUTPUT chain DNAT rule for locally-generated traffic.
+func (r *family) AddOutputDNAT(localAddr netip.Addr, protocol firewall.Protocol, originalPort, translatedPort uint16) error {
+	ruleID := firewall.RuleID(fmt.Sprintf("output-dnat-%s-%s-%d-%d", localAddr.String(), protocol, originalPort, translatedPort))
+
+	if _, exists := r.rules[ruleID]; exists {
+		return nil
+	}
+
+	if err := r.ensureNATOutputChain(); err != nil {
+		return err
+	}
+
+	protoNum, err := r.af.protoNum(protocol)
+	if err != nil {
+		return fmt.Errorf("convert protocol to number: %w", err)
+	}
+
+	exprs := []expr.Any{
+		&expr.Meta{Key: expr.MetaKeyL4PROTO, Register: 1},
+		&expr.Cmp{
+			Op:       expr.CmpOpEq,
+			Register: 1,
+			Data:     []byte{protoNum},
+		},
+		&expr.Payload{
+			DestRegister: 2,
+			Base:         expr.PayloadBaseTransportHeader,
+			Offset:       2,
+			Len:          2,
+		},
+		&expr.Cmp{
+			Op:       expr.CmpOpEq,
+			Register: 2,
+			Data:     binaryutil.BigEndian.PutUint16(originalPort),
+		},
+	}
+
+	bits := 32
+	if localAddr.Is6() {
+		bits = 128
+	}
+	exprs = append(exprs, prefixMatchExprs(r.af, netip.PrefixFrom(localAddr, bits), false)...)
+
+	exprs = append(exprs,
+		&expr.Immediate{
+			Register: 1,
+			Data:     localAddr.AsSlice(),
+		},
+		&expr.Immediate{
+			Register: 2,
+			Data:     binaryutil.BigEndian.PutUint16(translatedPort),
+		},
+		&expr.NAT{
+			Type:        expr.NATTypeDestNAT,
+			Family:      uint32(r.af.tableFamily),
+			RegAddrMin:  1,
+			RegProtoMin: 2,
+		},
+	)
+
+	dnatRule := &nftables.Rule{
+		Table:    r.workTable,
+		Chain:    r.chains[chainNameNATOutput],
+		Exprs:    exprs,
+		UserData: []byte(ruleID),
+	}
+	r.conn.AddRule(dnatRule)
+
+	if err := r.conn.Flush(); err != nil {
+		return fmt.Errorf("add output DNAT rule: %w", err)
+	}
+
+	r.rules[ruleID] = dnatRule
+
+	return nil
+}
+
+// RemoveOutputDNAT removes an OUTPUT chain DNAT rule.
+func (r *family) RemoveOutputDNAT(localAddr netip.Addr, protocol firewall.Protocol, originalPort, translatedPort uint16) error {
+	if err := r.refreshRulesMap(); err != nil {
+		return fmt.Errorf(refreshRulesMapError, err)
+	}
+
+	ruleID := firewall.RuleID(fmt.Sprintf("output-dnat-%s-%s-%d-%d", localAddr.String(), protocol, originalPort, translatedPort))
+
+	rule, exists := r.rules[ruleID]
+	if !exists {
+		return nil
+	}
+
+	if rule.Handle == 0 {
+		log.Warnf("output DNAT rule %s has no handle, removing stale entry", ruleID)
+		delete(r.rules, ruleID)
+		return nil
+	}
+
+	if err := r.conn.DelRule(rule); err != nil {
+		return fmt.Errorf("delete output DNAT rule %s: %w", ruleID, err)
+	}
+	if err := r.conn.Flush(); err != nil {
+		return fmt.Errorf("flush delete output DNAT rule: %w", err)
+	}
+	delete(r.rules, ruleID)
+
+	return nil
+}

client/firewall/nftables/family_linux.go

@@ -0,0 +1,249 @@
+//go:build !android
+
+package nftables
+
+import (
+	"fmt"
+	"net/netip"
+
+	"github.com/coreos/go-iptables/iptables"
+	"github.com/google/nftables"
+	"github.com/hashicorp/go-multierror"
+	log "github.com/sirupsen/logrus"
+
+	nberrors "github.com/netbirdio/netbird/client/errors"
+	"github.com/netbirdio/netbird/client/firewall/firewalld"
+	firewall "github.com/netbirdio/netbird/client/firewall/manager"
+	"github.com/netbirdio/netbird/client/internal/routemanager/ipfwdstate"
+	"github.com/netbirdio/netbird/client/internal/routemanager/refcounter"
+)
+
+const (
+	tableNat      = "nat"
+	tableMangle   = "mangle"
+	tableRaw      = "raw"
+	tableSecurity = "security"
+
+	chainNameNatPrerouting = "PREROUTING"
+	chainNameRoutingFw     = "netbird-rt-fwd"
+	chainNameRoutingNat    = "netbird-rt-postrouting"
+	chainNameRoutingRdr    = "netbird-rt-redirect"
+	chainNameNATOutput     = "netbird-nat-output"
+	chainNameForward       = "FORWARD"
+	chainNameMangleForward = "netbird-mangle-forward"
+
+	// Peer ACL chain names.
+	chainNameInputRules        = "netbird-acl-input-rules"
+	chainNameInputFilter       = "netbird-acl-input-filter"
+	chainNameForwardFilter     = "netbird-acl-forward-filter"
+	chainNameManglePrerouting  = "netbird-mangle-prerouting"
+	chainNameManglePostrouting = "netbird-mangle-postrouting"
+
+	flushError = "flush: %w"
+
+	firewalldTableName = "firewalld"
+
+	userDataAcceptForwardRuleIif = "frwacceptiif"
+	userDataAcceptForwardRuleOif = "frwacceptoif"
+	userDataAcceptInputRule      = "inputaccept"
+
+	dnatSuffix firewall.RuleID = "_dnat"
+	snatSuffix firewall.RuleID = "_snat"
+
+	// ipv4TCPHeaderSize is the minimum IPv4 (20) + TCP (20) header size for MSS calculation.
+	ipv4TCPHeaderSize = 40
+	// ipv6TCPHeaderSize is the minimum IPv6 (40) + TCP (20) header size for MSS calculation.
+	ipv6TCPHeaderSize = 60
+
+	// maxPrefixesSet 1638 prefixes start to fail, taking some margin
+	maxPrefixesSet       = 1500
+	refreshRulesMapError = "refresh rules map: %w"
+)
+
+var (
+	errFilterTableNotFound = fmt.Errorf("'filter' table not found")
+)
+
+type setInput struct {
+	set      firewall.Set
+	prefixes []netip.Prefix
+}
+
+// family holds the per-address-family nftables state. One instance
+// handles route ACLs, peer ACLs, NAT, DNAT, and MSS clamping for a
+// single family; the top-level Manager owns one for v4 and another
+// for v6. The name predates the peer-ACL absorption; it's effectively
+// the per-family backend now.
+type family struct {
+	conn        *nftables.Conn
+	workTable   *nftables.Table
+	filterTable *nftables.Table
+	chains      map[string]*nftables.Chain
+
+	// filters holds peer + route filter rules keyed by content hash.
+	// AddFilterRule writes here; DeleteFilterRule looks up by id.
+	filters map[firewall.RuleID]*Rule
+
+	// rules holds NAT, DNAT, and external accept rules (auxiliary
+	// plumbing that isn't a filter rule).
+	rules map[firewall.RuleID]*nftables.Rule
+
+	// Peer ACL chain handles.
+	chainInputRules    *nftables.Chain
+	chainPrerouting    *nftables.Chain
+	routingFwChainName string
+
+	ipsetCounter *refcounter.Counter[string, setInput, *nftables.Set]
+
+	af               addrFamily
+	wgIface          iFaceMapper
+	ipFwdState       *ipfwdstate.IPForwardingState
+	legacyManagement bool
+	mtu              uint16
+}
+
+func newFamily(workTable *nftables.Table, wgIface iFaceMapper, mtu uint16) *family {
+	r := &family{
+		conn:               &nftables.Conn{},
+		workTable:          workTable,
+		chains:             make(map[string]*nftables.Chain),
+		filters:            make(map[firewall.RuleID]*Rule),
+		rules:              make(map[firewall.RuleID]*nftables.Rule),
+		routingFwChainName: chainNameRoutingFw,
+		af:                 familyForAddr(workTable.Family == nftables.TableFamilyIPv4),
+		wgIface:            wgIface,
+		ipFwdState:         ipfwdstate.NewIPForwardingState(),
+		mtu:                mtu,
+	}
+
+	r.ipsetCounter = refcounter.New(
+		r.createIpSet,
+		r.deleteIpSet,
+	)
+
+	var err error
+	r.filterTable, err = r.loadFilterTable()
+	if err != nil {
+		log.Debugf("ip filter table not found: %v", err)
+	}
+
+	return r
+}
+
+func (r *family) init(workTable *nftables.Table) error {
+	r.workTable = workTable
+
+	if err := r.removeAcceptFilterRules(); err != nil {
+		log.Errorf("failed to clean up rules from filter table: %s", err)
+	}
+
+	if err := r.createContainers(); err != nil {
+		return fmt.Errorf("create containers: %w", err)
+	}
+
+	if err := r.setupDataPlaneMark(); err != nil {
+		log.Errorf("failed to set up data plane mark: %v", err)
+	}
+
+	if err := r.createDefaultChains(); err != nil {
+		return fmt.Errorf("create default acl chains: %w", err)
+	}
+
+	return nil
+}
+
+// Reset cleans existing nftables filter table rules from the system
+func (r *family) Reset() error {
+	// clear without deleting the ipsets, the nf table will be deleted by the caller
+	r.ipsetCounter.Clear()
+
+	var merr *multierror.Error
+
+	if err := r.removeAcceptFilterRules(); err != nil {
+		merr = multierror.Append(merr, fmt.Errorf("remove accept filter rules: %w", err))
+	}
+
+	if err := firewalld.UntrustInterface(r.wgIface.Name()); err != nil {
+		merr = multierror.Append(merr, err)
+	}
+
+	if err := r.removeNatPreroutingRules(); err != nil {
+		merr = multierror.Append(merr, fmt.Errorf("remove filter prerouting rules: %w", err))
+	}
+
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+func (r *family) loadFilterTable() (*nftables.Table, error) {
+	tables, err := r.conn.ListTablesOfFamily(r.af.tableFamily)
+	if err != nil {
+		return nil, fmt.Errorf("list tables: %w", err)
+	}
+
+	for _, table := range tables {
+		if table.Name == "filter" {
+			return table, nil
+		}
+	}
+
+	return nil, errFilterTableNotFound
+}
+
+func hookName(hook *nftables.ChainHook) string {
+	if hook == nil {
+		return "unknown"
+	}
+	switch *hook {
+	case *nftables.ChainHookForward:
+		return chainNameForward
+	case *nftables.ChainHookInput:
+		return chainNameInput
+	default:
+		return fmt.Sprintf("hook(%d)", *hook)
+	}
+}
+
+func familyName(family nftables.TableFamily) string {
+	switch family {
+	case nftables.TableFamilyIPv4:
+		return "ip"
+	case nftables.TableFamilyIPv6:
+		return "ip6"
+	case nftables.TableFamilyINet:
+		return "inet"
+	default:
+		return fmt.Sprintf("family(%d)", family)
+	}
+}
+
+func (r *family) iptablesProto() iptables.Protocol {
+	if r.af.tableFamily == nftables.TableFamilyIPv6 {
+		return iptables.ProtocolIPv6
+	}
+	return iptables.ProtocolIPv4
+}
+
+func (r *family) refreshRulesMap() error {
+	var merr *multierror.Error
+	newRules := make(map[firewall.RuleID]*nftables.Rule)
+	for _, chain := range r.chains {
+		rules, err := r.conn.GetRules(chain.Table, chain)
+		if err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("list rules for chain %s: %w", chain.Name, err))
+			// preserve existing entries for this chain since we can't verify their state
+			for k, v := range r.rules {
+				if v.Chain != nil && v.Chain.Name == chain.Name {
+					newRules[k] = v
+				}
+			}
+			continue
+		}
+		for _, rule := range rules {
+			if len(rule.UserData) > 0 {
+				newRules[firewall.RuleID(rule.UserData)] = rule
+			}
+		}
+	}
+	r.rules = newRules
+	return nberrors.FormatErrorOrNil(merr)
+}

client/firewall/nftables/filter_linux.go

@@ -0,0 +1,512 @@
+//go:build !android
+
+package nftables
+
+import (
+	"fmt"
+	"net"
+	"net/netip"
+	"slices"
+
+	"github.com/google/nftables"
+	"github.com/google/nftables/binaryutil"
+	"github.com/google/nftables/expr"
+	"github.com/hashicorp/go-multierror"
+	log "github.com/sirupsen/logrus"
+
+	nberrors "github.com/netbirdio/netbird/client/errors"
+	firewall "github.com/netbirdio/netbird/client/firewall/manager"
+	nbid "github.com/netbirdio/netbird/client/internal/acl/id"
+)
+
+// AddFilterRule installs one nftables packet-filter rule. With
+// destination empty the rule goes to the peer ACL input chain plus a
+// paired prerouting mangle rule for the redirect mark. With
+// destination set (prefix or named set) it goes to the route ACL
+// forward chain. Multi-source rules collapse to one nftables rule
+// backed by the shared refcounted hash:net set.
+func (r *family) AddFilterRule(
+	id []byte,
+	sources []netip.Prefix,
+	destination firewall.Network,
+	proto firewall.Protocol,
+	sPort *firewall.Port,
+	dPort *firewall.Port,
+	action firewall.Action,
+) (firewall.Rule, error) {
+	isRoute := !destination.IsZero()
+
+	ruleID := nbid.GenerateRuleID(sources, destination, proto, sPort, dPort, action)
+	if existing, ok := r.filters[ruleID]; ok {
+		return existing, nil
+	}
+
+	srcExprs, err := r.applyNetwork(sourceNetwork(sources), sources, true)
+	if err != nil {
+		return nil, fmt.Errorf("apply source: %w", err)
+	}
+
+	var exprs []expr.Any
+	if isRoute {
+		exprs, err = r.buildRouteFilterExprs(srcExprs, destination, proto, sPort, dPort)
+	} else {
+		exprs, err = r.buildPeerFilterExprs(srcExprs, proto, sPort, dPort)
+	}
+	if err != nil {
+		r.dropNetworkMatch(srcExprs)
+		return nil, err
+	}
+
+	mainExprs := slices.Clone(exprs)
+	verdict := expr.VerdictAccept
+	if action == firewall.ActionDrop {
+		verdict = expr.VerdictDrop
+	}
+	mainExprs = append(mainExprs, &expr.Verdict{Kind: verdict})
+
+	chain := r.chainInputRules
+	if isRoute {
+		chain = r.chains[chainNameRoutingFw]
+	}
+
+	userData := []byte(ruleID)
+
+	// Build the paired prerouting mangle rule before flushing so both
+	// rules commit in one transaction. An anonymous port set binds to
+	// exactly one rule, so the mangle rule needs its own expression list
+	// with fresh sets, not a clone of the main rule's. Guard on the
+	// prerouting chain first: building the expressions queues the port
+	// set, so skipping the build when there is no chain to bind it to
+	// keeps an unbound set out of the connection batch.
+	var mangleRule *nftables.Rule
+	if !isRoute && r.chainPrerouting != nil {
+		mangleExprs, err := r.buildPeerFilterExprs(srcExprs, proto, sPort, dPort)
+		if err != nil {
+			r.dropNetworkMatch(exprs)
+			return nil, fmt.Errorf("build mangle rule: %w", err)
+		}
+		mangleRule = r.queuePreroutingRule(mangleExprs, userData)
+	}
+
+	nftRule := &nftables.Rule{
+		Table:    r.workTable,
+		Chain:    chain,
+		Exprs:    mainExprs,
+		UserData: userData,
+	}
+	if action == firewall.ActionDrop {
+		nftRule = r.conn.InsertRule(nftRule)
+	} else {
+		nftRule = r.conn.AddRule(nftRule)
+	}
+	if err := r.conn.Flush(); err != nil {
+		r.dropNetworkMatch(exprs)
+		return nil, fmt.Errorf(flushError, err)
+	}
+
+	rule := &Rule{
+		nftRule:    nftRule,
+		mangleRule: mangleRule,
+		sources:    sources,
+		id:         ruleID,
+	}
+	r.filters[ruleID] = rule
+
+	log.Debugf("added filter rule: sources=%v, destination=%v, proto=%v, sPort=%v, dPort=%v, action=%v",
+		sources, destination, proto, sPort, dPort, action)
+	return rule, nil
+}
+
+// buildPeerFilterExprs assembles the input-chain (peer ACL) match: the
+// IP-header protocol byte read via Payload, then source, then ports
+// (no counter), matching the historical peer shape so per-rule kernel
+// state is identical to pre-unification.
+func (r *family) buildPeerFilterExprs(
+	srcExprs []expr.Any,
+	proto firewall.Protocol,
+	sPort, dPort *firewall.Port,
+) ([]expr.Any, error) {
+	var exprs []expr.Any
+
+	if proto != firewall.ProtocolALL {
+		protoNum, err := r.af.protoNum(proto)
+		if err != nil {
+			return nil, fmt.Errorf("convert protocol to number: %w", err)
+		}
+		exprs = append(exprs,
+			&expr.Payload{
+				DestRegister: 1,
+				Base:         expr.PayloadBaseNetworkHeader,
+				Offset:       r.af.protoOffset,
+				Len:          1,
+			},
+			&expr.Cmp{Op: expr.CmpOpEq, Register: 1, Data: []byte{protoNum}},
+		)
+	}
+	exprs = append(exprs, srcExprs...)
+
+	portExprs, err := r.applyPorts(sPort, dPort)
+	if err != nil {
+		return nil, err
+	}
+	exprs = append(exprs, portExprs...)
+	return exprs, nil
+}
+
+// buildRouteFilterExprs assembles the forward-chain (route ACL) match:
+// source, then destination, then optional proto/ports, then a counter.
+func (r *family) buildRouteFilterExprs(
+	srcExprs []expr.Any,
+	destination firewall.Network,
+	proto firewall.Protocol,
+	sPort, dPort *firewall.Port,
+) ([]expr.Any, error) {
+	exprs := append([]expr.Any{}, srcExprs...)
+
+	destExprs, err := r.applyNetwork(destination, nil, false)
+	if err != nil {
+		return nil, fmt.Errorf("apply destination: %w", err)
+	}
+	exprs = append(exprs, destExprs...)
+
+	if proto != firewall.ProtocolALL {
+		protoNum, err := r.af.protoNum(proto)
+		if err != nil {
+			r.dropNetworkMatch(destExprs)
+			return nil, fmt.Errorf("convert protocol to number: %w", err)
+		}
+		exprs = append(exprs,
+			&expr.Meta{Key: expr.MetaKeyL4PROTO, Register: 1},
+			&expr.Cmp{Op: expr.CmpOpEq, Register: 1, Data: []byte{protoNum}},
+		)
+
+		portExprs, err := r.applyPorts(sPort, dPort)
+		if err != nil {
+			r.dropNetworkMatch(destExprs)
+			return nil, err
+		}
+		exprs = append(exprs, portExprs...)
+	}
+
+	exprs = append(exprs, &expr.Counter{})
+	return exprs, nil
+}
+
+func (r *family) hasRule(id firewall.RuleID) bool {
+	_, ok := r.filters[id]
+	return ok
+}
+
+func (r *family) hasDNATRule(id firewall.RuleID) bool {
+	_, ok := r.rules[id+dnatSuffix]
+	return ok
+}
+
+// DeleteFilterRule removes a previously installed filter rule. Source
+// set references are recovered from the stored rule's expressions via
+// findSets and dropped from the shared refcounter.
+func (r *family) DeleteFilterRule(rule firewall.Rule) error {
+	ruleID := rule.ID()
+	pr, ok := r.filters[ruleID]
+	if !ok {
+		log.Debugf("filter rule %s not found", ruleID)
+		return nil
+	}
+
+	// A freshly added rule carries no handle until it is read back from
+	// the kernel, and Flush only refreshes the peer chains. Pull live
+	// handles for this rule's chain before deciding it is stale so route
+	// rules (which Flush never refreshes) can actually be deleted. A
+	// refresh failure aborts the delete without touching tracking state,
+	// so the caller can retry while the rule may still exist in the kernel.
+	if pr.nftRule.Handle == 0 {
+		if err := r.refreshRuleHandles(pr.nftRule.Chain, false); err != nil {
+			return fmt.Errorf("refresh handles for chain %s: %w", pr.nftRule.Chain.Name, err)
+		}
+	}
+	// Refresh the mangle handle independently: the main rule's handle can
+	// be populated while the prerouting refresh during Flush failed, and
+	// gating the mangle refresh on the main handle would leak the mangle
+	// rule on delete.
+	if pr.mangleRule != nil && pr.mangleRule.Handle == 0 {
+		if err := r.refreshRuleHandles(r.chainPrerouting, true); err != nil {
+			return fmt.Errorf("refresh mangle handles: %w", err)
+		}
+	}
+
+	if pr.nftRule.Handle == 0 {
+		log.Warnf("filter rule %s has no handle, removing stale entry", ruleID)
+		r.dropNetworkMatch(pr.nftRule.Exprs)
+		delete(r.filters, ruleID)
+		return nil
+	}
+
+	if err := r.conn.DelRule(pr.nftRule); err != nil {
+		log.Errorf("queue rule delete: %v", err)
+	}
+	if pr.mangleRule != nil {
+		if err := r.conn.DelRule(pr.mangleRule); err != nil {
+			log.Errorf("queue mangle rule delete: %v", err)
+		}
+	}
+	if err := r.conn.Flush(); err != nil {
+		return fmt.Errorf("flush delete %s: %w", ruleID, err)
+	}
+
+	r.dropNetworkMatch(pr.nftRule.Exprs)
+	delete(r.filters, ruleID)
+	return nil
+}
+
+func (r *family) decrementSetCounter(rule *nftables.Rule) error {
+	if r.ipsetCounter == nil {
+		return nil
+	}
+	sets := findSets(rule)
+
+	var merr *multierror.Error
+	for _, setName := range sets {
+		if _, err := r.ipsetCounter.Decrement(setName); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("decrement set counter: %w", err))
+		}
+	}
+
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+// dropNetworkMatch undoes whatever the source/destination match
+// reserved. Safe to call when the spec is empty or holds only inline
+// matchers.
+func (r *family) dropNetworkMatch(exprs []expr.Any) {
+	if r.ipsetCounter == nil {
+		return
+	}
+	for _, e := range exprs {
+		lookup, ok := e.(*expr.Lookup)
+		if !ok {
+			continue
+		}
+		if _, err := r.ipsetCounter.Decrement(lookup.SetName); err != nil {
+			log.Errorf("rollback ipset decrement %s: %v", lookup.SetName, err)
+		}
+	}
+}
+
+func (r *family) applyNetwork(
+	network firewall.Network,
+	setPrefixes []netip.Prefix,
+	isSource bool,
+) ([]expr.Any, error) {
+	if network.IsSet() {
+		exprs, err := r.getIpSet(network.Set, setPrefixes, isSource)
+		if err != nil {
+			side := "destination"
+			if isSource {
+				side = "source"
+			}
+			return nil, fmt.Errorf("%s set: %w", side, err)
+		}
+		return exprs, nil
+	}
+
+	if network.IsPrefix() {
+		return prefixMatchExprs(r.af, network.Prefix, isSource), nil
+	}
+
+	return nil, nil
+}
+
+// applyPort builds the transport-header port match. A single value
+// compares directly, a range uses a range expression, and multiple
+// values go through an anonymous constant set: consecutive cmp
+// expressions AND together, so chained equality comparisons could
+// never match more than one port. The set is queued on the
+// connection and committed by the caller's flush together with the
+// rule that binds it.
+func (r *family) applyPort(port *firewall.Port, isSource bool) ([]expr.Any, error) {
+	if port == nil || len(port.Values) == 0 {
+		return nil, nil
+	}
+
+	// dst port
+	offset := uint32(2)
+	if isSource {
+		// src port
+		offset = 0
+	}
+
+	exprs := []expr.Any{
+		&expr.Payload{
+			DestRegister: 1,
+			Base:         expr.PayloadBaseTransportHeader,
+			Offset:       offset,
+			Len:          2,
+		},
+	}
+
+	switch {
+	case port.IsRange && len(port.Values) == 2:
+		exprs = append(exprs, &expr.Range{
+			Op:       expr.CmpOpEq,
+			Register: 1,
+			FromData: binaryutil.BigEndian.PutUint16(port.Values[0]),
+			ToData:   binaryutil.BigEndian.PutUint16(port.Values[1]),
+		})
+	case len(port.Values) == 1:
+		exprs = append(exprs, &expr.Cmp{
+			Op:       expr.CmpOpEq,
+			Register: 1,
+			Data:     binaryutil.BigEndian.PutUint16(port.Values[0]),
+		})
+	default:
+		lookup, err := r.anonymousPortSet(port.Values)
+		if err != nil {
+			return nil, err
+		}
+		exprs = append(exprs, lookup)
+	}
+
+	return exprs, nil
+}
+
+// anonymousPortSet queues an anonymous constant set holding the given
+// ports on the connection and returns a lookup against it. The set is
+// committed by the caller's flush together with the rule that binds it.
+func (r *family) anonymousPortSet(values []uint16) (*expr.Lookup, error) {
+	set := &nftables.Set{
+		Anonymous: true,
+		Constant:  true,
+		Table:     r.workTable,
+		KeyType:   nftables.TypeInetService,
+	}
+	elements := make([]nftables.SetElement, 0, len(values))
+	for _, p := range values {
+		elements = append(elements, nftables.SetElement{Key: binaryutil.BigEndian.PutUint16(p)})
+	}
+	if err := r.conn.AddSet(set, elements); err != nil {
+		return nil, fmt.Errorf("add anonymous port set: %w", err)
+	}
+	return &expr.Lookup{
+		SourceRegister: 1,
+		SetID:          set.ID,
+		SetName:        set.Name,
+	}, nil
+}
+
+// applyPorts builds the source then destination port matches.
+func (r *family) applyPorts(sPort, dPort *firewall.Port) ([]expr.Any, error) {
+	sPortExprs, err := r.applyPort(sPort, true)
+	if err != nil {
+		return nil, fmt.Errorf("apply source port: %w", err)
+	}
+
+	dPortExprs, err := r.applyPort(dPort, false)
+	if err != nil {
+		return nil, fmt.Errorf("apply destination port: %w", err)
+	}
+
+	return append(sPortExprs, dPortExprs...), nil
+}
+
+// prefixMatchExprs is the family-aware match sequence for a CIDR
+// prefix. /0 returns nil; a host prefix (full bit length for the
+// family) skips the bitwise step since the mask is all-ones. Shared
+// between family and aclManager so both treat single prefixes
+// identically.
+func prefixMatchExprs(af addrFamily, prefix netip.Prefix, isSource bool) []expr.Any {
+	offset := af.dstAddrOffset
+	if isSource {
+		offset = af.srcAddrOffset
+	}
+
+	ones := prefix.Bits()
+	if ones == 0 {
+		return nil
+	}
+
+	payload := &expr.Payload{
+		DestRegister: 1,
+		Base:         expr.PayloadBaseNetworkHeader,
+		Offset:       offset,
+		Len:          af.addrLen,
+	}
+	cmp := &expr.Cmp{
+		Op:       expr.CmpOpEq,
+		Register: 1,
+		Data:     prefix.Masked().Addr().AsSlice(),
+	}
+
+	if ones == af.totalBits {
+		return []expr.Any{payload, cmp}
+	}
+
+	mask := net.CIDRMask(ones, af.totalBits)
+	xor := make([]byte, af.addrLen)
+	return []expr.Any{
+		payload,
+		&expr.Bitwise{
+			DestRegister:   1,
+			SourceRegister: 1,
+			Len:            af.addrLen,
+			Mask:           mask,
+			Xor:            xor,
+		},
+		cmp,
+	}
+}
+
+func getCtNewExprs() []expr.Any {
+	return []expr.Any{
+		&expr.Ct{
+			Key:      expr.CtKeySTATE,
+			Register: 1,
+		},
+		&expr.Bitwise{
+			SourceRegister: 1,
+			DestRegister:   1,
+			Len:            4,
+			Mask:           binaryutil.NativeEndian.PutUint32(expr.CtStateBitNEW),
+			Xor:            binaryutil.NativeEndian.PutUint32(0),
+		},
+		&expr.Cmp{
+			Op:       expr.CmpOpNeq,
+			Register: 1,
+			Data:     []byte{0, 0, 0, 0},
+		},
+	}
+}
+
+// sourceNetwork classifies a source-prefix list into the firewall.Network
+// shape the rest of the spec-builder consumes: empty for match-any, a
+// single prefix inline, or an ipset for multiple sources.
+func sourceNetwork(sources []netip.Prefix) firewall.Network {
+	switch {
+	case len(sources) == 0:
+		return firewall.Network{}
+	case len(sources) == 1 && sources[0].Bits() == 0:
+		return firewall.Network{}
+	case len(sources) == 1:
+		return firewall.Network{Prefix: sources[0]}
+	default:
+		return firewall.Network{Set: firewall.NewPrefixSet(sources)}
+	}
+}
+
+func ifname(n string) []byte {
+	b := make([]byte, 16)
+	copy(b, n+"\x00")
+	return b
+}
+
+// findSets scans an nftables rule's expressions for expr.Lookup and
+// returns the named sets in occurrence order. Used at delete time to
+// drop ipsetCounter references; peer and route ACLs go through it.
+func findSets(rule *nftables.Rule) []string {
+	var sets []string
+	for _, e := range rule.Exprs {
+		if lookup, ok := e.(*expr.Lookup); ok {
+			sets = append(sets, lookup.SetName)
+		}
+	}
+	return sets
+}

client/firewall/nftables/interface_allower_integration_linux_test.go

@@ -0,0 +1,90 @@
+//go:build privileged
+
+package nftables
+
+import (
+	"bytes"
+	"os"
+	"testing"
+
+	"github.com/google/nftables"
+	"github.com/stretchr/testify/require"
+
+	"github.com/netbirdio/netbird/client/iface"
+)
+
+// TestInterfaceAllowerInputOnly verifies the userspace-mode allower opens the
+// interface on the INPUT hook of foreign chains only (not FORWARD, since the
+// userspace router never forwards in the kernel), creates no netbird work
+// table, and removes its rules on Close.
+func TestInterfaceAllowerInputOnly(t *testing.T) {
+	if os.Geteuid() != 0 {
+		t.Skip("root required")
+	}
+
+	require.False(t, ipTableExists(t, getTableName()), "precondition: no stale netbird table")
+
+	conn := &nftables.Conn{}
+	extTable := conn.AddTable(&nftables.Table{Name: "nbtest_extchains", Family: nftables.TableFamilyINet})
+	inputChain := conn.AddChain(&nftables.Chain{
+		Name: "ext_input", Table: extTable,
+		Hooknum: nftables.ChainHookInput, Priority: nftables.ChainPriorityFilter, Type: nftables.ChainTypeFilter,
+	})
+	forwardChain := conn.AddChain(&nftables.Chain{
+		Name: "ext_forward", Table: extTable,
+		Hooknum: nftables.ChainHookForward, Priority: nftables.ChainPriorityFilter, Type: nftables.ChainTypeFilter,
+	})
+	require.NoError(t, conn.Flush(), "create external table and chains")
+	t.Cleanup(func() {
+		c := &nftables.Conn{}
+		c.DelTable(extTable)
+		_ = c.Flush()
+	})
+
+	allower, err := NewInterfaceAllower(ifaceMock, iface.DefaultMTU)
+	require.NoError(t, err, "create allower")
+	require.NoError(t, allower.Apply(), "apply")
+
+	require.True(t, chainHasUserData(t, extTable, inputChain, userDataAcceptInputRule),
+		"external INPUT chain should get the accept rule")
+	require.Len(t, listRules(t, extTable, forwardChain), 0,
+		"external FORWARD chain must not be opened in userspace mode")
+	require.False(t, ipTableExists(t, getTableName()),
+		"allower must not create a netbird work table")
+
+	require.NoError(t, allower.Close(), "close")
+	require.False(t, chainHasUserData(t, extTable, inputChain, userDataAcceptInputRule),
+		"accept rule should be removed on close")
+}
+
+func listRules(t *testing.T, table *nftables.Table, chain *nftables.Chain) []*nftables.Rule {
+	t.Helper()
+	c := &nftables.Conn{}
+	rules, err := c.GetRules(table, chain)
+	require.NoError(t, err)
+	return rules
+}
+
+func chainHasUserData(t *testing.T, table *nftables.Table, chain *nftables.Chain, ud string) bool {
+	for _, r := range listRules(t, table, chain) {
+		if bytes.Equal(r.UserData, []byte(ud)) {
+			return true
+		}
+	}
+	return false
+}
+
+func ipTableExists(t *testing.T, name string) bool {
+	t.Helper()
+	c := &nftables.Conn{}
+	for _, fam := range []nftables.TableFamily{nftables.TableFamilyIPv4, nftables.TableFamilyIPv6} {
+		tbls, err := c.ListTablesOfFamily(fam)
+		require.NoError(t, err)
+		for _, tb := range tbls {
+			if tb.Name == name {
+				return true
+			}
+		}
+	}
+	return false
+}

client/firewall/nftables/interface_allower_linux.go

@@ -0,0 +1,107 @@
+package nftables
+
+import (
+	"fmt"
+
+	"github.com/google/nftables"
+	"github.com/hashicorp/go-multierror"
+
+	nberrors "github.com/netbirdio/netbird/client/errors"
+)
+
+// InterfaceAllower opens the NetBird interface in the kernel's filter table and
+// external chains and keeps them reconciled via a netlink monitor, so the host
+// firewall doesn't drop traffic the NetBird firewall handles. It is used by the
+// userspace firewall, where routing happens in the forwarder, so only INPUT is
+// opened (the userspace router never forwards in the kernel).
+//
+// It owns its own families/connection and never creates a netbird work table.
+// firewalld trust is handled by the caller, not here. Its operations are serial
+// (Apply before the monitor starts; reconciles run on the single monitor
+// goroutine; Close stops the monitor before removing), so it needs no locking.
+//
+// TODO: this opens nftables and the iptables-nft filter table (detected via
+// nft), but not a legacy-iptables ruleset running in parallel with nftables.
+// Such a host would keep its legacy filter chains closed for the interface.
+type InterfaceAllower struct {
+	family4    *family
+	family6    *family
+	extMonitor *externalChainMonitor
+}
+
+// NewInterfaceAllower builds an allower for the given interface. It returns an
+// error when nftables is unavailable (e.g. an iptables-legacy host), so the
+// caller can fall back to firewalld trust.
+func NewInterfaceAllower(wgIface iFaceMapper, mtu uint16) (*InterfaceAllower, error) {
+	tableName := getTableName()
+
+	family4 := newFamily(&nftables.Table{Name: tableName, Family: nftables.TableFamilyIPv4}, wgIface, mtu)
+
+	// Probe nftables availability before committing to this backend.
+	if _, err := family4.conn.ListChainsOfTableFamily(nftables.TableFamilyINet); err != nil {
+		return nil, fmt.Errorf("nftables not available: %w", err)
+	}
+
+	a := &InterfaceAllower{family4: family4}
+
+	if wgIface.Address().HasIPv6() {
+		a.family6 = newFamily(&nftables.Table{Name: tableName, Family: nftables.TableFamilyIPv6}, wgIface, mtu)
+	}
+
+	a.extMonitor = newExternalChainMonitor(a)
+	return a, nil
+}
+
+// Apply opens the interface (INPUT only) in the foreign filter chains and starts
+// reconciling them on nftables changes.
+func (a *InterfaceAllower) Apply() error {
+	var merr *multierror.Error
+	for _, f := range a.families() {
+		// Remove any stale accepts first so a prior unclean exit (e.g. SIGKILL,
+		// where Close never ran) is recovered deterministically rather than
+		// accumulating duplicate rules on the iptables filter table.
+		if err := f.removeAcceptFilterRules(); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("clean stale accept rules: %w", err))
+		}
+		if err := f.openInterface(false); err != nil {
+			merr = multierror.Append(merr, err)
+		}
+	}
+
+	a.extMonitor.start()
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+// families returns the configured address families (v4, and v6 when present).
+func (a *InterfaceAllower) families() []*family {
+	families := []*family{a.family4}
+	if a.family6 != nil {
+		families = append(families, a.family6)
+	}
+	return families
+}
+
+// reconcileExternalChains re-applies the INPUT accepts to external chains. It
+// implements externalChainReconciler for the monitor.
+func (a *InterfaceAllower) reconcileExternalChains() error {
+	var merr *multierror.Error
+	for _, f := range a.families() {
+		if err := f.acceptExternalChainsRules(false); err != nil {
+			merr = multierror.Append(merr, err)
+		}
+	}
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+// Close stops the monitor and removes the accept rules.
+func (a *InterfaceAllower) Close() error {
+	a.extMonitor.stop()
+
+	var merr *multierror.Error
+	for _, f := range a.families() {
+		if err := f.removeAcceptFilterRules(); err != nil {
+			merr = multierror.Append(merr, err)
+		}
+	}
+	return nberrors.FormatErrorOrNil(merr)
+}

client/firewall/nftables/ipset_linux.go

@@ -0,0 +1,210 @@
+//go:build !android
+
+package nftables
+
+import (
+	"encoding/binary"
+	"fmt"
+	"net/netip"
+
+	"github.com/google/nftables"
+	"github.com/google/nftables/expr"
+	log "github.com/sirupsen/logrus"
+
+	firewall "github.com/netbirdio/netbird/client/firewall/manager"
+	"github.com/netbirdio/netbird/client/internal/routemanager/refcounter"
+)
+
+func (r *family) getIpSet(set firewall.Set, prefixes []netip.Prefix, isSource bool) ([]expr.Any, error) {
+	ref, err := r.ipsetCounter.Increment(set.HashedName(), setInput{
+		set:      set,
+		prefixes: prefixes,
+	})
+	if err != nil {
+		return nil, fmt.Errorf("create or get ipset: %w", err)
+	}
+
+	return r.getIpSetExprs(ref, isSource)
+}
+
+func (r *family) createIpSet(setName string, input setInput) (*nftables.Set, error) {
+	// overlapping prefixes will result in an error, so we need to merge them
+	prefixes := firewall.MergeIPRanges(input.prefixes)
+
+	nfset := &nftables.Set{
+		Name:    setName,
+		Comment: input.set.Comment(),
+		Table:   r.workTable,
+		// required for prefixes
+		Interval: true,
+		KeyType:  r.af.setKeyType,
+	}
+
+	elements := r.convertPrefixesToSet(prefixes)
+	nElements := len(elements)
+
+	maxElements := maxPrefixesSet * 2
+	initialElements := elements[:min(maxElements, nElements)]
+
+	if err := r.conn.AddSet(nfset, initialElements); err != nil {
+		return nil, fmt.Errorf("error adding set %s: %w", setName, err)
+	}
+	if err := r.conn.Flush(); err != nil {
+		return nil, fmt.Errorf("flush error: %w", err)
+	}
+	log.Debugf("Created new ipset: %s with %d initial prefixes (total prefixes %d)", setName, len(initialElements)/2, len(prefixes))
+
+	// The set is committed now. If a later batch fails, destroy it: the
+	// refcounter records nothing on a create-callback error, so it would
+	// otherwise leak, and a partial source set fails-open for deny rules.
+	if err := r.addRemainingElements(nfset, elements, maxElements); err != nil {
+		if derr := r.deleteIpSet(setName, nfset); derr != nil {
+			log.Warnf("rollback ipset %s after add failure: %v", setName, derr)
+		}
+		return nil, err
+	}
+
+	log.Infof("Created new ipset: %s with %d prefixes", setName, len(prefixes))
+	return nfset, nil
+}
+
+// addRemainingElements adds element batches beyond the initial one in
+// maxElements-sized chunks, flushing each. Called after the set has been
+// created with its first batch.
+func (r *family) addRemainingElements(nfset *nftables.Set, elements []nftables.SetElement, maxElements int) error {
+	nElements := len(elements)
+	for subStart := maxElements; subStart < nElements; subStart += maxElements {
+		subEnd := min(subStart+maxElements, nElements)
+		subElement := elements[subStart:subEnd]
+		nSubPrefixes := len(subElement) / 2
+		log.Tracef("Adding new prefixes (%d) in ipset: %s", nSubPrefixes, nfset.Name)
+		if err := r.conn.SetAddElements(nfset, subElement); err != nil {
+			return fmt.Errorf("error adding prefixes (%d) to set %s: %w", nSubPrefixes, nfset.Name, err)
+		}
+		if err := r.conn.Flush(); err != nil {
+			return fmt.Errorf("flush error: %w", err)
+		}
+		log.Debugf("Added new prefixes (%d) in ipset: %s", nSubPrefixes, nfset.Name)
+	}
+	return nil
+}
+
+func (r *family) convertPrefixesToSet(prefixes []netip.Prefix) []nftables.SetElement {
+	var elements []nftables.SetElement
+	for _, prefix := range prefixes {
+		// nftables needs half-open intervals [firstIP, lastIP) for prefixes
+		// e.g. 10.0.0.0/24 becomes [10.0.0.0, 10.0.1.0), 10.1.1.1/32 becomes [10.1.1.1, 10.1.1.2) etc
+		firstIP := prefix.Addr()
+
+		// For a /0 the last address is the broadcast and its Next() overflows
+		// to an invalid Addr with an empty key, so wrap to the zero address,
+		// which nftables reads as the open end of a full-range interval.
+		var lastKey []byte
+		if prefix.Bits() == 0 {
+			lastKey = make([]byte, r.af.addrLen)
+		} else {
+			lastKey = calculateLastIP(prefix).Next().AsSlice()
+		}
+
+		// the nft tool also adds a zero-address IntervalEnd element, see https://github.com/google/nftables/issues/247
+		// nftables.SetElement{Key: make([]byte, r.af.addrLen), IntervalEnd: true},
+		elements = append(elements,
+			nftables.SetElement{Key: firstIP.AsSlice()},
+			nftables.SetElement{Key: lastKey, IntervalEnd: true},
+		)
+	}
+	return elements
+}
+
+// calculateLastIP determines the last IP in a given prefix.
+func calculateLastIP(prefix netip.Prefix) netip.Addr {
+	masked := prefix.Masked()
+	if masked.Addr().Is4() {
+		hostMask := ^uint32(0) >> masked.Bits()
+		lastIP := uint32FromNetipAddr(masked.Addr()) | hostMask
+		return netip.AddrFrom4(uint32ToBytes(lastIP))
+	}
+
+	// IPv6: set host bits to all 1s
+	b := masked.Addr().As16()
+	bits := masked.Bits()
+	for i := bits; i < 128; i++ {
+		b[i/8] |= 1 << (7 - i%8)
+	}
+	return netip.AddrFrom16(b)
+}
+
+// Utility function to convert netip.Addr to uint32.
+func uint32FromNetipAddr(addr netip.Addr) uint32 {
+	b := addr.As4()
+	return binary.BigEndian.Uint32(b[:])
+}
+
+// Utility function to convert uint32 to a netip-compatible byte slice.
+func uint32ToBytes(ip uint32) [4]byte {
+	var b [4]byte
+	binary.BigEndian.PutUint32(b[:], ip)
+	return b
+}
+
+func (r *family) deleteIpSet(setName string, nfset *nftables.Set) error {
+	r.conn.DelSet(nfset)
+	if err := r.conn.Flush(); err != nil {
+		return fmt.Errorf(flushError, err)
+	}
+
+	log.Debugf("Deleted unused ipset %s", setName)
+	return nil
+}
+
+func (r *family) UpdateSet(set firewall.Set, prefixes []netip.Prefix) error {
+	nfset, err := r.conn.GetSetByName(r.workTable, set.HashedName())
+	if err != nil {
+		return fmt.Errorf("get set %s: %w", set.HashedName(), err)
+	}
+
+	// Overlapping prefixes (e.g. duplicate resolved addresses) make the
+	// interval set reject the batch, so merge them as createIpSet does.
+	prefixes = firewall.MergeIPRanges(prefixes)
+	elements := r.convertPrefixesToSet(prefixes)
+
+	// Add in batches sized like createIpSet so a large update does not
+	// exceed the netlink message size limit.
+	maxElements := maxPrefixesSet * 2
+	for start := 0; start < len(elements); start += maxElements {
+		end := min(start+maxElements, len(elements))
+		if err := r.conn.SetAddElements(nfset, elements[start:end]); err != nil {
+			return fmt.Errorf("add elements to set %s: %w", set.HashedName(), err)
+		}
+		if err := r.conn.Flush(); err != nil {
+			return fmt.Errorf(flushError, err)
+		}
+	}
+
+	log.Debugf("updated set %s with %d prefixes", set.HashedName(), len(prefixes))
+
+	return nil
+}
+
+func (r *family) getIpSetExprs(ref refcounter.Ref[*nftables.Set], isSource bool) ([]expr.Any, error) {
+	// dst offset by default
+	offset := r.af.dstAddrOffset
+	if isSource {
+		// src offset
+		offset = r.af.srcAddrOffset
+	}
+
+	return []expr.Any{
+		&expr.Payload{
+			DestRegister: 1,
+			Base:         expr.PayloadBaseNetworkHeader,
+			Offset:       offset,
+			Len:          r.af.addrLen,
+		},
+		&expr.Lookup{
+			SourceRegister: 1,
+			SetName:        ref.Out.Name,
+			SetID:          ref.Out.ID,
+		},
+	}, nil
+}

client/firewall/nftables/ipset_linux_test.go

@@ -0,0 +1,36 @@
+package nftables
+
+import (
+	"net/netip"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// TestConvertPrefixesToSetWildcard verifies that a /0 prefix produces a
+// usable interval. The last address of a /0 is the broadcast, whose Next()
+// overflows to an invalid Addr with an empty key; the IntervalEnd must wrap
+// to the zero address instead so nftables sees a full-range interval.
+func TestConvertPrefixesToSetWildcard(t *testing.T) {
+	tests := []struct {
+		name   string
+		af     addrFamily
+		prefix string
+	}{
+		{"IPv4 /0", afIPv4, "0.0.0.0/0"},
+		{"IPv6 /0", afIPv6, "::/0"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			r := &family{af: tt.af}
+			elements := r.convertPrefixesToSet([]netip.Prefix{netip.MustParsePrefix(tt.prefix)})
+
+			require.Len(t, elements, 2, "expected start and interval-end element")
+			assert.False(t, elements[0].IntervalEnd, "first element is the interval start")
+			assert.True(t, elements[1].IntervalEnd, "second element is the interval end")
+			assert.Len(t, elements[1].Key, int(tt.af.addrLen), "interval-end key must be a zero address, not empty")
+		})
+	}
+}

client/firewall/nftables/ipsetstore_linux.go

@@ -1,85 +0,0 @@
-package nftables
-
-import (
-	"net"
-)
-
-type ipsetStore struct {
-	ipsetReference map[string]int
-	ipsets         map[string]map[string]struct{} // ipsetName -> list of ips
-}
-
-func newIpsetStore() *ipsetStore {
-	return &ipsetStore{
-		ipsetReference: make(map[string]int),
-		ipsets:         make(map[string]map[string]struct{}),
-	}
-}
-
-func (s *ipsetStore) ips(ipsetName string) (map[string]struct{}, bool) {
-	r, ok := s.ipsets[ipsetName]
-	return r, ok
-}
-
-func (s *ipsetStore) newIpset(ipsetName string) map[string]struct{} {
-	s.ipsetReference[ipsetName] = 0
-	ipList := make(map[string]struct{})
-	s.ipsets[ipsetName] = ipList
-	return ipList
-}
-
-func (s *ipsetStore) deleteIpset(ipsetName string) {
-	delete(s.ipsetReference, ipsetName)
-	delete(s.ipsets, ipsetName)
-}
-
-func (s *ipsetStore) DeleteIpFromSet(ipsetName string, ip net.IP) {
-	ipList, ok := s.ipsets[ipsetName]
-	if !ok {
-		return
-	}
-	delete(ipList, ip.String())
-}
-
-func (s *ipsetStore) AddIpToSet(ipsetName string, ip net.IP) {
-	ipList, ok := s.ipsets[ipsetName]
-	if !ok {
-		return
-	}
-	ipList[ip.String()] = struct{}{}
-}
-
-func (s *ipsetStore) IsIpInSet(ipsetName string, ip net.IP) bool {
-	ipList, ok := s.ipsets[ipsetName]
-	if !ok {
-		return false
-	}
-	_, ok = ipList[ip.String()]
-	return ok
-}
-
-func (s *ipsetStore) AddReferenceToIpset(ipsetName string) {
-	s.ipsetReference[ipsetName]++
-}
-
-func (s *ipsetStore) DeleteReferenceFromIpSet(ipsetName string) {
-	r, ok := s.ipsetReference[ipsetName]
-	if !ok {
-		return
-	}
-	if r == 0 {
-		return
-	}
-	s.ipsetReference[ipsetName]--
-}
-
-func (s *ipsetStore) HasReferenceToSet(ipsetName string) bool {
-	if _, ok := s.ipsetReference[ipsetName]; !ok {
-		return false
-	}
-	if s.ipsetReference[ipsetName] == 0 {
-		return false
-	}
-
-	return true
-}

client/firewall/nftables/legacy_rule_linux_test.go

@@ -0,0 +1,60 @@
+package nftables
+
+import (
+	"testing"
+
+	"github.com/google/nftables/expr"
+	"github.com/stretchr/testify/require"
+)
+
+func TestBuildLegacyRouteRuleExpressions(t *testing.T) {
+	sourcePayload := &expr.Payload{}
+	sourceCmp := &expr.Cmp{}
+	destinationPayload := &expr.Payload{}
+	destinationCmp := &expr.Cmp{}
+	nilSourceDestination := &expr.Payload{}
+	nilDestinationSource := &expr.Cmp{}
+
+	tests := []struct {
+		name        string
+		source      []expr.Any
+		destination []expr.Any
+		matches     []expr.Any
+	}{
+		{
+			name:        "both non-empty",
+			source:      []expr.Any{sourcePayload, sourceCmp},
+			destination: []expr.Any{destinationPayload, destinationCmp},
+			matches:     []expr.Any{sourcePayload, sourceCmp, destinationPayload, destinationCmp},
+		},
+		{
+			name:        "nil source",
+			destination: []expr.Any{nilSourceDestination},
+			matches:     []expr.Any{nilSourceDestination},
+		},
+		{
+			name:    "nil destination",
+			source:  []expr.Any{nilDestinationSource},
+			matches: []expr.Any{nilDestinationSource},
+		},
+		{
+			name: "both nil",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := buildLegacyRouteRuleExpressions(tt.source, tt.destination)
+
+			require.Len(t, got, len(tt.matches)+2)
+			for i, match := range tt.matches {
+				require.Same(t, match, got[i])
+			}
+
+			require.IsType(t, &expr.Counter{}, got[len(tt.matches)])
+			verdict, ok := got[len(tt.matches)+1].(*expr.Verdict)
+			require.True(t, ok)
+			require.Equal(t, expr.VerdictAccept, verdict.Kind)
+		})
+	}
+}

client/firewall/nftables/manager_linux.go

@@ -3,7 +3,6 @@ package nftables
 import (
 	"context"
 	"fmt"
-	"net"
 	"net/netip"
 	"os"
 	"sync"
@@ -16,7 +15,6 @@ import (
 	"golang.org/x/sys/unix"
 
 	nberrors "github.com/netbirdio/netbird/client/errors"
-	"github.com/netbirdio/netbird/client/firewall/firewalld"
 	firewall "github.com/netbirdio/netbird/client/firewall/manager"
 	"github.com/netbirdio/netbird/client/iface/wgaddr"
 	"github.com/netbirdio/netbird/client/internal/statemanager"
@@ -45,18 +43,17 @@ type iFaceMapper interface {
 	Address() wgaddr.Address
 }
 
-// Manager of iptables firewall
+// Manager of nftables firewall. Per-family state (peer ACLs, route
+// ACLs, NAT, DNAT, MSS clamping) lives on family; Manager dispatches
+// by family and provides the public firewall.Manager surface.
 type Manager struct {
 	mutex   sync.Mutex
 	rConn   *nftables.Conn
 	wgIface iFaceMapper
 
-	router     *router
-	aclManager *AclManager
-
-	// IPv6 counterparts, nil when no v6 overlay
-	router6     *router
-	aclManager6 *AclManager
+	family4 *family
+	// IPv6 counterpart, nil when no v6 overlay.
+	family6 *family
 
 	notrackOutputChain     *nftables.Chain
 	notrackPreroutingChain *nftables.Chain
@@ -74,21 +71,10 @@ func Create(wgIface iFaceMapper, mtu uint16) (*Manager, error) {
 	tableName := getTableName()
 	workTable := &nftables.Table{Name: tableName, Family: nftables.TableFamilyIPv4}
 
-	var err error
-	m.router, err = newRouter(workTable, wgIface, mtu)
-	if err != nil {
-		return nil, fmt.Errorf("create router: %w", err)
-	}
-
-	m.aclManager, err = newAclManager(workTable, wgIface, chainNameRoutingFw)
-	if err != nil {
-		return nil, fmt.Errorf("create acl manager: %w", err)
-	}
+	m.family4 = newFamily(workTable, wgIface, mtu)
 
 	if wgIface.Address().HasIPv6() {
-		if err := m.createIPv6Components(tableName, wgIface, mtu); err != nil {
-			return nil, fmt.Errorf("create IPv6 firewall: %w", err)
-		}
+		m.createIPv6Components(tableName, wgIface, mtu)
 	}
 
 	m.extMonitor = newExternalChainMonitor(m)
@@ -96,30 +82,19 @@ func Create(wgIface iFaceMapper, mtu uint16) (*Manager, error) {
 	return m, nil
 }
 
-func (m *Manager) createIPv6Components(tableName string, wgIface iFaceMapper, mtu uint16) error {
+func (m *Manager) createIPv6Components(tableName string, wgIface iFaceMapper, mtu uint16) {
 	workTable6 := &nftables.Table{Name: tableName, Family: nftables.TableFamilyIPv6}
 
-	var err error
-	m.router6, err = newRouter(workTable6, wgIface, mtu)
-	if err != nil {
-		return fmt.Errorf("create v6 router: %w", err)
-	}
+	m.family6 = newFamily(workTable6, wgIface, mtu)
 
 	// Share the same IP forwarding state with the v4 router, since
 	// EnableIPForwarding controls both v4 and v6 sysctls.
-	m.router6.ipFwdState = m.router.ipFwdState
-
-	m.aclManager6, err = newAclManager(workTable6, wgIface, chainNameRoutingFw)
-	if err != nil {
-		return fmt.Errorf("create v6 acl manager: %w", err)
-	}
-
-	return nil
+	m.family6.ipFwdState = m.family4.ipFwdState
 }
 
 // hasIPv6 reports whether the manager has IPv6 components initialized.
 func (m *Manager) hasIPv6() bool {
-	return m.router6 != nil
+	return m.family6 != nil
 }
 
 func (m *Manager) initIPv6() error {
@@ -128,12 +103,8 @@ func (m *Manager) initIPv6() error {
 		return fmt.Errorf("create v6 work table: %w", err)
 	}
 
-	if err := m.router6.init(workTable6); err != nil {
-		return fmt.Errorf("v6 router init: %w", err)
-	}
-
-	if err := m.aclManager6.init(workTable6); err != nil {
-		return fmt.Errorf("v6 acl manager init: %w", err)
+	if err := m.family6.init(workTable6); err != nil {
+		return fmt.Errorf("v6 family init: %w", err)
 	}
 
 	return nil
@@ -156,19 +127,20 @@ func (m *Manager) Init(stateManager *statemanager.Manager) error {
 
 // reconcileExternalChains re-applies passthrough accept rules to external
 // filter chains for both IPv4 and IPv6 routers. Called by the monitor when
-// tables or chains appear (e.g. after firewalld reloads).
+// tables or chains appear (e.g. after firewalld reloads). Kernel routing opens
+// both INPUT and FORWARD.
 func (m *Manager) reconcileExternalChains() error {
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
 
 	var merr *multierror.Error
-	if m.router != nil {
-		if err := m.router.acceptExternalChainsRules(); err != nil {
+	if m.family4 != nil {
+		if err := m.family4.acceptExternalChainsRules(true); err != nil {
 			merr = multierror.Append(merr, fmt.Errorf("v4: %w", err))
 		}
 	}
 	if m.hasIPv6() {
-		if err := m.router6.acceptExternalChainsRules(); err != nil {
+		if err := m.family6.acceptExternalChainsRules(true); err != nil {
 			merr = multierror.Append(merr, fmt.Errorf("v6: %w", err))
 		}
 	}
@@ -187,12 +159,8 @@ func (m *Manager) initFirewall() (err error) {
 		}
 	}()
 
-	if err := m.router.init(workTable); err != nil {
-		return fmt.Errorf("router init: %w", err)
-	}
-
-	if err := m.aclManager.init(workTable); err != nil {
-		return fmt.Errorf("acl manager init: %w", err)
+	if err := m.family4.init(workTable); err != nil {
+		return fmt.Errorf("family init: %w", err)
 	}
 
 	if m.hasIPv6() {
@@ -220,7 +188,7 @@ func (m *Manager) persistState(stateManager *statemanager.Manager) {
 		InterfaceState: &InterfaceState{
 			NameStr:   m.wgIface.Name(),
 			WGAddress: m.wgIface.Address(),
-			MTU:       m.router.mtu,
+			MTU:       m.family4.mtu,
 		},
 	}); err != nil {
 		log.Errorf("failed to update state: %v", err)
@@ -235,12 +203,12 @@ func (m *Manager) persistState(stateManager *statemanager.Manager) {
 
 // rollbackInit performs best-effort cleanup of already-initialized state when Init fails partway through.
 func (m *Manager) rollbackInit() {
-	if err := m.router.Reset(); err != nil {
-		log.Warnf("rollback router: %v", err)
+	if err := m.family4.Reset(); err != nil {
+		log.Warnf("rollback family: %v", err)
 	}
 	if m.hasIPv6() {
-		if err := m.router6.Reset(); err != nil {
-			log.Warnf("rollback v6 router: %v", err)
+		if err := m.family6.Reset(); err != nil {
+			log.Warnf("rollback v6 family: %v", err)
 		}
 	}
 	if err := m.cleanupNetbirdTables(); err != nil {
@@ -251,118 +219,82 @@ func (m *Manager) rollbackInit() {
 	}
 }
 
-// AddPeerFiltering rule to the firewall
+// AddFilterRule installs a packet-filtering rule.
 //
-// If comment argument is empty firewall manager should set
-// rule ID as comment for the rule
-func (m *Manager) AddPeerFiltering(
-	id []byte,
-	ip net.IP,
-	proto firewall.Protocol,
-	sPort *firewall.Port,
-	dPort *firewall.Port,
-	action firewall.Action,
-	ipsetName string,
-) ([]firewall.Rule, error) {
-	m.mutex.Lock()
-	defer m.mutex.Unlock()
-
-	if ip.To4() != nil {
-		return m.aclManager.AddPeerFiltering(id, ip, proto, sPort, dPort, action, ipsetName)
-	}
-
-	if !m.hasIPv6() {
-		return nil, fmt.Errorf("add peer filtering for %s: %w", ip, firewall.ErrIPv6NotInitialized)
-	}
-	return m.aclManager6.AddPeerFiltering(id, ip, proto, sPort, dPort, action, ipsetName)
-}
-
-func (m *Manager) AddRouteFiltering(
+// Destination semantics: zero Network → input chain (peer ACL);
+// set Network → forward chain (route ACL).
+//
+// Sources are a single address family; the rule is dispatched to the
+// matching per-family backend.
+func (m *Manager) AddFilterRule(
 	id []byte,
 	sources []netip.Prefix,
 	destination firewall.Network,
 	proto firewall.Protocol,
-	sPort, dPort *firewall.Port,
+	sPort *firewall.Port,
+	dPort *firewall.Port,
 	action firewall.Action,
 ) (firewall.Rule, error) {
+	if len(sources) == 0 {
+		return nil, firewall.ErrNoSources
+	}
+
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
 
-	if isIPv6RouteRule(sources, destination) {
+	fam := m.family4
+	if isIPv6Rule(sources, destination) {
 		if !m.hasIPv6() {
-			return nil, fmt.Errorf("add route filtering: %w", firewall.ErrIPv6NotInitialized)
+			return nil, fmt.Errorf("add filtering: %w", firewall.ErrIPv6NotInitialized)
 		}
-		return m.router6.AddRouteFiltering(id, sources, destination, proto, sPort, dPort, action)
+		fam = m.family6
 	}
-
-	return m.router.AddRouteFiltering(id, sources, destination, proto, sPort, dPort, action)
+	return fam.AddFilterRule(id, sources, destination, proto, sPort, dPort, action)
 }
 
-// DeletePeerRule from the firewall by rule definition
-func (m *Manager) DeletePeerRule(rule firewall.Rule) error {
+// DeleteFilterRule removes a filtering rule. The owning family is found
+// by id in the in-memory filter maps, which are the only tracking for
+// filter rules. family.DeleteFilterRule is idempotent when the id is
+// absent.
+func (m *Manager) DeleteFilterRule(rule firewall.Rule) error {
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
 
-	if m.hasIPv6() && isIPv6Rule(rule) {
-		return m.aclManager6.DeletePeerRule(rule)
-	}
-	return m.aclManager.DeletePeerRule(rule)
-}
-
-func isIPv6Rule(rule firewall.Rule) bool {
-	r, ok := rule.(*Rule)
-	return ok && r.nftRule != nil && r.nftRule.Table != nil && r.nftRule.Table.Family == nftables.TableFamilyIPv6
-}
-
-// isIPv6RouteRule determines whether a route rule belongs to the v6 table.
-// For static routes, the destination prefix determines the family. For dynamic
-// routes (DomainSet), the sources determine the family since management
-// duplicates dynamic rules per family.
-func isIPv6RouteRule(sources []netip.Prefix, destination firewall.Network) bool {
-	if destination.IsPrefix() {
-		return destination.Prefix.Addr().Is6()
-	}
-	return len(sources) > 0 && sources[0].Addr().Is6()
-}
-
-// DeleteRouteRule deletes a routing rule. Route rules live in exactly one
-// router; the cached maps are normally authoritative, so the kernel is only
-// consulted when neither map knows about the rule.
-func (m *Manager) DeleteRouteRule(rule firewall.Rule) error {
-	m.mutex.Lock()
-	defer m.mutex.Unlock()
-
-	id := rule.ID()
-	r, err := m.routerForRuleID(id, (*router).hasRule)
+	fam, err := m.familyForRuleID(rule.ID(), (*family).hasRule, false)
 	if err != nil {
 		return err
 	}
-	return r.DeleteRouteRule(rule)
+	return fam.DeleteFilterRule(rule)
 }
 
-// routerForRuleID picks the router holding the rule with the given id, using
-// the supplied lookup. If the cached maps disagree (or both miss), it refreshes
-// from the kernel once and re-checks before falling back to the v4 router.
-func (m *Manager) routerForRuleID(id string, has func(*router, string) bool) (*router, error) {
-	if has(m.router, id) {
-		return m.router, nil
-	}
-	if m.hasIPv6() && has(m.router6, id) {
-		return m.router6, nil
+// familyForRuleID picks the family holding the rule with the given id, using
+// the supplied lookup. With refresh set, a miss in both cached maps reloads
+// the NAT/DNAT rule maps from the kernel once and re-checks before falling
+// back to the v4 family. Filter rules are tracked only in memory and have no
+// kernel-backed reload, so their callers pass refresh as false.
+func (m *Manager) familyForRuleID(id firewall.RuleID, has func(*family, firewall.RuleID) bool, refresh bool) (*family, error) {
+	if has(m.family4, id) {
+		return m.family4, nil
 	}
 	if !m.hasIPv6() {
-		return m.router, nil
+		return m.family4, nil
 	}
-	if err := m.router.refreshRulesMap(); err != nil {
+	if has(m.family6, id) {
+		return m.family6, nil
+	}
+	if !refresh {
+		return m.family4, nil
+	}
+	if err := m.family4.refreshRulesMap(); err != nil {
 		return nil, fmt.Errorf("refresh v4 rules: %w", err)
 	}
-	if err := m.router6.refreshRulesMap(); err != nil {
+	if err := m.family6.refreshRulesMap(); err != nil {
 		return nil, fmt.Errorf("refresh v6 rules: %w", err)
 	}
-	if has(m.router6, id) && !has(m.router, id) {
-		return m.router6, nil
+	if has(m.family6, id) && !has(m.family4, id) {
+		return m.family6, nil
 	}
-	return m.router, nil
+	return m.family4, nil
 }
 
 func (m *Manager) IsServerRouteSupported() bool {
@@ -381,10 +313,10 @@ func (m *Manager) AddNatRule(pair firewall.RouterPair) error {
 		if !m.hasIPv6() {
 			return fmt.Errorf("add NAT rule: %w", firewall.ErrIPv6NotInitialized)
 		}
-		return m.router6.AddNatRule(pair)
+		return m.family6.AddNatRule(pair)
 	}
 
-	if err := m.router.AddNatRule(pair); err != nil {
+	if err := m.family4.AddNatRule(pair); err != nil {
 		return err
 	}
 
@@ -396,7 +328,7 @@ func (m *Manager) AddNatRule(pair firewall.RouterPair) error {
 	// so the eventual cleanup still works.
 	if m.hasIPv6() && pair.Dynamic {
 		v6Pair := firewall.ToV6NatPair(pair)
-		if err := m.router6.AddNatRule(v6Pair); err != nil {
+		if err := m.family6.AddNatRule(v6Pair); err != nil {
 			return fmt.Errorf("add v6 NAT rule: %w", err)
 		}
 	}
@@ -412,18 +344,18 @@ func (m *Manager) RemoveNatRule(pair firewall.RouterPair) error {
 		if !m.hasIPv6() {
 			return nil
 		}
-		return m.router6.RemoveNatRule(pair)
+		return m.family6.RemoveNatRule(pair)
 	}
 
 	var merr *multierror.Error
 
-	if err := m.router.RemoveNatRule(pair); err != nil {
+	if err := m.family4.RemoveNatRule(pair); err != nil {
 		merr = multierror.Append(merr, fmt.Errorf("remove v4 NAT rule: %w", err))
 	}
 
 	if m.hasIPv6() && pair.Dynamic {
 		v6Pair := firewall.ToV6NatPair(pair)
-		if err := m.router6.RemoveNatRule(v6Pair); err != nil {
+		if err := m.family6.RemoveNatRule(v6Pair); err != nil {
 			merr = multierror.Append(merr, fmt.Errorf("remove v6 NAT rule: %w", err))
 		}
 	}
@@ -431,46 +363,13 @@ func (m *Manager) RemoveNatRule(pair firewall.RouterPair) error {
 	return nberrors.FormatErrorOrNil(merr)
 }
 
-// AllowNetbird allows netbird interface traffic.
-// This is called when USPFilter wraps the native firewall, adding blanket accept
-// rules so that packet filtering is handled in userspace instead of by netfilter.
-//
-// TODO: In USP mode this only adds ACCEPT to the netbird table's own chains,
-// which doesn't override DROP rules in external tables (e.g. firewalld).
-// Should add passthrough rules to external chains (like the native mode router's
-// addExternalChainsRules does) for both the netbird table family and inet tables.
-// The netbird table itself is fine (routing chains already exist there), but
-// non-netbird tables with INPUT/FORWARD hooks can still DROP our WG traffic.
-func (m *Manager) AllowNetbird() error {
-	m.mutex.Lock()
-	defer m.mutex.Unlock()
-
-	if err := m.aclManager.createDefaultAllowRules(); err != nil {
-		return fmt.Errorf("create default allow rules: %w", err)
-	}
-	if m.hasIPv6() {
-		if err := m.aclManager6.createDefaultAllowRules(); err != nil {
-			return fmt.Errorf("create v6 default allow rules: %w", err)
-		}
-	}
-	if err := m.rConn.Flush(); err != nil {
-		return fmt.Errorf("flush allow input netbird rules: %w", err)
-	}
-
-	if err := firewalld.TrustInterface(m.wgIface.Name()); err != nil {
-		log.Warnf("failed to trust interface in firewalld: %v", err)
-	}
-
-	return nil
-}
-
 // SetLegacyManagement sets the route manager to use legacy management
 func (m *Manager) SetLegacyManagement(isLegacy bool) error {
-	if err := firewall.SetLegacyManagement(m.router, isLegacy); err != nil {
+	if err := firewall.SetLegacyManagement(m.family4, isLegacy); err != nil {
 		return err
 	}
 	if m.hasIPv6() {
-		return firewall.SetLegacyManagement(m.router6, isLegacy)
+		return firewall.SetLegacyManagement(m.family6, isLegacy)
 	}
 	return nil
 }
@@ -484,13 +383,13 @@ func (m *Manager) Close(stateManager *statemanager.Manager) error {
 
 	var merr *multierror.Error
 
-	if err := m.router.Reset(); err != nil {
-		merr = multierror.Append(merr, fmt.Errorf("reset router: %v", err))
+	if err := m.family4.Reset(); err != nil {
+		merr = multierror.Append(merr, fmt.Errorf("reset family: %w", err))
 	}
 
 	if m.hasIPv6() {
-		if err := m.router6.Reset(); err != nil {
-			merr = multierror.Append(merr, fmt.Errorf("reset v6 router: %v", err))
+		if err := m.family6.Reset(); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("reset v6 family: %w", err))
 		}
 	}
 
@@ -530,14 +429,14 @@ func (m *Manager) SetLogLevel(log.Level) {
 }
 
 func (m *Manager) EnableRouting() error {
-	if err := m.router.ipFwdState.RequestForwarding(); err != nil {
+	if err := m.family4.ipFwdState.RequestForwarding(); err != nil {
 		return fmt.Errorf("enable IP forwarding: %w", err)
 	}
 	return nil
 }
 
 func (m *Manager) DisableRouting() error {
-	if err := m.router.ipFwdState.ReleaseForwarding(); err != nil {
+	if err := m.family4.ipFwdState.ReleaseForwarding(); err != nil {
 		return fmt.Errorf("disable IP forwarding: %w", err)
 	}
 	return nil
@@ -551,13 +450,13 @@ func (m *Manager) Flush() error {
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
 
-	if err := m.aclManager.Flush(); err != nil {
+	if err := m.family4.Flush(); err != nil {
 		return err
 	}
 
 	if m.hasIPv6() {
-		if err := m.aclManager6.Flush(); err != nil {
-			return fmt.Errorf("flush v6 acl: %w", err)
+		if err := m.family6.Flush(); err != nil {
+			return fmt.Errorf("flush v6 family: %w", err)
 		}
 	}
 
@@ -577,9 +476,9 @@ func (m *Manager) AddDNATRule(rule firewall.ForwardRule) (firewall.Rule, error)
 		if !m.hasIPv6() {
 			return nil, fmt.Errorf("add DNAT rule: %w", firewall.ErrIPv6NotInitialized)
 		}
-		return m.router6.AddDNATRule(rule)
+		return m.family6.AddDNATRule(rule)
 	}
-	return m.router.AddDNATRule(rule)
+	return m.family4.AddDNATRule(rule)
 }
 
 // DeleteDNATRule deletes a DNAT rule
@@ -587,7 +486,7 @@ func (m *Manager) DeleteDNATRule(rule firewall.Rule) error {
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
 
-	r, err := m.routerForRuleID(rule.ID(), (*router).hasDNATRule)
+	r, err := m.familyForRuleID(rule.ID(), (*family).hasDNATRule, true)
 	if err != nil {
 		return err
 	}
@@ -608,12 +507,12 @@ func (m *Manager) UpdateSet(set firewall.Set, prefixes []netip.Prefix) error {
 		}
 	}
 
-	if err := m.router.UpdateSet(set, v4Prefixes); err != nil {
+	if err := m.family4.UpdateSet(set, v4Prefixes); err != nil {
 		return err
 	}
 
 	if m.hasIPv6() && len(v6Prefixes) > 0 {
-		if err := m.router6.UpdateSet(set, v6Prefixes); err != nil {
+		if err := m.family6.UpdateSet(set, v6Prefixes); err != nil {
 			return fmt.Errorf("update v6 set: %w", err)
 		}
 	}
@@ -630,9 +529,9 @@ func (m *Manager) AddInboundDNAT(localAddr netip.Addr, protocol firewall.Protoco
 		if !m.hasIPv6() {
 			return fmt.Errorf("add inbound DNAT: %w", firewall.ErrIPv6NotInitialized)
 		}
-		return m.router6.AddInboundDNAT(localAddr, protocol, originalPort, translatedPort)
+		return m.family6.AddInboundDNAT(localAddr, protocol, originalPort, translatedPort)
 	}
-	return m.router.AddInboundDNAT(localAddr, protocol, originalPort, translatedPort)
+	return m.family4.AddInboundDNAT(localAddr, protocol, originalPort, translatedPort)
 }
 
 // RemoveInboundDNAT removes an inbound DNAT rule.
@@ -644,9 +543,9 @@ func (m *Manager) RemoveInboundDNAT(localAddr netip.Addr, protocol firewall.Prot
 		if !m.hasIPv6() {
 			return fmt.Errorf("remove inbound DNAT: %w", firewall.ErrIPv6NotInitialized)
 		}
-		return m.router6.RemoveInboundDNAT(localAddr, protocol, originalPort, translatedPort)
+		return m.family6.RemoveInboundDNAT(localAddr, protocol, originalPort, translatedPort)
 	}
-	return m.router.RemoveInboundDNAT(localAddr, protocol, originalPort, translatedPort)
+	return m.family4.RemoveInboundDNAT(localAddr, protocol, originalPort, translatedPort)
 }
 
 // AddOutputDNAT adds an OUTPUT chain DNAT rule for locally-generated traffic.
@@ -658,9 +557,9 @@ func (m *Manager) AddOutputDNAT(localAddr netip.Addr, protocol firewall.Protocol
 		if !m.hasIPv6() {
 			return fmt.Errorf("add output DNAT: %w", firewall.ErrIPv6NotInitialized)
 		}
-		return m.router6.AddOutputDNAT(localAddr, protocol, originalPort, translatedPort)
+		return m.family6.AddOutputDNAT(localAddr, protocol, originalPort, translatedPort)
 	}
-	return m.router.AddOutputDNAT(localAddr, protocol, originalPort, translatedPort)
+	return m.family4.AddOutputDNAT(localAddr, protocol, originalPort, translatedPort)
 }
 
 // RemoveOutputDNAT removes an OUTPUT chain DNAT rule.
@@ -672,9 +571,9 @@ func (m *Manager) RemoveOutputDNAT(localAddr netip.Addr, protocol firewall.Proto
 		if !m.hasIPv6() {
 			return fmt.Errorf("remove output DNAT: %w", firewall.ErrIPv6NotInitialized)
 		}
-		return m.router6.RemoveOutputDNAT(localAddr, protocol, originalPort, translatedPort)
+		return m.family6.RemoveOutputDNAT(localAddr, protocol, originalPort, translatedPort)
 	}
-	return m.router.RemoveOutputDNAT(localAddr, protocol, originalPort, translatedPort)
+	return m.family4.RemoveOutputDNAT(localAddr, protocol, originalPort, translatedPort)
 }
 
 const (
@@ -903,3 +802,14 @@ func getEstablishedExprs(register uint32) []expr.Any {
 		},
 	}
 }
+
+// isIPv6Rule reports whether the rule belongs to the v6 table. For a
+// prefix destination the destination family decides; otherwise the
+// (single-family) sources do, since management duplicates rules per
+// family.
+func isIPv6Rule(sources []netip.Prefix, destination firewall.Network) bool {
+	if destination.IsPrefix() {
+		return destination.Prefix.Addr().Is6()
+	}
+	return len(sources) > 0 && sources[0].Addr().Is6()
+}

client/firewall/nftables/manager_linux_test.go

@@ -72,13 +72,13 @@ func TestNftablesManager(t *testing.T) {
 
 	testClient := &nftables.Conn{}
 
-	rule, err := manager.AddPeerFiltering(nil, ip.AsSlice(), fw.ProtocolTCP, nil, &fw.Port{Values: []uint16{53}}, fw.ActionDrop, "")
+	rule, err := manager.AddFilterRule(nil, pfx(ip.AsSlice()), fw.Network{}, fw.ProtocolTCP, nil, &fw.Port{Values: []uint16{53}}, fw.ActionDrop)
 	require.NoError(t, err, "failed to add rule")
 
 	err = manager.Flush()
 	require.NoError(t, err, "failed to flush")
 
-	rules, err := testClient.GetRules(manager.aclManager.workTable, manager.aclManager.chainInputRules)
+	rules, err := testClient.GetRules(manager.family4.workTable, manager.family4.chainInputRules)
 	require.NoError(t, err, "failed to get rules")
 
 	require.Len(t, rules, 2, "expected 2 rules")
@@ -149,15 +149,12 @@ func TestNftablesManager(t *testing.T) {
 	// Compare connection tracking rule at position 1 (pushed down by DROP rule insertion)
 	compareExprsIgnoringCounters(t, rules[1].Exprs, expectedExprs1)
 
-	for _, r := range rule {
-		err = manager.DeletePeerRule(r)
-		require.NoError(t, err, "failed to delete rule")
-	}
+	require.NoError(t, manager.DeleteFilterRule(rule), "failed to delete rule")
 
 	err = manager.Flush()
 	require.NoError(t, err, "failed to flush")
 
-	rules, err = testClient.GetRules(manager.aclManager.workTable, manager.aclManager.chainInputRules)
+	rules, err = testClient.GetRules(manager.family4.workTable, manager.family4.chainInputRules)
 	require.NoError(t, err, "failed to get rules")
 	// established rule remains
 	require.Len(t, rules, 1, "expected 1 rules after deletion")
@@ -182,47 +179,39 @@ func TestNftablesManagerRuleOrder(t *testing.T) {
 	testClient := &nftables.Conn{}
 
 	// Add accept rule first
-	_, err = manager.AddPeerFiltering(nil, ip.AsSlice(), fw.ProtocolTCP, nil, &fw.Port{Values: []uint16{80}}, fw.ActionAccept, "accept-http")
+	_, err = manager.AddFilterRule(nil, pfx(ip.AsSlice()), fw.Network{}, fw.ProtocolTCP, nil, &fw.Port{Values: []uint16{80}}, fw.ActionAccept)
 	require.NoError(t, err, "failed to add accept rule")
 
 	// Add deny rule second for the same traffic
-	_, err = manager.AddPeerFiltering(nil, ip.AsSlice(), fw.ProtocolTCP, nil, &fw.Port{Values: []uint16{80}}, fw.ActionDrop, "deny-http")
+	_, err = manager.AddFilterRule(nil, pfx(ip.AsSlice()), fw.Network{}, fw.ProtocolTCP, nil, &fw.Port{Values: []uint16{80}}, fw.ActionDrop)
 	require.NoError(t, err, "failed to add deny rule")
 
 	err = manager.Flush()
 	require.NoError(t, err, "failed to flush")
 
-	rules, err := testClient.GetRules(manager.aclManager.workTable, manager.aclManager.chainInputRules)
+	rules, err := testClient.GetRules(manager.family4.workTable, manager.family4.chainInputRules)
 	require.NoError(t, err, "failed to get rules")
 
 	t.Logf("Found %d rules in nftables chain", len(rules))
 
-	// Find the accept and deny rules and verify deny comes before accept
+	// Single-source rules emit a direct payload+cmp on the source IP
+	// (no set lookup). Match by source-IP + port + verdict instead of
+	// the legacy per-(action,port) set names ("deny-http"/"accept-http")
+	// that this test predates.
+	wantSrc := ip.AsSlice()
 	var acceptRuleIndex, denyRuleIndex = -1, -1
 	for i, rule := range rules {
-		hasAcceptHTTPSet := false
-		hasDenyHTTPSet := false
-		hasPort80 := false
+		var hasSrc, hasPort80 bool
 		var action string
-
 		for _, e := range rule.Exprs {
-			// Check for set lookup
-			if lookup, ok := e.(*expr.Lookup); ok {
-				switch lookup.SetName {
-				case "accept-http":
-					hasAcceptHTTPSet = true
-				case "deny-http":
-					hasDenyHTTPSet = true
+			if cmp, ok := e.(*expr.Cmp); ok && cmp.Op == expr.CmpOpEq {
+				if bytes.Equal(cmp.Data, wantSrc) {
+					hasSrc = true
 				}
-
-			}
-			// Check for port 80
-			if cmp, ok := e.(*expr.Cmp); ok {
-				if cmp.Op == expr.CmpOpEq && len(cmp.Data) == 2 && binary.BigEndian.Uint16(cmp.Data) == 80 {
+				if len(cmp.Data) == 2 && binary.BigEndian.Uint16(cmp.Data) == 80 {
 					hasPort80 = true
 				}
 			}
-			// Check for verdict
 			if verdict, ok := e.(*expr.Verdict); ok {
 				switch verdict.Kind {
 				case expr.VerdictAccept:
@@ -233,11 +222,15 @@ func TestNftablesManagerRuleOrder(t *testing.T) {
 			}
 		}
 
-		if hasAcceptHTTPSet && hasPort80 && action == "ACCEPT" {
-			t.Logf("Rule [%d]: accept-http set + Port 80 + ACCEPT", i)
+		if !hasSrc || !hasPort80 {
+			continue
+		}
+		switch action {
+		case "ACCEPT":
+			t.Logf("Rule [%d]: src=%s port=80 ACCEPT", i, ip)
 			acceptRuleIndex = i
-		} else if hasDenyHTTPSet && hasPort80 && action == "DROP" {
-			t.Logf("Rule [%d]: deny-http set + Port 80 + DROP", i)
+		case "DROP":
+			t.Logf("Rule [%d]: src=%s port=80 DROP", i, ip)
 			denyRuleIndex = i
 		}
 	}
@@ -281,7 +274,7 @@ func TestNFtablesCreatePerformance(t *testing.T) {
 			start := time.Now()
 			for i := 0; i < testMax; i++ {
 				port := &fw.Port{Values: []uint16{uint16(1000 + i)}}
-				_, err = manager.AddPeerFiltering(nil, ip.AsSlice(), "tcp", nil, port, fw.ActionAccept, "")
+				_, err = manager.AddFilterRule(nil, pfx(ip.AsSlice()), fw.Network{}, "tcp", nil, port, fw.ActionAccept)
 				require.NoError(t, err, "failed to add rule")
 
 				if i%100 == 0 {
@@ -363,10 +356,10 @@ func TestNftablesManagerCompatibilityWithIptables(t *testing.T) {
 	})
 
 	ip := netip.MustParseAddr("100.96.0.1")
-	_, err = manager.AddPeerFiltering(nil, ip.AsSlice(), fw.ProtocolTCP, nil, &fw.Port{Values: []uint16{80}}, fw.ActionAccept, "")
+	_, err = manager.AddFilterRule(nil, pfx(ip.AsSlice()), fw.Network{}, fw.ProtocolTCP, nil, &fw.Port{Values: []uint16{80}}, fw.ActionAccept)
 	require.NoError(t, err, "failed to add peer filtering rule")
 
-	_, err = manager.AddRouteFiltering(
+	_, err = manager.AddFilterRule(
 		nil,
 		[]netip.Prefix{netip.MustParsePrefix("192.168.2.0/24")},
 		fw.Network{Prefix: netip.MustParsePrefix("10.1.0.0/24")},
@@ -439,10 +432,10 @@ func TestNftablesManagerIPv6CompatibilityWithIp6tables(t *testing.T) {
 	})
 
 	ip := netip.MustParseAddr("fd00::2")
-	_, err = manager.AddPeerFiltering(nil, ip.AsSlice(), fw.ProtocolTCP, nil, &fw.Port{Values: []uint16{80}}, fw.ActionAccept, "")
+	_, err = manager.AddFilterRule(nil, pfx(ip.AsSlice()), fw.Network{}, fw.ProtocolTCP, nil, &fw.Port{Values: []uint16{80}}, fw.ActionAccept)
 	require.NoError(t, err, "add v6 peer filtering rule")
 
-	_, err = manager.AddRouteFiltering(
+	_, err = manager.AddFilterRule(
 		nil,
 		[]netip.Prefix{netip.MustParsePrefix("fd00:1::/64")},
 		fw.Network{Prefix: netip.MustParsePrefix("2001:db8::/48")},
@@ -552,7 +545,7 @@ func TestNftablesManagerCompatibilityWithIptablesFor6kPrefixes(t *testing.T) {
 			prefixes = append(prefixes, netip.PrefixFrom(addr, 24))
 		}
 	}
-	_, err = manager.AddRouteFiltering(
+	_, err = manager.AddFilterRule(
 		nil,
 		prefixes,
 		fw.Network{Prefix: netip.MustParsePrefix("10.2.0.0/24")},
@@ -567,7 +560,7 @@ func TestNftablesManagerCompatibilityWithIptablesFor6kPrefixes(t *testing.T) {
 	verifyIptablesOutput(t, stdout, stderr)
 }
 
-func TestNftablesManagerCompatibilityWithIptablesForEmptyPrefixes(t *testing.T) {
+func TestNftablesManagerCompatibilityWithIptablesForWildcardSource(t *testing.T) {
 	if check() != NFTABLES {
 		t.Skip("nftables not supported on this system")
 	}
@@ -593,9 +586,9 @@ func TestNftablesManagerCompatibilityWithIptablesForEmptyPrefixes(t *testing.T)
 		verifyIptablesOutput(t, stdout, stderr)
 	})
 
-	_, err = manager.AddRouteFiltering(
+	_, err = manager.AddFilterRule(
 		nil,
-		[]netip.Prefix{},
+		[]netip.Prefix{netip.MustParsePrefix("0.0.0.0/0")},
 		fw.Network{Prefix: netip.MustParsePrefix("10.2.0.0/24")},
 		fw.ProtocolTCP,
 		nil,
@@ -608,6 +601,73 @@ func TestNftablesManagerCompatibilityWithIptablesForEmptyPrefixes(t *testing.T)
 	verifyIptablesOutput(t, stdout, stderr)
 }
 
+func TestNftablesManagerMultiPortFilter(t *testing.T) {
+	if check() != NFTABLES {
+		t.Skip("nftables not supported on this system")
+	}
+
+	manager, err := Create(ifaceMock, iface.DefaultMTU)
+	require.NoError(t, err)
+	require.NoError(t, manager.Init(nil))
+
+	t.Cleanup(func() {
+		require.NoError(t, manager.Close(nil), "failed to reset manager state")
+	})
+
+	ip := netip.MustParseAddr("100.96.0.1")
+
+	rule, err := manager.AddFilterRule(nil, pfx(ip.AsSlice()), fw.Network{}, fw.ProtocolTCP, nil, &fw.Port{Values: []uint16{80, 443}}, fw.ActionAccept)
+	require.NoError(t, err, "failed to add multi-port rule")
+
+	testClient := &nftables.Conn{}
+	rules, err := testClient.GetRules(manager.family4.workTable, manager.family4.chainInputRules)
+	require.NoError(t, err, "failed to get rules")
+
+	var lookup *expr.Lookup
+	for _, kernelRule := range rules {
+		if string(kernelRule.UserData) != string(rule.ID()) {
+			continue
+		}
+		for _, e := range kernelRule.Exprs {
+			if l, ok := e.(*expr.Lookup); ok {
+				lookup = l
+			}
+		}
+	}
+	require.NotNil(t, lookup, "multi-port rule must match ports via a set lookup")
+
+	sets, err := testClient.GetSets(manager.family4.workTable)
+	require.NoError(t, err, "failed to get sets")
+
+	var portSet *nftables.Set
+	for _, s := range sets {
+		if s.Name == lookup.SetName {
+			portSet = s
+		}
+	}
+	require.NotNil(t, portSet, "anonymous port set not found in kernel")
+
+	portSet.Table = manager.family4.workTable
+	elements, err := testClient.GetSetElements(portSet)
+	require.NoError(t, err, "failed to get set elements")
+
+	ports := make(map[uint16]bool)
+	for _, e := range elements {
+		require.Len(t, e.Key, 2, "port set element key should be 2 bytes")
+		ports[binary.BigEndian.Uint16(e.Key)] = true
+	}
+	require.True(t, ports[80], "port set should contain port 80")
+	require.True(t, ports[443], "port set should contain port 443")
+
+	require.NoError(t, manager.DeleteFilterRule(rule), "failed to delete rule")
+
+	rules, err = testClient.GetRules(manager.family4.workTable, manager.family4.chainInputRules)
+	require.NoError(t, err, "failed to get rules after delete")
+	for _, kernelRule := range rules {
+		require.NotEqual(t, string(rule.ID()), string(kernelRule.UserData), "rule should be removed from kernel")
+	}
+}
+
 func compareExprsIgnoringCounters(t *testing.T, got, want []expr.Any) {
 	t.Helper()
 	require.Equal(t, len(got), len(want), "expression count mismatch")

client/firewall/nftables/router_linux_test.go

@@ -37,7 +37,7 @@ func TestNftablesManager_AddNatRule(t *testing.T) {
 
 	for _, testCase := range test.InsertRuleTestCases {
 		t.Run(testCase.Name, func(t *testing.T) {
-			// need fw manager to init both acl mgr and router for all chains to be present
+			// need fw manager to init both acl mgr and family for all chains to be present
 			manager, err := Create(ifaceMock, iface.DefaultMTU)
 			t.Cleanup(func() {
 				require.NoError(t, manager.Close(nil))
@@ -47,7 +47,7 @@ func TestNftablesManager_AddNatRule(t *testing.T) {
 
 			nftablesTestingClient := &nftables.Conn{}
 
-			rtr := manager.router
+			rtr := manager.family4
 			err = rtr.AddNatRule(testCase.InputPair)
 			require.NoError(t, err, "pair should be inserted")
 
@@ -90,9 +90,9 @@ func TestNftablesManager_AddNatRule(t *testing.T) {
 				}
 
 				// Build CIDR matching expressions
-				testRouter := &router{af: afIPv4}
-				sourceExp := testRouter.applyPrefix(testCase.InputPair.Source.Prefix, true)
-				destExp := testRouter.applyPrefix(testCase.InputPair.Destination.Prefix, false)
+				testRouter := &family{af: afIPv4}
+				sourceExp := prefixMatchExprs(testRouter.af, testCase.InputPair.Source.Prefix, true)
+				destExp := prefixMatchExprs(testRouter.af, testCase.InputPair.Destination.Prefix, false)
 
 				// Combine all expressions in the correct order
 				// nolint:gocritic
@@ -100,14 +100,14 @@ func TestNftablesManager_AddNatRule(t *testing.T) {
 				testingExpression = append(testingExpression, sourceExp...)
 				testingExpression = append(testingExpression, destExp...)
 
-				natRuleKey := firewall.GenKey(firewall.PreroutingFormat, testCase.InputPair)
+				natRuleKey := testCase.InputPair.GenKey(firewall.PreroutingFormat)
 				found := 0
 				for _, chain := range rtr.chains {
 					if chain.Name == chainNameManglePrerouting {
 						rules, err := nftablesTestingClient.GetRules(chain.Table, chain)
 						require.NoError(t, err, "should list rules for %s table and %s chain", chain.Table.Name, chain.Name)
 						for _, rule := range rules {
-							if len(rule.UserData) > 0 && string(rule.UserData) == natRuleKey {
+							if len(rule.UserData) > 0 && firewall.RuleID(rule.UserData) == natRuleKey {
 								// Compare expressions up to the mark setting expressions
 								require.ElementsMatchf(t, rule.Exprs[:len(testingExpression)], testingExpression, "prerouting nat rule elements should match")
 								found = 1
@@ -135,19 +135,19 @@ func TestNftablesManager_RemoveNatRule(t *testing.T) {
 			require.NoError(t, err)
 			require.NoError(t, manager.Init(nil))
 
-			rtr := manager.router
+			rtr := manager.family4
 
-			// First add the NAT rule using the router's method
+			// First add the NAT rule using the family's method
 			err = rtr.AddNatRule(testCase.InputPair)
 			require.NoError(t, err, "should add NAT rule")
 
 			// Verify the rule was added
-			natRuleKey := firewall.GenKey(firewall.PreroutingFormat, testCase.InputPair)
+			natRuleKey := testCase.InputPair.GenKey(firewall.PreroutingFormat)
 			found := false
 			rules, err := rtr.conn.GetRules(rtr.workTable, rtr.chains[chainNameManglePrerouting])
 			require.NoError(t, err, "should list rules")
 			for _, rule := range rules {
-				if len(rule.UserData) > 0 && string(rule.UserData) == natRuleKey {
+				if len(rule.UserData) > 0 && firewall.RuleID(rule.UserData) == natRuleKey {
 					found = true
 					break
 				}
@@ -163,7 +163,7 @@ func TestNftablesManager_RemoveNatRule(t *testing.T) {
 			rules, err = rtr.conn.GetRules(rtr.workTable, rtr.chains[chainNameManglePrerouting])
 			require.NoError(t, err, "should list rules after removal")
 			for _, rule := range rules {
-				if len(rule.UserData) > 0 && string(rule.UserData) == natRuleKey {
+				if len(rule.UserData) > 0 && firewall.RuleID(rule.UserData) == natRuleKey {
 					found = true
 					break
 				}
@@ -200,11 +200,10 @@ func TestRouter_AddRouteFiltering(t *testing.T) {
 
 	defer deleteWorkTable()
 
-	r, err := newRouter(workTable, ifaceMock, iface.DefaultMTU)
-	require.NoError(t, err, "Failed to create router")
+	r := newFamily(workTable, ifaceMock, iface.DefaultMTU)
 	require.NoError(t, r.init(workTable))
 
-	defer func(r *router) {
+	defer func(r *family) {
 		require.NoError(t, r.Reset(), "Failed to reset rules")
 	}(r)
 
@@ -314,16 +313,16 @@ func TestRouter_AddRouteFiltering(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			ruleKey, err := r.AddRouteFiltering(nil, tt.sources, firewall.Network{Prefix: tt.destination}, tt.proto, tt.sPort, tt.dPort, tt.action)
-			require.NoError(t, err, "AddRouteFiltering failed")
+			ruleKey, err := r.AddFilterRule(nil, tt.sources, firewall.Network{Prefix: tt.destination}, tt.proto, tt.sPort, tt.dPort, tt.action)
+			require.NoError(t, err, "AddFilterRule failed")
 
 			t.Cleanup(func() {
-				require.NoError(t, r.DeleteRouteRule(ruleKey), "Failed to delete rule")
+				require.NoError(t, r.DeleteFilterRule(ruleKey), "Failed to delete rule")
 			})
 
-			// Check if the rule is in the internal map
-			rule, ok := r.rules[ruleKey.ID()]
-			assert.True(t, ok, "Rule not found in internal map")
+			stored, ok := r.filters[id.RuleID(ruleKey.ID())]
+			require.True(t, ok, "Rule not found in filters map")
+			rule := stored.nftRule
 
 			t.Log("Internal rule expressions:")
 			for i, expr := range rule.Exprs {
@@ -339,7 +338,7 @@ func TestRouter_AddRouteFiltering(t *testing.T) {
 
 			var nftRule *nftables.Rule
 			for _, rule := range rules {
-				if string(rule.UserData) == ruleKey.ID() {
+				if firewall.RuleID(rule.UserData) == ruleKey.ID() {
 					nftRule = rule
 					break
 				}
@@ -367,12 +366,11 @@ func TestNftablesCreateIpSet(t *testing.T) {
 
 	defer deleteWorkTable()
 
-	r, err := newRouter(workTable, ifaceMock, iface.DefaultMTU)
-	require.NoError(t, err, "Failed to create router")
+	r := newFamily(workTable, ifaceMock, iface.DefaultMTU)
 	require.NoError(t, r.init(workTable))
 
 	defer func() {
-		require.NoError(t, r.Reset(), "Failed to reset router")
+		require.NoError(t, r.Reset(), "Failed to reset family")
 	}()
 
 	tests := []struct {
@@ -509,6 +507,41 @@ func TestNftablesCreateIpSet(t *testing.T) {
 	}
 }
 
+// TestNftablesUpdateSetMergesOverlapping verifies that UpdateSet merges
+// overlapping prefixes before adding them. An interval set rejects
+// overlapping elements, so without the merge a batch holding a /32 already
+// covered by a /24, or a duplicate address as DNS resolution can produce,
+// would fail.
+func TestNftablesUpdateSetMergesOverlapping(t *testing.T) {
+	if check() != NFTABLES {
+		t.Skip("nftables not supported on this system")
+	}
+
+	workTable, err := createWorkTable()
+	require.NoError(t, err, "create work table")
+	defer deleteWorkTable()
+
+	r := newFamily(workTable, ifaceMock, iface.DefaultMTU)
+	require.NoError(t, r.init(workTable))
+	defer func() {
+		require.NoError(t, r.Reset(), "reset family")
+	}()
+
+	initial := []netip.Prefix{netip.MustParsePrefix("10.0.0.0/24")}
+	set := firewall.NewPrefixSet(initial)
+
+	created, err := r.createIpSet(set.HashedName(), setInput{prefixes: initial})
+	require.NoError(t, err, "create ip set")
+	require.NotNil(t, created)
+
+	overlapping := []netip.Prefix{
+		netip.MustParsePrefix("192.168.1.0/24"),
+		netip.MustParsePrefix("192.168.1.1/32"),
+		netip.MustParsePrefix("192.168.1.1/32"),
+	}
+	require.NoError(t, r.UpdateSet(set, overlapping), "UpdateSet must merge overlapping prefixes")
+}
+
 func TestNftablesCreateIpSet_IPv6(t *testing.T) {
 	if check() != NFTABLES {
 		t.Skip("nftables not supported on this system")
@@ -518,11 +551,10 @@ func TestNftablesCreateIpSet_IPv6(t *testing.T) {
 	require.NoError(t, err, "Failed to create v6 work table")
 	defer deleteWorkTableIPv6()
 
-	r, err := newRouter(workTable, ifaceMock, iface.DefaultMTU)
-	require.NoError(t, err, "Failed to create router")
+	r := newFamily(workTable, ifaceMock, iface.DefaultMTU)
 	require.NoError(t, r.init(workTable))
 	defer func() {
-		require.NoError(t, r.Reset(), "Failed to reset router")
+		require.NoError(t, r.Reset(), "Failed to reset family")
 	}()
 
 	tests := []struct {
@@ -748,6 +780,14 @@ func containsPort(exprs []expr.Any, port *firewall.Port, isSource bool) bool {
 					}
 				}
 			}
+		case *expr.Lookup:
+			// Multiple discrete ports compile to an anonymous set lookup
+			// rather than a chain of comparisons. The set's id and name are
+			// assigned dynamically, so matching the lookup is enough here;
+			// the set elements are verified separately.
+			if !port.IsRange && len(port.Values) > 1 {
+				portMatchFound = true
+			}
 		}
 		if payloadFound && portMatchFound {
 			return true
@@ -861,13 +901,12 @@ func TestRouter_RefreshRulesMap_RemovesStaleEntries(t *testing.T) {
 	require.NoError(t, err)
 	defer deleteWorkTable()
 
-	r, err := newRouter(workTable, ifaceMock, iface.DefaultMTU)
-	require.NoError(t, err)
+	r := newFamily(workTable, ifaceMock, iface.DefaultMTU)
 	require.NoError(t, r.init(workTable))
 	defer func() { require.NoError(t, r.Reset()) }()
 
 	// Add a real rule to the kernel
-	ruleKey, err := r.AddRouteFiltering(
+	ruleKey, err := r.AddFilterRule(
 		nil,
 		[]netip.Prefix{netip.MustParsePrefix("192.168.1.0/24")},
 		firewall.Network{Prefix: netip.MustParsePrefix("10.0.0.0/24")},
@@ -878,11 +917,11 @@ func TestRouter_RefreshRulesMap_RemovesStaleEntries(t *testing.T) {
 	)
 	require.NoError(t, err)
 	t.Cleanup(func() {
-		require.NoError(t, r.DeleteRouteRule(ruleKey))
+		require.NoError(t, r.DeleteFilterRule(ruleKey))
 	})
 
 	// Inject a stale entry with Handle=0 (simulates store-before-flush failure)
-	staleKey := "stale-rule-that-does-not-exist"
+	staleKey := firewall.RuleID("stale-rule-that-does-not-exist")
 	r.rules[staleKey] = &nftables.Rule{
 		Table:    r.workTable,
 		Chain:    r.chains[chainNameRoutingFw],
@@ -902,6 +941,54 @@ func TestRouter_RefreshRulesMap_RemovesStaleEntries(t *testing.T) {
 	assert.NotZero(t, realRule.Handle, "real rule should have a valid handle")
 }
 
+// TestRouter_DeleteRouteRule_RemovesKernelRule verifies a route filter
+// rule is actually removed from the kernel on delete. The route chain is
+// not refreshed by Flush, so the stored rule carries a zero handle;
+// DeleteFilterRule must pull live handles itself before issuing the
+// delete or the kernel rule leaks. Regression test for that path.
+func TestRouter_DeleteRouteRule_RemovesKernelRule(t *testing.T) {
+	if check() != NFTABLES {
+		t.Skip("nftables not supported on this system")
+	}
+
+	workTable, err := createWorkTable()
+	require.NoError(t, err)
+	defer deleteWorkTable()
+
+	r := newFamily(workTable, ifaceMock, iface.DefaultMTU)
+	require.NoError(t, r.init(workTable))
+	defer func() { require.NoError(t, r.Reset()) }()
+
+	ruleKey, err := r.AddFilterRule(
+		nil,
+		[]netip.Prefix{netip.MustParsePrefix("192.168.1.0/24")},
+		firewall.Network{Prefix: netip.MustParsePrefix("10.0.0.0/24")},
+		firewall.ProtocolTCP,
+		nil,
+		&firewall.Port{Values: []uint16{80}},
+		firewall.ActionAccept,
+	)
+	require.NoError(t, err)
+
+	countKernelRules := func() int {
+		list, err := r.conn.GetRules(r.workTable, r.chains[chainNameRoutingFw])
+		require.NoError(t, err)
+		n := 0
+		for _, rule := range list {
+			if string(rule.UserData) == string(ruleKey.ID()) {
+				n++
+			}
+		}
+		return n
+	}
+
+	require.Equal(t, 1, countKernelRules(), "rule should be present in the kernel after add")
+
+	require.NoError(t, r.DeleteFilterRule(ruleKey))
+	assert.Equal(t, 0, countKernelRules(), "rule must be removed from the kernel after delete")
+	assert.NotContains(t, r.filters, ruleKey.ID(), "filters map entry should be cleared")
+}
+
 func TestRouter_DeleteRouteRule_StaleHandle(t *testing.T) {
 	if check() != NFTABLES {
 		t.Skip("nftables not supported on this system")
@@ -911,24 +998,27 @@ func TestRouter_DeleteRouteRule_StaleHandle(t *testing.T) {
 	require.NoError(t, err)
 	defer deleteWorkTable()
 
-	r, err := newRouter(workTable, ifaceMock, iface.DefaultMTU)
-	require.NoError(t, err)
+	r := newFamily(workTable, ifaceMock, iface.DefaultMTU)
 	require.NoError(t, r.init(workTable))
 	defer func() { require.NoError(t, r.Reset()) }()
 
 	// Inject a stale entry with Handle=0
-	staleKey := "stale-route-rule"
-	r.rules[staleKey] = &nftables.Rule{
-		Table:    r.workTable,
-		Chain:    r.chains[chainNameRoutingFw],
-		Handle:   0,
-		UserData: []byte(staleKey),
+	staleKey := id.RuleID("stale-route-rule")
+	staleRule := &Rule{
+		nftRule: &nftables.Rule{
+			Table:    r.workTable,
+			Chain:    r.chains[chainNameRoutingFw],
+			Handle:   0,
+			UserData: []byte(staleKey),
+		},
+		id: staleKey,
 	}
+	r.filters[staleKey] = staleRule
 
-	// DeleteRouteRule should not return an error for stale handles
-	err = r.DeleteRouteRule(id.RuleID(staleKey))
+	// DeleteFilterRule should not return an error for stale handles
+	err = r.DeleteFilterRule(staleRule)
 	assert.NoError(t, err, "deleting a stale rule should not error")
-	assert.NotContains(t, r.rules, staleKey, "stale entry should be cleaned up")
+	assert.NotContains(t, r.filters, staleKey, "stale entry should be cleaned up")
 }
 
 func TestRouter_AddNatRule_WithStaleEntry(t *testing.T) {
@@ -950,7 +1040,7 @@ func TestRouter_AddNatRule_WithStaleEntry(t *testing.T) {
 		Masquerade:  true,
 	}
 
-	rtr := manager.router
+	rtr := manager.family4
 
 	// First add succeeds
 	err = rtr.AddNatRule(pair)
@@ -960,11 +1050,11 @@ func TestRouter_AddNatRule_WithStaleEntry(t *testing.T) {
 	})
 
 	// Corrupt the handle to simulate stale state
-	natRuleKey := firewall.GenKey(firewall.PreroutingFormat, pair)
+	natRuleKey := pair.GenKey(firewall.PreroutingFormat)
 	if rule, exists := rtr.rules[natRuleKey]; exists {
 		rule.Handle = 0
 	}
-	inverseKey := firewall.GenKey(firewall.PreroutingFormat, firewall.GetInversePair(pair))
+	inverseKey := firewall.GetInversePair(pair).GenKey(firewall.PreroutingFormat)
 	if rule, exists := rtr.rules[inverseKey]; exists {
 		rule.Handle = 0
 	}
@@ -979,7 +1069,7 @@ func TestRouter_AddNatRule_WithStaleEntry(t *testing.T) {
 
 	found := 0
 	for _, rule := range rules {
-		if len(rule.UserData) > 0 && string(rule.UserData) == natRuleKey {
+		if len(rule.UserData) > 0 && firewall.RuleID(rule.UserData) == natRuleKey {
 			found++
 		}
 	}
@@ -1010,7 +1100,7 @@ func TestCalculateLastIP(t *testing.T) {
 }
 
 func TestConvertPrefixesToSet_IPv6(t *testing.T) {
-	r := &router{af: afIPv6}
+	r := &family{af: afIPv6}
 	prefixes := []netip.Prefix{
 		netip.MustParsePrefix("fd00::/64"),
 		netip.MustParsePrefix("2001:db8::1/128"),

client/firewall/nftables/routing_linux.go

@@ -0,0 +1,505 @@
+//go:build !android
+
+package nftables
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/google/nftables"
+	"github.com/google/nftables/binaryutil"
+	"github.com/google/nftables/expr"
+	"github.com/hashicorp/go-multierror"
+	log "github.com/sirupsen/logrus"
+	"golang.org/x/sys/unix"
+
+	nberrors "github.com/netbirdio/netbird/client/errors"
+	firewall "github.com/netbirdio/netbird/client/firewall/manager"
+	nbnet "github.com/netbirdio/netbird/client/net"
+)
+
+func (r *family) AddNatRule(pair firewall.RouterPair) error {
+	if err := r.refreshRulesMap(); err != nil {
+		return fmt.Errorf(refreshRulesMapError, err)
+	}
+
+	if r.legacyManagement {
+		log.Warnf("This peer is connected to a NetBird Management service with an older version. Allowing all traffic for %s", pair.Destination)
+		if err := r.addLegacyRouteRule(pair); err != nil {
+			r.rollbackRules(pair)
+			return fmt.Errorf("add legacy routing rule: %w", err)
+		}
+	}
+
+	if pair.Masquerade {
+		if err := r.addNatRule(pair); err != nil {
+			r.rollbackRules(pair)
+			return fmt.Errorf("add nat rule: %w", err)
+		}
+
+		if err := r.addNatRule(firewall.GetInversePair(pair)); err != nil {
+			r.rollbackRules(pair)
+			return fmt.Errorf("add inverse nat rule: %w", err)
+		}
+	}
+
+	if err := r.conn.Flush(); err != nil {
+		r.rollbackRules(pair)
+		return fmt.Errorf("insert rules for %s: %w", pair.Destination, err)
+	}
+
+	return nil
+}
+
+// rollbackRules cleans up unflushed rules and their set counters after a flush failure.
+func (r *family) rollbackRules(pair firewall.RouterPair) {
+	keys := []firewall.RuleID{
+		pair.GenKey(firewall.ForwardingFormat),
+		pair.GenKey(firewall.PreroutingFormat),
+		firewall.GetInversePair(pair).GenKey(firewall.PreroutingFormat),
+	}
+	for _, key := range keys {
+		rule, ok := r.rules[key]
+		if !ok {
+			continue
+		}
+		if err := r.decrementSetCounter(rule); err != nil {
+			log.Warnf("rollback set counter for %s: %v", key, err)
+		}
+		delete(r.rules, key)
+	}
+}
+
+// addNatRule inserts a nftables rule to the conn client flush queue
+func (r *family) addNatRule(pair firewall.RouterPair) error {
+	sourceExp, err := r.applyNetwork(pair.Source, nil, true)
+	if err != nil {
+		return fmt.Errorf("apply source: %w", err)
+	}
+
+	destExp, err := r.applyNetwork(pair.Destination, nil, false)
+	if err != nil {
+		r.dropNetworkMatch(sourceExp)
+		return fmt.Errorf("apply destination: %w", err)
+	}
+
+	op := expr.CmpOpEq
+	if pair.Inverse {
+		op = expr.CmpOpNeq
+	}
+
+	exprs := []expr.Any{
+		&expr.Meta{
+			Key:      expr.MetaKeyIIFNAME,
+			Register: 1,
+		},
+		&expr.Cmp{
+			Op:       op,
+			Register: 1,
+			Data:     ifname(r.wgIface.Name()),
+		},
+	}
+	// We only care about NEW connections to mark them and later identify them in the postrouting chain for masquerading.
+	// Masquerading will take care of the conntrack state, which means we won't need to mark established connections.
+	exprs = append(exprs, getCtNewExprs()...)
+
+	exprs = append(exprs, sourceExp...)
+	exprs = append(exprs, destExp...)
+
+	var markValue uint32 = nbnet.PreroutingFwmarkMasquerade
+	if pair.Inverse {
+		markValue = nbnet.PreroutingFwmarkMasqueradeReturn
+	}
+
+	exprs = append(exprs,
+		&expr.Immediate{
+			Register: 1,
+			Data:     binaryutil.NativeEndian.PutUint32(markValue),
+		},
+		&expr.Meta{
+			Key:            expr.MetaKeyMARK,
+			SourceRegister: true,
+			Register:       1,
+		},
+	)
+
+	ruleID := pair.GenKey(firewall.PreroutingFormat)
+
+	if _, exists := r.rules[ruleID]; exists {
+		if err := r.removeNatRule(pair); err != nil {
+			r.dropNetworkMatch(sourceExp)
+			r.dropNetworkMatch(destExp)
+			return fmt.Errorf("remove prerouting rule: %w", err)
+		}
+	}
+
+	// Ensure nat rules come first, so the mark can be overwritten.
+	// Currently overwritten by the dst-type LOCAL rules for redirected traffic.
+	r.rules[ruleID] = r.conn.InsertRule(&nftables.Rule{
+		Table:    r.workTable,
+		Chain:    r.chains[chainNameManglePrerouting],
+		Exprs:    exprs,
+		UserData: []byte(ruleID),
+	})
+
+	return nil
+}
+
+func (r *family) addPostroutingRules() {
+	// First masquerade rule for traffic coming in from WireGuard interface
+	exprs := []expr.Any{
+		// Match on the first fwmark
+		&expr.Meta{
+			Key:      expr.MetaKeyMARK,
+			Register: 1,
+		},
+		&expr.Cmp{
+			Op:       expr.CmpOpEq,
+			Register: 1,
+			Data:     binaryutil.NativeEndian.PutUint32(nbnet.PreroutingFwmarkMasquerade),
+		},
+
+		// We need to exclude the loopback interface as this changes the ebpf proxy port
+		&expr.Meta{
+			Key:      expr.MetaKeyOIFNAME,
+			Register: 1,
+		},
+		&expr.Cmp{
+			Op:       expr.CmpOpNeq,
+			Register: 1,
+			Data:     ifname("lo"),
+		},
+		&expr.Counter{},
+		&expr.Masq{},
+	}
+
+	r.conn.AddRule(&nftables.Rule{
+		Table: r.workTable,
+		Chain: r.chains[chainNameRoutingNat],
+		Exprs: exprs,
+	})
+
+	// Second masquerade rule for traffic going out through WireGuard interface
+	exprs2 := []expr.Any{
+		// Match on the second fwmark
+		&expr.Meta{
+			Key:      expr.MetaKeyMARK,
+			Register: 1,
+		},
+		&expr.Cmp{
+			Op:       expr.CmpOpEq,
+			Register: 1,
+			Data:     binaryutil.NativeEndian.PutUint32(nbnet.PreroutingFwmarkMasqueradeReturn),
+		},
+
+		// Match WireGuard interface
+		&expr.Meta{
+			Key:      expr.MetaKeyOIFNAME,
+			Register: 1,
+		},
+		&expr.Cmp{
+			Op:       expr.CmpOpEq,
+			Register: 1,
+			Data:     ifname(r.wgIface.Name()),
+		},
+		&expr.Counter{},
+		&expr.Masq{},
+	}
+
+	r.conn.AddRule(&nftables.Rule{
+		Table: r.workTable,
+		Chain: r.chains[chainNameRoutingNat],
+		Exprs: exprs2,
+	})
+}
+
+// addMSSClampingRules adds MSS clamping rules to prevent fragmentation for forwarded traffic.
+func (r *family) addMSSClampingRules() error {
+	overhead := uint16(ipv4TCPHeaderSize)
+	if r.af.tableFamily == nftables.TableFamilyIPv6 {
+		overhead = ipv6TCPHeaderSize
+	}
+	if r.mtu <= overhead {
+		log.Debugf("MTU %d too small for MSS clamping (overhead %d), skipping", r.mtu, overhead)
+		return nil
+	}
+	mss := r.mtu - overhead
+
+	exprsOut := []expr.Any{
+		&expr.Meta{
+			Key:      expr.MetaKeyOIFNAME,
+			Register: 1,
+		},
+		&expr.Cmp{
+			Op:       expr.CmpOpEq,
+			Register: 1,
+			Data:     ifname(r.wgIface.Name()),
+		},
+		&expr.Meta{
+			Key:      expr.MetaKeyL4PROTO,
+			Register: 1,
+		},
+		&expr.Cmp{
+			Op:       expr.CmpOpEq,
+			Register: 1,
+			Data:     []byte{unix.IPPROTO_TCP},
+		},
+		&expr.Payload{
+			DestRegister: 1,
+			Base:         expr.PayloadBaseTransportHeader,
+			Offset:       13,
+			Len:          1,
+		},
+		&expr.Bitwise{
+			DestRegister:   1,
+			SourceRegister: 1,
+			Len:            1,
+			Mask:           []byte{0x02},
+			Xor:            []byte{0x00},
+		},
+		&expr.Cmp{
+			Op:       expr.CmpOpNeq,
+			Register: 1,
+			Data:     []byte{0x00},
+		},
+		&expr.Counter{},
+		&expr.Exthdr{
+			DestRegister: 1,
+			Type:         2,
+			Offset:       2,
+			Len:          2,
+			Op:           expr.ExthdrOpTcpopt,
+		},
+		&expr.Cmp{
+			Op:       expr.CmpOpGt,
+			Register: 1,
+			Data:     binaryutil.BigEndian.PutUint16(uint16(mss)),
+		},
+		&expr.Immediate{
+			Register: 1,
+			Data:     binaryutil.BigEndian.PutUint16(uint16(mss)),
+		},
+		&expr.Exthdr{
+			SourceRegister: 1,
+			Type:           2,
+			Offset:         2,
+			Len:            2,
+			Op:             expr.ExthdrOpTcpopt,
+		},
+	}
+
+	r.conn.AddRule(&nftables.Rule{
+		Table: r.workTable,
+		Chain: r.chains[chainNameMangleForward],
+		Exprs: exprsOut,
+	})
+
+	return r.conn.Flush()
+}
+
+func buildLegacyRouteRuleExpressions(sourceExp, destExp []expr.Any) []expr.Any {
+	exprs := make([]expr.Any, 0, len(sourceExp)+len(destExp)+2)
+	exprs = append(exprs, sourceExp...)
+	exprs = append(exprs, destExp...)
+	exprs = append(exprs,
+		&expr.Counter{},
+		&expr.Verdict{Kind: expr.VerdictAccept},
+	)
+	return exprs
+}
+
+func (r *family) addLegacyRouteRule(pair firewall.RouterPair) error {
+	sourceExp, err := r.applyNetwork(pair.Source, nil, true)
+	if err != nil {
+		return fmt.Errorf("apply source: %w", err)
+	}
+
+	destExp, err := r.applyNetwork(pair.Destination, nil, false)
+	if err != nil {
+		r.dropNetworkMatch(sourceExp)
+		return fmt.Errorf("apply destination: %w", err)
+	}
+
+	exprs := buildLegacyRouteRuleExpressions(sourceExp, destExp)
+
+	ruleID := pair.GenKey(firewall.ForwardingFormat)
+
+	if _, exists := r.rules[ruleID]; exists {
+		if err := r.removeLegacyRouteRule(pair); err != nil {
+			r.dropNetworkMatch(sourceExp)
+			r.dropNetworkMatch(destExp)
+			return fmt.Errorf("remove legacy routing rule: %w", err)
+		}
+	}
+
+	r.rules[ruleID] = r.conn.AddRule(&nftables.Rule{
+		Table:    r.workTable,
+		Chain:    r.chains[chainNameRoutingFw],
+		Exprs:    exprs,
+		UserData: []byte(ruleID),
+	})
+	return nil
+}
+
+// removeLegacyRouteRule removes a legacy routing rule for mgmt servers pre route acls
+func (r *family) removeLegacyRouteRule(pair firewall.RouterPair) error {
+	ruleID := pair.GenKey(firewall.ForwardingFormat)
+
+	rule, exists := r.rules[ruleID]
+	if !exists {
+		return nil
+	}
+
+	return r.deleteLegacyRuleEntry(ruleID, rule)
+}
+
+// deleteLegacyRuleEntry removes one legacy forwarding rule and drops its
+// ipset references. It also clears stale entries that never got a handle.
+func (r *family) deleteLegacyRuleEntry(ruleID firewall.RuleID, rule *nftables.Rule) error {
+	if rule.Handle == 0 {
+		log.Warnf("legacy forwarding rule %s has no handle, removing stale entry", ruleID)
+		if err := r.decrementSetCounter(rule); err != nil {
+			log.Warnf("decrement set counter for stale rule %s: %v", ruleID, err)
+		}
+		delete(r.rules, ruleID)
+		return nil
+	}
+
+	if err := r.conn.DelRule(rule); err != nil {
+		return fmt.Errorf("remove legacy forwarding rule %s: %w", ruleID, err)
+	}
+
+	delete(r.rules, ruleID)
+
+	if err := r.decrementSetCounter(rule); err != nil {
+		return fmt.Errorf("decrement set counter: %w", err)
+	}
+
+	return nil
+}
+
+// GetLegacyManagement returns the route manager's legacy management mode
+func (r *family) GetLegacyManagement() bool {
+	return r.legacyManagement
+}
+
+// SetLegacyManagement sets the route manager to use legacy management mode
+func (r *family) SetLegacyManagement(isLegacy bool) {
+	r.legacyManagement = isLegacy
+}
+
+// RemoveAllLegacyRouteRules removes all legacy routing rules for mgmt servers pre route acls
+func (r *family) RemoveAllLegacyRouteRules() error {
+	if err := r.refreshRulesMap(); err != nil {
+		return fmt.Errorf(refreshRulesMapError, err)
+	}
+
+	var merr *multierror.Error
+	for k, rule := range r.rules {
+		if !strings.HasPrefix(string(k), firewall.ForwardingFormatPrefix) {
+			continue
+		}
+		if err := r.deleteLegacyRuleEntry(k, rule); err != nil {
+			merr = multierror.Append(merr, err)
+		}
+	}
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+func (r *family) removeNatPreroutingRules() error {
+	table := &nftables.Table{
+		Name:   tableNat,
+		Family: r.af.tableFamily,
+	}
+	chain := &nftables.Chain{
+		Name:     chainNameNatPrerouting,
+		Table:    table,
+		Hooknum:  nftables.ChainHookPrerouting,
+		Priority: nftables.ChainPriorityNATDest,
+		Type:     nftables.ChainTypeNAT,
+	}
+	rules, err := r.conn.GetRules(table, chain)
+	if err != nil {
+		return fmt.Errorf("get rules from nat table: %w", err)
+	}
+
+	var merr *multierror.Error
+
+	// Delete rules that have our UserData suffix
+	for _, rule := range rules {
+		if len(rule.UserData) == 0 || !strings.HasSuffix(string(rule.UserData), string(dnatSuffix)) {
+			continue
+		}
+		if err := r.conn.DelRule(rule); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("delete rule %s: %w", rule.UserData, err))
+		}
+	}
+
+	if err := r.conn.Flush(); err != nil {
+		merr = multierror.Append(merr, fmt.Errorf(flushError, err))
+	}
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+func (r *family) RemoveNatRule(pair firewall.RouterPair) error {
+	if err := r.refreshRulesMap(); err != nil {
+		return fmt.Errorf(refreshRulesMapError, err)
+	}
+
+	var merr *multierror.Error
+
+	if pair.Masquerade {
+		if err := r.removeNatRule(pair); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("remove prerouting rule: %w", err))
+		}
+
+		if err := r.removeNatRule(firewall.GetInversePair(pair)); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("remove inverse prerouting rule: %w", err))
+		}
+	}
+
+	if err := r.removeLegacyRouteRule(pair); err != nil {
+		merr = multierror.Append(merr, fmt.Errorf("remove legacy routing rule: %w", err))
+	}
+
+	// Set counters are decremented in the sub-methods above before flush. If flush fails,
+	// counters will be off until the next successful removal or refresh cycle.
+	if err := r.conn.Flush(); err != nil {
+		merr = multierror.Append(merr, fmt.Errorf("flush remove nat rules %s: %w", pair.Destination, err))
+	}
+
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+func (r *family) removeNatRule(pair firewall.RouterPair) error {
+	ruleID := pair.GenKey(firewall.PreroutingFormat)
+
+	rule, exists := r.rules[ruleID]
+	if !exists {
+		log.Debugf("prerouting rule %s not found", ruleID)
+		return nil
+	}
+
+	if rule.Handle == 0 {
+		log.Warnf("prerouting rule %s has no handle, removing stale entry", ruleID)
+		if err := r.decrementSetCounter(rule); err != nil {
+			log.Warnf("decrement set counter for stale rule %s: %v", ruleID, err)
+		}
+		delete(r.rules, ruleID)
+		return nil
+	}
+
+	if err := r.conn.DelRule(rule); err != nil {
+		return fmt.Errorf("remove prerouting rule %s -> %s: %w", pair.Source, pair.Destination, err)
+	}
+
+	log.Debugf("removed prerouting rule %s -> %s", pair.Source, pair.Destination)
+
+	delete(r.rules, ruleID)
+
+	if err := r.decrementSetCounter(rule); err != nil {
+		return fmt.Errorf("decrement set counter: %w", err)
+	}
+
+	return nil
+}

client/firewall/nftables/rule_linux.go

@@ -1,21 +1,26 @@
 package nftables
 
 import (
-	"net"
+	"net/netip"
 
 	"github.com/google/nftables"
+
+	"github.com/netbirdio/netbird/client/firewall/manager"
 )
 
-// Rule to handle management of rules
+// Rule wraps an installed filter rule (peer or route). Source set
+// membership is encoded in the rule's expressions; DeleteFilterRule
+// recovers the set name via findSets so the refcounter can drop the
+// right reference. mangleRule is set only for peer rules.
 type Rule struct {
 	nftRule    *nftables.Rule
 	mangleRule *nftables.Rule
-	nftSet     *nftables.Set
-	ruleID     string
-	ip         net.IP
+	// sources is the canonical source list this rule was created for.
+	sources []netip.Prefix
+	id      manager.RuleID
 }
 
-// GetRuleID returns the rule id
-func (r *Rule) ID() string {
-	return r.ruleID
+// ID returns the rule id
+func (r *Rule) ID() manager.RuleID {
+	return r.id
 }

client/firewall/nftables/testhelpers_linux_test.go

@@ -0,0 +1,27 @@
+//go:build privileged
+
+package nftables
+
+import (
+	"fmt"
+	"net"
+	"net/netip"
+)
+
+func pfx(ip net.IP) []netip.Prefix {
+	if ip == nil {
+		return []netip.Prefix{netip.PrefixFrom(netip.IPv4Unspecified(), 0)}
+	}
+	if ip.IsUnspecified() {
+		if ip.To4() != nil {
+			return []netip.Prefix{netip.PrefixFrom(netip.IPv4Unspecified(), 0)}
+		}
+		return []netip.Prefix{netip.PrefixFrom(netip.IPv6Unspecified(), 0)}
+	}
+	a, ok := netip.AddrFromSlice(ip)
+	if !ok {
+		panic(fmt.Sprintf("invalid IP length: %d", len(ip)))
+	}
+	a = a.Unmap()
+	return []netip.Prefix{netip.PrefixFrom(a, a.BitLen())}
+}

client/firewall/uspfilter/allow_netbird.go

@@ -1,37 +0,0 @@
-//go:build !windows
-
-package uspfilter
-
-import (
-	log "github.com/sirupsen/logrus"
-
-	"github.com/netbirdio/netbird/client/firewall/firewalld"
-	"github.com/netbirdio/netbird/client/internal/statemanager"
-)
-
-// Close cleans up the firewall manager by removing all rules and closing trackers
-func (m *Manager) Close(stateManager *statemanager.Manager) error {
-	m.mutex.Lock()
-	defer m.mutex.Unlock()
-
-	m.resetState()
-
-	if m.nativeFirewall != nil {
-		return m.nativeFirewall.Close(stateManager)
-	}
-	if err := firewalld.UntrustInterface(m.wgIface.Name()); err != nil {
-		log.Warnf("failed to untrust interface in firewalld: %v", err)
-	}
-	return nil
-}
-
-// AllowNetbird allows netbird interface traffic
-func (m *Manager) AllowNetbird() error {
-	if m.nativeFirewall != nil {
-		return m.nativeFirewall.AllowNetbird()
-	}
-	if err := firewalld.TrustInterface(m.wgIface.Name()); err != nil {
-		log.Warnf("failed to trust interface in firewalld: %v", err)
-	}
-	return nil
-}

client/firewall/uspfilter/common/iface.go

@@ -1,17 +0,0 @@
-package common
-
-import (
-	wgdevice "golang.zx2c4.com/wireguard/device"
-
-	"github.com/netbirdio/netbird/client/iface/device"
-	"github.com/netbirdio/netbird/client/iface/wgaddr"
-)
-
-// IFaceMapper defines subset methods of interface required for manager
-type IFaceMapper interface {
-	Name() string
-	SetFilter(device.PacketFilter) error
-	Address() wgaddr.Address
-	GetWGDevice() *wgdevice.Device
-	GetDevice() *device.FilteredDevice
-}

client/firewall/uspfilter/filter.go

@@ -5,7 +5,6 @@ import (
 	"encoding/binary"
 	"errors"
 	"fmt"
-	"net"
 	"net/netip"
 	"os"
 	"slices"
@@ -20,14 +19,18 @@ import (
 	"github.com/google/uuid"
 	"github.com/hashicorp/go-multierror"
 	log "github.com/sirupsen/logrus"
+	wgdevice "golang.zx2c4.com/wireguard/device"
 
 	nberrors "github.com/netbirdio/netbird/client/errors"
+	"github.com/netbirdio/netbird/client/firewall/firewalld"
 	firewall "github.com/netbirdio/netbird/client/firewall/manager"
 	"github.com/netbirdio/netbird/client/firewall/uspfilter/common"
 	"github.com/netbirdio/netbird/client/firewall/uspfilter/conntrack"
 	"github.com/netbirdio/netbird/client/firewall/uspfilter/forwarder"
 	nblog "github.com/netbirdio/netbird/client/firewall/uspfilter/log"
+	"github.com/netbirdio/netbird/client/iface/device"
 	"github.com/netbirdio/netbird/client/iface/netstack"
+	"github.com/netbirdio/netbird/client/iface/wgaddr"
 	nbid "github.com/netbirdio/netbird/client/internal/acl/id"
 	nftypes "github.com/netbirdio/netbird/client/internal/netflow/types"
 	"github.com/netbirdio/netbird/client/internal/statemanager"
@@ -58,7 +61,10 @@ const (
 	// EnvDisableMSSClamping disables TCP MSS clamping for forwarded traffic.
 	EnvDisableMSSClamping = "NB_DISABLE_MSS_CLAMPING"
 
-	// EnvForceUserspaceRouter forces userspace routing even if native routing is available.
+	// EnvForceUserspaceRouter is a deprecated alias for
+	// NB_FORCE_USERSPACE_FIREWALL: the userspace firewall always routes in
+	// userspace, so forcing one forces the other. Kept for backward
+	// compatibility.
 	EnvForceUserspaceRouter = "NB_FORCE_USERSPACE_ROUTER"
 
 	// EnvEnableLocalForwarding enables forwarding of local traffic to the native stack for internal (non-NetBird) interfaces.
@@ -70,14 +76,20 @@ const (
 	EnvEnableNetstackLocalForwarding = "NB_ENABLE_NETSTACK_LOCAL_FORWARDING"
 )
 
-var errNatNotSupported = errors.New("nat not supported with userspace firewall")
+// errNotSupported is returned by firewall operations that only make sense with
+// a kernel firewall (kernel NAT/DNAT, eBPF) and are not implemented in
+// userspace mode, where they should not be called.
+var errNotSupported = errors.New("not supported with userspace firewall")
 
-// RuleSet is a set of rules grouped by a string key
-type RuleSet map[string]PeerRule
+// peerRules is the canonical list-based storage for peer ACL rules.
+// Drop and accept rules live in separate slices; drop-before-accept
+// ordering comes from consulting the deny slice (and its index) before
+// the accept one.
+type peerRules []*PeerRule
 
-type RouteRules []*RouteRule
+type routeRules []*RouteRule
 
-func (r RouteRules) Sort() {
+func (r routeRules) Sort() {
 	slices.SortStableFunc(r, func(a, b *RouteRule) int {
 		// Deny rules come first
 		if a.action == firewall.ActionDrop && b.action != firewall.ActionDrop {
@@ -86,22 +98,74 @@ func (r RouteRules) Sort() {
 		if a.action != firewall.ActionDrop && b.action == firewall.ActionDrop {
 			return 1
 		}
-		return strings.Compare(a.id, b.id)
+		return strings.Compare(string(a.id), string(b.id))
 	})
 }
 
+// peerRuleSpec carries the parameters that define a peer filter rule,
+// threaded together through the build path so the builders take a single
+// argument instead of a long parameter list.
+type peerRuleSpec struct {
+	mgmtID  []byte
+	sources []netip.Prefix
+	ipLayer gopacket.LayerType
+	proto   firewall.Protocol
+	sPort   *firewall.Port
+	dPort   *firewall.Port
+	action  firewall.Action
+}
+
+// Iface is the network interface the userspace firewall attaches to: the
+// methods of the WireGuard device it actually uses.
+type Iface interface {
+	Name() string
+	Address() wgaddr.Address
+	SetFilter(device.PacketFilter) error
+	GetWGDevice() *wgdevice.Device
+}
+
+// InterfaceAllower opens the NetBird interface in the host firewall so it
+// doesn't drop traffic the userspace firewall handles, without taking over
+// packet filtering. Implementations (nftables, iptables, firewalld, the windows
+// netsh rule) are selected per platform and injected into Create; Apply runs at
+// creation and Close on teardown.
+type InterfaceAllower interface {
+	Apply() error
+	Close() error
+}
+
+// Config holds the dependencies and options for the userspace firewall.
+type Config struct {
+	// IFace is the overlay interface the filter attaches to.
+	IFace Iface
+	// InterfaceAllower opens the NetBird interface in foreign kernel filter
+	// chains so the kernel doesn't drop traffic the userspace firewall handles.
+	// Nil in netstack mode, on non-Linux platforms without a backend, or when
+	// neither nftables nor iptables is available. firewalld trust is applied by
+	// the manager regardless, since firewalld owns its own chains and we cannot
+	// insert into them.
+	InterfaceAllower InterfaceAllower
+	// DisableServerRoutes indicates whether server routes are disabled.
+	DisableServerRoutes bool
+	FlowLogger          nftypes.FlowLogger
+	MTU                 uint16
+}
+
 // Manager userspace firewall manager
 type Manager struct {
-	outgoingRules     map[netip.Addr]RuleSet
-	incomingDenyRules map[netip.Addr]RuleSet
-	incomingRules     map[netip.Addr]RuleSet
-	routeRules        RouteRules
-	routeRulesMap     map[nbid.RuleID]*RouteRule
-	decoders          sync.Pool
-	wgIface           common.IFaceMapper
-	nativeFirewall    firewall.Manager
+	decoders     sync.Pool
+	wgIface      Iface
+	ifaceAllower InterfaceAllower
+	mutex        sync.RWMutex
 
-	mutex sync.RWMutex
+	incomingDenyRules   peerRules
+	incomingAcceptRules peerRules
+	incomingDenyIndex   peerRuleIndex
+	incomingAcceptIndex peerRuleIndex
+	peerRulesMap        map[nbid.RuleID]*PeerRule
+
+	routeRules    routeRules
+	routeRulesMap map[nbid.RuleID]*RouteRule
 
 	// indicates whether server routes are disabled
 	disableServerRoutes bool
@@ -219,24 +283,6 @@ func (d *decoder) decodeTransport(proto layers.IPProtocol, payload []byte) bool
 	return true
 }
 
-// Create userspace firewall manager constructor
-func Create(iface common.IFaceMapper, disableServerRoutes bool, flowLogger nftypes.FlowLogger, mtu uint16) (*Manager, error) {
-	return create(iface, nil, disableServerRoutes, flowLogger, mtu)
-}
-
-func CreateWithNativeFirewall(iface common.IFaceMapper, nativeFirewall firewall.Manager, disableServerRoutes bool, flowLogger nftypes.FlowLogger, mtu uint16) (*Manager, error) {
-	if nativeFirewall == nil {
-		return nil, errors.New("native firewall is nil")
-	}
-
-	mgr, err := create(iface, nativeFirewall, disableServerRoutes, flowLogger, mtu)
-	if err != nil {
-		return nil, err
-	}
-
-	return mgr, nil
-}
-
 func parseCreateEnv() (bool, bool, bool) {
 	var disableConntrack, enableLocalForwarding, disableMSSClamping bool
 	var err error
@@ -267,7 +313,7 @@ func parseCreateEnv() (bool, bool, bool) {
 	return disableConntrack, enableLocalForwarding, disableMSSClamping
 }
 
-func create(iface common.IFaceMapper, nativeFirewall firewall.Manager, disableServerRoutes bool, flowLogger nftypes.FlowLogger, mtu uint16) (*Manager, error) {
+func Create(cfg Config) (_ *Manager, err error) {
 	disableConntrack, enableLocalForwarding, disableMSSClamping := parseCreateEnv()
 
 	m := &Manager{
@@ -290,65 +336,133 @@ func create(iface common.IFaceMapper, nativeFirewall firewall.Manager, disableSe
 				return d
 			},
 		},
-		nativeFirewall:      nativeFirewall,
-		outgoingRules:       make(map[netip.Addr]RuleSet),
-		incomingDenyRules:   make(map[netip.Addr]RuleSet),
-		incomingRules:       make(map[netip.Addr]RuleSet),
-		wgIface:             iface,
+		wgIface:             cfg.IFace,
+		ifaceAllower:        cfg.InterfaceAllower,
 		localipmanager:      newLocalIPManager(),
-		disableServerRoutes: disableServerRoutes,
+		disableServerRoutes: cfg.DisableServerRoutes,
 		stateful:            !disableConntrack,
 		logger:              nblog.NewFromLogrus(log.StandardLogger()),
-		flowLogger:          flowLogger,
+		flowLogger:          cfg.FlowLogger,
 		netstack:            netstack.IsEnabled(),
 		localForwarding:     enableLocalForwarding,
+		peerRulesMap:        make(map[nbid.RuleID]*PeerRule),
 		routeRulesMap:       make(map[nbid.RuleID]*RouteRule),
 		dnatMappings:        make(map[netip.Addr]netip.Addr),
 		portDNATRules:       []portDNATRule{},
 		netstackServices:    make(map[serviceKey]struct{}),
-		mtu:                 mtu,
+		mtu:                 cfg.MTU,
 	}
 	m.routingEnabled.Store(false)
 
+	// Release the allower (and its monitor) if setup fails after it was wired in.
+	defer func() {
+		if err != nil {
+			m.closeAllowerOnError()
+		}
+	}()
+
 	if !disableMSSClamping {
-		m.mssClampEnabled = true
-		if mtu > ipv4TCPHeaderMinSize {
-			m.mssClampValueIPv4 = mtu - ipv4TCPHeaderMinSize
-		}
-		if mtu > ipv6TCPHeaderMinSize {
-			m.mssClampValueIPv6 = mtu - ipv6TCPHeaderMinSize
-		}
+		m.enableMSSClamping(cfg.MTU)
 	}
-	if err := m.localipmanager.UpdateLocalIPs(iface); err != nil {
+	if err := m.localipmanager.UpdateLocalIPs(cfg.IFace); err != nil {
 		return nil, fmt.Errorf("update local IPs: %w", err)
 	}
 	m.fragments = newFragmentTracker(m.logger)
-
-	if disableConntrack {
-		log.Info("conntrack is disabled")
-	} else {
-		m.udpTracker = conntrack.NewUDPTracker(conntrack.DefaultUDPTimeout, m.logger, flowLogger)
-		m.icmpTracker = conntrack.NewICMPTracker(conntrack.DefaultICMPTimeout, m.logger, flowLogger)
-		m.tcpTracker = conntrack.NewTCPTracker(conntrack.DefaultTCPTimeout, m.logger, flowLogger)
-	}
+	m.setupConntrack(disableConntrack)
 	if m.netstack && m.localForwarding {
 		if err := m.initForwarder(); err != nil {
 			log.Errorf("failed to initialize forwarder: %v", err)
 		}
 	}
-	if err := iface.SetFilter(m); err != nil {
+	if err := cfg.IFace.SetFilter(m); err != nil {
 		m.fragments.Close()
 		return nil, fmt.Errorf("set filter: %w", err)
 	}
+
+	m.openHostFirewall(cfg.IFace.Name())
+
 	return m, nil
 }
 
+// closeAllowerOnError releases the allower (and its monitor) when Create fails
+// after the allower was wired in.
+func (m *Manager) closeAllowerOnError() {
+	if m.ifaceAllower == nil {
+		return
+	}
+	if err := m.ifaceAllower.Close(); err != nil {
+		log.Warnf("close interface allower after failed firewall setup: %v", err)
+	}
+}
+
+// enableMSSClamping enables MSS clamping and computes the per-family clamp values.
+func (m *Manager) enableMSSClamping(mtu uint16) {
+	m.mssClampEnabled = true
+	if mtu > ipv4TCPHeaderMinSize {
+		m.mssClampValueIPv4 = mtu - ipv4TCPHeaderMinSize
+	}
+	if mtu > ipv6TCPHeaderMinSize {
+		m.mssClampValueIPv6 = mtu - ipv6TCPHeaderMinSize
+	}
+}
+
+// setupConntrack initializes the stateful trackers unless conntrack is disabled.
+func (m *Manager) setupConntrack(disabled bool) {
+	if disabled {
+		log.Info("conntrack is disabled")
+		return
+	}
+	m.udpTracker = conntrack.NewUDPTracker(conntrack.DefaultUDPTimeout, m.logger, m.flowLogger)
+	m.icmpTracker = conntrack.NewICMPTracker(conntrack.DefaultICMPTimeout, m.logger, m.flowLogger)
+	m.tcpTracker = conntrack.NewTCPTracker(conntrack.DefaultTCPTimeout, m.logger, m.flowLogger)
+}
+
+// openHostFirewall opens the NetBird interface in the kernel firewall so it
+// doesn't drop traffic the userspace firewall handles. Best-effort: failures
+// here shouldn't prevent the firewall from coming up.
+func (m *Manager) openHostFirewall(ifaceName string) {
+	if m.ifaceAllower != nil {
+		if err := m.ifaceAllower.Apply(); err != nil {
+			log.Errorf("failed to allow netbird interface traffic: %v", err)
+		}
+	}
+	// firewalld owns its own chains we can't insert into, so trust the interface
+	// there in addition to the allower. Netstack has no kernel interface.
+	if !m.netstack {
+		if err := firewalld.TrustInterface(ifaceName); err != nil {
+			log.Warnf("failed to trust interface in firewalld: %v", err)
+		}
+	}
+}
+
+// Close cleans up the firewall manager: removes rules, closes trackers, and
+// closes the interface allower.
+func (m *Manager) Close(*statemanager.Manager) error {
+	m.mutex.Lock()
+	defer m.mutex.Unlock()
+
+	m.resetState()
+
+	var merr *multierror.Error
+	if m.ifaceAllower != nil {
+		if err := m.ifaceAllower.Close(); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("close interface allower: %w", err))
+		}
+	}
+	if !m.netstack {
+		if err := firewalld.UntrustInterface(m.wgIface.Name()); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("untrust interface in firewalld: %w", err))
+		}
+	}
+	return nberrors.FormatErrorOrNil(merr)
+}
+
 // blockInvalidRouted installs drop rules for traffic to the wg overlay that
 // arrives via the routing path. v4 and v6 are independent: a v6 install
 // failure leaves v4 protection in place (and vice versa) so the returned
 // slice always contains whatever was successfully installed, even on error.
 // Callers must persist the slice so DisableRouting can clean partial state.
-func (m *Manager) blockInvalidRouted(iface common.IFaceMapper) ([]firewall.Rule, error) {
+func (m *Manager) blockInvalidRouted(iface Iface) ([]firewall.Rule, error) {
 	wgPrefix := iface.Address().Network
 	log.Debugf("blocking invalid routed traffic for %s", wgPrefix)
 
@@ -359,7 +473,7 @@ func (m *Manager) blockInvalidRouted(iface common.IFaceMapper) ([]firewall.Rule,
 	}
 
 	var rules []firewall.Rule
-	v4Rule, err := m.addRouteFiltering(
+	v4Rule, err := m.addRouteRule(
 		nil,
 		sources,
 		firewall.Network{Prefix: wgPrefix},
@@ -375,7 +489,7 @@ func (m *Manager) blockInvalidRouted(iface common.IFaceMapper) ([]firewall.Rule,
 
 	if v6Net.IsValid() {
 		log.Debugf("blocking invalid routed traffic for %s", v6Net)
-		v6Rule, err := m.addRouteFiltering(
+		v6Rule, err := m.addRouteRule(
 			nil,
 			sources,
 			firewall.Network{Prefix: v6Net},
@@ -396,20 +510,14 @@ func (m *Manager) blockInvalidRouted(iface common.IFaceMapper) ([]firewall.Rule,
 }
 
 func (m *Manager) determineRouting() error {
-	var disableUspRouting, forceUserspaceRouter bool
-	var err error
+	var disableUspRouting bool
 	if val := os.Getenv(EnvDisableUserspaceRouting); val != "" {
+		var err error
 		disableUspRouting, err = strconv.ParseBool(val)
 		if err != nil {
 			log.Warnf("failed to parse %s: %v", EnvDisableUserspaceRouting, err)
 		}
 	}
-	if val := os.Getenv(EnvForceUserspaceRouter); val != "" {
-		forceUserspaceRouter, err = strconv.ParseBool(val)
-		if err != nil {
-			log.Warnf("failed to parse %s: %v", EnvForceUserspaceRouter, err)
-		}
-	}
 
 	switch {
 	case disableUspRouting:
@@ -424,26 +532,11 @@ func (m *Manager) determineRouting() error {
 
 		log.Info("server routes are disabled")
 
-	case forceUserspaceRouter:
-		m.routingEnabled.Store(true)
-		m.nativeRouter.Store(false)
-
-		log.Info("userspace routing is forced")
-
-	case !m.netstack && m.nativeFirewall != nil:
-		// if the OS supports routing natively, then we don't need to filter/route ourselves
-		// netstack mode won't support native routing as there is no interface
-
-		m.routingEnabled.Store(true)
-		m.nativeRouter.Store(true)
-
-		log.Info("native routing is enabled")
-
 	default:
 		m.routingEnabled.Store(true)
 		m.nativeRouter.Store(false)
 
-		log.Info("userspace routing enabled by default")
+		log.Info("userspace routing enabled")
 	}
 
 	if m.routingEnabled.Load() && !m.nativeRouter.Load() {
@@ -509,96 +602,118 @@ func (m *Manager) IsStateful() bool {
 	return m.stateful
 }
 
-func (m *Manager) AddNatRule(pair firewall.RouterPair) error {
-	if m.nativeRouter.Load() && m.nativeFirewall != nil {
-		return m.nativeFirewall.AddNatRule(pair)
-	}
-
+func (m *Manager) AddNatRule(firewall.RouterPair) error {
 	// userspace routed packets are always SNATed to the inbound direction
 	// TODO: implement outbound SNAT
 	return nil
 }
 
 // RemoveNatRule removes a routing firewall rule
-func (m *Manager) RemoveNatRule(pair firewall.RouterPair) error {
-	if m.nativeRouter.Load() && m.nativeFirewall != nil {
-		return m.nativeFirewall.RemoveNatRule(pair)
-	}
+func (m *Manager) RemoveNatRule(firewall.RouterPair) error {
 	return nil
 }
 
-// AddPeerFiltering rule to the firewall
-//
-// If comment argument is empty firewall manager should set
-// rule ID as comment for the rule
-func (m *Manager) AddPeerFiltering(
+// addPeerRule installs an input-chain rule that matches packets
+// by source only. Called from AddFilterRule when the caller doesn't
+// specify a destination. Sources are expected to share one address
+// family; the family selects the ipLayer so the ICMP variant matches
+// what the decoder produces.
+func (m *Manager) addPeerRule(
 	id []byte,
-	ip net.IP,
+	sources []netip.Prefix,
 	proto firewall.Protocol,
 	sPort *firewall.Port,
 	dPort *firewall.Port,
 	action firewall.Action,
-	_ string,
-) ([]firewall.Rule, error) {
-	// TODO: fix in upper layers
-	i, ok := netip.AddrFromSlice(ip)
-	if !ok {
-		return nil, fmt.Errorf("invalid IP: %s", ip)
-	}
-
-	i = i.Unmap()
-	r := PeerRule{
-		id:        uuid.New().String(),
-		mgmtId:    id,
-		ip:        i,
-		ipLayer:   layers.LayerTypeIPv6,
-		matchByIP: true,
-		drop:      action == firewall.ActionDrop,
-	}
-	if i.Is4() {
-		r.ipLayer = layers.LayerTypeIPv4
-	}
-
-	if s := r.ip.String(); s == "0.0.0.0" || s == "::" {
-		r.matchByIP = false
-	}
-
-	r.sPort = sPort
-	r.dPort = dPort
-
-	r.protoLayer = protoToLayer(proto, r.ipLayer)
-
-	m.mutex.Lock()
-	var targetMap map[netip.Addr]RuleSet
-	if r.drop {
-		targetMap = m.incomingDenyRules
-	} else {
-		targetMap = m.incomingRules
-	}
-
-	if _, ok := targetMap[r.ip]; !ok {
-		targetMap[r.ip] = make(RuleSet)
-	}
-	targetMap[r.ip][r.id] = r
-	m.mutex.Unlock()
-	return []firewall.Rule{&r}, nil
-}
-
-func (m *Manager) AddRouteFiltering(
-	id []byte,
-	sources []netip.Prefix,
-	destination firewall.Network,
-	proto firewall.Protocol,
-	sPort, dPort *firewall.Port,
-	action firewall.Action,
 ) (firewall.Rule, error) {
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
 
-	return m.addRouteFiltering(id, sources, destination, proto, sPort, dPort, action)
+	// Sources are a single family; normalize v4-mapped prefixes to plain
+	// v4 and pick the matching IP layer. A /0 source matches any address
+	// of its own family only, mirroring the kernel backends.
+	normalized := make([]netip.Prefix, len(sources))
+	ipLayer := layers.LayerTypeIPv4
+	for i, p := range sources {
+		normalized[i] = firewall.UnmapPrefix(p)
+		if normalized[i].Addr().Is6() {
+			ipLayer = layers.LayerTypeIPv6
+		}
+	}
+	spec := peerRuleSpec{
+		mgmtID:  id,
+		sources: normalized,
+		ipLayer: ipLayer,
+		proto:   proto,
+		sPort:   sPort,
+		dPort:   dPort,
+		action:  action,
+	}
+	return m.addOnePeerRule(spec), nil
 }
 
-func (m *Manager) addRouteFiltering(
+// addOnePeerRule builds and registers a single-family peer rule, or
+// returns the existing rule when one with the same content key is
+// already installed. The caller must hold m.mutex. The content key is
+// the shared GenerateRuleID with an empty destination, so peer rules
+// dedup the same way route rules and the kernel backends do; it is
+// order-independent, so callers passing the same sources in any order
+// dedup to one rule.
+//
+// There is no refcount: a content key is installed once and deleted on
+// the first DeleteFilterRule for that key. The caller must therefore
+// key its own tracking by the returned rule id so add and delete stay
+// balanced per content key; the acl manager does this via
+// peerRulesPairs.
+func (m *Manager) addOnePeerRule(spec peerRuleSpec) *PeerRule {
+	ruleID := nbid.GenerateRuleID(spec.sources, firewall.Network{}, spec.proto, spec.sPort, spec.dPort, spec.action)
+	if existing, ok := m.peerRulesMap[ruleID]; ok {
+		return existing
+	}
+
+	rule := m.buildPeerRule(ruleID, spec)
+	m.registerPeerRule(rule)
+	return rule
+}
+
+func (m *Manager) buildPeerRule(ruleID nbid.RuleID, spec peerRuleSpec) *PeerRule {
+	r := &PeerRule{
+		id:      ruleID,
+		mgmtId:  spec.mgmtID,
+		sources: spec.sources,
+		action:  spec.action,
+		srcPort: spec.sPort,
+		dstPort: spec.dPort,
+	}
+	r.sourceAddrs = make(map[netip.Addr]struct{}, len(spec.sources))
+	for _, p := range spec.sources {
+		if p.Bits() == p.Addr().BitLen() {
+			r.sourceAddrs[p.Addr()] = struct{}{}
+		}
+	}
+	r.protoLayer = protoToLayer(spec.proto, spec.ipLayer)
+	return r
+}
+
+// registerPeerRule records a freshly built peer rule in the matching
+// slice, index, and dedup map. The caller must hold m.mutex.
+func (m *Manager) registerPeerRule(r *PeerRule) {
+	if r.action == firewall.ActionDrop {
+		m.incomingDenyRules = append(m.incomingDenyRules, r)
+		m.incomingDenyIndex.add(r)
+	} else {
+		m.incomingAcceptRules = append(m.incomingAcceptRules, r)
+		m.incomingAcceptIndex.add(r)
+	}
+	m.peerRulesMap[r.id] = r
+}
+
+// AddFilterRule is the unified entry point for both peer (input chain)
+// and route (forward chain) filtering rules. The destination
+// distinguishes the two semantics: a zero Network installs an
+// input-side rule that matches by source only; a set Network installs
+// a forward-side rule that also matches the destination.
+func (m *Manager) AddFilterRule(
 	id []byte,
 	sources []netip.Prefix,
 	destination firewall.Network,
@@ -606,19 +721,49 @@ func (m *Manager) addRouteFiltering(
 	sPort, dPort *firewall.Port,
 	action firewall.Action,
 ) (firewall.Rule, error) {
-	if m.nativeRouter.Load() && m.nativeFirewall != nil {
-		return m.nativeFirewall.AddRouteFiltering(id, sources, destination, proto, sPort, dPort, action)
+	if len(sources) == 0 {
+		return nil, firewall.ErrNoSources
 	}
 
-	ruleKey := nbid.GenerateRouteRuleKey(sources, destination, proto, sPort, dPort, action)
+	if destination.IsZero() {
+		return m.addPeerRule(id, sources, proto, sPort, dPort, action)
+	}
 
-	if existingRule, ok := m.routeRulesMap[ruleKey]; ok {
+	m.mutex.Lock()
+	defer m.mutex.Unlock()
+	return m.addRouteRule(id, sources, destination, proto, sPort, dPort, action)
+}
+
+// DeleteFilterRule deletes a filtering rule. The rule's underlying type
+// is used to route to the correct internal path.
+func (m *Manager) DeleteFilterRule(rule firewall.Rule) error {
+	m.mutex.Lock()
+	defer m.mutex.Unlock()
+
+	if r, ok := rule.(*PeerRule); ok {
+		return m.deletePeerRuleLocked(r)
+	}
+
+	// Anything else is a route rule (matched on the forward path).
+	return m.deleteRouteRule(rule)
+}
+
+func (m *Manager) addRouteRule(
+	id []byte,
+	sources []netip.Prefix,
+	destination firewall.Network,
+	proto firewall.Protocol,
+	sPort, dPort *firewall.Port,
+	action firewall.Action,
+) (firewall.Rule, error) {
+	ruleID := nbid.GenerateRuleID(sources, destination, proto, sPort, dPort, action)
+
+	if existingRule, ok := m.routeRulesMap[ruleID]; ok {
 		return existingRule, nil
 	}
 
 	rule := RouteRule{
-		// TODO: consolidate these IDs
-		id:         string(ruleKey),
+		id:         ruleID,
 		mgmtId:     id,
 		sources:    sources,
 		dstSet:     destination.Set,
@@ -633,78 +778,58 @@ func (m *Manager) addRouteFiltering(
 
 	m.routeRules = append(m.routeRules, &rule)
 	m.routeRules.Sort()
-	m.routeRulesMap[ruleKey] = &rule
+	m.routeRulesMap[ruleID] = &rule
 
 	return &rule, nil
 }
 
-func (m *Manager) DeleteRouteRule(rule firewall.Rule) error {
-	m.mutex.Lock()
-	defer m.mutex.Unlock()
-
-	return m.deleteRouteRule(rule)
-}
-
 func (m *Manager) deleteRouteRule(rule firewall.Rule) error {
-	if m.nativeRouter.Load() && m.nativeFirewall != nil {
-		return m.nativeFirewall.DeleteRouteRule(rule)
+	ruleID := rule.ID()
+	trimmed, _, ok := removeRuleByID(m.routeRules, ruleID)
+	if !ok {
+		return fmt.Errorf("route rule not found: %s", ruleID)
 	}
-
-	ruleKey := nbid.RuleID(rule.ID())
-	if _, ok := m.routeRulesMap[ruleKey]; !ok {
-		return fmt.Errorf("route rule not found: %s", ruleKey)
-	}
-
-	idx := slices.IndexFunc(m.routeRules, func(r *RouteRule) bool {
-		return r.id == string(ruleKey)
-	})
-	if idx < 0 {
-		return fmt.Errorf("route rule not found in slice: %s", ruleKey)
-	}
-
-	m.routeRules = slices.Delete(m.routeRules, idx, idx+1)
-	delete(m.routeRulesMap, ruleKey)
+	m.routeRules = trimmed
+	delete(m.routeRulesMap, ruleID)
 	return nil
 }
 
-// DeletePeerRule from the firewall by rule definition
-func (m *Manager) DeletePeerRule(rule firewall.Rule) error {
-	m.mutex.Lock()
-	defer m.mutex.Unlock()
+// deletePeerRuleLocked removes a peer rule from the matching slice,
+// index, and dedup map. The caller must hold m.mutex.
+func (m *Manager) deletePeerRuleLocked(r *PeerRule) error {
+	target, index := &m.incomingAcceptRules, &m.incomingAcceptIndex
+	if r.action == firewall.ActionDrop {
+		target, index = &m.incomingDenyRules, &m.incomingDenyIndex
+	}
 
-	r, ok := rule.(*PeerRule)
+	trimmed, stored, ok := removeRuleByID(*target, r.id)
 	if !ok {
-		return fmt.Errorf("delete rule: invalid rule type: %T", rule)
-	}
-
-	var sourceMap map[netip.Addr]RuleSet
-	if r.drop {
-		sourceMap = m.incomingDenyRules
-	} else {
-		sourceMap = m.incomingRules
-	}
-
-	if ruleset, ok := sourceMap[r.ip]; ok {
-		if _, exists := ruleset[r.id]; !exists {
-			return fmt.Errorf("delete rule: no rule with such id: %v", r.id)
-		}
-		delete(ruleset, r.id)
-		if len(ruleset) == 0 {
-			delete(sourceMap, r.ip)
-		}
-	} else {
 		return fmt.Errorf("delete rule: no rule with such id: %v", r.id)
 	}
-
+	*target = trimmed
+	index.remove(stored)
+	delete(m.peerRulesMap, r.id)
 	return nil
 }
 
-// SetLegacyManagement doesn't need to be implemented for this manager
-func (m *Manager) SetLegacyManagement(isLegacy bool) error {
-	if m.nativeFirewall == nil {
-		return nil
+// removeRuleByID removes the first rule whose id matches ruleID from
+// rules, preserving order. It returns the trimmed slice, the removed
+// rule, and whether a match was found.
+func removeRuleByID[S ~[]T, T firewall.Rule](rules S, ruleID firewall.RuleID) (S, T, bool) {
+	idx := slices.IndexFunc(rules, func(r T) bool { return r.ID() == ruleID })
+	var removed T
+	if idx < 0 {
+		return rules, removed, false
 	}
-	return m.nativeFirewall.SetLegacyManagement(isLegacy)
+	removed = rules[idx]
+	return slices.Delete(rules, idx, idx+1), removed, true
+}
+
+// SetLegacyManagement is a no-op for the userspace firewall: it only matters
+// when an old management server can't send route firewall rules, which the
+// userspace router doesn't rely on.
+func (m *Manager) SetLegacyManagement(bool) error {
+	return nil
 }
 
 // Flush doesn't need to be implemented for this manager
@@ -713,11 +838,14 @@ func (m *Manager) Flush() error { return nil }
 // resetState clears all firewall rules and closes connection trackers.
 // Must be called with m.mutex held.
 func (m *Manager) resetState() {
-	clear(m.outgoingRules)
-	clear(m.incomingDenyRules)
-	clear(m.incomingRules)
+	m.incomingDenyRules = m.incomingDenyRules[:0]
+	m.incomingAcceptRules = m.incomingAcceptRules[:0]
+	m.incomingDenyIndex.reset()
+	m.incomingAcceptIndex.reset()
+	clear(m.peerRulesMap)
 	clear(m.routeRulesMap)
 	m.routeRules = m.routeRules[:0]
+	m.blockRules = nil
 	m.udpHookOut.Store(nil)
 	m.tcpHookOut.Store(nil)
 
@@ -751,21 +879,15 @@ func (m *Manager) resetState() {
 	}
 }
 
-// SetupEBPFProxyNoTrack creates notrack rules for eBPF proxy loopback traffic.
-func (m *Manager) SetupEBPFProxyNoTrack(proxyPort, wgPort uint16) error {
-	if m.nativeFirewall == nil {
-		return nil
-	}
-	return m.nativeFirewall.SetupEBPFProxyNoTrack(proxyPort, wgPort)
+// SetupEBPFProxyNoTrack is not supported by the userspace firewall: eBPF isn't
+// used in userspace mode, so this should never be called.
+func (m *Manager) SetupEBPFProxyNoTrack(uint16, uint16) error {
+	return errNotSupported
 }
 
 // UpdateSet updates the rule destinations associated with the given set
 // by merging the existing prefixes with the new ones, then deduplicating.
 func (m *Manager) UpdateSet(set firewall.Set, prefixes []netip.Prefix) error {
-	if m.nativeRouter.Load() && m.nativeFirewall != nil {
-		return m.nativeFirewall.UpdateSet(set, prefixes)
-	}
-
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
 
@@ -863,11 +985,11 @@ func (m *Manager) extractIPs(d *decoder) (srcIP, dstIP netip.Addr) {
 	case layers.LayerTypeIPv4:
 		src, _ := netip.AddrFromSlice(d.ip4.SrcIP)
 		dst, _ := netip.AddrFromSlice(d.ip4.DstIP)
-		return src, dst
+		return src.Unmap(), dst.Unmap()
 	case layers.LayerTypeIPv6:
 		src, _ := netip.AddrFromSlice(d.ip6.SrcIP)
 		dst, _ := netip.AddrFromSlice(d.ip6.DstIP)
-		return src, dst
+		return src.Unmap(), dst.Unmap()
 	default:
 		return netip.Addr{}, netip.Addr{}
 	}
@@ -1622,20 +1744,12 @@ func (m *Manager) peerACLsBlock(srcIP netip.Addr, d *decoder, packetData []byte)
 		return nil, false
 	}
 
-	if mgmtId, filter, ok := validateRule(srcIP, packetData, m.incomingDenyRules[srcIP], d); ok {
+	if mgmtId, filter, ok := m.incomingDenyIndex.match(srcIP, d); ok {
 		return mgmtId, filter
 	}
-
-	if mgmtId, filter, ok := validateRule(srcIP, packetData, m.incomingRules[srcIP], d); ok {
+	if mgmtId, filter, ok := m.incomingAcceptIndex.match(srcIP, d); ok {
 		return mgmtId, filter
 	}
-	if mgmtId, filter, ok := validateRule(srcIP, packetData, m.incomingRules[netip.IPv4Unspecified()], d); ok {
-		return mgmtId, filter
-	}
-	if mgmtId, filter, ok := validateRule(srcIP, packetData, m.incomingRules[netip.IPv6Unspecified()], d); ok {
-		return mgmtId, filter
-	}
-
 	return nil, true
 }
 
@@ -1656,39 +1770,6 @@ func portsMatch(rulePort *firewall.Port, packetPort uint16) bool {
 	return false
 }
 
-func validateRule(ip netip.Addr, packetData []byte, rules map[string]PeerRule, d *decoder) ([]byte, bool, bool) {
-	payloadLayer := d.decoded[1]
-
-	for _, rule := range rules {
-		if rule.matchByIP && ip.Compare(rule.ip) != 0 {
-			continue
-		}
-
-		if rule.protoLayer == layerTypeAll {
-			return rule.mgmtId, rule.drop, true
-		}
-
-		if !protoLayerMatches(rule.protoLayer, payloadLayer) {
-			continue
-		}
-
-		switch payloadLayer {
-		case layers.LayerTypeTCP:
-			if portsMatch(rule.sPort, uint16(d.tcp.SrcPort)) && portsMatch(rule.dPort, uint16(d.tcp.DstPort)) {
-				return rule.mgmtId, rule.drop, true
-			}
-		case layers.LayerTypeUDP:
-			if portsMatch(rule.sPort, uint16(d.udp.SrcPort)) && portsMatch(rule.dPort, uint16(d.udp.DstPort)) {
-				return rule.mgmtId, rule.drop, true
-			}
-		case layers.LayerTypeICMPv4, layers.LayerTypeICMPv6:
-			return rule.mgmtId, rule.drop, true
-		}
-	}
-
-	return nil, false, false
-}
-
 // routeACLsPass returns true if the packet is allowed by the route ACLs
 func (m *Manager) routeACLsPass(srcIP, dstIP netip.Addr, protoLayer gopacket.LayerType, srcPort, dstPort uint16) ([]byte, bool) {
 	m.mutex.RLock()
@@ -1765,10 +1846,13 @@ func (m *Manager) EnableRouting() error {
 	}
 
 	rules, err := m.blockInvalidRouted(m.wgIface)
-	// Persist whatever was installed even on partial failure, so DisableRouting
-	// can clean it up later.
 	m.blockRules = rules
 	if err != nil {
+		// Roll back so forwarding can't stay active without the full set of
+		// block rules.
+		if derr := m.disableRouting(); derr != nil {
+			log.Warnf("roll back routing after block rule failure: %v", derr)
+		}
 		return fmt.Errorf("block invalid routed: %w", err)
 	}
 
@@ -1779,6 +1863,10 @@ func (m *Manager) DisableRouting() error {
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
 
+	return m.disableRouting()
+}
+
+func (m *Manager) disableRouting() error {
 	fwder := m.forwarder.Load()
 	if fwder == nil {
 		return nil

client/firewall/uspfilter/filter_bench_test.go

@@ -94,7 +94,7 @@ func BenchmarkCoreFiltering(b *testing.B) {
 			stateful: false,
 			setupFunc: func(m *Manager) {
 				// Single rule allowing all traffic
-				_, err := m.AddPeerFiltering(nil, net.ParseIP("0.0.0.0"), fw.ProtocolALL, nil, nil, fw.ActionAccept, "")
+				_, err := m.AddFilterRule(nil, pfx(net.ParseIP("0.0.0.0")), fw.Network{}, fw.ProtocolALL, nil, nil, fw.ActionAccept)
 				require.NoError(b, err)
 			},
 			desc: "Baseline: Single 'allow all' rule without connection tracking",
@@ -114,15 +114,13 @@ func BenchmarkCoreFiltering(b *testing.B) {
 				// Add explicit rules matching return traffic pattern
 				for i := 0; i < 1000; i++ { // Simulate realistic ruleset size
 					ip := generateRandomIPs(1)[0]
-					_, err := m.AddPeerFiltering(
+					_, err := m.AddFilterRule(
 						nil,
-						ip,
+						pfx(ip), fw.Network{},
 						fw.ProtocolTCP,
 						&fw.Port{Values: []uint16{uint16(1024 + i)}},
 						&fw.Port{Values: []uint16{80}},
-						fw.ActionAccept,
-						"",
-					)
+						fw.ActionAccept)
 					require.NoError(b, err)
 				}
 			},
@@ -133,15 +131,13 @@ func BenchmarkCoreFiltering(b *testing.B) {
 			stateful: true,
 			setupFunc: func(m *Manager) {
 				// Add some basic rules but rely on state for established connections
-				_, err := m.AddPeerFiltering(
+				_, err := m.AddFilterRule(
 					nil,
-					net.ParseIP("0.0.0.0"),
+					pfx(net.ParseIP("0.0.0.0")), fw.Network{},
 					fw.ProtocolTCP,
 					nil,
 					nil,
-					fw.ActionDrop,
-					"",
-				)
+					fw.ActionDrop)
 				require.NoError(b, err)
 			},
 			desc: "Connection tracking with established connections",
@@ -168,9 +164,12 @@ func BenchmarkCoreFiltering(b *testing.B) {
 				}
 
 				// Create manager and basic setup
-				manager, _ := Create(&IFaceMock{
-					SetFilterFunc: func(device.PacketFilter) error { return nil },
-				}, false, flowLogger, iface.DefaultMTU)
+				manager, err := Create(Config{
+					IFace: &IFaceMock{
+						SetFilterFunc: func(device.PacketFilter) error { return nil },
+					},
+					FlowLogger: flowLogger, MTU: iface.DefaultMTU})
+				require.NoError(b, err)
 				defer b.Cleanup(func() {
 					require.NoError(b, manager.Close(nil))
 				})
@@ -208,9 +207,12 @@ func BenchmarkStateScaling(b *testing.B) {
 
 	for _, count := range connCounts {
 		b.Run(fmt.Sprintf("conns_%d", count), func(b *testing.B) {
-			manager, _ := Create(&IFaceMock{
-				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			}, false, flowLogger, iface.DefaultMTU)
+			manager, err := Create(Config{
+				IFace: &IFaceMock{
+					SetFilterFunc: func(device.PacketFilter) error { return nil },
+				},
+				FlowLogger: flowLogger, MTU: iface.DefaultMTU})
+			require.NoError(b, err)
 			b.Cleanup(func() {
 				require.NoError(b, manager.Close(nil))
 			})
@@ -251,9 +253,12 @@ func BenchmarkEstablishmentOverhead(b *testing.B) {
 
 	for _, sc := range scenarios {
 		b.Run(sc.name, func(b *testing.B) {
-			manager, _ := Create(&IFaceMock{
-				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			}, false, flowLogger, iface.DefaultMTU)
+			manager, err := Create(Config{
+				IFace: &IFaceMock{
+					SetFilterFunc: func(device.PacketFilter) error { return nil },
+				},
+				FlowLogger: flowLogger, MTU: iface.DefaultMTU})
+			require.NoError(b, err)
 			b.Cleanup(func() {
 				require.NoError(b, manager.Close(nil))
 			})
@@ -409,9 +414,12 @@ func BenchmarkRoutedNetworkReturn(b *testing.B) {
 
 	for _, sc := range scenarios {
 		b.Run(sc.name, func(b *testing.B) {
-			manager, _ := Create(&IFaceMock{
-				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			}, false, flowLogger, iface.DefaultMTU)
+			manager, err := Create(Config{
+				IFace: &IFaceMock{
+					SetFilterFunc: func(device.PacketFilter) error { return nil },
+				},
+				FlowLogger: flowLogger, MTU: iface.DefaultMTU})
+			require.NoError(b, err)
 			b.Cleanup(func() {
 				require.NoError(b, manager.Close(nil))
 			})
@@ -536,9 +544,12 @@ func BenchmarkLongLivedConnections(b *testing.B) {
 				require.NoError(b, os.Unsetenv("NB_DISABLE_CONNTRACK"))
 			}
 
-			manager, _ := Create(&IFaceMock{
-				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			}, false, flowLogger, iface.DefaultMTU)
+			manager, err := Create(Config{
+				IFace: &IFaceMock{
+					SetFilterFunc: func(device.PacketFilter) error { return nil },
+				},
+				FlowLogger: flowLogger, MTU: iface.DefaultMTU})
+			require.NoError(b, err)
 			defer b.Cleanup(func() {
 				require.NoError(b, manager.Close(nil))
 			})
@@ -546,7 +557,7 @@ func BenchmarkLongLivedConnections(b *testing.B) {
 			// Setup initial state based on scenario
 			if sc.rules {
 				// Single rule to allow all return traffic from port 80
-				_, err := manager.AddPeerFiltering(nil, net.ParseIP("0.0.0.0"), fw.ProtocolTCP, &fw.Port{Values: []uint16{80}}, nil, fw.ActionAccept, "")
+				_, err := manager.AddFilterRule(nil, pfx(net.ParseIP("0.0.0.0")), fw.Network{}, fw.ProtocolTCP, &fw.Port{Values: []uint16{80}}, nil, fw.ActionAccept)
 				require.NoError(b, err)
 			}
 
@@ -619,9 +630,12 @@ func BenchmarkShortLivedConnections(b *testing.B) {
 				require.NoError(b, os.Unsetenv("NB_DISABLE_CONNTRACK"))
 			}
 
-			manager, _ := Create(&IFaceMock{
-				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			}, false, flowLogger, iface.DefaultMTU)
+			manager, err := Create(Config{
+				IFace: &IFaceMock{
+					SetFilterFunc: func(device.PacketFilter) error { return nil },
+				},
+				FlowLogger: flowLogger, MTU: iface.DefaultMTU})
+			require.NoError(b, err)
 			defer b.Cleanup(func() {
 				require.NoError(b, manager.Close(nil))
 			})
@@ -629,7 +643,7 @@ func BenchmarkShortLivedConnections(b *testing.B) {
 			// Setup initial state based on scenario
 			if sc.rules {
 				// Single rule to allow all return traffic from port 80
-				_, err := manager.AddPeerFiltering(nil, net.ParseIP("0.0.0.0"), fw.ProtocolTCP, &fw.Port{Values: []uint16{80}}, nil, fw.ActionAccept, "")
+				_, err := manager.AddFilterRule(nil, pfx(net.ParseIP("0.0.0.0")), fw.Network{}, fw.ProtocolTCP, &fw.Port{Values: []uint16{80}}, nil, fw.ActionAccept)
 				require.NoError(b, err)
 			}
 
@@ -730,16 +744,19 @@ func BenchmarkParallelLongLivedConnections(b *testing.B) {
 				require.NoError(b, os.Unsetenv("NB_DISABLE_CONNTRACK"))
 			}
 
-			manager, _ := Create(&IFaceMock{
-				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			}, false, flowLogger, iface.DefaultMTU)
+			manager, err := Create(Config{
+				IFace: &IFaceMock{
+					SetFilterFunc: func(device.PacketFilter) error { return nil },
+				},
+				FlowLogger: flowLogger, MTU: iface.DefaultMTU})
+			require.NoError(b, err)
 			defer b.Cleanup(func() {
 				require.NoError(b, manager.Close(nil))
 			})
 
 			// Setup initial state based on scenario
 			if sc.rules {
-				_, err := manager.AddPeerFiltering(nil, net.ParseIP("0.0.0.0"), fw.ProtocolTCP, &fw.Port{Values: []uint16{80}}, nil, fw.ActionAccept, "")
+				_, err := manager.AddFilterRule(nil, pfx(net.ParseIP("0.0.0.0")), fw.Network{}, fw.ProtocolTCP, &fw.Port{Values: []uint16{80}}, nil, fw.ActionAccept)
 				require.NoError(b, err)
 			}
 
@@ -810,15 +827,18 @@ func BenchmarkParallelShortLivedConnections(b *testing.B) {
 				require.NoError(b, os.Unsetenv("NB_DISABLE_CONNTRACK"))
 			}
 
-			manager, _ := Create(&IFaceMock{
-				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			}, false, flowLogger, iface.DefaultMTU)
+			manager, err := Create(Config{
+				IFace: &IFaceMock{
+					SetFilterFunc: func(device.PacketFilter) error { return nil },
+				},
+				FlowLogger: flowLogger, MTU: iface.DefaultMTU})
+			require.NoError(b, err)
 			defer b.Cleanup(func() {
 				require.NoError(b, manager.Close(nil))
 			})
 
 			if sc.rules {
-				_, err := manager.AddPeerFiltering(nil, net.ParseIP("0.0.0.0"), fw.ProtocolTCP, &fw.Port{Values: []uint16{80}}, nil, fw.ActionAccept, "")
+				_, err := manager.AddFilterRule(nil, pfx(net.ParseIP("0.0.0.0")), fw.Network{}, fw.ProtocolTCP, &fw.Port{Values: []uint16{80}}, nil, fw.ActionAccept)
 				require.NoError(b, err)
 			}
 
@@ -931,7 +951,7 @@ func BenchmarkRouteACLs(b *testing.B) {
 
 	for _, r := range rules {
 		dst := fw.Network{Prefix: r.dest}
-		_, err := manager.AddRouteFiltering(nil, r.sources, dst, r.proto, nil, r.port, fw.ActionAccept)
+		_, err := manager.AddFilterRule(nil, r.sources, dst, r.proto, nil, r.port, fw.ActionAccept)
 		if err != nil {
 			b.Fatal(err)
 		}
@@ -1014,9 +1034,11 @@ func BenchmarkMSSClamping(b *testing.B) {
 
 	for _, sc := range scenarios {
 		b.Run(sc.name, func(b *testing.B) {
-			manager, err := Create(&IFaceMock{
-				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			}, false, flowLogger, iface.DefaultMTU)
+			manager, err := Create(Config{
+				IFace: &IFaceMock{
+					SetFilterFunc: func(device.PacketFilter) error { return nil },
+				},
+				FlowLogger: flowLogger, MTU: iface.DefaultMTU})
 			require.NoError(b, err)
 			defer func() {
 				require.NoError(b, manager.Close(nil))
@@ -1079,9 +1101,11 @@ func BenchmarkMSSClampingOverhead(b *testing.B) {
 
 	for _, sc := range scenarios {
 		b.Run(sc.name, func(b *testing.B) {
-			manager, err := Create(&IFaceMock{
-				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			}, false, flowLogger, iface.DefaultMTU)
+			manager, err := Create(Config{
+				IFace: &IFaceMock{
+					SetFilterFunc: func(device.PacketFilter) error { return nil },
+				},
+				FlowLogger: flowLogger, MTU: iface.DefaultMTU})
 			require.NoError(b, err)
 			defer func() {
 				require.NoError(b, manager.Close(nil))
@@ -1134,9 +1158,11 @@ func BenchmarkMSSClampingMemory(b *testing.B) {
 
 	for _, sc := range scenarios {
 		b.Run(sc.name, func(b *testing.B) {
-			manager, err := Create(&IFaceMock{
-				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			}, false, flowLogger, iface.DefaultMTU)
+			manager, err := Create(Config{
+				IFace: &IFaceMock{
+					SetFilterFunc: func(device.PacketFilter) error { return nil },
+				},
+				FlowLogger: flowLogger, MTU: iface.DefaultMTU})
 			require.NoError(b, err)
 			defer func() {
 				require.NoError(b, manager.Close(nil))

client/firewall/uspfilter/filter_filter_test.go

@@ -32,7 +32,7 @@ func TestPeerACLFiltering(t *testing.T) {
 		},
 	}
 
-	manager, err := Create(ifaceMock, false, flowLogger, iface.DefaultMTU)
+	manager, err := Create(Config{IFace: ifaceMock, FlowLogger: flowLogger, MTU: iface.DefaultMTU})
 	require.NoError(t, err)
 	require.NotNil(t, manager)
 
@@ -496,40 +496,32 @@ func TestPeerACLFiltering(t *testing.T) {
 		t.Run(tc.name, func(t *testing.T) {
 			if tc.ruleAction == fw.ActionDrop {
 				// add general accept rule for the same IP to test drop rule precedence
-				rules, err := manager.AddPeerFiltering(
+				rules, err := manager.AddFilterRule(
 					nil,
-					net.ParseIP(tc.ruleIP),
+					pfx(net.ParseIP(tc.ruleIP)), fw.Network{},
 					fw.ProtocolALL,
 					nil,
 					nil,
-					fw.ActionAccept,
-					"",
-				)
+					fw.ActionAccept)
 				require.NoError(t, err)
-				require.NotEmpty(t, rules)
+				require.NotNil(t, rules)
 				t.Cleanup(func() {
-					for _, rule := range rules {
-						require.NoError(t, manager.DeletePeerRule(rule))
-					}
+					require.NoError(t, manager.DeleteFilterRule(rules))
 				})
 			}
 
-			rules, err := manager.AddPeerFiltering(
+			rules, err := manager.AddFilterRule(
 				nil,
-				net.ParseIP(tc.ruleIP),
+				pfx(net.ParseIP(tc.ruleIP)), fw.Network{},
 				tc.ruleProto,
 				tc.ruleSrcPort,
 				tc.ruleDstPort,
-				tc.ruleAction,
-				"",
-			)
+				tc.ruleAction)
 			require.NoError(t, err)
-			require.NotEmpty(t, rules)
+			require.NotNil(t, rules)
 
 			t.Cleanup(func() {
-				for _, rule := range rules {
-					require.NoError(t, manager.DeletePeerRule(rule))
-				}
+				require.NoError(t, manager.DeleteFilterRule(rules))
 			})
 
 			packet := createTestPacket(t, tc.srcIP, tc.dstIP, tc.proto, tc.srcPort, tc.dstPort)
@@ -557,7 +549,7 @@ func TestPeerACLFilteringIPv6(t *testing.T) {
 		},
 	}
 
-	manager, err := Create(ifaceMock, false, flowLogger, iface.DefaultMTU)
+	manager, err := Create(Config{IFace: ifaceMock, FlowLogger: flowLogger, MTU: iface.DefaultMTU})
 	require.NoError(t, err)
 	t.Cleanup(func() { require.NoError(t, manager.Close(nil)) })
 
@@ -652,14 +644,24 @@ func TestPeerACLFilteringIPv6(t *testing.T) {
 			shouldBeBlocked: false,
 		},
 		{
-			name:            "IPv6: v4 wildcard ICMP rule matches ICMPv6 via protoLayerMatches",
+			name:            "IPv6: v4 wildcard ICMP rule does not match ICMPv6",
 			srcIP:           "fd00::1",
 			dstIP:           "fd00::100",
 			proto:           fw.ProtocolICMP,
 			ruleIP:          "0.0.0.0",
 			ruleProto:       fw.ProtocolICMP,
 			ruleAction:      fw.ActionAccept,
-			shouldBeBlocked: false,
+			shouldBeBlocked: true,
+		},
+		{
+			name:            "IPv4: v6 wildcard ICMP rule does not match ICMPv4",
+			srcIP:           "100.10.0.1",
+			dstIP:           "100.10.0.100",
+			proto:           fw.ProtocolICMP,
+			ruleIP:          "::",
+			ruleProto:       fw.ProtocolICMP,
+			ruleAction:      fw.ActionAccept,
+			shouldBeBlocked: true,
 		},
 	}
 
@@ -672,22 +674,18 @@ func TestPeerACLFilteringIPv6(t *testing.T) {
 	for _, tc := range testCases {
 		t.Run(tc.name, func(t *testing.T) {
 			if tc.ruleAction == fw.ActionDrop {
-				rules, err := manager.AddPeerFiltering(nil, net.ParseIP(tc.ruleIP), fw.ProtocolALL, nil, nil, fw.ActionAccept, "")
+				rules, err := manager.AddFilterRule(nil, pfx(net.ParseIP(tc.ruleIP)), fw.Network{}, fw.ProtocolALL, nil, nil, fw.ActionAccept)
 				require.NoError(t, err)
 				t.Cleanup(func() {
-					for _, rule := range rules {
-						require.NoError(t, manager.DeletePeerRule(rule))
-					}
+					require.NoError(t, manager.DeleteFilterRule(rules))
 				})
 			}
 
-			rules, err := manager.AddPeerFiltering(nil, net.ParseIP(tc.ruleIP), tc.ruleProto, nil, tc.ruleDstPort, tc.ruleAction, "")
+			rules, err := manager.AddFilterRule(nil, pfx(net.ParseIP(tc.ruleIP)), fw.Network{}, tc.ruleProto, nil, tc.ruleDstPort, tc.ruleAction)
 			require.NoError(t, err)
-			require.NotEmpty(t, rules)
+			require.NotNil(t, rules)
 			t.Cleanup(func() {
-				for _, rule := range rules {
-					require.NoError(t, manager.DeletePeerRule(rule))
-				}
+				require.NoError(t, manager.DeleteFilterRule(rules))
 			})
 
 			packet := createTestPacket(t, tc.srcIP, tc.dstIP, tc.proto, tc.srcPort, tc.dstPort)
@@ -800,7 +798,7 @@ func setupRoutedManager(tb testing.TB, network string) *Manager {
 		},
 	}
 
-	manager, err := Create(ifaceMock, false, flowLogger, iface.DefaultMTU)
+	manager, err := Create(Config{IFace: ifaceMock, FlowLogger: flowLogger, MTU: iface.DefaultMTU})
 	require.NoError(tb, err)
 	require.NoError(tb, manager.EnableRouting())
 	require.NotNil(tb, manager)
@@ -1405,7 +1403,7 @@ func TestRouteACLFiltering(t *testing.T) {
 		t.Run(tc.name, func(t *testing.T) {
 			if tc.rule.action == fw.ActionDrop {
 				// add general accept rule to test drop rule
-				rule, err := manager.AddRouteFiltering(
+				rule, err := manager.AddFilterRule(
 					nil,
 					[]netip.Prefix{netip.MustParsePrefix("0.0.0.0/0")},
 					fw.Network{Prefix: netip.MustParsePrefix("0.0.0.0/0")},
@@ -1415,13 +1413,13 @@ func TestRouteACLFiltering(t *testing.T) {
 					fw.ActionAccept,
 				)
 				require.NoError(t, err)
-				require.NotNil(t, rule)
+				require.NotEmpty(t, rule)
 				t.Cleanup(func() {
-					require.NoError(t, manager.DeleteRouteRule(rule))
+					require.NoError(t, manager.DeleteFilterRule(rule))
 				})
 			}
 
-			rule, err := manager.AddRouteFiltering(
+			rule, err := manager.AddFilterRule(
 				nil,
 				tc.rule.sources,
 				tc.rule.dest,
@@ -1431,10 +1429,10 @@ func TestRouteACLFiltering(t *testing.T) {
 				tc.rule.action,
 			)
 			require.NoError(t, err)
-			require.NotNil(t, rule)
+			require.NotEmpty(t, rule)
 
 			t.Cleanup(func() {
-				require.NoError(t, manager.DeleteRouteRule(rule))
+				require.NoError(t, manager.DeleteFilterRule(rule))
 			})
 
 			srcIP := netip.MustParseAddr(tc.srcIP)
@@ -1602,9 +1600,9 @@ func TestRouteACLOrder(t *testing.T) {
 
 	for _, tc := range testCases {
 		t.Run(tc.name, func(t *testing.T) {
-			var rules []fw.Rule
+			var addedRules []fw.Rule
 			for _, r := range tc.rules {
-				rule, err := manager.AddRouteFiltering(
+				rule, err := manager.AddFilterRule(
 					nil,
 					r.sources,
 					r.dest,
@@ -1615,12 +1613,12 @@ func TestRouteACLOrder(t *testing.T) {
 				)
 				require.NoError(t, err)
 				require.NotNil(t, rule)
-				rules = append(rules, rule)
+				addedRules = append(addedRules, rule)
 			}
 
 			t.Cleanup(func() {
-				for _, rule := range rules {
-					require.NoError(t, manager.DeleteRouteRule(rule))
+				for _, rule := range addedRules {
+					require.NoError(t, manager.DeleteFilterRule(rule))
 				}
 			})
 
@@ -1646,7 +1644,7 @@ func TestRouteACLSet(t *testing.T) {
 		},
 	}
 
-	manager, err := Create(ifaceMock, false, flowLogger, iface.DefaultMTU)
+	manager, err := Create(Config{IFace: ifaceMock, FlowLogger: flowLogger, MTU: iface.DefaultMTU})
 	require.NoError(t, err)
 	t.Cleanup(func() {
 		require.NoError(t, manager.Close(nil))
@@ -1655,7 +1653,7 @@ func TestRouteACLSet(t *testing.T) {
 	set := fw.NewDomainSet(domain.List{"example.org"})
 
 	// Add rule that uses the set (initially empty)
-	rule, err := manager.AddRouteFiltering(
+	rule, err := manager.AddFilterRule(
 		nil,
 		[]netip.Prefix{netip.MustParsePrefix("0.0.0.0/0")},
 		fw.Network{Set: set},
@@ -1689,7 +1687,7 @@ func TestRouteACLFilteringIPv6(t *testing.T) {
 	manager := setupRoutedManager(t, "10.10.0.100/16")
 
 	v6Dst := netip.MustParsePrefix("fd00:dead:beef::/48")
-	_, err := manager.AddRouteFiltering(
+	_, err := manager.AddFilterRule(
 		nil,
 		[]netip.Prefix{netip.MustParsePrefix("fd00::/16")},
 		fw.Network{Prefix: v6Dst},
@@ -1700,7 +1698,7 @@ func TestRouteACLFilteringIPv6(t *testing.T) {
 	)
 	require.NoError(t, err)
 
-	_, err = manager.AddRouteFiltering(
+	_, err = manager.AddFilterRule(
 		nil,
 		[]netip.Prefix{netip.MustParsePrefix("fd00::/16")},
 		fw.Network{Prefix: netip.MustParsePrefix("fd00:dead:beef:1::/64")},

client/firewall/uspfilter/filter_routeacl_test.go

@@ -29,7 +29,7 @@ func TestAddRouteFilteringReturnsExistingRule(t *testing.T) {
 	destination := fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")}
 
 	// Add rule first time
-	rule1, err := manager.AddRouteFiltering(
+	rule1, err := manager.AddFilterRule(
 		[]byte("policy-1"),
 		sources,
 		destination,
@@ -42,7 +42,7 @@ func TestAddRouteFilteringReturnsExistingRule(t *testing.T) {
 	require.NotNil(t, rule1)
 
 	// Add the same rule again
-	rule2, err := manager.AddRouteFiltering(
+	rule2, err := manager.AddFilterRule(
 		[]byte("policy-1"),
 		sources,
 		destination,
@@ -74,7 +74,7 @@ func TestAddRouteFilteringDifferentRulesGetDifferentIDs(t *testing.T) {
 	sources := []netip.Prefix{netip.MustParsePrefix("100.64.1.0/24")}
 
 	// Add first rule
-	rule1, err := manager.AddRouteFiltering(
+	rule1, err := manager.AddFilterRule(
 		[]byte("policy-1"),
 		sources,
 		fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
@@ -86,7 +86,7 @@ func TestAddRouteFilteringDifferentRulesGetDifferentIDs(t *testing.T) {
 	require.NoError(t, err)
 
 	// Add different rule (different destination)
-	rule2, err := manager.AddRouteFiltering(
+	rule2, err := manager.AddFilterRule(
 		[]byte("policy-2"),
 		sources,
 		fw.Network{Prefix: netip.MustParsePrefix("192.168.2.0/24")}, // Different!
@@ -115,7 +115,7 @@ func TestRouteRuleUpdateDoesNotCauseGap(t *testing.T) {
 	sources := []netip.Prefix{netip.MustParsePrefix("100.64.1.0/24")}
 	destination := fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")}
 
-	rule1, err := manager.AddRouteFiltering(
+	rule1, err := manager.AddFilterRule(
 		[]byte("policy-1"),
 		sources,
 		destination,
@@ -132,7 +132,7 @@ func TestRouteRuleUpdateDoesNotCauseGap(t *testing.T) {
 	require.True(t, pass, "Traffic should pass with rule in place")
 
 	// Re-add same rule (simulates network map update)
-	rule2, err := manager.AddRouteFiltering(
+	rule2, err := manager.AddFilterRule(
 		[]byte("policy-1"),
 		sources,
 		destination,
@@ -147,7 +147,7 @@ func TestRouteRuleUpdateDoesNotCauseGap(t *testing.T) {
 	// won't delete rule1 during cleanup. If IDs differed, deleting rule1
 	// would remove the only matching rule and cause a traffic gap.
 	if rule1.ID() != rule2.ID() {
-		err = manager.DeleteRouteRule(rule1)
+		err = manager.DeleteFilterRule(rule1)
 		require.NoError(t, err)
 	}
 
@@ -156,6 +156,59 @@ func TestRouteRuleUpdateDoesNotCauseGap(t *testing.T) {
 		"Traffic should still pass after rule update - no gap should occur")
 }
 
+// TestBlockInvalidRoutedDualStack verifies that when the interface has an
+// IPv6 overlay address, blockInvalidRouted installs a block rule for both
+// the v4 and v6 WG prefixes and that routed traffic to the v6 prefix is
+// denied. The v4-only soft-skip path is covered by
+// TestBlockInvalidRoutedIdempotent, whose mock leaves IPv6Net invalid.
+func TestBlockInvalidRoutedDualStack(t *testing.T) {
+	ctrl := gomock.NewController(t)
+	dev := mocks.NewMockDevice(ctrl)
+	dev.EXPECT().MTU().Return(1500, nil).AnyTimes()
+
+	wgNet := netip.MustParsePrefix("100.64.0.1/16")
+	wgNet6 := netip.MustParsePrefix("fd00:1234::1/64")
+
+	ifaceMock := &IFaceMock{
+		SetFilterFunc: func(device.PacketFilter) error { return nil },
+		AddressFunc: func() wgaddr.Address {
+			return wgaddr.Address{
+				IP:      wgNet.Addr(),
+				Network: wgNet,
+				IPv6:    wgNet6.Addr(),
+				IPv6Net: wgNet6,
+			}
+		},
+		GetDeviceFunc: func() *device.FilteredDevice {
+			return &device.FilteredDevice{Device: dev}
+		},
+		GetWGDeviceFunc: func() *wgdevice.Device {
+			return &wgdevice.Device{}
+		},
+	}
+
+	manager, err := Create(Config{IFace: ifaceMock, FlowLogger: flowLogger, MTU: iface.DefaultMTU})
+	require.NoError(t, err)
+	t.Cleanup(func() {
+		require.NoError(t, manager.Close(nil))
+	})
+
+	rules, err := manager.blockInvalidRouted(ifaceMock)
+	require.NoError(t, err)
+	require.Len(t, rules, 2, "dual-stack interface must produce a v4 and a v6 block rule")
+
+	manager.mutex.RLock()
+	ruleCount := len(manager.routeRules)
+	manager.mutex.RUnlock()
+	assert.Equal(t, 2, ruleCount, "should have one block rule per family")
+
+	// v6 routed traffic to the WG prefix must be denied.
+	srcIP := netip.MustParseAddr("2001:db8::1")
+	dstIP := netip.MustParseAddr("fd00:1234::50")
+	_, pass := manager.routeACLsPass(srcIP, dstIP, layers.LayerTypeTCP, 12345, 80)
+	assert.False(t, pass, "block rule should deny routed traffic to the v6 WG prefix")
+}
+
 // TestBlockInvalidRoutedIdempotent verifies that blockInvalidRouted creates
 // exactly one drop rule for the WireGuard network prefix, and calling it again
 // returns the same rule without duplicating.
@@ -182,7 +235,7 @@ func TestBlockInvalidRoutedIdempotent(t *testing.T) {
 		},
 	}
 
-	manager, err := Create(ifaceMock, false, flowLogger, iface.DefaultMTU)
+	manager, err := Create(Config{IFace: ifaceMock, FlowLogger: flowLogger, MTU: iface.DefaultMTU})
 	require.NoError(t, err)
 	t.Cleanup(func() {
 		require.NoError(t, manager.Close(nil))
@@ -245,7 +298,7 @@ func TestBlockRuleNotAccumulatedOnRepeatedEnableRouting(t *testing.T) {
 		},
 	}
 
-	manager, err := Create(ifaceMock, false, flowLogger, iface.DefaultMTU)
+	manager, err := Create(Config{IFace: ifaceMock, FlowLogger: flowLogger, MTU: iface.DefaultMTU})
 	require.NoError(t, err)
 	t.Cleanup(func() {
 		require.NoError(t, manager.Close(nil))
@@ -274,7 +327,7 @@ func TestRouteRuleCountStableAcrossUpdates(t *testing.T) {
 
 	// Simulate 5 network map updates with the same route rule
 	for i := 0; i < 5; i++ {
-		rule, err := manager.AddRouteFiltering(
+		rule, err := manager.AddFilterRule(
 			[]byte("policy-1"),
 			sources,
 			destination,
@@ -304,7 +357,7 @@ func TestDeleteRouteRuleAfterIdempotentAdd(t *testing.T) {
 	destination := fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")}
 
 	// Add same rule twice
-	rule1, err := manager.AddRouteFiltering(
+	rule1, err := manager.AddFilterRule(
 		[]byte("policy-1"),
 		sources,
 		destination,
@@ -315,7 +368,7 @@ func TestDeleteRouteRuleAfterIdempotentAdd(t *testing.T) {
 	)
 	require.NoError(t, err)
 
-	rule2, err := manager.AddRouteFiltering(
+	rule2, err := manager.AddFilterRule(
 		[]byte("policy-1"),
 		sources,
 		destination,
@@ -329,7 +382,7 @@ func TestDeleteRouteRuleAfterIdempotentAdd(t *testing.T) {
 	require.Equal(t, rule1.ID(), rule2.ID(), "Should return same rule ID")
 
 	// Delete using first reference
-	err = manager.DeleteRouteRule(rule1)
+	err = manager.DeleteFilterRule(rule1)
 	require.NoError(t, err)
 
 	// Verify traffic no longer passes
@@ -364,7 +417,7 @@ func setupTestManager(t *testing.T) *Manager {
 		},
 	}
 
-	manager, err := Create(ifaceMock, false, flowLogger, iface.DefaultMTU)
+	manager, err := Create(Config{IFace: ifaceMock, FlowLogger: flowLogger, MTU: iface.DefaultMTU})
 	require.NoError(t, err)
 	require.NoError(t, manager.EnableRouting())
 

client/firewall/uspfilter/filter_test.go

@@ -78,18 +78,19 @@ func TestManagerCreate(t *testing.T) {
 		SetFilterFunc: func(device.PacketFilter) error { return nil },
 	}
 
-	m, err := Create(ifaceMock, false, flowLogger, nbiface.DefaultMTU)
+	m, err := Create(Config{IFace: ifaceMock, FlowLogger: flowLogger, MTU: nbiface.DefaultMTU})
 	if err != nil {
 		t.Errorf("failed to create Manager: %v", err)
 		return
 	}
+	t.Cleanup(func() { require.NoError(t, m.Close(nil)) })
 
 	if m == nil {
 		t.Error("Manager is nil")
 	}
 }
 
-func TestManagerAddPeerFiltering(t *testing.T) {
+func TestManagerAddFilterRule(t *testing.T) {
 	isSetFilterCalled := false
 	ifaceMock := &IFaceMock{
 		SetFilterFunc: func(device.PacketFilter) error {
@@ -98,18 +99,19 @@ func TestManagerAddPeerFiltering(t *testing.T) {
 		},
 	}
 
-	m, err := Create(ifaceMock, false, flowLogger, nbiface.DefaultMTU)
+	m, err := Create(Config{IFace: ifaceMock, FlowLogger: flowLogger, MTU: nbiface.DefaultMTU})
 	if err != nil {
 		t.Errorf("failed to create Manager: %v", err)
 		return
 	}
+	t.Cleanup(func() { require.NoError(t, m.Close(nil)) })
 
 	ip := net.ParseIP("192.168.1.1")
 	proto := fw.ProtocolTCP
 	port := &fw.Port{Values: []uint16{80}}
 	action := fw.ActionDrop
 
-	rule, err := m.AddPeerFiltering(nil, ip, proto, nil, port, action, "")
+	rule, err := m.AddFilterRule(nil, pfx(ip), fw.Network{}, proto, nil, port, action)
 	if err != nil {
 		t.Errorf("failed to add filtering: %v", err)
 		return
@@ -131,74 +133,47 @@ func TestManagerDeleteRule(t *testing.T) {
 		SetFilterFunc: func(device.PacketFilter) error { return nil },
 	}
 
-	m, err := Create(ifaceMock, false, flowLogger, nbiface.DefaultMTU)
+	m, err := Create(Config{IFace: ifaceMock, FlowLogger: flowLogger, MTU: nbiface.DefaultMTU})
 	if err != nil {
 		t.Errorf("failed to create Manager: %v", err)
 		return
 	}
+	t.Cleanup(func() { require.NoError(t, m.Close(nil)) })
 
 	ip := netip.MustParseAddr("192.168.1.1")
 	proto := fw.ProtocolTCP
 	port := &fw.Port{Values: []uint16{80}}
 	action := fw.ActionDrop
 
-	rule2, err := m.AddPeerFiltering(nil, ip.AsSlice(), proto, nil, port, action, "")
+	rule2, err := m.AddFilterRule(nil, pfx(ip.AsSlice()), fw.Network{}, proto, nil, port, action)
 	if err != nil {
 		t.Errorf("failed to add filtering: %v", err)
 		return
 	}
 
-	// Check rules exist in appropriate maps
-	for _, r := range rule2 {
-		peerRule, ok := r.(*PeerRule)
-		if !ok {
-			t.Errorf("rule should be a PeerRule")
-			continue
-		}
-		// Check if rule exists in deny or allow maps based on action
-		var found bool
-		if peerRule.drop {
-			_, found = m.incomingDenyRules[ip][r.ID()]
-		} else {
-			_, found = m.incomingRules[ip][r.ID()]
-		}
-		if !found {
-			t.Errorf("rule2 is not in the expected rules map")
+	peerRule, ok := rule2.(*PeerRule)
+	require.True(t, ok, "rule should be a peer rule")
+
+	inMap := func() bool {
+		if peerRule.action == fw.ActionDrop {
+			return findRuleByID(m.incomingDenyRules, ip, rule2.ID())
 		}
+		return findRuleByID(m.incomingAcceptRules, ip, rule2.ID())
 	}
 
-	for _, r := range rule2 {
-		err = m.DeletePeerRule(r)
-		if err != nil {
-			t.Errorf("failed to delete rule: %v", err)
-			return
-		}
-	}
+	require.True(t, inMap(), "rule2 should be in the expected rules list")
 
-	// Check rules are removed from appropriate maps
-	for _, r := range rule2 {
-		peerRule, ok := r.(*PeerRule)
-		if !ok {
-			t.Errorf("rule should be a PeerRule")
-			continue
-		}
-		// Check if rule is removed from deny or allow maps based on action
-		var found bool
-		if peerRule.drop {
-			_, found = m.incomingDenyRules[ip][r.ID()]
-		} else {
-			_, found = m.incomingRules[ip][r.ID()]
-		}
-		if found {
-			t.Errorf("rule2 should be removed from the rules map")
-		}
-	}
+	require.NoError(t, m.DeleteFilterRule(rule2), "failed to delete rule")
+
+	require.False(t, inMap(), "rule2 should be removed from the rules list")
 }
 
 func TestSetUDPPacketHook(t *testing.T) {
-	manager, err := Create(&IFaceMock{
-		SetFilterFunc: func(device.PacketFilter) error { return nil },
-	}, false, flowLogger, nbiface.DefaultMTU)
+	manager, err := Create(Config{
+		IFace: &IFaceMock{
+			SetFilterFunc: func(device.PacketFilter) error { return nil },
+		},
+		FlowLogger: flowLogger, MTU: nbiface.DefaultMTU})
 	require.NoError(t, err)
 	t.Cleanup(func() { require.NoError(t, manager.Close(nil)) })
 
@@ -220,9 +195,11 @@ func TestSetUDPPacketHook(t *testing.T) {
 }
 
 func TestSetTCPPacketHook(t *testing.T) {
-	manager, err := Create(&IFaceMock{
-		SetFilterFunc: func(device.PacketFilter) error { return nil },
-	}, false, flowLogger, nbiface.DefaultMTU)
+	manager, err := Create(Config{
+		IFace: &IFaceMock{
+			SetFilterFunc: func(device.PacketFilter) error { return nil },
+		},
+		FlowLogger: flowLogger, MTU: nbiface.DefaultMTU})
 	require.NoError(t, err)
 	t.Cleanup(func() { require.NoError(t, manager.Close(nil)) })
 
@@ -250,7 +227,7 @@ func TestPeerRuleLifecycleDenyRules(t *testing.T) {
 		SetFilterFunc: func(device.PacketFilter) error { return nil },
 	}
 
-	m, err := Create(ifaceMock, false, flowLogger, nbiface.DefaultMTU)
+	m, err := Create(Config{IFace: ifaceMock, FlowLogger: flowLogger, MTU: nbiface.DefaultMTU})
 	require.NoError(t, err)
 	defer func() {
 		require.NoError(t, m.Close(nil))
@@ -260,36 +237,34 @@ func TestPeerRuleLifecycleDenyRules(t *testing.T) {
 	addr := netip.MustParseAddr("192.168.1.1")
 
 	// Add multiple deny rules for different ports
-	rule1, err := m.AddPeerFiltering(nil, ip, fw.ProtocolTCP, nil,
-		&fw.Port{Values: []uint16{22}}, fw.ActionDrop, "")
+	rule1, err := m.AddFilterRule(nil, pfx(ip), fw.Network{}, fw.ProtocolTCP, nil, &fw.Port{Values: []uint16{22}}, fw.ActionDrop)
 	require.NoError(t, err)
 
-	rule2, err := m.AddPeerFiltering(nil, ip, fw.ProtocolTCP, nil,
-		&fw.Port{Values: []uint16{80}}, fw.ActionDrop, "")
+	rule2, err := m.AddFilterRule(nil, pfx(ip), fw.Network{}, fw.ProtocolTCP, nil, &fw.Port{Values: []uint16{80}}, fw.ActionDrop)
 	require.NoError(t, err)
 
 	m.mutex.RLock()
-	denyCount := len(m.incomingDenyRules[addr])
+	denyCount := countRulesForAddr(m.incomingDenyRules, addr)
 	m.mutex.RUnlock()
 	require.Equal(t, 2, denyCount, "Should have exactly 2 deny rules")
 
 	// Delete the first deny rule
-	err = m.DeletePeerRule(rule1[0])
+	err = m.DeleteFilterRule(rule1)
 	require.NoError(t, err)
 
 	m.mutex.RLock()
-	denyCount = len(m.incomingDenyRules[addr])
+	denyCount = countRulesForAddr(m.incomingDenyRules, addr)
 	m.mutex.RUnlock()
 	require.Equal(t, 1, denyCount, "Should have 1 deny rule after deleting first")
 
 	// Delete the second deny rule
-	err = m.DeletePeerRule(rule2[0])
+	err = m.DeleteFilterRule(rule2)
 	require.NoError(t, err)
 
 	m.mutex.RLock()
-	_, exists := m.incomingDenyRules[addr]
+	exists := countRulesForAddr(m.incomingDenyRules, addr) > 0
 	m.mutex.RUnlock()
-	require.False(t, exists, "Deny rules IP entry should be cleaned up when empty")
+	require.False(t, exists, "Deny rules should be cleaned up when empty")
 }
 
 // TestPeerRuleAddAndDeleteDontLeak verifies that repeatedly adding and deleting
@@ -299,7 +274,7 @@ func TestPeerRuleAddAndDeleteDontLeak(t *testing.T) {
 		SetFilterFunc: func(device.PacketFilter) error { return nil },
 	}
 
-	m, err := Create(ifaceMock, false, flowLogger, nbiface.DefaultMTU)
+	m, err := Create(Config{IFace: ifaceMock, FlowLogger: flowLogger, MTU: nbiface.DefaultMTU})
 	require.NoError(t, err)
 	defer func() {
 		require.NoError(t, m.Close(nil))
@@ -311,27 +286,21 @@ func TestPeerRuleAddAndDeleteDontLeak(t *testing.T) {
 	// Simulate 10 network map updates: add rule, delete old, add new
 	for i := 0; i < 10; i++ {
 		// Add a deny rule
-		rules, err := m.AddPeerFiltering(nil, ip, fw.ProtocolTCP, nil,
-			&fw.Port{Values: []uint16{22}}, fw.ActionDrop, "")
+		rules, err := m.AddFilterRule(nil, pfx(ip), fw.Network{}, fw.ProtocolTCP, nil, &fw.Port{Values: []uint16{22}}, fw.ActionDrop)
 		require.NoError(t, err)
 
 		// Add an allow rule
-		allowRules, err := m.AddPeerFiltering(nil, ip, fw.ProtocolTCP, nil,
-			&fw.Port{Values: []uint16{80}}, fw.ActionAccept, "")
+		allowRules, err := m.AddFilterRule(nil, pfx(ip), fw.Network{}, fw.ProtocolTCP, nil, &fw.Port{Values: []uint16{80}}, fw.ActionAccept)
 		require.NoError(t, err)
 
 		// Delete them (simulating ACL manager cleanup)
-		for _, r := range rules {
-			require.NoError(t, m.DeletePeerRule(r))
-		}
-		for _, r := range allowRules {
-			require.NoError(t, m.DeletePeerRule(r))
-		}
+		require.NoError(t, m.DeleteFilterRule(rules))
+		require.NoError(t, m.DeleteFilterRule(allowRules))
 	}
 
 	m.mutex.RLock()
-	denyCount := len(m.incomingDenyRules[addr])
-	allowCount := len(m.incomingRules[addr])
+	denyCount := countRulesForAddr(m.incomingDenyRules, addr)
+	allowCount := countRulesForAddr(m.incomingAcceptRules, addr)
 	m.mutex.RUnlock()
 
 	require.Equal(t, 0, denyCount, "No deny rules should remain after cleanup")
@@ -345,7 +314,7 @@ func TestMixedAllowDenyRulesSameIP(t *testing.T) {
 		SetFilterFunc: func(device.PacketFilter) error { return nil },
 	}
 
-	m, err := Create(ifaceMock, false, flowLogger, nbiface.DefaultMTU)
+	m, err := Create(Config{IFace: ifaceMock, FlowLogger: flowLogger, MTU: nbiface.DefaultMTU})
 	require.NoError(t, err)
 	defer func() {
 		require.NoError(t, m.Close(nil))
@@ -354,41 +323,39 @@ func TestMixedAllowDenyRulesSameIP(t *testing.T) {
 	ip := net.ParseIP("192.168.1.1")
 
 	// Add allow rule for port 80
-	allowRule, err := m.AddPeerFiltering(nil, ip, fw.ProtocolTCP, nil,
-		&fw.Port{Values: []uint16{80}}, fw.ActionAccept, "")
+	allowRule, err := m.AddFilterRule(nil, pfx(ip), fw.Network{}, fw.ProtocolTCP, nil, &fw.Port{Values: []uint16{80}}, fw.ActionAccept)
 	require.NoError(t, err)
 
 	// Add deny rule for port 22
-	denyRule, err := m.AddPeerFiltering(nil, ip, fw.ProtocolTCP, nil,
-		&fw.Port{Values: []uint16{22}}, fw.ActionDrop, "")
+	denyRule, err := m.AddFilterRule(nil, pfx(ip), fw.Network{}, fw.ProtocolTCP, nil, &fw.Port{Values: []uint16{22}}, fw.ActionDrop)
 	require.NoError(t, err)
 
 	addr := netip.MustParseAddr("192.168.1.1")
 	m.mutex.RLock()
-	allowCount := len(m.incomingRules[addr])
-	denyCount := len(m.incomingDenyRules[addr])
+	allowCount := countRulesForAddr(m.incomingAcceptRules, addr)
+	denyCount := countRulesForAddr(m.incomingDenyRules, addr)
 	m.mutex.RUnlock()
 
 	require.Equal(t, 1, allowCount, "Should have 1 allow rule")
 	require.Equal(t, 1, denyCount, "Should have 1 deny rule")
 
 	// Delete allow rule should not affect deny rule
-	err = m.DeletePeerRule(allowRule[0])
+	err = m.DeleteFilterRule(allowRule)
 	require.NoError(t, err)
 
 	m.mutex.RLock()
-	denyCountAfter := len(m.incomingDenyRules[addr])
+	denyCountAfter := countRulesForAddr(m.incomingDenyRules, addr)
 	m.mutex.RUnlock()
 
 	require.Equal(t, 1, denyCountAfter, "Deny rule should still exist after deleting allow rule")
 
 	// Delete deny rule
-	err = m.DeletePeerRule(denyRule[0])
+	err = m.DeleteFilterRule(denyRule)
 	require.NoError(t, err)
 
 	m.mutex.RLock()
-	_, denyExists := m.incomingDenyRules[addr]
-	_, allowExists := m.incomingRules[addr]
+	denyExists := countRulesForAddr(m.incomingDenyRules, addr) > 0
+	allowExists := countRulesForAddr(m.incomingAcceptRules, addr) > 0
 	m.mutex.RUnlock()
 
 	require.False(t, denyExists, "Deny rules should be empty")
@@ -400,7 +367,7 @@ func TestManagerReset(t *testing.T) {
 		SetFilterFunc: func(device.PacketFilter) error { return nil },
 	}
 
-	m, err := Create(ifaceMock, false, flowLogger, nbiface.DefaultMTU)
+	m, err := Create(Config{IFace: ifaceMock, FlowLogger: flowLogger, MTU: nbiface.DefaultMTU})
 	if err != nil {
 		t.Errorf("failed to create Manager: %v", err)
 		return
@@ -411,7 +378,7 @@ func TestManagerReset(t *testing.T) {
 	port := &fw.Port{Values: []uint16{80}}
 	action := fw.ActionDrop
 
-	_, err = m.AddPeerFiltering(nil, ip, proto, nil, port, action, "")
+	_, err = m.AddFilterRule(nil, pfx(ip), fw.Network{}, proto, nil, port, action)
 	if err != nil {
 		t.Errorf("failed to add filtering: %v", err)
 		return
@@ -423,7 +390,7 @@ func TestManagerReset(t *testing.T) {
 		return
 	}
 
-	if len(m.outgoingRules) != 0 || len(m.incomingRules) != 0 || len(m.incomingDenyRules) != 0 {
+	if len(m.incomingAcceptRules) != 0 || len(m.incomingDenyRules) != 0 {
 		t.Errorf("rules are not empty")
 	}
 }
@@ -439,7 +406,7 @@ func TestNotMatchByIP(t *testing.T) {
 		},
 	}
 
-	m, err := Create(ifaceMock, false, flowLogger, nbiface.DefaultMTU)
+	m, err := Create(Config{IFace: ifaceMock, FlowLogger: flowLogger, MTU: nbiface.DefaultMTU})
 	if err != nil {
 		t.Errorf("failed to create Manager: %v", err)
 		return
@@ -449,7 +416,7 @@ func TestNotMatchByIP(t *testing.T) {
 	proto := fw.ProtocolUDP
 	action := fw.ActionAccept
 
-	_, err = m.AddPeerFiltering(nil, ip, proto, nil, nil, action, "")
+	_, err = m.AddFilterRule(nil, pfx(ip), fw.Network{}, proto, nil, nil, action)
 	if err != nil {
 		t.Errorf("failed to add filtering: %v", err)
 		return
@@ -502,7 +469,7 @@ func TestRemovePacketHook(t *testing.T) {
 	}
 
 	// creating manager instance
-	manager, err := Create(iface, false, flowLogger, nbiface.DefaultMTU)
+	manager, err := Create(Config{IFace: iface, FlowLogger: flowLogger, MTU: nbiface.DefaultMTU})
 	if err != nil {
 		t.Fatalf("Failed to create Manager: %s", err)
 	}
@@ -519,9 +486,11 @@ func TestRemovePacketHook(t *testing.T) {
 }
 
 func TestProcessOutgoingHooks(t *testing.T) {
-	manager, err := Create(&IFaceMock{
-		SetFilterFunc: func(device.PacketFilter) error { return nil },
-	}, false, flowLogger, nbiface.DefaultMTU)
+	manager, err := Create(Config{
+		IFace: &IFaceMock{
+			SetFilterFunc: func(device.PacketFilter) error { return nil },
+		},
+		FlowLogger: flowLogger, MTU: nbiface.DefaultMTU})
 	require.NoError(t, err)
 
 	manager.udpTracker.Close()
@@ -606,7 +575,7 @@ func TestUSPFilterCreatePerformance(t *testing.T) {
 			ifaceMock := &IFaceMock{
 				SetFilterFunc: func(device.PacketFilter) error { return nil },
 			}
-			manager, err := Create(ifaceMock, false, flowLogger, nbiface.DefaultMTU)
+			manager, err := Create(Config{IFace: ifaceMock, FlowLogger: flowLogger, MTU: nbiface.DefaultMTU})
 			require.NoError(t, err)
 			time.Sleep(time.Second)
 
@@ -621,7 +590,7 @@ func TestUSPFilterCreatePerformance(t *testing.T) {
 			start := time.Now()
 			for i := 0; i < testMax; i++ {
 				port := &fw.Port{Values: []uint16{uint16(1000 + i)}}
-				_, err = manager.AddPeerFiltering(nil, ip, "tcp", nil, port, fw.ActionAccept, "")
+				_, err = manager.AddFilterRule(nil, pfx(ip), fw.Network{}, "tcp", nil, port, fw.ActionAccept)
 
 				require.NoError(t, err, "failed to add rule")
 			}
@@ -631,9 +600,11 @@ func TestUSPFilterCreatePerformance(t *testing.T) {
 }
 
 func TestStatefulFirewall_UDPTracking(t *testing.T) {
-	manager, err := Create(&IFaceMock{
-		SetFilterFunc: func(device.PacketFilter) error { return nil },
-	}, false, flowLogger, nbiface.DefaultMTU)
+	manager, err := Create(Config{
+		IFace: &IFaceMock{
+			SetFilterFunc: func(device.PacketFilter) error { return nil },
+		},
+		FlowLogger: flowLogger, MTU: nbiface.DefaultMTU})
 	require.NoError(t, err)
 
 	manager.udpTracker.Close() // Close the existing tracker
@@ -845,7 +816,7 @@ func TestUpdateSetMerge(t *testing.T) {
 		SetFilterFunc: func(device.PacketFilter) error { return nil },
 	}
 
-	manager, err := Create(ifaceMock, false, flowLogger, nbiface.DefaultMTU)
+	manager, err := Create(Config{IFace: ifaceMock, FlowLogger: flowLogger, MTU: nbiface.DefaultMTU})
 	require.NoError(t, err)
 	t.Cleanup(func() {
 		require.NoError(t, manager.Close(nil))
@@ -858,7 +829,7 @@ func TestUpdateSetMerge(t *testing.T) {
 		netip.MustParsePrefix("192.168.1.0/24"),
 	}
 
-	rule, err := manager.AddRouteFiltering(
+	rule, err := manager.AddFilterRule(
 		nil,
 		[]netip.Prefix{netip.MustParsePrefix("0.0.0.0/0")},
 		fw.Network{Set: set},
@@ -931,7 +902,7 @@ func TestUpdateSetDeduplication(t *testing.T) {
 		SetFilterFunc: func(device.PacketFilter) error { return nil },
 	}
 
-	manager, err := Create(ifaceMock, false, flowLogger, nbiface.DefaultMTU)
+	manager, err := Create(Config{IFace: ifaceMock, FlowLogger: flowLogger, MTU: nbiface.DefaultMTU})
 	require.NoError(t, err)
 	t.Cleanup(func() {
 		require.NoError(t, manager.Close(nil))
@@ -939,7 +910,7 @@ func TestUpdateSetDeduplication(t *testing.T) {
 
 	set := fw.NewDomainSet(domain.List{"example.org"})
 
-	rule, err := manager.AddRouteFiltering(
+	rule, err := manager.AddFilterRule(
 		nil,
 		[]netip.Prefix{netip.MustParsePrefix("0.0.0.0/0")},
 		fw.Network{Set: set},
@@ -1051,7 +1022,7 @@ func TestMSSClamping(t *testing.T) {
 		},
 	}
 
-	manager, err := Create(ifaceMock, false, flowLogger, 1280)
+	manager, err := Create(Config{IFace: ifaceMock, FlowLogger: flowLogger, MTU: 1280})
 	require.NoError(t, err)
 	defer func() {
 		require.NoError(t, manager.Close(nil))
@@ -1243,7 +1214,7 @@ func TestShouldForward(t *testing.T) {
 		return wgaddr.Address{IP: wgIP, Network: netip.PrefixFrom(wgIP, 24)}
 	}
 
-	manager, err := Create(ifaceMock, false, flowLogger, nbiface.DefaultMTU)
+	manager, err := Create(Config{IFace: ifaceMock, FlowLogger: flowLogger, MTU: nbiface.DefaultMTU})
 	require.NoError(t, err)
 	defer func() {
 		require.NoError(t, manager.Close(nil))
@@ -1358,7 +1329,7 @@ func TestShouldForward(t *testing.T) {
 
 	// Re-create manager to pick up the new address with IPv6
 	require.NoError(t, manager.Close(nil))
-	manager, err = Create(ifaceMock, false, flowLogger, nbiface.DefaultMTU)
+	manager, err = Create(Config{IFace: ifaceMock, FlowLogger: flowLogger, MTU: nbiface.DefaultMTU})
 	require.NoError(t, err)
 
 	v6Cases := []struct {

client/firewall/uspfilter/forwarder/forwarder.go

@@ -12,6 +12,7 @@ import (
 	"time"
 
 	log "github.com/sirupsen/logrus"
+	wgdevice "golang.zx2c4.com/wireguard/device"
 	"gvisor.dev/gvisor/pkg/buffer"
 	"gvisor.dev/gvisor/pkg/tcpip"
 	"gvisor.dev/gvisor/pkg/tcpip/header"
@@ -22,9 +23,9 @@ import (
 	"gvisor.dev/gvisor/pkg/tcpip/transport/tcp"
 	"gvisor.dev/gvisor/pkg/tcpip/transport/udp"
 
-	"github.com/netbirdio/netbird/client/firewall/uspfilter/common"
 	"github.com/netbirdio/netbird/client/firewall/uspfilter/conntrack"
 	nblog "github.com/netbirdio/netbird/client/firewall/uspfilter/log"
+	"github.com/netbirdio/netbird/client/iface/wgaddr"
 	nftypes "github.com/netbirdio/netbird/client/internal/netflow/types"
 )
 
@@ -40,6 +41,12 @@ const (
 	envForceTCPRACK = "NB_FORCE_TCP_RACK"
 )
 
+// IFace provides the WireGuard device and overlay addresses the forwarder needs.
+type IFace interface {
+	GetWGDevice() *wgdevice.Device
+	Address() wgaddr.Address
+}
+
 type Forwarder struct {
 	logger     *nblog.Logger
 	flowLogger nftypes.FlowLogger
@@ -58,7 +65,7 @@ type Forwarder struct {
 	pingSemaphore      chan struct{}
 }
 
-func New(iface common.IFaceMapper, logger *nblog.Logger, flowLogger nftypes.FlowLogger, netstack bool, mtu uint16) (*Forwarder, error) {
+func New(iface IFace, logger *nblog.Logger, flowLogger nftypes.FlowLogger, netstack bool, mtu uint16) (*Forwarder, error) {
 	s := stack.New(stack.Options{
 		NetworkProtocols: []stack.NetworkProtocolFactory{
 			ipv4.NewProtocol,

client/firewall/uspfilter/fragment_test.go

@@ -39,7 +39,7 @@ func newFragmentTestManager(tb testing.TB) *Manager {
 		},
 	}
 
-	m, err := Create(ifaceMock, false, flowLogger, nbiface.DefaultMTU)
+	m, err := Create(Config{IFace: ifaceMock, FlowLogger: flowLogger, MTU: nbiface.DefaultMTU})
 	require.NoError(tb, err)
 	require.NoError(tb, m.UpdateLocalIPs())
 	tb.Cleanup(func() { require.NoError(tb, m.Close(nil)) })
@@ -175,8 +175,8 @@ func normalUDPPacket(tb testing.TB, dstPort uint16, payloadLen int) []byte {
 
 func allowUDP(tb testing.TB, m *Manager, dstPort uint16) {
 	tb.Helper()
-	_, err := m.AddPeerFiltering(nil, net.ParseIP(fragTestSrc), fw.ProtocolUDP, nil,
-		&fw.Port{Values: []uint16{dstPort}}, fw.ActionAccept, "")
+	_, err := m.AddFilterRule(nil, pfx(net.ParseIP(fragTestSrc)), fw.Network{}, fw.ProtocolUDP, nil,
+		&fw.Port{Values: []uint16{dstPort}}, fw.ActionAccept)
 	require.NoError(tb, err)
 }
 
@@ -228,8 +228,8 @@ func TestFragment_DeniedFirstDropsTrailing(t *testing.T) {
 // the overlap lands on real header bytes (the flags at byte 13).
 func TestFragment_OverlappingHeaderDropped(t *testing.T) {
 	m := newFragmentTestManager(t)
-	_, err := m.AddPeerFiltering(nil, net.ParseIP(fragTestSrc), fw.ProtocolTCP, nil,
-		&fw.Port{Values: []uint16{8080}}, fw.ActionAccept, "")
+	_, err := m.AddFilterRule(nil, pfx(net.ParseIP(fragTestSrc)), fw.Network{}, fw.ProtocolTCP, nil,
+		&fw.Port{Values: []uint16{8080}}, fw.ActionAccept)
 	require.NoError(t, err)
 
 	// First fragment: TCP header (20) + 12 data = 32 bytes -> headerEnd = 4 octets.
@@ -290,8 +290,8 @@ func TestFragment_TinyFirstDropped(t *testing.T) {
 // trailing fragments inherit the verdict.
 func TestFragment_TCPFirstFragment(t *testing.T) {
 	m := newFragmentTestManager(t)
-	_, err := m.AddPeerFiltering(nil, net.ParseIP(fragTestSrc), fw.ProtocolTCP, nil,
-		&fw.Port{Values: []uint16{8080}}, fw.ActionAccept, "")
+	_, err := m.AddFilterRule(nil, pfx(net.ParseIP(fragTestSrc)), fw.Network{}, fw.ProtocolTCP, nil,
+		&fw.Port{Values: []uint16{8080}}, fw.ActionAccept)
 	require.NoError(t, err)
 
 	// TCP header (20) + 12 data = 32 bytes -> headerEnd = 4 octets.
@@ -308,8 +308,8 @@ func TestFragment_TCPFirstFragment(t *testing.T) {
 // bytes would satisfy a UDP header but falls short of the 20-byte TCP header.
 func TestFragment_TCPTinyFirstDropped(t *testing.T) {
 	m := newFragmentTestManager(t)
-	_, err := m.AddPeerFiltering(nil, net.ParseIP(fragTestSrc), fw.ProtocolTCP, nil,
-		&fw.Port{Values: []uint16{8080}}, fw.ActionAccept, "")
+	_, err := m.AddFilterRule(nil, pfx(net.ParseIP(fragTestSrc)), fw.Network{}, fw.ProtocolTCP, nil,
+		&fw.Port{Values: []uint16{8080}}, fw.ActionAccept)
 	require.NoError(t, err)
 
 	tiny := trailingFragmentTo(t, fragTestDst, layers.IPProtocolTCP, 0x7777, 0, true, 12)
@@ -353,7 +353,7 @@ func TestFragment_RouteACL(t *testing.T) {
 	m.routingEnabled.Store(true)
 	m.nativeRouter.Store(false)
 
-	_, err := m.AddRouteFiltering(
+	_, err := m.AddFilterRule(
 		[]byte("rt-1"),
 		[]netip.Prefix{netip.MustParsePrefix("100.10.0.0/16")},
 		fw.Network{Prefix: netip.MustParsePrefix("198.51.100.0/24")},
@@ -511,8 +511,8 @@ func TestFragmentV6_TrailingWithoutFirstDropped(t *testing.T) {
 // through.
 func TestFragmentV6_AllowedFirstPassesTrailing(t *testing.T) {
 	m := newFragmentTestManager(t)
-	_, err := m.AddPeerFiltering(nil, net.ParseIP(fragTestSrcV6), fw.ProtocolUDP, nil,
-		&fw.Port{Values: []uint16{8080}}, fw.ActionAccept, "")
+	_, err := m.AddFilterRule(nil, pfx(net.ParseIP(fragTestSrcV6)), fw.Network{}, fw.ProtocolUDP, nil,
+		&fw.Port{Values: []uint16{8080}}, fw.ActionAccept)
 	require.NoError(t, err)
 
 	// First fragment: UDP header (8) + 32 data = 40 octets -> headerEnd = 5.
@@ -531,8 +531,8 @@ func TestFragmentV6_AllowedFirstPassesTrailing(t *testing.T) {
 // exhaust the verdict table.
 func TestFragmentV6_AtomicNotCached(t *testing.T) {
 	m := newFragmentTestManager(t)
-	_, err := m.AddPeerFiltering(nil, net.ParseIP(fragTestSrcV6), fw.ProtocolUDP, nil,
-		&fw.Port{Values: []uint16{8080}}, fw.ActionAccept, "")
+	_, err := m.AddFilterRule(nil, pfx(net.ParseIP(fragTestSrcV6)), fw.Network{}, fw.ProtocolUDP, nil,
+		&fw.Port{Values: []uint16{8080}}, fw.ActionAccept)
 	require.NoError(t, err)
 
 	atomic := fragmentUDPv6(t, 0xA70301C, 8080, 16, false)

client/firewall/uspfilter/interface_allower_windows.go

@@ -9,7 +9,6 @@ import (
 	log "github.com/sirupsen/logrus"
 
 	nberrors "github.com/netbirdio/netbird/client/errors"
-	"github.com/netbirdio/netbird/client/internal/statemanager"
 )
 
 type action string
@@ -20,35 +19,20 @@ const (
 	firewallRuleName        = "Netbird"
 )
 
-// Close cleans up the firewall manager by removing all rules and closing trackers
-func (m *Manager) Close(*statemanager.Manager) error {
-	m.mutex.Lock()
-	defer m.mutex.Unlock()
-
-	m.resetState()
-
-	if !isWindowsFirewallReachable() {
-		return nil
-	}
-
-	var merr *multierror.Error
-	if isFirewallRuleActive(firewallRuleName) {
-		if err := manageFirewallRule(firewallRuleName, deleteRule); err != nil {
-			merr = multierror.Append(merr, fmt.Errorf("remove windows firewall rule: %w", err))
-		}
-	}
-
-	if isFirewallRuleActive(firewallRuleName + "-v6") {
-		if err := manageFirewallRule(firewallRuleName+"-v6", deleteRule); err != nil {
-			merr = multierror.Append(merr, fmt.Errorf("remove windows v6 firewall rule: %w", err))
-		}
-	}
-
-	return nberrors.FormatErrorOrNil(merr)
+// WindowsInterfaceAllower opens the NetBird interface in the Windows firewall
+// via netsh advfirewall rules. It implements InterfaceAllower for the userspace
+// firewall on Windows.
+type WindowsInterfaceAllower struct {
+	iface Iface
 }
 
-// AllowNetbird allows netbird interface traffic
-func (m *Manager) AllowNetbird() error {
+// NewWindowsInterfaceAllower builds the Windows netsh-based interface allower.
+func NewWindowsInterfaceAllower(iface Iface) *WindowsInterfaceAllower {
+	return &WindowsInterfaceAllower{iface: iface}
+}
+
+// Apply adds inbound-allow netsh rules for the interface's addresses.
+func (a *WindowsInterfaceAllower) Apply() error {
 	if !isWindowsFirewallReachable() {
 		return nil
 	}
@@ -60,13 +44,13 @@ func (m *Manager) AllowNetbird() error {
 			"enable=yes",
 			"action=allow",
 			"profile=any",
-			"localip="+m.wgIface.Address().IP.String(),
+			"localip="+a.iface.Address().IP.String(),
 		); err != nil {
 			return err
 		}
 	}
 
-	if v6 := m.wgIface.Address().IPv6; v6.IsValid() && !isFirewallRuleActive(firewallRuleName+"-v6") {
+	if v6 := a.iface.Address().IPv6; v6.IsValid() && !isFirewallRuleActive(firewallRuleName+"-v6") {
 		if err := manageFirewallRule(firewallRuleName+"-v6",
 			addRule,
 			"dir=in",
@@ -82,8 +66,27 @@ func (m *Manager) AllowNetbird() error {
 	return nil
 }
 
-func manageFirewallRule(ruleName string, action action, extraArgs ...string) error {
+// Close removes the netsh rules added by Apply.
+func (a *WindowsInterfaceAllower) Close() error {
+	if !isWindowsFirewallReachable() {
+		return nil
+	}
 
+	var merr *multierror.Error
+	if isFirewallRuleActive(firewallRuleName) {
+		if err := manageFirewallRule(firewallRuleName, deleteRule); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("remove windows firewall rule: %w", err))
+		}
+	}
+	if isFirewallRuleActive(firewallRuleName + "-v6") {
+		if err := manageFirewallRule(firewallRuleName+"-v6", deleteRule); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("remove windows v6 firewall rule: %w", err))
+		}
+	}
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+func manageFirewallRule(ruleName string, action action, extraArgs ...string) error {
 	args := []string{"advfirewall", "firewall", string(action), "rule", "name=" + ruleName}
 	if action == addRule {
 		args = append(args, extraArgs...)

client/firewall/uspfilter/localip.go

@@ -7,8 +7,6 @@ import (
 	"sync/atomic"
 
 	log "github.com/sirupsen/logrus"
-
-	"github.com/netbirdio/netbird/client/firewall/uspfilter/common"
 )
 
 // localIPSnapshot is an immutable snapshot of local IP addresses, swapped
@@ -60,7 +58,7 @@ func processInterface(iface net.Interface, ips map[netip.Addr]struct{}, addresse
 }
 
 // UpdateLocalIPs rebuilds the local IP snapshot and swaps it in atomically.
-func (m *localIPManager) UpdateLocalIPs(iface common.IFaceMapper) (err error) {
+func (m *localIPManager) UpdateLocalIPs(iface Iface) (err error) {
 	defer func() {
 		if r := recover(); r != nil {
 			err = fmt.Errorf("panic: %v", r)

client/firewall/uspfilter/nat.go

@@ -487,19 +487,13 @@ func incrementalUpdate(oldChecksum uint16, oldBytes, newBytes []byte) uint16 {
 }
 
 // AddDNATRule adds outbound DNAT rule for forwarding external traffic to NetBird network.
-func (m *Manager) AddDNATRule(rule firewall.ForwardRule) (firewall.Rule, error) {
-	if m.nativeFirewall == nil {
-		return nil, errNatNotSupported
-	}
-	return m.nativeFirewall.AddDNATRule(rule)
+func (m *Manager) AddDNATRule(firewall.ForwardRule) (firewall.Rule, error) {
+	return nil, errNotSupported
 }
 
 // DeleteDNATRule deletes outbound DNAT rule.
-func (m *Manager) DeleteDNATRule(rule firewall.Rule) error {
-	if m.nativeFirewall == nil {
-		return errNatNotSupported
-	}
-	return m.nativeFirewall.DeleteDNATRule(rule)
+func (m *Manager) DeleteDNATRule(firewall.Rule) error {
+	return errNotSupported
 }
 
 // addPortRedirection adds a port redirection rule.
@@ -521,7 +515,6 @@ func (m *Manager) addPortRedirection(targetIP netip.Addr, protocol gopacket.Laye
 }
 
 // AddInboundDNAT adds an inbound DNAT rule redirecting traffic from NetBird peers to local services.
-// TODO: also delegate to nativeFirewall when available for kernel WG mode
 func (m *Manager) AddInboundDNAT(localAddr netip.Addr, protocol firewall.Protocol, originalPort, translatedPort uint16) error {
 	var layerType gopacket.LayerType
 	switch protocol {
@@ -567,20 +560,16 @@ func (m *Manager) RemoveInboundDNAT(localAddr netip.Addr, protocol firewall.Prot
 	return m.removePortRedirection(localAddr, layerType, originalPort, translatedPort)
 }
 
-// AddOutputDNAT delegates to the native firewall if available.
-func (m *Manager) AddOutputDNAT(localAddr netip.Addr, protocol firewall.Protocol, originalPort, translatedPort uint16) error {
-	if m.nativeFirewall == nil {
-		return fmt.Errorf("output DNAT not supported without native firewall")
-	}
-	return m.nativeFirewall.AddOutputDNAT(localAddr, protocol, originalPort, translatedPort)
+// AddOutputDNAT is not supported by the userspace firewall: it backs kernel DNS
+// redirection, but userspace DNS is served in-process on the gVisor netstack, so
+// this should never be called.
+func (m *Manager) AddOutputDNAT(netip.Addr, firewall.Protocol, uint16, uint16) error {
+	return errNotSupported
 }
 
-// RemoveOutputDNAT delegates to the native firewall if available.
-func (m *Manager) RemoveOutputDNAT(localAddr netip.Addr, protocol firewall.Protocol, originalPort, translatedPort uint16) error {
-	if m.nativeFirewall == nil {
-		return nil
-	}
-	return m.nativeFirewall.RemoveOutputDNAT(localAddr, protocol, originalPort, translatedPort)
+// RemoveOutputDNAT is a no-op for the userspace firewall (see AddOutputDNAT).
+func (m *Manager) RemoveOutputDNAT(netip.Addr, firewall.Protocol, uint16, uint16) error {
+	return nil
 }
 
 // translateInboundPortDNAT applies port-specific DNAT translation to inbound packets.

client/firewall/uspfilter/nat_bench_test.go

@@ -64,9 +64,11 @@ func BenchmarkDNATTranslation(b *testing.B) {
 
 	for _, sc := range scenarios {
 		b.Run(sc.name, func(b *testing.B) {
-			manager, err := Create(&IFaceMock{
-				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			}, false, flowLogger, iface.DefaultMTU)
+			manager, err := Create(Config{
+				IFace: &IFaceMock{
+					SetFilterFunc: func(device.PacketFilter) error { return nil },
+				},
+				FlowLogger: flowLogger, MTU: iface.DefaultMTU})
 			require.NoError(b, err)
 			defer func() {
 				require.NoError(b, manager.Close(nil))
@@ -124,9 +126,11 @@ func BenchmarkDNATTranslation(b *testing.B) {
 
 // BenchmarkDNATConcurrency tests DNAT performance under concurrent load
 func BenchmarkDNATConcurrency(b *testing.B) {
-	manager, err := Create(&IFaceMock{
-		SetFilterFunc: func(device.PacketFilter) error { return nil },
-	}, false, flowLogger, iface.DefaultMTU)
+	manager, err := Create(Config{
+		IFace: &IFaceMock{
+			SetFilterFunc: func(device.PacketFilter) error { return nil },
+		},
+		FlowLogger: flowLogger, MTU: iface.DefaultMTU})
 	require.NoError(b, err)
 	defer func() {
 		require.NoError(b, manager.Close(nil))
@@ -196,9 +200,11 @@ func BenchmarkDNATScaling(b *testing.B) {
 
 	for _, count := range mappingCounts {
 		b.Run(fmt.Sprintf("mappings_%d", count), func(b *testing.B) {
-			manager, err := Create(&IFaceMock{
-				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			}, false, flowLogger, iface.DefaultMTU)
+			manager, err := Create(Config{
+				IFace: &IFaceMock{
+					SetFilterFunc: func(device.PacketFilter) error { return nil },
+				},
+				FlowLogger: flowLogger, MTU: iface.DefaultMTU})
 			require.NoError(b, err)
 			defer func() {
 				require.NoError(b, manager.Close(nil))
@@ -308,9 +314,11 @@ func BenchmarkChecksumUpdate(b *testing.B) {
 
 // BenchmarkDNATMemoryAllocations checks for memory allocations in DNAT operations
 func BenchmarkDNATMemoryAllocations(b *testing.B) {
-	manager, err := Create(&IFaceMock{
-		SetFilterFunc: func(device.PacketFilter) error { return nil },
-	}, false, flowLogger, iface.DefaultMTU)
+	manager, err := Create(Config{
+		IFace: &IFaceMock{
+			SetFilterFunc: func(device.PacketFilter) error { return nil },
+		},
+		FlowLogger: flowLogger, MTU: iface.DefaultMTU})
 	require.NoError(b, err)
 	defer func() {
 		require.NoError(b, manager.Close(nil))
@@ -481,9 +489,11 @@ func BenchmarkPortDNAT(b *testing.B) {
 
 	for _, sc := range scenarios {
 		b.Run(sc.name, func(b *testing.B) {
-			manager, err := Create(&IFaceMock{
-				SetFilterFunc: func(device.PacketFilter) error { return nil },
-			}, false, flowLogger, iface.DefaultMTU)
+			manager, err := Create(Config{
+				IFace: &IFaceMock{
+					SetFilterFunc: func(device.PacketFilter) error { return nil },
+				},
+				FlowLogger: flowLogger, MTU: iface.DefaultMTU})
 			require.NoError(b, err)
 			defer func() {
 				require.NoError(b, manager.Close(nil))

client/firewall/uspfilter/nat_stateful_test.go

@@ -13,9 +13,11 @@ import (
 
 // TestPortDNATBasic tests basic port DNAT functionality
 func TestPortDNATBasic(t *testing.T) {
-	manager, err := Create(&IFaceMock{
-		SetFilterFunc: func(device.PacketFilter) error { return nil },
-	}, false, flowLogger, iface.DefaultMTU)
+	manager, err := Create(Config{
+		IFace: &IFaceMock{
+			SetFilterFunc: func(device.PacketFilter) error { return nil },
+		},
+		FlowLogger: flowLogger, MTU: iface.DefaultMTU})
 	require.NoError(t, err)
 	defer func() {
 		require.NoError(t, manager.Close(nil))
@@ -49,9 +51,11 @@ func TestPortDNATBasic(t *testing.T) {
 
 // TestPortDNATMultipleRules tests multiple port DNAT rules
 func TestPortDNATMultipleRules(t *testing.T) {
-	manager, err := Create(&IFaceMock{
-		SetFilterFunc: func(device.PacketFilter) error { return nil },
-	}, false, flowLogger, iface.DefaultMTU)
+	manager, err := Create(Config{
+		IFace: &IFaceMock{
+			SetFilterFunc: func(device.PacketFilter) error { return nil },
+		},
+		FlowLogger: flowLogger, MTU: iface.DefaultMTU})
 	require.NoError(t, err)
 	defer func() {
 		require.NoError(t, manager.Close(nil))

client/firewall/uspfilter/nat_test.go

@@ -15,9 +15,11 @@ import (
 
 // TestDNATTranslationCorrectness verifies DNAT translation works correctly
 func TestDNATTranslationCorrectness(t *testing.T) {
-	manager, err := Create(&IFaceMock{
-		SetFilterFunc: func(device.PacketFilter) error { return nil },
-	}, false, flowLogger, iface.DefaultMTU)
+	manager, err := Create(Config{
+		IFace: &IFaceMock{
+			SetFilterFunc: func(device.PacketFilter) error { return nil },
+		},
+		FlowLogger: flowLogger, MTU: iface.DefaultMTU})
 	require.NoError(t, err)
 	defer func() {
 		require.NoError(t, manager.Close(nil))
@@ -104,9 +106,11 @@ func parsePacket(t testing.TB, packetData []byte) *decoder {
 
 // TestDNATMappingManagement tests adding/removing DNAT mappings
 func TestDNATMappingManagement(t *testing.T) {
-	manager, err := Create(&IFaceMock{
-		SetFilterFunc: func(device.PacketFilter) error { return nil },
-	}, false, flowLogger, iface.DefaultMTU)
+	manager, err := Create(Config{
+		IFace: &IFaceMock{
+			SetFilterFunc: func(device.PacketFilter) error { return nil },
+		},
+		FlowLogger: flowLogger, MTU: iface.DefaultMTU})
 	require.NoError(t, err)
 	defer func() {
 		require.NoError(t, manager.Close(nil))
@@ -152,9 +156,11 @@ func TestDNATMappingManagement(t *testing.T) {
 }
 
 func TestInboundPortDNAT(t *testing.T) {
-	manager, err := Create(&IFaceMock{
-		SetFilterFunc: func(device.PacketFilter) error { return nil },
-	}, false, flowLogger, iface.DefaultMTU)
+	manager, err := Create(Config{
+		IFace: &IFaceMock{
+			SetFilterFunc: func(device.PacketFilter) error { return nil },
+		},
+		FlowLogger: flowLogger, MTU: iface.DefaultMTU})
 	require.NoError(t, err)
 	defer func() {
 		require.NoError(t, manager.Close(nil))
@@ -202,9 +208,11 @@ func TestInboundPortDNAT(t *testing.T) {
 }
 
 func TestInboundPortDNATNegative(t *testing.T) {
-	manager, err := Create(&IFaceMock{
-		SetFilterFunc: func(device.PacketFilter) error { return nil },
-	}, false, flowLogger, iface.DefaultMTU)
+	manager, err := Create(Config{
+		IFace: &IFaceMock{
+			SetFilterFunc: func(device.PacketFilter) error { return nil },
+		},
+		FlowLogger: flowLogger, MTU: iface.DefaultMTU})
 	require.NoError(t, err)
 	defer func() {
 		require.NoError(t, manager.Close(nil))

client/firewall/uspfilter/peer_acl_bench_test.go

@@ -0,0 +1,333 @@
+//go:build uspbench
+
+package uspfilter
+
+import (
+	"fmt"
+	"io"
+	"math/rand"
+	"net"
+	"net/netip"
+	"runtime"
+	"testing"
+
+	"github.com/google/gopacket"
+	"github.com/google/gopacket/layers"
+	log "github.com/sirupsen/logrus"
+	"github.com/stretchr/testify/require"
+
+	fw "github.com/netbirdio/netbird/client/firewall/manager"
+	"github.com/netbirdio/netbird/client/iface"
+	"github.com/netbirdio/netbird/client/iface/device"
+	"github.com/netbirdio/netbird/client/iface/wgaddr"
+)
+
+// BenchmarkPeerACLMatch measures the per-packet cost of the peer ACL
+// matcher (peerACLsBlock) across realistic shapes: M distinct policy
+// rules, each with K source peers in its set.
+//
+// With the reverse-source index, miss cost is independent of M and
+// hit cost grows only with the number of rules touching a single
+// srcIP, not with total rule count.
+func BenchmarkPeerACLMatch(b *testing.B) {
+	shapes := []struct{ M, K int }{
+		{1, 100}, {10, 100}, {50, 100}, {100, 100}, {100, 1000},
+	}
+	families := []struct {
+		name string
+		v6   bool
+	}{{"v4", false}, {"v6", true}}
+
+	for _, fam := range families {
+		for _, s := range shapes {
+			b.Run(fmt.Sprintf("%s/M=%d/K=%d/hit", fam.name, s.M, s.K), func(b *testing.B) {
+				runPeerACLBench(b, s.M, s.K, true, fam.v6)
+			})
+			b.Run(fmt.Sprintf("%s/M=%d/K=%d/miss", fam.name, s.M, s.K), func(b *testing.B) {
+				runPeerACLBench(b, s.M, s.K, false, fam.v6)
+			})
+		}
+	}
+}
+
+func runPeerACLBench(b *testing.B, m, k int, hit, v6 bool) {
+	log.SetOutput(io.Discard) // keep manager logs out of the benchmark output
+
+	// Miss packets are dropped, so they always traverse the full peer
+	// ACL matcher (every bucket) without short-circuiting and without
+	// touching conntrack. Disable conntrack for the miss case so it
+	// measures the matcher, not established-state lookups. The hit case
+	// keeps conntrack on: an accepted packet reaches trackInbound, which
+	// needs the trackers conntrack creates.
+	if !hit {
+		b.Setenv("NB_DISABLE_CONNTRACK", "1")
+	}
+
+	bits := 32
+	genPkt := generatePacket
+	addrs := uniqueAddrs
+	if v6 {
+		bits = 128
+		genPkt = generatePacket6
+		addrs = uniqueAddrs6
+	}
+
+	// dstIP must be a local IP so filterInbound takes the local-traffic
+	// path (handleLocalTraffic → peerACLsBlock) we are measuring; an
+	// address the manager doesn't own would be treated as routed and
+	// short-circuit before the peer matcher.
+	dstIP := addrs(1, 2)[0]
+	mockAddr := wgaddr.Address{IP: dstIP, Network: netip.PrefixFrom(dstIP, bits)}
+	if v6 {
+		// The local-IP manager needs a valid v4 address too; expose the v6
+		// dst as the interface's IPv6 so IsLocalIP recognizes it.
+		mockAddr = wgaddr.Address{
+			IP:      netip.MustParseAddr("100.64.0.1"),
+			Network: netip.MustParsePrefix("100.64.0.0/16"),
+			IPv6:    dstIP,
+			IPv6Net: netip.PrefixFrom(dstIP, bits),
+		}
+	}
+	manager, err := Create(Config{
+		IFace: &IFaceMock{
+			SetFilterFunc: func(device.PacketFilter) error { return nil },
+			AddressFunc:   func() wgaddr.Address { return mockAddr },
+		},
+		FlowLogger: flowLogger, MTU: iface.DefaultMTU})
+	require.NoError(b, err)
+	b.Cleanup(func() { require.NoError(b, manager.Close(nil)) })
+
+	// Generate M policies × K source peers, all distinct.
+	all := addrs(m*k, 1)
+	for i := 0; i < m; i++ {
+		sources := make([]netip.Prefix, k)
+		for j, a := range all[i*k : (i+1)*k] {
+			sources[j] = netip.PrefixFrom(a, bits)
+		}
+		_, err := manager.AddFilterRule(
+			nil, sources, fw.Network{}, fw.ProtocolTCP, nil,
+			&fw.Port{Values: []uint16{uint16(80 + i)}},
+			fw.ActionAccept)
+		require.NoError(b, err)
+	}
+
+	// Hit: cycle through real sources, picking the matching policy's port.
+	// Miss: a source from a disjoint range, port 80 (matches no policy).
+	var pktFn func(i int) []byte
+	if hit {
+		pktFn = func(i int) []byte {
+			policy := i % m
+			src := all[policy*k+(i%k)]
+			return genPkt(b, src.AsSlice(), dstIP.AsSlice(),
+				uint16(1024+i%60000), uint16(80+policy), layers.IPProtocolTCP)
+		}
+	} else {
+		miss := addrs(4096, 99)
+		pktFn = func(i int) []byte {
+			return genPkt(b, miss[i%len(miss)].AsSlice(), dstIP.AsSlice(),
+				uint16(1024+i%60000), 80, layers.IPProtocolTCP)
+		}
+	}
+
+	// Pre-build a pool to avoid allocations dominating the measurement.
+	pool := make([][]byte, 1024)
+	for i := range pool {
+		pool[i] = pktFn(i)
+	}
+
+	// Confirm the matcher is actually exercised: a hit packet must be
+	// allowed and a miss packet dropped. Without this the benchmark
+	// could silently time the routed early-return instead.
+	require.Equal(b, !hit, manager.filterInbound(pool[0], 0),
+		"benchmark must reach the peer ACL matcher")
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		manager.filterInbound(pool[i%len(pool)], 0)
+	}
+}
+
+// BenchmarkPeerACLIndexMemory reports the resident memory cost of
+// the source-keyed index across realistic deployment shapes. Two
+// dimensions matter: (M, K), the number of policies × peers-per-policy,
+// and overlap, the fraction of peers shared between policies.
+//
+// The output uses ReportMetric("bytes/rule") so the cost can be
+// compared across shapes directly. Total bytes = bytes/rule * M.
+func BenchmarkPeerACLIndexMemory(b *testing.B) {
+	cases := []struct {
+		name        string
+		M, K        int
+		overlapFrac float64 // 0 = disjoint per-policy sources, 1 = all share the same pool
+	}{
+		{"M=10/K=100/disjoint", 10, 100, 0},
+		{"M=100/K=100/disjoint", 100, 100, 0},
+		{"M=100/K=1000/disjoint", 100, 1000, 0},
+		{"M=100/K=1000/overlap=0.5", 100, 1000, 0.5},
+		{"M=100/K=1000/overlap=1.0", 100, 1000, 1.0},
+		{"M=1000/K=100/overlap=1.0", 1000, 100, 1.0},
+	}
+
+	for _, c := range cases {
+		b.Run(c.name, func(b *testing.B) {
+			b.ReportAllocs()
+			for i := 0; i < b.N; i++ {
+				mgr, err := Create(Config{
+					IFace: &IFaceMock{
+						SetFilterFunc: func(device.PacketFilter) error { return nil },
+					},
+					FlowLogger: flowLogger, MTU: iface.DefaultMTU})
+				require.NoError(b, err)
+
+				populateIndexedRules(b, mgr, c.M, c.K, c.overlapFrac)
+
+				runtime.GC()
+				var ms runtime.MemStats
+				runtime.ReadMemStats(&ms)
+				before := ms.HeapAlloc
+
+				// Drop the manager's external roots so we can isolate
+				// the index cost. We hold the manager itself live; the
+				// index is what we measure on the second pass.
+				mgr.incomingAcceptIndex.reset()
+				mgr.incomingDenyIndex.reset()
+				mgr.incomingAcceptRules = mgr.incomingAcceptRules[:0]
+				mgr.incomingDenyRules = mgr.incomingDenyRules[:0]
+				runtime.GC()
+				runtime.ReadMemStats(&ms)
+				after := ms.HeapAlloc
+
+				delta := int64(before) - int64(after)
+				if delta < 0 {
+					delta = 0
+				}
+				b.ReportMetric(float64(delta)/float64(c.M), "bytes/rule")
+				b.ReportMetric(float64(delta), "bytes/total")
+
+				require.NoError(b, mgr.Close(nil))
+			}
+		})
+	}
+}
+
+func populateIndexedRules(b *testing.B, mgr *Manager, m, k int, overlapFrac float64) {
+	b.Helper()
+	pool := uniqueAddrs(k+m*k, 1) // big enough universe
+	sharedLen := int(float64(k) * overlapFrac)
+	if sharedLen > k {
+		sharedLen = k
+	}
+	shared := pool[:sharedLen]
+	uniquePool := pool[sharedLen:]
+
+	for i := 0; i < m; i++ {
+		sources := make([]netip.Prefix, 0, k)
+		for _, a := range shared {
+			sources = append(sources, netip.PrefixFrom(a, 32))
+		}
+		// each policy gets (k-sharedLen) addresses unique to it from the unique pool
+		unique := uniquePool[i*(k-sharedLen) : (i+1)*(k-sharedLen)]
+		for _, a := range unique {
+			sources = append(sources, netip.PrefixFrom(a, 32))
+		}
+		_, err := mgr.AddFilterRule(
+			nil, sources, fw.Network{}, fw.ProtocolTCP, nil,
+			&fw.Port{Values: []uint16{uint16(80 + i)}},
+			fw.ActionAccept)
+		require.NoError(b, err)
+	}
+}
+
+// uniqueAddrs returns n distinct addrs. Seeds 1, 2 are used for
+// policy sources / dst; seed 99 puts misses in 10/8.
+func uniqueAddrs(n int, seed int64) []netip.Addr {
+	out := make([]netip.Addr, 0, n)
+	seen := make(map[netip.Addr]struct{}, n)
+	r := rand.New(rand.NewSource(seed))
+	miss := seed == 99
+	for len(out) < n {
+		var b [4]byte
+		if miss {
+			b[0] = 10
+			b[1] = byte(r.Intn(256))
+		} else {
+			b[0] = 100
+			b[1] = byte(64 + r.Intn(63))
+		}
+		b[2] = byte(r.Intn(256))
+		b[3] = byte(1 + r.Intn(254))
+		a := netip.AddrFrom4(b)
+		if _, ok := seen[a]; ok {
+			continue
+		}
+		seen[a] = struct{}{}
+		out = append(out, a)
+	}
+	return out
+}
+
+// uniqueAddrs6 mirrors uniqueAddrs for IPv6: sources come from the ULA
+// range fd00::/8, the miss set (seed 99) from 2001:db8::/32 so it is
+// disjoint from any source.
+func uniqueAddrs6(n int, seed int64) []netip.Addr {
+	out := make([]netip.Addr, 0, n)
+	seen := make(map[netip.Addr]struct{}, n)
+	r := rand.New(rand.NewSource(seed))
+	miss := seed == 99
+	for len(out) < n {
+		var b [16]byte
+		if miss {
+			b[0], b[1], b[2], b[3] = 0x20, 0x01, 0x0d, 0xb8
+		} else {
+			b[0] = 0xfd
+		}
+		for x := 8; x < 16; x++ {
+			b[x] = byte(r.Intn(256))
+		}
+		a := netip.AddrFrom16(b)
+		if _, ok := seen[a]; ok {
+			continue
+		}
+		seen[a] = struct{}{}
+		out = append(out, a)
+	}
+	return out
+}
+
+// generatePacket6 builds an IPv6 TCP/UDP packet, mirroring
+// generatePacket for the v4 case.
+func generatePacket6(b *testing.B, srcIP, dstIP net.IP, srcPort, dstPort uint16, protocol layers.IPProtocol) []byte {
+	b.Helper()
+
+	ipv6 := &layers.IPv6{
+		Version:    6,
+		HopLimit:   64,
+		NextHeader: protocol,
+		SrcIP:      srcIP,
+		DstIP:      dstIP,
+	}
+
+	var transportLayer gopacket.SerializableLayer
+	switch protocol {
+	case layers.IPProtocolTCP:
+		tcp := &layers.TCP{
+			SrcPort: layers.TCPPort(srcPort),
+			DstPort: layers.TCPPort(dstPort),
+			SYN:     true,
+		}
+		require.NoError(b, tcp.SetNetworkLayerForChecksum(ipv6))
+		transportLayer = tcp
+	case layers.IPProtocolUDP:
+		udp := &layers.UDP{
+			SrcPort: layers.UDPPort(srcPort),
+			DstPort: layers.UDPPort(dstPort),
+		}
+		require.NoError(b, udp.SetNetworkLayerForChecksum(ipv6))
+		transportLayer = udp
+	}
+
+	buf := gopacket.NewSerializeBuffer()
+	opts := gopacket.SerializeOptions{ComputeChecksums: true, FixLengths: true}
+	require.NoError(b, gopacket.SerializeLayers(buf, opts, ipv6, transportLayer, gopacket.Payload("test")))
+	return buf.Bytes()
+}

client/firewall/uspfilter/peer_acl_dedup_test.go

@@ -0,0 +1,150 @@
+package uspfilter
+
+import (
+	"net"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	fw "github.com/netbirdio/netbird/client/firewall/manager"
+	nbiface "github.com/netbirdio/netbird/client/iface"
+	"github.com/netbirdio/netbird/client/iface/device"
+)
+
+func newTestManager(t *testing.T) *Manager {
+	t.Helper()
+	ifaceMock := &IFaceMock{
+		SetFilterFunc: func(device.PacketFilter) error { return nil },
+	}
+	m, err := Create(Config{IFace: ifaceMock, FlowLogger: flowLogger, MTU: nbiface.DefaultMTU})
+	require.NoError(t, err, "create manager")
+	t.Cleanup(func() { require.NoError(t, m.Close(nil)) })
+	return m
+}
+
+// TestAddPeerFiltering_DeduplicatesIdenticalRules verifies that adding
+// the same peer rule twice does not create two backing rules. The acl
+// manager keys its own cache, but the firewall backend must be
+// idempotent on its own so a double-apply cannot leak rules, matching
+// the route path and the kernel backends.
+func TestAddPeerFiltering_DeduplicatesIdenticalRules(t *testing.T) {
+	m := newTestManager(t)
+
+	ip := net.ParseIP("192.168.1.1")
+	proto := fw.ProtocolTCP
+	port := &fw.Port{Values: []uint16{80}}
+	action := fw.ActionDrop
+
+	first, err := m.AddFilterRule(nil, pfx(ip), fw.Network{}, proto, nil, port, action)
+	require.NoError(t, err, "first add")
+
+	second, err := m.AddFilterRule(nil, pfx(ip), fw.Network{}, proto, nil, port, action)
+	require.NoError(t, err, "second add")
+
+	assert.Equal(t, first.ID(), second.ID(), "duplicate add should return the same rule id")
+	assert.Len(t, m.incomingDenyRules, 1, "duplicate add must not create a second backing rule")
+}
+
+// TestDeletePeerFiltering_NoRefcountSingleDeleteRemoves locks the
+// backend's owner accounting for the same-owner case: a content key
+// installed twice by the same owner registers one owner claim, so the
+// first DeleteFilterRule removes the rule. Owner counting only kicks
+// in for distinct management rule IDs (see the peer owner tests); the
+// acl manager keys its tracking per (policy, content) and deletes once
+// per key, so adds and deletes stay balanced.
+func TestDeletePeerFiltering_NoRefcountSingleDeleteRemoves(t *testing.T) {
+	m := newTestManager(t)
+
+	ip := net.ParseIP("192.168.1.1")
+	proto := fw.ProtocolTCP
+	port := &fw.Port{Values: []uint16{80}}
+	action := fw.ActionDrop
+
+	first, err := m.AddFilterRule(nil, pfx(ip), fw.Network{}, proto, nil, port, action)
+	require.NoError(t, err, "first add")
+
+	second, err := m.AddFilterRule(nil, pfx(ip), fw.Network{}, proto, nil, port, action)
+	require.NoError(t, err, "second add")
+	require.Equal(t, first.ID(), second.ID(), "dedup to one rule")
+	require.Len(t, m.incomingDenyRules, 1, "still one backing rule after duplicate add")
+
+	require.NoError(t, m.DeleteFilterRule(first), "delete once")
+	assert.Empty(t, m.incomingDenyRules, "single delete removes the backing rule (no refcount)")
+	assert.NotContains(t, m.peerRulesMap, first.ID(), "dedup map entry cleared")
+}
+
+// TestAddPeerFiltering_DeterministicID verifies the peer rule id is a
+// content hash, not a random UUID: identical inputs produce the same id
+// across independent managers. A random id breaks caller-side dedup.
+func TestAddPeerFiltering_DeterministicID(t *testing.T) {
+	ip := net.ParseIP("10.0.0.5")
+	proto := fw.ProtocolUDP
+	port := &fw.Port{Values: []uint16{53}}
+	action := fw.ActionAccept
+
+	m1 := newTestManager(t)
+	r1, err := m1.AddFilterRule(nil, pfx(ip), fw.Network{}, proto, nil, port, action)
+	require.NoError(t, err)
+
+	m2 := newTestManager(t)
+	r2, err := m2.AddFilterRule(nil, pfx(ip), fw.Network{}, proto, nil, port, action)
+	require.NoError(t, err)
+
+	assert.Equal(t, r1.ID(), r2.ID(), "same inputs must produce the same rule id")
+}
+
+// TestAddPeerFiltering_DistinctRulesNotDeduped verifies that rules
+// differing only by port are kept separate.
+func TestAddPeerFiltering_DistinctRulesNotDeduped(t *testing.T) {
+	m := newTestManager(t)
+
+	ip := net.ParseIP("192.168.1.1")
+	proto := fw.ProtocolTCP
+	action := fw.ActionAccept
+
+	r80, err := m.AddFilterRule(nil, pfx(ip), fw.Network{}, proto, nil, &fw.Port{Values: []uint16{80}}, action)
+	require.NoError(t, err)
+
+	r443, err := m.AddFilterRule(nil, pfx(ip), fw.Network{}, proto, nil, &fw.Port{Values: []uint16{443}}, action)
+	require.NoError(t, err)
+
+	assert.NotEqual(t, r80.ID(), r443.ID(), "different ports must produce different rule ids")
+	assert.Len(t, m.incomingAcceptRules, 2, "distinct rules must both be stored")
+}
+
+// TestAddPeerFiltering_SourceVsDestPortNotDeduped verifies that a rule
+// matching on source port and one matching on destination port for the
+// same selector do not collide: the port lands in a different slot, so
+// the content key must differ.
+func TestAddPeerFiltering_SourceVsDestPortNotDeduped(t *testing.T) {
+	m := newTestManager(t)
+
+	ip := net.ParseIP("192.168.1.1")
+	proto := fw.ProtocolTCP
+	port := &fw.Port{Values: []uint16{80}}
+	action := fw.ActionAccept
+
+	dPortRule, err := m.AddFilterRule(nil, pfx(ip), fw.Network{}, proto, nil, port, action)
+	require.NoError(t, err)
+
+	sPortRule, err := m.AddFilterRule(nil, pfx(ip), fw.Network{}, proto, port, nil, action)
+	require.NoError(t, err)
+
+	assert.NotEqual(t, dPortRule.ID(), sPortRule.ID(), "source-port and dest-port matches must produce different rule ids")
+}
+
+// TestAddFilterRule_EmptySourcesRejected verifies that an empty source
+// list is rejected rather than treated as "match any". "Match any" must
+// be an explicit /0, so a zeroed list can never silently widen a rule to
+// every source.
+func TestAddFilterRule_EmptySourcesRejected(t *testing.T) {
+	m := newTestManager(t)
+
+	proto := fw.ProtocolTCP
+	port := &fw.Port{Values: []uint16{80}}
+
+	_, err := m.AddFilterRule(nil, nil, fw.Network{}, proto, nil, port, fw.ActionAccept)
+	require.ErrorIs(t, err, fw.ErrNoSources, "empty sources must be rejected")
+	assert.Empty(t, m.incomingAcceptRules, "no rule should be stored for empty sources")
+}

client/firewall/uspfilter/peer_acl_ipv6_test.go

@@ -0,0 +1,105 @@
+package uspfilter
+
+import (
+	"net"
+	"net/netip"
+	"testing"
+
+	"github.com/google/gopacket"
+	"github.com/google/gopacket/layers"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	fw "github.com/netbirdio/netbird/client/firewall/manager"
+	nbiface "github.com/netbirdio/netbird/client/iface"
+	"github.com/netbirdio/netbird/client/iface/device"
+	"github.com/netbirdio/netbird/client/iface/wgaddr"
+)
+
+func newV6TestManager(t *testing.T, localV6 string) *Manager {
+	t.Helper()
+	ifaceMock := &IFaceMock{
+		SetFilterFunc: func(device.PacketFilter) error { return nil },
+		AddressFunc: func() wgaddr.Address {
+			return wgaddr.Address{
+				IP:      netip.MustParseAddr("100.10.0.100"),
+				Network: netip.MustParsePrefix("100.10.0.0/16"),
+				IPv6:    netip.MustParseAddr(localV6),
+				IPv6Net: netip.MustParsePrefix("fd00::/64"),
+			}
+		},
+	}
+	m, err := Create(Config{IFace: ifaceMock, FlowLogger: flowLogger, MTU: nbiface.DefaultMTU})
+	require.NoError(t, err, "create manager")
+	t.Cleanup(func() { require.NoError(t, m.Close(nil)) })
+	return m
+}
+
+func v6UDPPacket(t *testing.T, src, dst string, dstPort uint16) []byte {
+	t.Helper()
+	ip6 := &layers.IPv6{
+		Version:    6,
+		HopLimit:   64,
+		NextHeader: layers.IPProtocolUDP,
+		SrcIP:      net.ParseIP(src),
+		DstIP:      net.ParseIP(dst),
+	}
+	udp := &layers.UDP{SrcPort: 51334, DstPort: layers.UDPPort(dstPort)}
+	require.NoError(t, udp.SetNetworkLayerForChecksum(ip6))
+
+	buf := gopacket.NewSerializeBuffer()
+	opts := gopacket.SerializeOptions{ComputeChecksums: true, FixLengths: true}
+	require.NoError(t, gopacket.SerializeLayers(buf, opts, ip6, udp, gopacket.Payload("test")))
+	return buf.Bytes()
+}
+
+// TestPeerACL_IPv6HostRule verifies the source index resolves /128 v6
+// rules: a matching v6 source is accepted, a non-matching one is
+// denied by the default. This is the end-to-end proof that the index
+// is not v4-only.
+func TestPeerACL_IPv6HostRule(t *testing.T) {
+	m := newV6TestManager(t, "fd00::100")
+
+	src := net.ParseIP("fd00::1")
+	_, err := m.AddFilterRule(nil, pfx(src), fw.Network{}, fw.ProtocolUDP, nil, &fw.Port{Values: []uint16{53}}, fw.ActionAccept)
+	require.NoError(t, err, "add v6 accept rule")
+
+	require.False(t, m.filterInbound(v6UDPPacket(t, "fd00::1", "fd00::100", 53), 0),
+		"v6 packet from the allowed /128 source must be accepted")
+	require.True(t, m.filterInbound(v6UDPPacket(t, "fd00::2", "fd00::100", 53), 0),
+		"v6 packet from an unlisted source must be denied by default")
+}
+
+// TestPeerACL_IPv6IndexBuckets verifies that v6 sources land in the
+// right index bucket: a /128 in bySource keyed by its address, and
+// coarser prefixes (including ::/0) in the nonHost slice.
+func TestPeerACL_IPv6IndexBuckets(t *testing.T) {
+	m := newV6TestManager(t, "fd00::100")
+	port := &fw.Port{Values: []uint16{53}}
+
+	host := netip.MustParseAddr("fd00::1")
+	_, err := m.AddFilterRule(nil, []netip.Prefix{netip.PrefixFrom(host, 128)}, fw.Network{}, fw.ProtocolUDP, nil, port, fw.ActionAccept)
+	require.NoError(t, err)
+	assert.Contains(t, m.incomingAcceptIndex.bySource, host, "/128 v6 source must be indexed by address")
+
+	_, err = m.AddFilterRule(nil, []netip.Prefix{netip.MustParsePrefix("fd00:dead::/64")}, fw.Network{}, fw.ProtocolUDP, nil, port, fw.ActionAccept)
+	require.NoError(t, err)
+	require.Len(t, m.incomingAcceptIndex.nonHost, 1, "coarser v6 prefix must land in nonHost")
+
+	_, err = m.AddFilterRule(nil, []netip.Prefix{netip.MustParsePrefix("::/0")}, fw.Network{}, fw.ProtocolUDP, nil, port, fw.ActionAccept)
+	require.NoError(t, err)
+	require.Len(t, m.incomingAcceptIndex.nonHost, 2, "::/0 source must also land in nonHost")
+}
+
+// TestPeerACL_IPv4MappedSourceNormalized verifies a v4-mapped v6
+// source prefix is normalized to v4 so a plain v4 packet matches it.
+func TestPeerACL_IPv4MappedSourceNormalized(t *testing.T) {
+	m := newTestManager(t)
+
+	mapped := netip.MustParseAddr("::ffff:192.168.1.1")
+	_, err := m.AddFilterRule(nil, []netip.Prefix{netip.PrefixFrom(mapped, mapped.BitLen())}, fw.Network{}, fw.ProtocolUDP, nil, &fw.Port{Values: []uint16{53}}, fw.ActionAccept)
+	require.NoError(t, err)
+
+	v4 := netip.MustParseAddr("192.168.1.1")
+	assert.Contains(t, m.incomingAcceptIndex.bySource, v4, "v4-mapped v6 source must be indexed as plain v4")
+}

client/firewall/uspfilter/peer_family_scope_test.go

@@ -0,0 +1,106 @@
+package uspfilter
+
+import (
+	"net"
+	"net/netip"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	fw "github.com/netbirdio/netbird/client/firewall/manager"
+)
+
+// peerACLCheck decodes the packet and runs it through the peer ACLs,
+// returning the attributed management rule id and the drop verdict.
+func peerACLCheck(t *testing.T, m *Manager, packet []byte) ([]byte, bool) {
+	t.Helper()
+	d := m.decoders.Get().(*decoder)
+	defer m.decoders.Put(d)
+	require.NoError(t, d.decodePacket(packet))
+	src, _ := m.extractIPs(d)
+	return m.peerACLsBlock(src, d, packet)
+}
+
+// TestPeerACL_MultiValuePortMatchesEachListedPort guards the multi-value
+// port path: a rule listing several discrete destination ports must
+// match a packet to each listed port and drop one that is not listed.
+// Management currently splits a multi-port policy into one rule per port
+// (and the wire format carries a single port), so this list shape is not
+// emitted today; the test locks correct matching in case that changes.
+func TestPeerACL_MultiValuePortMatchesEachListedPort(t *testing.T) {
+	m := newTestManager(t)
+
+	src := net.ParseIP("192.168.1.1")
+	ports := &fw.Port{Values: []uint16{80, 443}}
+	_, err := m.AddFilterRule(nil, pfx(src), fw.Network{}, fw.ProtocolTCP, nil, ports, fw.ActionAccept)
+	require.NoError(t, err, "add multi-value port rule")
+
+	for _, p := range []uint16{80, 443} {
+		_, blocked := peerACLCheck(t, m, createTestPacket(t, "192.168.1.1", "10.0.0.2", fw.ProtocolTCP, 12345, p))
+		assert.False(t, blocked, "packet to listed port %d must match the rule", p)
+	}
+
+	_, blocked := peerACLCheck(t, m, createTestPacket(t, "192.168.1.1", "10.0.0.2", fw.ProtocolTCP, 12345, 8080))
+	assert.True(t, blocked, "packet to a port not in the list must not match the rule")
+}
+
+// TestPeerACL_MatchAnyIsFamilyScoped verifies that a /0 source matches
+// only packets of its own family: 0.0.0.0/0 must not match IPv6 packets
+// and ::/0 must not match IPv4 packets, matching kernel backend
+// semantics.
+func TestPeerACL_MatchAnyIsFamilyScoped(t *testing.T) {
+	m := newTestManager(t)
+
+	v4Packet := createTestPacket(t, "10.0.0.1", "10.0.0.2", fw.ProtocolUDP, 12345, 53)
+	v6Packet := v6UDPPacket(t, "fd00::1", "fd00::100", 53)
+
+	v4Any := []netip.Prefix{netip.PrefixFrom(netip.IPv4Unspecified(), 0)}
+	rule, err := m.AddFilterRule(nil, v4Any, fw.Network{}, fw.ProtocolALL, nil, nil, fw.ActionAccept)
+	require.NoError(t, err, "add v4 /0 rule")
+
+	_, blocked := peerACLCheck(t, m, v4Packet)
+	assert.False(t, blocked, "0.0.0.0/0 must match IPv4 packets")
+	_, blocked = peerACLCheck(t, m, v6Packet)
+	assert.True(t, blocked, "0.0.0.0/0 must not match IPv6 packets")
+
+	require.NoError(t, m.DeleteFilterRule(rule))
+
+	v6Any := []netip.Prefix{netip.PrefixFrom(netip.IPv6Unspecified(), 0)}
+	_, err = m.AddFilterRule(nil, v6Any, fw.Network{}, fw.ProtocolALL, nil, nil, fw.ActionAccept)
+	require.NoError(t, err, "add v6 /0 rule")
+
+	_, blocked = peerACLCheck(t, m, v6Packet)
+	assert.False(t, blocked, "::/0 must match IPv6 packets")
+	_, blocked = peerACLCheck(t, m, v4Packet)
+	assert.True(t, blocked, "::/0 must not match IPv4 packets")
+}
+
+// TestRouteACL_MixedFamilyZeroSourcesStayFamilySafe verifies the route
+// path keeps per-prefix family matching when a single rule carries both
+// 0.0.0.0/0 and ::/0 sources, as blockInvalidRouted does.
+func TestRouteACL_MixedFamilyZeroSourcesStayFamilySafe(t *testing.T) {
+	m := newTestManager(t)
+
+	sources := []netip.Prefix{
+		netip.PrefixFrom(netip.IPv4Unspecified(), 0),
+		netip.PrefixFrom(netip.IPv6Unspecified(), 0),
+	}
+
+	_, err := m.AddFilterRule(nil, sources, fw.Network{Prefix: netip.MustParsePrefix("10.0.0.0/24")},
+		fw.ProtocolALL, nil, nil, fw.ActionAccept)
+	require.NoError(t, err)
+	_, err = m.AddFilterRule(nil, sources, fw.Network{Prefix: netip.MustParsePrefix("fd00:1::/64")},
+		fw.ProtocolALL, nil, nil, fw.ActionAccept)
+	require.NoError(t, err)
+
+	v4Src := netip.MustParseAddr("192.168.1.1")
+	v6Src := netip.MustParseAddr("fd00::1")
+
+	_, pass := m.routeACLsPass(v4Src, netip.MustParseAddr("10.0.0.5"), 255, 0, 0)
+	assert.True(t, pass, "v4 source must match the v4 destination rule via 0.0.0.0/0")
+	_, pass = m.routeACLsPass(v6Src, netip.MustParseAddr("fd00:1::5"), 255, 0, 0)
+	assert.True(t, pass, "v6 source must match the v6 destination rule via ::/0")
+	_, pass = m.routeACLsPass(v6Src, netip.MustParseAddr("10.0.0.5"), 255, 0, 0)
+	assert.True(t, pass, "v6 source still passes the v4 destination rule via ::/0 in the same source list")
+}

client/firewall/uspfilter/peer_index.go

@@ -0,0 +1,140 @@
+package uspfilter
+
+import (
+	"net/netip"
+	"slices"
+
+	"github.com/google/gopacket"
+	"github.com/google/gopacket/layers"
+
+	firewall "github.com/netbirdio/netbird/client/firewall/manager"
+)
+
+// peerRuleIndex is the source-side dispatcher consulted on the packet
+// hot path. It splits rules into two buckets by the shape of their
+// source list:
+//
+//   - bySource: every source is a host prefix (/32 for v4, /128 for
+//     v6). Keyed by the concrete source address, so a hit guarantees
+//     the source filter passes and the matcher goes straight to
+//     proto/port checks. This is the common case for peer ACLs.
+//   - nonHost: any source list with a prefix coarser than a host,
+//     including a /0 "match any". Walked linearly with a per-rule
+//     Contains() check. Expected small or empty for typical peer ACLs.
+//
+// Maintained incrementally by add/remove, never rebuilt.
+type peerRuleIndex struct {
+	bySource map[netip.Addr][]*PeerRule
+	nonHost  []*PeerRule
+}
+
+func (i *peerRuleIndex) add(r *PeerRule) {
+	if hasNonHostSource(r) {
+		i.nonHost = append(i.nonHost, r)
+		return
+	}
+	if i.bySource == nil {
+		i.bySource = make(map[netip.Addr][]*PeerRule)
+	}
+	for a := range r.sourceAddrs {
+		i.bySource[a] = append(i.bySource[a], r)
+	}
+}
+
+func (i *peerRuleIndex) remove(r *PeerRule) {
+	if hasNonHostSource(r) {
+		i.nonHost = slices.DeleteFunc(i.nonHost, eqRule(r))
+		return
+	}
+	if i.bySource == nil {
+		return
+	}
+	for a := range r.sourceAddrs {
+		entries := slices.DeleteFunc(i.bySource[a], eqRule(r))
+		if len(entries) == 0 {
+			delete(i.bySource, a)
+		} else {
+			i.bySource[a] = entries
+		}
+	}
+}
+
+func (i *peerRuleIndex) reset() {
+	i.bySource = nil
+	i.nonHost = i.nonHost[:0]
+}
+
+// match returns the first rule matching src and the decoded packet.
+// Host rules are found by direct map lookup; nonHost rules run a
+// per-rule source Contains() check. Containment is family-scoped, so
+// a /0 source matches every address of its own family only (0.0.0.0/0
+// never matches v6 sources and ::/0 never matches v4). Within either
+// bucket the matcher runs the proto/port filter.
+func (i *peerRuleIndex) match(src netip.Addr, d *decoder) ([]byte, bool, bool) {
+	payloadLayer := d.decoded[1]
+
+	for _, rule := range i.bySource[src] {
+		if id, drop, ok := matchProto(rule, d, payloadLayer); ok {
+			return id, drop, true
+		}
+	}
+	for _, rule := range i.nonHost {
+		if !prefixesContain(rule.sources, src) {
+			continue
+		}
+		if id, drop, ok := matchProto(rule, d, payloadLayer); ok {
+			return id, drop, true
+		}
+	}
+	return nil, false, false
+}
+
+func eqRule(target *PeerRule) func(*PeerRule) bool {
+	return func(p *PeerRule) bool { return p == target }
+}
+
+// hasNonHostSource reports whether the rule has any source prefix
+// that is not a single host address. Called only at add/remove time,
+// not on the packet path.
+func hasNonHostSource(r *PeerRule) bool {
+	for _, p := range r.sources {
+		if p.Bits() != p.Addr().BitLen() {
+			return true
+		}
+	}
+	return false
+}
+
+// matchProto applies the proto/port half of a rule against the
+// decoded packet. Source matching is the caller's responsibility.
+func matchProto(rule *PeerRule, d *decoder, payloadLayer gopacket.LayerType) ([]byte, bool, bool) {
+	drop := rule.action == firewall.ActionDrop
+	if rule.protoLayer == layerTypeAll {
+		return rule.mgmtId, drop, true
+	}
+	if !protoLayerMatches(rule.protoLayer, payloadLayer) {
+		return nil, false, false
+	}
+	switch payloadLayer {
+	case layers.LayerTypeTCP:
+		if portsMatch(rule.srcPort, uint16(d.tcp.SrcPort)) && portsMatch(rule.dstPort, uint16(d.tcp.DstPort)) {
+			return rule.mgmtId, drop, true
+		}
+	case layers.LayerTypeUDP:
+		if portsMatch(rule.srcPort, uint16(d.udp.SrcPort)) && portsMatch(rule.dstPort, uint16(d.udp.DstPort)) {
+			return rule.mgmtId, drop, true
+		}
+	case layers.LayerTypeICMPv4, layers.LayerTypeICMPv6:
+		return rule.mgmtId, drop, true
+	}
+	return nil, false, false
+}
+
+func prefixesContain(sources []netip.Prefix, src netip.Addr) bool {
+	for _, p := range sources {
+		if p.Contains(src) {
+			return true
+		}
+	}
+	return false
+}

client/firewall/uspfilter/rule.go

@@ -10,24 +10,43 @@ import (
 
 // PeerRule to handle management of rules
 type PeerRule struct {
-	id         string
-	mgmtId     []byte
-	ip         netip.Addr
-	ipLayer    gopacket.LayerType
-	matchByIP  bool
-	protoLayer gopacket.LayerType
-	sPort      *firewall.Port
-	dPort      *firewall.Port
-	drop bool
+	id     firewall.RuleID
+	mgmtId []byte
+	// sources is the canonical list of source prefixes this rule
+	// matches against.
+	sources []netip.Prefix
+	// sourceAddrs is a fast-path membership set for host-prefix
+	// sources (/32 v4, /128 v6). Populated alongside sources;
+	// consulted before falling back to prefix scan.
+	sourceAddrs map[netip.Addr]struct{}
+	protoLayer  gopacket.LayerType
+	srcPort     *firewall.Port
+	dstPort     *firewall.Port
+	action      firewall.Action
+}
+
+// matchesSource reports whether the given source address is covered
+// by this rule's source list. Prefix containment is family-scoped, so
+// a /0 source matches every address of its own family only.
+func (r *PeerRule) matchesSource(src netip.Addr) bool {
+	if _, ok := r.sourceAddrs[src]; ok {
+		return true
+	}
+	for _, p := range r.sources {
+		if p.Contains(src) {
+			return true
+		}
+	}
+	return false
 }
 
 // ID returns the rule id
-func (r *PeerRule) ID() string {
+func (r *PeerRule) ID() firewall.RuleID {
 	return r.id
 }
 
 type RouteRule struct {
-	id           string
+	id           firewall.RuleID
 	mgmtId       []byte
 	sources      []netip.Prefix
 	dstSet       firewall.Set
@@ -39,6 +58,6 @@ type RouteRule struct {
 }
 
 // ID returns the rule id
-func (r *RouteRule) ID() string {
+func (r *RouteRule) ID() firewall.RuleID {
 	return r.id
 }

client/firewall/uspfilter/testhelpers_test.go

@@ -0,0 +1,50 @@
+package uspfilter
+
+import (
+	"net"
+	"net/netip"
+
+	firewall "github.com/netbirdio/netbird/client/firewall/manager"
+)
+
+// countRulesForAddr reports how many rules in the given slice match
+// the supplied source address.
+func countRulesForAddr(rules peerRules, src netip.Addr) int {
+	n := 0
+	for _, r := range rules {
+		if r.matchesSource(src) {
+			n++
+		}
+	}
+	return n
+}
+
+// findRuleByID returns true if the rules slice contains a rule with
+// the given id whose source set covers src.
+func findRuleByID(rules peerRules, src netip.Addr, id firewall.RuleID) bool {
+	for _, r := range rules {
+		if r.id == id && r.matchesSource(src) {
+			return true
+		}
+	}
+	return false
+}
+
+// pfx converts a single net.IP into the []netip.Prefix form
+// AddFilterRule expects. A nil or unspecified address becomes a /0
+// ("match any") prefix in the matching family; any other address
+// becomes its /32 (or /128) host prefix.
+func pfx(ip net.IP) []netip.Prefix {
+	if ip == nil {
+		return []netip.Prefix{netip.PrefixFrom(netip.IPv4Unspecified(), 0)}
+	}
+	if ip.IsUnspecified() {
+		if ip.To4() != nil {
+			return []netip.Prefix{netip.PrefixFrom(netip.IPv4Unspecified(), 0)}
+		}
+		return []netip.Prefix{netip.PrefixFrom(netip.IPv6Unspecified(), 0)}
+	}
+	a, _ := netip.AddrFromSlice(ip)
+	a = a.Unmap()
+	return []netip.Prefix{netip.PrefixFrom(a, a.BitLen())}
+}

client/firewall/uspfilter/tracer.go

@@ -285,6 +285,14 @@ func (m *Manager) TracePacket(packetData []byte, direction fw.RuleDirection) *Pa
 	trace.SourceIP = srcIP
 	trace.DestinationIP = dstIP
 
+	// A fragment or otherwise truncated packet has no transport layer.
+	// The inbound datapath drops these via isValidPacket; the tracer must
+	// guard explicitly since every downstream stage reads d.decoded[1].
+	if len(d.decoded) < 2 {
+		trace.AddResult(StageReceived, "Packet has no transport layer (fragment or unsupported protocol)", false)
+		return trace
+	}
+
 	// Determine protocol and ports
 	switch d.decoded[1] {
 	case layers.LayerTypeTCP:

client/firewall/uspfilter/tracer_test.go

@@ -45,7 +45,7 @@ func TestTracePacket(t *testing.T) {
 			},
 		}
 
-		m, err := Create(ifaceMock, false, flowLogger, iface.DefaultMTU)
+		m, err := Create(Config{IFace: ifaceMock, FlowLogger: flowLogger, MTU: iface.DefaultMTU})
 		require.NoError(t, err)
 
 		if !statefulMode {
@@ -97,7 +97,7 @@ func TestTracePacket(t *testing.T) {
 				proto := fw.ProtocolTCP
 				port := &fw.Port{Values: []uint16{80}}
 				action := fw.ActionAccept
-				_, err := m.AddPeerFiltering(nil, ip, proto, nil, port, action, "")
+				_, err := m.AddFilterRule(nil, pfx(ip), fw.Network{}, proto, nil, port, action)
 				require.NoError(t, err)
 			},
 			packetBuilder: func() *PacketBuilder {
@@ -121,7 +121,7 @@ func TestTracePacket(t *testing.T) {
 				proto := fw.ProtocolTCP
 				port := &fw.Port{Values: []uint16{80}}
 				action := fw.ActionDrop
-				_, err := m.AddPeerFiltering(nil, ip, proto, nil, port, action, "")
+				_, err := m.AddFilterRule(nil, pfx(ip), fw.Network{}, proto, nil, port, action)
 				require.NoError(t, err)
 			},
 			packetBuilder: func() *PacketBuilder {
@@ -150,7 +150,7 @@ func TestTracePacket(t *testing.T) {
 				proto := fw.ProtocolTCP
 				port := &fw.Port{Values: []uint16{80}}
 				action := fw.ActionAccept
-				_, err := m.AddPeerFiltering(nil, ip, proto, nil, port, action, "")
+				_, err := m.AddFilterRule(nil, pfx(ip), fw.Network{}, proto, nil, port, action)
 				require.NoError(t, err)
 			},
 			packetBuilder: func() *PacketBuilder {
@@ -178,7 +178,7 @@ func TestTracePacket(t *testing.T) {
 				proto := fw.ProtocolTCP
 				port := &fw.Port{Values: []uint16{80}}
 				action := fw.ActionAccept
-				_, err := m.AddPeerFiltering(nil, ip, proto, nil, port, action, "")
+				_, err := m.AddFilterRule(nil, pfx(ip), fw.Network{}, proto, nil, port, action)
 				require.NoError(t, err)
 			},
 			packetBuilder: func() *PacketBuilder {
@@ -205,7 +205,7 @@ func TestTracePacket(t *testing.T) {
 
 				src := netip.PrefixFrom(netip.AddrFrom4([4]byte{1, 1, 1, 1}), 32)
 				dst := netip.PrefixFrom(netip.AddrFrom4([4]byte{192, 168, 17, 2}), 32)
-				_, err := m.AddRouteFiltering(nil, []netip.Prefix{src}, fw.Network{Prefix: dst}, fw.ProtocolTCP, nil, &fw.Port{Values: []uint16{80}}, fw.ActionAccept)
+				_, err := m.AddFilterRule(nil, []netip.Prefix{src}, fw.Network{Prefix: dst}, fw.ProtocolTCP, nil, &fw.Port{Values: []uint16{80}}, fw.ActionAccept)
 				require.NoError(t, err)
 			},
 			packetBuilder: func() *PacketBuilder {
@@ -231,7 +231,7 @@ func TestTracePacket(t *testing.T) {
 
 				src := netip.PrefixFrom(netip.AddrFrom4([4]byte{1, 1, 1, 1}), 32)
 				dst := netip.PrefixFrom(netip.AddrFrom4([4]byte{192, 168, 17, 2}), 32)
-				_, err := m.AddRouteFiltering(nil, []netip.Prefix{src}, fw.Network{Prefix: dst}, fw.ProtocolTCP, nil, &fw.Port{Values: []uint16{80}}, fw.ActionDrop)
+				_, err := m.AddFilterRule(nil, []netip.Prefix{src}, fw.Network{Prefix: dst}, fw.ProtocolTCP, nil, &fw.Port{Values: []uint16{80}}, fw.ActionDrop)
 				require.NoError(t, err)
 			},
 			packetBuilder: func() *PacketBuilder {
@@ -332,7 +332,7 @@ func TestTracePacket(t *testing.T) {
 				ip := net.ParseIP("1.1.1.1")
 				proto := fw.ProtocolICMP
 				action := fw.ActionAccept
-				_, err := m.AddPeerFiltering(nil, ip, proto, nil, nil, action, "")
+				_, err := m.AddFilterRule(nil, pfx(ip), fw.Network{}, proto, nil, nil, action)
 				require.NoError(t, err)
 			},
 			packetBuilder: func() *PacketBuilder {
@@ -355,7 +355,7 @@ func TestTracePacket(t *testing.T) {
 				ip := net.ParseIP("1.1.1.1")
 				proto := fw.ProtocolICMP
 				action := fw.ActionDrop
-				_, err := m.AddPeerFiltering(nil, ip, proto, nil, nil, action, "")
+				_, err := m.AddFilterRule(nil, pfx(ip), fw.Network{}, proto, nil, nil, action)
 				require.NoError(t, err)
 			},
 			packetBuilder: func() *PacketBuilder {
@@ -379,7 +379,7 @@ func TestTracePacket(t *testing.T) {
 				proto := fw.ProtocolUDP
 				port := &fw.Port{Values: []uint16{53}}
 				action := fw.ActionAccept
-				_, err := m.AddPeerFiltering(nil, ip, proto, nil, port, action, "")
+				_, err := m.AddFilterRule(nil, pfx(ip), fw.Network{}, proto, nil, port, action)
 				require.NoError(t, err)
 			},
 			packetBuilder: func() *PacketBuilder {
@@ -423,7 +423,7 @@ func TestTracePacket(t *testing.T) {
 				proto := fw.ProtocolTCP
 				port := &fw.Port{Values: []uint16{80}}
 				action := fw.ActionDrop
-				_, err := m.AddPeerFiltering(nil, ip, proto, nil, port, action, "")
+				_, err := m.AddFilterRule(nil, pfx(ip), fw.Network{}, proto, nil, port, action)
 				require.NoError(t, err)
 			},
 			packetBuilder: func() *PacketBuilder {

client/internal/acl/dispatch_test.go

@@ -0,0 +1,190 @@
+package acl
+
+import (
+	"net/netip"
+	"sync"
+	"testing"
+
+	"github.com/golang/mock/gomock"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/netbirdio/netbird/client/firewall"
+	fwmgr "github.com/netbirdio/netbird/client/firewall/manager"
+	"github.com/netbirdio/netbird/client/iface"
+	"github.com/netbirdio/netbird/client/iface/wgaddr"
+	"github.com/netbirdio/netbird/client/internal/acl/mocks"
+	mgmProto "github.com/netbirdio/netbird/shared/management/proto"
+)
+
+// TestNetworkZeroPrefixIsRoute guards the route-vs-peer dispatch
+// invariant: the backends classify a rule as a peer rule purely by the
+// absence of a destination (neither prefix nor set). A default route
+// (0.0.0.0/0 or ::/0) is a valid prefix and must therefore classify as
+// a route, not collapse into the peer path.
+func TestNetworkZeroPrefixIsRoute(t *testing.T) {
+	for _, p := range []string{"0.0.0.0/0", "::/0", "10.0.0.0/8"} {
+		n := fwmgr.Network{Prefix: netip.MustParsePrefix(p)}
+		assert.True(t, n.IsPrefix(), "%s must report IsPrefix", p)
+		assert.True(t, n.IsPrefix() || n.IsSet(), "%s must classify as a route", p)
+	}
+
+	// A zero-value Network is the only peer-rule shape.
+	var empty fwmgr.Network
+	assert.False(t, empty.IsPrefix(), "zero Network must not be a prefix")
+	assert.False(t, empty.IsSet(), "zero Network must not be a set")
+}
+
+// TestDetermineDestinationAlwaysRoute verifies determineDestination
+// never yields an empty Network for a valid route rule: every branch
+// (static prefix, default route, dynamic with/without domains, with and
+// without a local resolver) produces a destination that classifies as a
+// route. If this regresses, a route rule would be dispatched down the
+// peer path, which matches on source only.
+func TestDetermineDestinationAlwaysRoute(t *testing.T) {
+	v4 := []netip.Prefix{netip.MustParsePrefix("10.0.0.0/24")}
+	v6 := []netip.Prefix{netip.MustParsePrefix("2001:db8::/48")}
+
+	cases := []struct {
+		name     string
+		rule     *mgmProto.RouteFirewallRule
+		resolver bool
+		sources  []netip.Prefix
+	}{
+		{"static prefix", &mgmProto.RouteFirewallRule{Destination: "192.168.0.0/16"}, false, v4},
+		{"static default route", &mgmProto.RouteFirewallRule{Destination: "0.0.0.0/0"}, false, v4},
+		{"dynamic with domains + resolver", &mgmProto.RouteFirewallRule{IsDynamic: true, Domains: []string{"example.com"}}, true, v4},
+		{"dynamic no domains + resolver (v4)", &mgmProto.RouteFirewallRule{IsDynamic: true}, true, v4},
+		{"dynamic no domains + resolver (v6)", &mgmProto.RouteFirewallRule{IsDynamic: true}, true, v6},
+		{"dynamic + no local resolver (v4)", &mgmProto.RouteFirewallRule{IsDynamic: true}, false, v4},
+		{"dynamic + no local resolver (v6)", &mgmProto.RouteFirewallRule{IsDynamic: true}, false, v6},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			dest, err := determineDestination(tc.rule, tc.resolver, tc.sources)
+			require.NoError(t, err)
+			assert.True(t, dest.IsPrefix() || dest.IsSet(),
+				"destination must classify as a route, got empty Network")
+		})
+	}
+}
+
+// countingFirewall wraps a real firewall.Manager and counts filter-rule
+// add/delete calls so a test can assert how many backing rules the acl
+// manager actually creates and tears down.
+type countingFirewall struct {
+	fwmgr.Manager
+	mu       sync.Mutex
+	addCalls int
+	dels     int
+	ruleIDs  map[fwmgr.RuleID]struct{}
+}
+
+// distinctRules returns the number of distinct backing rules the
+// backend produced. Because the backend dedups identical content,
+// repeated AddFilterRule calls for the same rule resolve to one id.
+func (f *countingFirewall) distinctRules() int {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	return len(f.ruleIDs)
+}
+
+func (f *countingFirewall) AddFilterRule(id []byte, sources []netip.Prefix, destination fwmgr.Network, proto fwmgr.Protocol, sPort, dPort *fwmgr.Port, action fwmgr.Action) (fwmgr.Rule, error) {
+	rule, err := f.Manager.AddFilterRule(id, sources, destination, proto, sPort, dPort, action)
+	if err == nil {
+		f.mu.Lock()
+		f.addCalls++
+		if f.ruleIDs == nil {
+			f.ruleIDs = make(map[fwmgr.RuleID]struct{})
+		}
+		if rule != nil {
+			f.ruleIDs[rule.ID()] = struct{}{}
+		}
+		f.mu.Unlock()
+	}
+	return rule, err
+}
+
+func (f *countingFirewall) DeleteFilterRule(r fwmgr.Rule) error {
+	err := f.Manager.DeleteFilterRule(r)
+	if err == nil {
+		f.mu.Lock()
+		f.dels++
+		delete(f.ruleIDs, r.ID())
+		f.mu.Unlock()
+	}
+	return err
+}
+
+func newCountingACL(t *testing.T) (*DefaultManager, *countingFirewall, func()) {
+	t.Helper()
+	t.Setenv("NB_WG_KERNEL_DISABLED", "true")
+	t.Setenv(firewall.EnvForceUserspaceFirewall, "true")
+
+	ctrl := gomock.NewController(t)
+	ifaceMock := mocks.NewMockIFaceMapper(ctrl)
+	ifaceMock.EXPECT().IsUserspaceBind().Return(true).AnyTimes()
+	ifaceMock.EXPECT().SetFilter(gomock.Any())
+	network := netip.MustParsePrefix("172.0.0.1/32")
+	ifaceMock.EXPECT().Name().Return("lo").AnyTimes()
+	ifaceMock.EXPECT().Address().Return(wgaddr.Address{IP: network.Addr(), Network: network}).AnyTimes()
+	ifaceMock.EXPECT().GetWGDevice().Return(nil).AnyTimes()
+
+	realFW, err := firewall.NewFirewall(ifaceMock, nil, flowLogger, false, iface.DefaultMTU)
+	require.NoError(t, err)
+
+	fw := &countingFirewall{Manager: realFW}
+	cleanup := func() {
+		require.NoError(t, realFW.Close(nil))
+		ctrl.Finish()
+	}
+	return NewDefaultManager(fw), fw, cleanup
+}
+
+// TestDuplicateContentPoliciesShareOneRule verifies the dedup contract
+// the backends rely on: two policies that authorize an identical flow
+// (same selector and sources) collapse to a single backing firewall
+// rule, and that rule survives until BOTH policies are gone. This is
+// why the backend can dedup on add without refcounting on delete: the
+// acl manager's pair key matches the backend's content key, so add and
+// delete stay balanced per content key across full-state reapplies.
+func TestDuplicateContentPoliciesShareOneRule(t *testing.T) {
+	acl, fw, cleanup := newCountingACL(t)
+	defer cleanup()
+
+	ruleA := &mgmProto.FirewallRule{
+		PolicyID:  []byte("policy-A"),
+		PeerIP:    "10.0.0.1",
+		Direction: mgmProto.RuleDirection_IN,
+		Action:    mgmProto.RuleAction_ACCEPT,
+		Protocol:  mgmProto.RuleProtocol_TCP,
+		Port:      "443",
+	}
+	ruleB := &mgmProto.FirewallRule{
+		PolicyID:  []byte("policy-B"),
+		PeerIP:    "10.0.0.1",
+		Direction: mgmProto.RuleDirection_IN,
+		Action:    mgmProto.RuleAction_ACCEPT,
+		Protocol:  mgmProto.RuleProtocol_TCP,
+		Port:      "443",
+	}
+
+	// Both policies present: identical content collapses to one rule.
+	acl.ApplyFiltering(&mgmProto.NetworkMap{FirewallRules: []*mgmProto.FirewallRule{ruleA, ruleB}, FirewallRulesIsEmpty: false}, false)
+	assert.Equal(t, 1, fw.distinctRules(), "identical-content policies must produce one backing rule")
+	assert.Equal(t, 1, len(acl.peerRulesPairs), "one content key, one pair")
+
+	// Drop policy A only: the shared rule is still authorized by B, so
+	// nothing is deleted.
+	acl.ApplyFiltering(&mgmProto.NetworkMap{FirewallRules: []*mgmProto.FirewallRule{ruleB}, FirewallRulesIsEmpty: false}, false)
+	assert.Equal(t, 1, fw.distinctRules(), "no new backing rule on reapply")
+	assert.Equal(t, 0, fw.dels, "rule must survive while any policy still authorizes it")
+	assert.Equal(t, 1, len(acl.peerRulesPairs))
+
+	// Drop policy B too: now the content key has no authorizer and the
+	// single backing rule is removed exactly once.
+	acl.ApplyFiltering(&mgmProto.NetworkMap{FirewallRules: nil, FirewallRulesIsEmpty: true}, false)
+	assert.Equal(t, 1, fw.dels, "rule removed once when last policy is gone")
+	assert.Equal(t, 0, len(acl.peerRulesPairs))
+}

client/internal/acl/grouping_test.go

@@ -0,0 +1,318 @@
+package acl
+
+import (
+	"errors"
+	"net/netip"
+	"testing"
+
+	"github.com/golang/mock/gomock"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/netbirdio/netbird/client/firewall"
+	fwmgr "github.com/netbirdio/netbird/client/firewall/manager"
+	"github.com/netbirdio/netbird/client/iface"
+	"github.com/netbirdio/netbird/client/iface/wgaddr"
+	"github.com/netbirdio/netbird/client/internal/acl/mocks"
+	mgmProto "github.com/netbirdio/netbird/shared/management/proto"
+	"github.com/netbirdio/netbird/shared/netiputil"
+)
+
+// TestGroupPeerRulesPolicyIDSeparates verifies that two FirewallRules
+// with identical selectors but different PolicyIDs do NOT get merged
+// into one group, so each policy's sources merge under its own
+// attribution id. (Identical-content groups may still dedup to one
+// backing rule at the backend; see TestDuplicateContentPoliciesShareOneRule.)
+func TestGroupPeerRulesPolicyIDSeparates(t *testing.T) {
+	rules := []*mgmProto.FirewallRule{
+		{
+			PolicyID:  []byte("policy-A"),
+			PeerIP:    "10.0.0.1",
+			Direction: mgmProto.RuleDirection_IN,
+			Action:    mgmProto.RuleAction_ACCEPT,
+			Protocol:  mgmProto.RuleProtocol_TCP,
+			Port:      "443",
+		},
+		{
+			PolicyID:  []byte("policy-B"),
+			PeerIP:    "10.0.0.1",
+			Direction: mgmProto.RuleDirection_IN,
+			Action:    mgmProto.RuleAction_ACCEPT,
+			Protocol:  mgmProto.RuleProtocol_TCP,
+			Port:      "443",
+		},
+	}
+
+	groups, denyErr, err := groupPeerRules(rules)
+	require.NoError(t, denyErr)
+	require.NoError(t, err)
+	require.Len(t, groups, 2, "rules with different PolicyIDs must produce separate groups")
+}
+
+// TestGroupPeerRulesFamilySeparates verifies that v4 and v6 rules
+// belonging to the same policy don't merge.
+func TestGroupPeerRulesFamilySeparates(t *testing.T) {
+	rules := []*mgmProto.FirewallRule{
+		{
+			PolicyID:  []byte("policy-A"),
+			PeerIP:    "10.0.0.1",
+			Direction: mgmProto.RuleDirection_IN,
+			Action:    mgmProto.RuleAction_ACCEPT,
+			Protocol:  mgmProto.RuleProtocol_TCP,
+			Port:      "443",
+		},
+		{
+			PolicyID:  []byte("policy-A"),
+			PeerIP:    "2001:db8::1",
+			Direction: mgmProto.RuleDirection_IN,
+			Action:    mgmProto.RuleAction_ACCEPT,
+			Protocol:  mgmProto.RuleProtocol_TCP,
+			Port:      "443",
+		},
+	}
+
+	groups, denyErr, err := groupPeerRules(rules)
+	require.NoError(t, denyErr)
+	require.NoError(t, err)
+	require.Len(t, groups, 2, "rules of different families must produce separate groups")
+
+	var sawV4, sawV6 bool
+	for _, g := range groups {
+		require.Len(t, g.sources, 1)
+		if g.sources[0].Addr().Is4() {
+			sawV4 = true
+		}
+		if g.sources[0].Addr().Is6() {
+			sawV6 = true
+		}
+	}
+	assert.True(t, sawV4 && sawV6)
+}
+
+// TestGroupPeerRulesSplitsMixedFamilySingleRule verifies that a single
+// FirewallRule carrying both v4 and v6 source prefixes is split into one
+// group per family. Each backend keys a rule to a single family, so a
+// group whose sources span families would mismatch the other family's
+// sources. mgmt normally emits one rule per family; this guards against
+// a mixed-family rule slipping through.
+func TestGroupPeerRulesSplitsMixedFamilySingleRule(t *testing.T) {
+	srcs := [][]byte{
+		netiputil.EncodeAddr(netip.MustParseAddr("10.0.0.1")),
+		netiputil.EncodeAddr(netip.MustParseAddr("2001:db8::1")),
+		netiputil.EncodeAddr(netip.MustParseAddr("10.0.0.2")),
+		netiputil.EncodeAddr(netip.MustParseAddr("2001:db8::2")),
+	}
+	rules := []*mgmProto.FirewallRule{
+		{
+			PolicyID:       []byte("policy-A"),
+			SourcePrefixes: srcs,
+			Direction:      mgmProto.RuleDirection_IN,
+			Action:         mgmProto.RuleAction_ACCEPT,
+			Protocol:       mgmProto.RuleProtocol_TCP,
+			Port:           "443",
+		},
+	}
+
+	groups, denyErr, err := groupPeerRules(rules)
+	require.NoError(t, denyErr)
+	require.NoError(t, err)
+	require.Len(t, groups, 2, "mixed-family sources in one rule must split into two groups")
+
+	for _, g := range groups {
+		require.Len(t, g.sources, 2)
+		v6 := prefixIsV6(g.sources[0])
+		for _, s := range g.sources {
+			assert.Equal(t, v6, prefixIsV6(s), "every source in a group must share one family")
+		}
+	}
+}
+
+// TestGroupPeerRulesMergesSameSelector verifies that rules sharing
+// every distinguishing field (policy, family, direction, action,
+// proto, port) collapse into a single multi-source group.
+func TestGroupPeerRulesMergesSameSelector(t *testing.T) {
+	mk := func(peerIP string) *mgmProto.FirewallRule {
+		return &mgmProto.FirewallRule{
+			PolicyID:  []byte("policy-A"),
+			PeerIP:    peerIP,
+			Direction: mgmProto.RuleDirection_IN,
+			Action:    mgmProto.RuleAction_ACCEPT,
+			Protocol:  mgmProto.RuleProtocol_TCP,
+			Port:      "443",
+		}
+	}
+	rules := []*mgmProto.FirewallRule{mk("10.0.0.1"), mk("10.0.0.2"), mk("10.0.0.3")}
+
+	groups, denyErr, err := groupPeerRules(rules)
+	require.NoError(t, denyErr)
+	require.NoError(t, err)
+	require.Len(t, groups, 1)
+	require.Len(t, groups[0].sources, 3)
+}
+
+// TestGroupPeerRulesPortSeparates verifies that PortInfo is part of the
+// selector key: rules differing only in port must not merge, and a
+// single port must not merge with a range. A regression dropping the
+// port from the key would collapse rules for different ports into one.
+func TestGroupPeerRulesPortSeparates(t *testing.T) {
+	mkPort := func(peerIP string, port uint32) *mgmProto.FirewallRule {
+		return &mgmProto.FirewallRule{
+			PolicyID:  []byte("policy-A"),
+			PeerIP:    peerIP,
+			Direction: mgmProto.RuleDirection_IN,
+			Action:    mgmProto.RuleAction_ACCEPT,
+			Protocol:  mgmProto.RuleProtocol_TCP,
+			PortInfo:  &mgmProto.PortInfo{PortSelection: &mgmProto.PortInfo_Port{Port: port}},
+		}
+	}
+
+	groups, denyErr, err := groupPeerRules([]*mgmProto.FirewallRule{
+		mkPort("10.0.0.1", 80), mkPort("10.0.0.2", 80), mkPort("10.0.0.3", 443),
+	})
+	require.NoError(t, denyErr)
+	require.NoError(t, err)
+	require.Len(t, groups, 2, "rules on different ports must not merge")
+
+	rangeRule := &mgmProto.FirewallRule{
+		PolicyID:  []byte("policy-A"),
+		PeerIP:    "10.0.0.4",
+		Direction: mgmProto.RuleDirection_IN,
+		Action:    mgmProto.RuleAction_ACCEPT,
+		Protocol:  mgmProto.RuleProtocol_TCP,
+		PortInfo:  &mgmProto.PortInfo{PortSelection: &mgmProto.PortInfo_Range_{Range: &mgmProto.PortInfo_Range{Start: 80, End: 90}}},
+	}
+	groups, denyErr, err = groupPeerRules([]*mgmProto.FirewallRule{mkPort("10.0.0.1", 80), rangeRule})
+	require.NoError(t, denyErr)
+	require.NoError(t, err)
+	require.Len(t, groups, 2, "a single port and a range must not merge")
+}
+
+// TestGroupPeerRulesUsesSourcePrefixesWhenPresent verifies that the
+// new sourcePrefixes wire field is consumed and produces a
+// multi-source group in one shot (no client-side merging needed).
+func TestGroupPeerRulesUsesSourcePrefixesWhenPresent(t *testing.T) {
+	srcs := [][]byte{
+		netiputil.EncodeAddr(netip.MustParseAddr("10.0.0.1")),
+		netiputil.EncodeAddr(netip.MustParseAddr("10.0.0.2")),
+		netiputil.EncodeAddr(netip.MustParseAddr("10.0.0.3")),
+	}
+	rules := []*mgmProto.FirewallRule{
+		{
+			PolicyID:       []byte("policy-A"),
+			SourcePrefixes: srcs,
+			Direction:      mgmProto.RuleDirection_IN,
+			Action:         mgmProto.RuleAction_ACCEPT,
+			Protocol:       mgmProto.RuleProtocol_TCP,
+			Port:           "443",
+		},
+	}
+
+	groups, denyErr, err := groupPeerRules(rules)
+	require.NoError(t, denyErr)
+	require.NoError(t, err)
+	require.Len(t, groups, 1)
+	require.Len(t, groups[0].sources, 3)
+}
+
+// TestGroupPeerRulesActionSeparates verifies the obvious: accept
+// and drop rules with the same selector don't merge.
+func TestGroupPeerRulesActionSeparates(t *testing.T) {
+	rules := []*mgmProto.FirewallRule{
+		{
+			PolicyID:  []byte("policy-A"),
+			PeerIP:    "10.0.0.1",
+			Direction: mgmProto.RuleDirection_IN,
+			Action:    mgmProto.RuleAction_ACCEPT,
+			Protocol:  mgmProto.RuleProtocol_TCP,
+			Port:      "443",
+		},
+		{
+			PolicyID:  []byte("policy-A"),
+			PeerIP:    "10.0.0.1",
+			Direction: mgmProto.RuleDirection_IN,
+			Action:    mgmProto.RuleAction_DROP,
+			Protocol:  mgmProto.RuleProtocol_TCP,
+			Port:      "443",
+		},
+	}
+
+	groups, denyErr, err := groupPeerRules(rules)
+	require.NoError(t, denyErr)
+	require.NoError(t, err)
+	require.Len(t, groups, 2)
+}
+
+// failingDeleteFirewall wraps a real firewall.Manager and forces the
+// next N DeleteFilterRule calls to fail. Used to verify that the acl
+// manager retains rules whose deletion was rejected by the backend,
+// so they get retried on the next ApplyFiltering pass instead of
+// becoming orphans.
+type failingDeleteFirewall struct {
+	fwmgr.Manager
+	failCount int
+}
+
+func (f *failingDeleteFirewall) DeleteFilterRule(r fwmgr.Rule) error {
+	if f.failCount > 0 {
+		f.failCount--
+		return errors.New("simulated delete failure")
+	}
+	return f.Manager.DeleteFilterRule(r)
+}
+
+// TestApplyFilteringRetainsRulesOnDeleteFailure verifies that a
+// transient DeleteFilterRule error doesn't make the acl manager
+// forget about a rule. The rule must remain in peerRulesPairs so the
+// next ApplyFiltering pass attempts the delete again.
+func TestApplyFilteringRetainsRulesOnDeleteFailure(t *testing.T) {
+	t.Setenv("NB_WG_KERNEL_DISABLED", "true")
+	t.Setenv(firewall.EnvForceUserspaceFirewall, "true")
+
+	ctrl := gomock.NewController(t)
+	defer ctrl.Finish()
+
+	ifaceMock := mocks.NewMockIFaceMapper(ctrl)
+	ifaceMock.EXPECT().IsUserspaceBind().Return(true).AnyTimes()
+	ifaceMock.EXPECT().SetFilter(gomock.Any())
+	network := netip.MustParsePrefix("172.0.0.1/32")
+	ifaceMock.EXPECT().Name().Return("lo").AnyTimes()
+	ifaceMock.EXPECT().Address().Return(wgaddr.Address{IP: network.Addr(), Network: network}).AnyTimes()
+	ifaceMock.EXPECT().GetWGDevice().Return(nil).AnyTimes()
+
+	realFW, err := firewall.NewFirewall(ifaceMock, nil, flowLogger, false, iface.DefaultMTU)
+	require.NoError(t, err)
+	defer func() { require.NoError(t, realFW.Close(nil)) }()
+
+	fw := &failingDeleteFirewall{Manager: realFW}
+	acl := NewDefaultManager(fw)
+
+	// First pass: install a rule.
+	netmap1 := &mgmProto.NetworkMap{
+		FirewallRules: []*mgmProto.FirewallRule{
+			{
+				PolicyID:  []byte("policy-A"),
+				PeerIP:    "10.0.0.1",
+				Direction: mgmProto.RuleDirection_IN,
+				Action:    mgmProto.RuleAction_DROP,
+				Protocol:  mgmProto.RuleProtocol_TCP,
+				Port:      "22",
+			},
+		},
+		FirewallRulesIsEmpty: false,
+	}
+	acl.ApplyFiltering(netmap1, false)
+	require.Equal(t, 1, len(acl.peerRulesPairs), "rule should be installed")
+
+	// Second pass: remove the rule from the map. The backend will
+	// fail the delete; the acl manager must retain the rule.
+	fw.failCount = 1
+	netmap2 := &mgmProto.NetworkMap{FirewallRules: nil, FirewallRulesIsEmpty: true}
+	acl.ApplyFiltering(netmap2, false)
+	require.Equal(t, 1, len(acl.peerRulesPairs),
+		"rule must be retained when DeleteFilterRule fails so it gets retried")
+
+	// Third pass: same map, backend no longer fails. The rule
+	// should now succeed in being removed.
+	acl.ApplyFiltering(netmap2, false)
+	require.Equal(t, 0, len(acl.peerRulesPairs), "retry should succeed")
+}

client/internal/acl/id/id.go

@@ -5,18 +5,18 @@ import (
 	"encoding/hex"
 	"fmt"
 	"net/netip"
+	"slices"
 	"strconv"
 
 	"github.com/netbirdio/netbird/client/firewall/manager"
 )
 
-type RuleID string
+// RuleID aliases manager.RuleID so existing nbid.RuleID references
+// keep working while the canonical type lives in the firewall package.
+type RuleID = manager.RuleID
 
-func (r RuleID) ID() string {
-	return string(r)
-}
-
-func GenerateRouteRuleKey(
+// GenerateRuleID returns a deterministic content hash identifying a filter rule.
+func GenerateRuleID(
 	sources []netip.Prefix,
 	destination manager.Network,
 	proto manager.Protocol,
@@ -24,6 +24,7 @@ func GenerateRouteRuleKey(
 	dPort *manager.Port,
 	action manager.Action,
 ) RuleID {
+	sources = slices.Clone(sources)
 	manager.SortPrefixes(sources)
 
 	h := sha256.New()

client/internal/acl/legacy_fallback_test.go

@@ -0,0 +1,75 @@
+package acl
+
+import (
+	"net/netip"
+	"sync"
+	"testing"
+
+	"github.com/golang/mock/gomock"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/netbirdio/netbird/client/firewall"
+	fwmgr "github.com/netbirdio/netbird/client/firewall/manager"
+	"github.com/netbirdio/netbird/client/iface"
+	"github.com/netbirdio/netbird/client/iface/wgaddr"
+	"github.com/netbirdio/netbird/client/internal/acl/mocks"
+	mgmProto "github.com/netbirdio/netbird/shared/management/proto"
+)
+
+// sourcesRecordingFirewall wraps a real firewall.Manager and records
+// the source prefixes of every AddFilterRule call.
+type sourcesRecordingFirewall struct {
+	fwmgr.Manager
+	mu      sync.Mutex
+	sources [][]netip.Prefix
+}
+
+func (f *sourcesRecordingFirewall) AddFilterRule(id []byte, sources []netip.Prefix, destination fwmgr.Network, proto fwmgr.Protocol, sPort, dPort *fwmgr.Port, action fwmgr.Action) (fwmgr.Rule, error) {
+	f.mu.Lock()
+	f.sources = append(f.sources, sources)
+	f.mu.Unlock()
+	return f.Manager.AddFilterRule(id, sources, destination, proto, sPort, dPort, action)
+}
+
+// TestLegacyManagementFallbackUsesMatchAnySources verifies the
+// allow-all fallback for old management servers (empty FirewallRules
+// without the FirewallRulesIsEmpty flag) reaches the firewall as /0
+// match-any sources. The fallback rule carries PeerIP 0.0.0.0; if that
+// were converted to a host prefix (0.0.0.0/32) it would match nothing
+// and all peer traffic would be dropped.
+func TestLegacyManagementFallbackUsesMatchAnySources(t *testing.T) {
+	t.Setenv("NB_WG_KERNEL_DISABLED", "true")
+	t.Setenv(firewall.EnvForceUserspaceFirewall, "true")
+
+	ctrl := gomock.NewController(t)
+	defer ctrl.Finish()
+
+	ifaceMock := mocks.NewMockIFaceMapper(ctrl)
+	ifaceMock.EXPECT().IsUserspaceBind().Return(true).AnyTimes()
+	ifaceMock.EXPECT().SetFilter(gomock.Any())
+	network := netip.MustParsePrefix("172.0.0.1/32")
+	ifaceMock.EXPECT().Name().Return("lo").AnyTimes()
+	ifaceMock.EXPECT().Address().Return(wgaddr.Address{IP: network.Addr(), Network: network}).AnyTimes()
+	ifaceMock.EXPECT().GetWGDevice().Return(nil).AnyTimes()
+
+	realFW, err := firewall.NewFirewall(ifaceMock, nil, flowLogger, false, iface.DefaultMTU)
+	require.NoError(t, err)
+	defer func() { require.NoError(t, realFW.Close(nil)) }()
+
+	fw := &sourcesRecordingFirewall{Manager: realFW}
+	acl := NewDefaultManager(fw)
+
+	// Old management: no rules and no FirewallRulesIsEmpty flag.
+	acl.ApplyFiltering(&mgmProto.NetworkMap{FirewallRules: nil, FirewallRulesIsEmpty: false}, false)
+
+	fw.mu.Lock()
+	defer fw.mu.Unlock()
+	require.NotEmpty(t, fw.sources, "legacy fallback must install at least one allow-all rule")
+	for _, sources := range fw.sources {
+		require.NotEmpty(t, sources)
+		for _, p := range sources {
+			assert.Equal(t, 0, p.Bits(), "legacy fallback source %s must be a /0 match-any prefix", p)
+		}
+	}
+}

client/internal/acl/manager.go

@@ -1,8 +1,6 @@
 package acl
 
 import (
-	"crypto/md5"
-	"encoding/hex"
 	"errors"
 	"fmt"
 	"net/netip"
@@ -24,6 +22,10 @@ import (
 
 var ErrSourceRangesEmpty = errors.New("sources range is empty")
 
+// ErrNoRuleReturned is returned when the firewall backend reports success
+// from AddFilterRule but yields no rule to track.
+var ErrNoRuleReturned = errors.New("backend returned no rule")
+
 // Manager is a ACL rules manager
 type Manager interface {
 	ApplyFiltering(networkMap *mgmProto.NetworkMap, dnsRouteFeatureFlag bool)
@@ -32,19 +34,48 @@ type Manager interface {
 // DefaultManager uses firewall manager to handle
 type DefaultManager struct {
 	firewall           firewall.Manager
-	ipsetCounter       int
 	peerRulesPairs     map[id.RuleID][]firewall.Rule
-	routeRules         map[id.RuleID]struct{}
+	routeRules         map[id.RuleID]firewall.Rule
 	previousConfigHash uint64
 	hasAppliedConfig   bool
 	mutex              sync.Mutex
 }
 
+// peerRuleGroup collapses a set of single-source FirewallRules sharing
+// the same selector into one multi-source rule to push to the backend.
+type peerRuleGroup struct {
+	direction mgmProto.RuleDirection
+	action    mgmProto.RuleAction
+	protocol  mgmProto.RuleProtocol
+	port      *mgmProto.PortInfo
+	// legacyPort is used only when PortInfo is empty (old management).
+	legacyPort string
+	policyID   []byte
+	sources    []netip.Prefix
+}
+
+// peerRuleKey is the comparable selector that decides which single-source
+// rules merge into one group. Rules with an equal key collapse into one
+// multi-source backend rule. PortInfo is flattened into its scalar fields
+// so the key compares by value; policyID keeps policies separate so two
+// policies authorizing different peers don't merge under one attribution.
+type peerRuleKey struct {
+	v6         bool
+	policyID   string
+	direction  mgmProto.RuleDirection
+	action     mgmProto.RuleAction
+	protocol   mgmProto.RuleProtocol
+	legacyPort string
+	port       uint16
+	rangeStart uint16
+	rangeEnd   uint16
+}
+
 func NewDefaultManager(fm firewall.Manager) *DefaultManager {
 	return &DefaultManager{
 		firewall:       fm,
 		peerRulesPairs: make(map[id.RuleID][]firewall.Rule),
-		routeRules:     make(map[id.RuleID]struct{}),
+		routeRules:     make(map[id.RuleID]firewall.Rule),
 	}
 }
 
@@ -88,11 +119,14 @@ func (d *DefaultManager) ApplyFiltering(networkMap *mgmProto.NetworkMap, dnsRout
 			time.Since(start), total)
 	}()
 
-	d.applyPeerACLs(networkMap)
+	peerErr := d.applyPeerACLs(networkMap)
+	if peerErr != nil {
+		log.Errorf("apply peer ACLs: %v", peerErr)
+	}
 
 	routeErr := d.applyRouteACLs(networkMap.RoutesFirewallRules, dnsRouteFeatureFlag)
 	if routeErr != nil {
-		log.Errorf("Failed to apply route ACLs: %v", routeErr)
+		log.Errorf("apply route ACLs: %v", routeErr)
 	}
 
 	flushErr := d.firewall.Flush()
@@ -104,7 +138,7 @@ func (d *DefaultManager) ApplyFiltering(networkMap *mgmProto.NetworkMap, dnsRout
 	// If applying or flushing failed, leave the previous hash untouched so the
 	// next (possibly identical) update is not skipped and gets a chance to
 	// reconcile the firewall state.
-	if err == nil && routeErr == nil && flushErr == nil {
+	if err == nil && peerErr == nil && routeErr == nil && flushErr == nil {
 		d.previousConfigHash = hash
 		d.hasAppliedConfig = true
 	} else {
@@ -116,11 +150,11 @@ func (d *DefaultManager) ApplyFiltering(networkMap *mgmProto.NetworkMap, dnsRout
 // firewall state, so an identical hash means an identical resulting ruleset.
 func (d *DefaultManager) firewallConfigHash(networkMap *mgmProto.NetworkMap, dnsRouteFeatureFlag bool) (uint64, error) {
 	return hashstructure.Hash(struct {
-		PeerRules            []*mgmProto.FirewallRule
-		PeerRulesIsEmpty     bool
-		RouteRules           []*mgmProto.RouteFirewallRule
-		RouteRulesIsEmpty    bool
-		DNSRouteFeatureFlag  bool
+		PeerRules           []*mgmProto.FirewallRule
+		PeerRulesIsEmpty    bool
+		RouteRules          []*mgmProto.RouteFirewallRule
+		RouteRulesIsEmpty   bool
+		DNSRouteFeatureFlag bool
 	}{
 		PeerRules:           networkMap.GetFirewallRules(),
 		PeerRulesIsEmpty:    networkMap.GetFirewallRulesIsEmpty(),
@@ -135,7 +169,7 @@ func (d *DefaultManager) firewallConfigHash(networkMap *mgmProto.NetworkMap, dns
 	})
 }
 
-func (d *DefaultManager) applyPeerACLs(networkMap *mgmProto.NetworkMap) {
+func (d *DefaultManager) applyPeerACLs(networkMap *mgmProto.NetworkMap) error {
 	rules := networkMap.FirewallRules
 
 	// if we got empty rules list but management not set networkMap.FirewallRulesIsEmpty flag
@@ -158,59 +192,167 @@ func (d *DefaultManager) applyPeerACLs(networkMap *mgmProto.NetworkMap) {
 		)
 	}
 
-	newRulePairs := make(map[id.RuleID][]firewall.Rule)
-	ipsetByRuleSelectors := make(map[string]string)
+	// Group incoming single-source rules from management by their
+	// (direction, action, proto, port) selector and merge sources.
+	// One call to the firewall backend per merged rule.
+	// A deny we cannot decode would leave its traffic unblocked, so skip
+	// the whole pass and keep existing rules until the next sync.
+	groups, denyErr, err := groupPeerRules(rules)
+	if denyErr != nil {
+		return fmt.Errorf("decode deny rule sources: %w", denyErr)
+	}
 
-	// TODO: deny rules should be fatal: if a deny rule fails to apply, we must
-	// roll back all allow rules to avoid a fail-open where allowed traffic bypasses
-	// the missing deny. Currently we accumulate errors and continue.
+	newRulePairs := make(map[id.RuleID][]firewall.Rule)
 	var merr *multierror.Error
-	for _, r := range rules {
-		// if this rule is member of rule selection with more than DefaultIPsCountForSet
-		// it's IP address can be used in the ipset for firewall manager which supports it
-		selector := d.getRuleGroupingSelector(r)
-		ipsetName, ok := ipsetByRuleSelectors[selector]
-		if !ok {
-			d.ipsetCounter++
-			ipsetName = fmt.Sprintf("nb%07d", d.ipsetCounter)
-			ipsetByRuleSelectors[selector] = ipsetName
-		}
-		pairID, rulePair, err := d.protoRuleToFirewallRule(r, ipsetName)
-		if err != nil {
-			merr = multierror.Append(merr, fmt.Errorf("apply firewall rule: %w", err))
+	if err != nil {
+		merr = multierror.Append(merr, err)
+	}
+
+	// Apply denies first. A deny that fails to install is a security
+	// failure (fail-open), so if any deny errors we roll back the
+	// denies we already installed in this pass and bail out without
+	// installing any accept. Pre-existing rules stay untouched until
+	// the next successful pass clears them.
+	denies, accepts := splitDenyAccept(groups)
+	if err := d.installPeerGroups(denies, newRulePairs, true); err != nil {
+		return fmt.Errorf("install deny rules: %w", err)
+	}
+
+	if err := d.installPeerGroups(accepts, newRulePairs, false); err != nil {
+		merr = multierror.Append(merr, err)
+	}
+
+	// Tear down rules that disappeared from the networkmap. Any rule
+	// the backend refuses to delete stays in our tracking so it gets
+	// retried on the next ApplyFiltering. Otherwise a transient
+	// delete failure would leak the rule in the firewall until the
+	// process exits.
+	for pairID, rules := range d.peerRulesPairs {
+		if _, ok := newRulePairs[pairID]; ok {
 			continue
 		}
-		if len(rulePair) > 0 {
-			d.peerRulesPairs[pairID] = rulePair
-			newRulePairs[pairID] = rulePair
-		}
-	}
-
-	if merr != nil {
-		log.Errorf("failed to apply %d peer ACL rule(s): %v", merr.Len(), nberrors.FormatErrorOrNil(merr))
-	}
-
-	for pairID, rules := range d.peerRulesPairs {
-		if _, ok := newRulePairs[pairID]; !ok {
-			for _, rule := range rules {
-				if err := d.firewall.DeletePeerRule(rule); err != nil {
-					log.Errorf("failed to delete peer firewall rule: %v", err)
-					continue
-				}
+		var remaining []firewall.Rule
+		for _, rule := range rules {
+			if err := d.firewall.DeleteFilterRule(rule); err != nil {
+				merr = multierror.Append(merr, fmt.Errorf("delete peer rule, will retry: %w", err))
+				remaining = append(remaining, rule)
 			}
-			delete(d.peerRulesPairs, pairID)
+		}
+		if len(remaining) > 0 {
+			newRulePairs[pairID] = remaining
 		}
 	}
 	d.peerRulesPairs = newRulePairs
+
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+// installPeerGroups applies each group and records the resulting rule
+// pairs in newRulePairs. With atomic set (deny rules), a single failure
+// rolls back every rule installed in this call and returns, leaving the
+// firewall exactly as before: denies are fail-closed and must be applied
+// all-or-nothing. With atomic unset (accept rules), failures are
+// accumulated and the remaining groups still install, so one malformed
+// allow cannot drop every other legitimate allow in the pass.
+func (d *DefaultManager) installPeerGroups(groups []*peerRuleGroup, newRulePairs map[id.RuleID][]firewall.Rule, atomic bool) error {
+	var freshlyInstalled []id.RuleID
+	var merr *multierror.Error
+	for _, g := range groups {
+		pairID, rulePair, err := d.applyPeerGroup(g)
+		if err != nil {
+			if atomic {
+				d.rollbackInstalled(freshlyInstalled)
+				return fmt.Errorf("apply firewall rule: %w", err)
+			}
+			merr = multierror.Append(merr, fmt.Errorf("apply firewall rule: %w", err))
+			continue
+		}
+		if len(rulePair) == 0 {
+			continue
+		}
+		if _, existed := d.peerRulesPairs[pairID]; !existed {
+			freshlyInstalled = append(freshlyInstalled, pairID)
+		}
+		d.peerRulesPairs[pairID] = rulePair
+		newRulePairs[pairID] = rulePair
+	}
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+func (d *DefaultManager) rollbackInstalled(pairIDs []id.RuleID) {
+	var merr *multierror.Error
+	for _, pairID := range pairIDs {
+		// Keep any rule the backend refuses to delete tracked so it is
+		// retried on the next ApplyFiltering instead of leaking in the
+		// firewall with no tracking left to remove it.
+		var remaining []firewall.Rule
+		for _, rule := range d.peerRulesPairs[pairID] {
+			if err := d.firewall.DeleteFilterRule(rule); err != nil {
+				merr = multierror.Append(merr, fmt.Errorf("rule %s: %w", pairID, err))
+				remaining = append(remaining, rule)
+			}
+		}
+		if len(remaining) > 0 {
+			d.peerRulesPairs[pairID] = remaining
+		} else {
+			delete(d.peerRulesPairs, pairID)
+		}
+	}
+	if err := nberrors.FormatErrorOrNil(merr); err != nil {
+		log.Errorf("rollback peer rules: %v", err)
+	}
+}
+
+func (d *DefaultManager) applyPeerGroup(g *peerRuleGroup) (id.RuleID, []firewall.Rule, error) {
+	protocol, err := ConvertToFirewallProtocol(g.protocol)
+	if err != nil {
+		return "", nil, fmt.Errorf("skipping firewall rule: %w", err)
+	}
+	action, err := convertFirewallAction(g.action)
+	if err != nil {
+		return "", nil, fmt.Errorf("skipping firewall rule: %w", err)
+	}
+	port, err := resolveGroupPort(g)
+	if err != nil {
+		return "", nil, err
+	}
+
+	var fwRule firewall.Rule
+	switch g.direction {
+	case mgmProto.RuleDirection_IN:
+		fwRule, err = d.firewall.AddFilterRule(g.policyID, g.sources, firewall.Network{}, protocol, nil, port, action)
+	case mgmProto.RuleDirection_OUT:
+		if d.firewall.IsStateful() {
+			return "", nil, nil
+		}
+		if shouldSkipInvertedRule(protocol, port) {
+			return "", nil, nil
+		}
+		fwRule, err = d.firewall.AddFilterRule(g.policyID, g.sources, firewall.Network{}, protocol, port, nil, action)
+	default:
+		return "", nil, errors.New("invalid direction")
+	}
+
+	if err != nil {
+		return "", nil, fmt.Errorf("add firewall rule: %w", err)
+	}
+	if fwRule == nil {
+		return "", nil, fmt.Errorf("add firewall rule: %w", ErrNoRuleReturned)
+	}
+
+	// Derive the pair id from the backend rule, like the route path:
+	// the backend dedups identical content, so two policies authorizing
+	// the same flow resolve to the same id and a single backing rule.
+	return fwRule.ID(), []firewall.Rule{fwRule}, nil
 }
 
 func (d *DefaultManager) applyRouteACLs(rules []*mgmProto.RouteFirewallRule, dynamicResolver bool) error {
-	newRouteRules := make(map[id.RuleID]struct{}, len(rules))
+	newRouteRules := make(map[id.RuleID]firewall.Rule, len(rules))
 	var merr *multierror.Error
 
-	// Apply new rules - firewall manager will return existing rule ID if already present
+	// Apply new rules - firewall manager will return the existing rule if already present
 	for _, rule := range rules {
-		id, err := d.applyRouteACL(rule, dynamicResolver)
+		addedRule, err := d.applyRouteACL(rule, dynamicResolver)
 		if err != nil {
 			if errors.Is(err, ErrSourceRangesEmpty) {
 				log.Debugf("skipping empty sources rule with destination %s: %v", rule.Destination, err)
@@ -219,16 +361,18 @@ func (d *DefaultManager) applyRouteACLs(rules []*mgmProto.RouteFirewallRule, dyn
 			}
 			continue
 		}
-		newRouteRules[id] = struct{}{}
+		newRouteRules[addedRule.ID()] = addedRule
 	}
 
-	// Clean up old firewall rules
-	for id := range d.routeRules {
-		if _, exists := newRouteRules[id]; !exists {
-			if err := d.firewall.DeleteRouteRule(id); err != nil {
-				merr = multierror.Append(merr, fmt.Errorf("delete route rule: %w", err))
-			}
-			// implicitly deleted from the map
+	// Tear down old route rules; retain ones the backend refused so a
+	// transient failure doesn't leave orphaned rules in the firewall.
+	for ruleID, rule := range d.routeRules {
+		if _, exists := newRouteRules[ruleID]; exists {
+			continue
+		}
+		if err := d.firewall.DeleteFilterRule(rule); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("delete route rule, will retry: %w", err))
+			newRouteRules[ruleID] = rule
 		}
 	}
 
@@ -236,102 +380,202 @@ func (d *DefaultManager) applyRouteACLs(rules []*mgmProto.RouteFirewallRule, dyn
 	return nberrors.FormatErrorOrNil(merr)
 }
 
-func (d *DefaultManager) applyRouteACL(rule *mgmProto.RouteFirewallRule, dynamicResolver bool) (id.RuleID, error) {
+func (d *DefaultManager) applyRouteACL(rule *mgmProto.RouteFirewallRule, dynamicResolver bool) (firewall.Rule, error) {
 	if len(rule.SourceRanges) == 0 {
-		return "", ErrSourceRangesEmpty
+		return nil, ErrSourceRangesEmpty
 	}
 
 	var sources []netip.Prefix
 	for _, sourceRange := range rule.SourceRanges {
 		source, err := netip.ParsePrefix(sourceRange)
 		if err != nil {
-			return "", fmt.Errorf("parse source range: %w", err)
+			return nil, fmt.Errorf("parse source range: %w", err)
 		}
-		sources = append(sources, source)
+		sources = append(sources, firewall.UnmapPrefix(source))
 	}
 
 	destination, err := determineDestination(rule, dynamicResolver, sources)
 	if err != nil {
-		return "", fmt.Errorf("determine destination: %w", err)
+		return nil, fmt.Errorf("determine destination: %w", err)
 	}
 
-	protocol, err := convertToFirewallProtocol(rule.Protocol)
+	protocol, err := ConvertToFirewallProtocol(rule.Protocol)
 	if err != nil {
-		return "", fmt.Errorf("invalid protocol: %w", err)
+		return nil, fmt.Errorf("invalid protocol: %w", err)
 	}
 
 	action, err := convertFirewallAction(rule.Action)
 	if err != nil {
-		return "", fmt.Errorf("invalid action: %w", err)
+		return nil, fmt.Errorf("invalid action: %w", err)
 	}
 
 	dPorts := convertPortInfo(rule.PortInfo)
 
-	addedRule, err := d.firewall.AddRouteFiltering(rule.PolicyID, sources, destination, protocol, nil, dPorts, action)
+	addedRule, err := d.firewall.AddFilterRule(rule.PolicyID, sources, destination, protocol, nil, dPorts, action)
 	if err != nil {
-		return "", fmt.Errorf("add route rule: %w", err)
+		return nil, fmt.Errorf("add route rule: %w", err)
+	}
+	if addedRule == nil {
+		return nil, fmt.Errorf("add route rule: %w", ErrNoRuleReturned)
 	}
 
-	return id.RuleID(addedRule.ID()), nil
+	return addedRule, nil
 }
 
-func (d *DefaultManager) protoRuleToFirewallRule(
-	r *mgmProto.FirewallRule,
-	ipsetName string,
-) (id.RuleID, []firewall.Rule, error) {
-	ip, err := extractRuleIP(r)
-	if err != nil {
-		return "", nil, err
+// splitDenyAccept partitions groups by action so denies can be
+// applied before accepts. Order within each bucket is preserved.
+func splitDenyAccept(groups []*peerRuleGroup) (denies, accepts []*peerRuleGroup) {
+	for _, g := range groups {
+		if g.action == mgmProto.RuleAction_DROP {
+			denies = append(denies, g)
+		} else {
+			accepts = append(accepts, g)
+		}
+	}
+	return denies, accepts
+}
+
+// groupPeerRules merges single-source rules sharing a selector into
+// multi-source groups. It splits source-decode failures by action:
+// denyErr is non-nil when a deny rule could not be decoded, which is a
+// fail-open risk the caller must treat as fatal for the pass; err
+// carries the tolerable accept-rule failures the caller can log and
+// continue past.
+func groupPeerRules(rules []*mgmProto.FirewallRule) (groups []*peerRuleGroup, denyErr error, err error) {
+	var denyMerr, acceptMerr *multierror.Error
+	byKey := make(map[peerRuleKey]*peerRuleGroup)
+	order := make([]peerRuleKey, 0)
+
+	for _, r := range rules {
+		srcs, decErr := extractRuleSources(r)
+		if decErr != nil {
+			if r.Action == mgmProto.RuleAction_DROP {
+				denyMerr = multierror.Append(denyMerr, decErr)
+			} else {
+				acceptMerr = multierror.Append(acceptMerr, decErr)
+			}
+			continue
+		}
+		// A single FirewallRule normally carries one address family, but
+		// split by family defensively: each backend keys a rule to one
+		// family and would mismatch sources of the other, so a group's
+		// sources must never span families.
+		v4, v6 := splitPrefixesByFamily(srcs)
+		for _, sub := range []struct {
+			isV6    bool
+			sources []netip.Prefix
+		}{{false, v4}, {true, v6}} {
+			if len(sub.sources) == 0 {
+				continue
+			}
+			key := ruleGroupKey(r, sub.isV6)
+			g, ok := byKey[key]
+			if !ok {
+				g = &peerRuleGroup{
+					direction:  r.Direction,
+					action:     r.Action,
+					protocol:   r.Protocol,
+					port:       r.PortInfo,
+					legacyPort: r.Port,
+					policyID:   r.PolicyID,
+				}
+				byKey[key] = g
+				order = append(order, key)
+			}
+			g.sources = append(g.sources, sub.sources...)
+		}
 	}
 
-	protocol, err := convertToFirewallProtocol(r.Protocol)
-	if err != nil {
-		return "", nil, fmt.Errorf("skipping firewall rule: %s", err)
+	out := make([]*peerRuleGroup, 0, len(order))
+	for _, k := range order {
+		out = append(out, byKey[k])
+	}
+	return out, nberrors.FormatErrorOrNil(denyMerr), nberrors.FormatErrorOrNil(acceptMerr)
+}
+
+func prefixIsV6(p netip.Prefix) bool {
+	return p.Addr().Is6() && !p.Addr().Is4In6()
+}
+
+// splitPrefixesByFamily partitions prefixes into IPv4 and IPv6 groups.
+func splitPrefixesByFamily(prefixes []netip.Prefix) (v4, v6 []netip.Prefix) {
+	for _, p := range prefixes {
+		if prefixIsV6(p) {
+			v6 = append(v6, p)
+		} else {
+			v4 = append(v4, p)
+		}
+	}
+	return v4, v6
+}
+
+// ruleGroupKey builds the selector key for a rule. v6 must reflect the
+// rule's source family: mgmt emits one rule per family and mixing them
+// would break ICMP-variant selection in uspfilter.
+func ruleGroupKey(r *mgmProto.FirewallRule, v6 bool) peerRuleKey {
+	k := peerRuleKey{
+		v6:         v6,
+		policyID:   string(r.PolicyID),
+		direction:  r.Direction,
+		action:     r.Action,
+		protocol:   r.Protocol,
+		legacyPort: r.Port,
+	}
+	if pi := r.PortInfo; pi != nil {
+		k.port = uint16(pi.GetPort())
+		if rng := pi.GetRange(); rng != nil {
+			k.rangeStart = uint16(rng.GetStart())
+			k.rangeEnd = uint16(rng.GetEnd())
+		}
+	}
+	return k
+}
+
+// extractRuleSources returns all source prefixes the rule applies to.
+// New management populates sourcePrefixes; older management sets PeerIP.
+func extractRuleSources(r *mgmProto.FirewallRule) ([]netip.Prefix, error) {
+	if len(r.SourcePrefixes) > 0 {
+		out := make([]netip.Prefix, 0, len(r.SourcePrefixes))
+		for _, raw := range r.SourcePrefixes {
+			addr, err := netiputil.DecodeAddr(raw)
+			if err != nil {
+				return nil, fmt.Errorf("decode source prefix: %w", err)
+			}
+			out = append(out, netip.PrefixFrom(addr.Unmap(), addr.Unmap().BitLen()))
+		}
+		return out, nil
 	}
 
-	action, err := convertFirewallAction(r.Action)
+	peerIP := r.PeerIP //nolint:staticcheck // PeerIP is the legacy source field for old management servers
+	addr, err := netip.ParseAddr(peerIP)
 	if err != nil {
-		return "", nil, fmt.Errorf("skipping firewall rule: %s", err)
+		return nil, fmt.Errorf("parse peer IP %q: %w", peerIP, err)
 	}
+	addr = addr.Unmap()
+	// An unspecified PeerIP means "any peer" (legacy management
+	// allow-all fallback); only a /0 prefix matches any source in the
+	// backends, a full-length prefix would match nothing.
+	if addr.IsUnspecified() {
+		return []netip.Prefix{netip.PrefixFrom(addr, 0)}, nil
+	}
+	return []netip.Prefix{netip.PrefixFrom(addr, addr.BitLen())}, nil
+}
 
-	var port *firewall.Port
-	if !portInfoEmpty(r.PortInfo) {
-		port = convertPortInfo(r.PortInfo)
-	} else if r.Port != "" {
-		// old version of management, single port
-		value, err := strconv.Atoi(r.Port)
+func resolveGroupPort(g *peerRuleGroup) (*firewall.Port, error) {
+	if !portInfoEmpty(g.port) {
+		return convertPortInfo(g.port), nil
+	}
+	if g.legacyPort != "" {
+		value, err := strconv.ParseUint(g.legacyPort, 10, 16)
 		if err != nil {
-			return "", nil, fmt.Errorf("invalid port: %w", err)
+			return nil, fmt.Errorf("invalid port: %w", err)
 		}
-		port = &firewall.Port{
+		return &firewall.Port{
 			Values: []uint16{uint16(value)},
-		}
+		}, nil
 	}
-
-	ruleID := d.getPeerRuleID(ip, protocol, int(r.Direction), port, action)
-	if rulesPair, ok := d.peerRulesPairs[ruleID]; ok {
-		return ruleID, rulesPair, nil
-	}
-
-	var rules []firewall.Rule
-	switch r.Direction {
-	case mgmProto.RuleDirection_IN:
-		rules, err = d.addInRules(r.PolicyID, ip, protocol, port, action, ipsetName)
-	case mgmProto.RuleDirection_OUT:
-		if d.firewall.IsStateful() {
-			return "", nil, nil
-		}
-		// return traffic for outbound connections if firewall is stateless
-		rules, err = d.addOutRules(r.PolicyID, ip, protocol, port, action, ipsetName)
-	default:
-		return "", nil, fmt.Errorf("invalid direction, skipping firewall rule")
-	}
-
-	if err != nil {
-		return "", nil, err
-	}
-
-	return ruleID, rules, nil
+	// nolint:nilnil // a nil port legitimately means "no port restriction"
+	return nil, nil
 }
 
 func portInfoEmpty(portInfo *mgmProto.PortInfo) bool {
@@ -350,85 +594,9 @@ func portInfoEmpty(portInfo *mgmProto.PortInfo) bool {
 	}
 }
 
-func (d *DefaultManager) addInRules(
-	id []byte,
-	ip netip.Addr,
-	protocol firewall.Protocol,
-	port *firewall.Port,
-	action firewall.Action,
-	ipsetName string,
-) ([]firewall.Rule, error) {
-	rule, err := d.firewall.AddPeerFiltering(id, ip.AsSlice(), protocol, nil, port, action, ipsetName)
-	if err != nil {
-		return nil, fmt.Errorf("add firewall rule: %w", err)
-	}
-
-	return rule, nil
-}
-
-func (d *DefaultManager) addOutRules(
-	id []byte,
-	ip netip.Addr,
-	protocol firewall.Protocol,
-	port *firewall.Port,
-	action firewall.Action,
-	ipsetName string,
-) ([]firewall.Rule, error) {
-	if shouldSkipInvertedRule(protocol, port) {
-		return nil, nil
-	}
-
-	rule, err := d.firewall.AddPeerFiltering(id, ip.AsSlice(), protocol, port, nil, action, ipsetName)
-	if err != nil {
-		return nil, fmt.Errorf("add firewall rule: %w", err)
-	}
-
-	return rule, nil
-}
-
-// getPeerRuleID returns unique ID for the rule based on its parameters.
-func (d *DefaultManager) getPeerRuleID(
-	ip netip.Addr,
-	proto firewall.Protocol,
-	direction int,
-	port *firewall.Port,
-	action firewall.Action,
-) id.RuleID {
-	idStr := ip.String() + string(proto) + strconv.Itoa(direction) + strconv.Itoa(int(action))
-	if port != nil {
-		idStr += port.String()
-	}
-
-	return id.RuleID(hex.EncodeToString(md5.New().Sum([]byte(idStr))))
-}
-
-// getRuleGroupingSelector takes all rule properties except IP address to build selector
-func (d *DefaultManager) getRuleGroupingSelector(rule *mgmProto.FirewallRule) string {
-	return fmt.Sprintf("%v:%v:%v:%s:%v", strconv.Itoa(int(rule.Direction)), rule.Action, rule.Protocol, rule.Port, rule.PortInfo)
-}
-
-
-// extractRuleIP extracts the peer IP from a firewall rule.
-// If sourcePrefixes is populated (new management), decode the first entry and use its address.
-// Otherwise fall back to the deprecated PeerIP string field (old management).
-func extractRuleIP(r *mgmProto.FirewallRule) (netip.Addr, error) {
-	if len(r.SourcePrefixes) > 0 {
-		addr, err := netiputil.DecodeAddr(r.SourcePrefixes[0])
-		if err != nil {
-			return netip.Addr{}, fmt.Errorf("decode source prefix: %w", err)
-		}
-		return addr.Unmap(), nil
-	}
-
-	//nolint:staticcheck // PeerIP used for backward compatibility with old management
-	addr, err := netip.ParseAddr(r.PeerIP)
-	if err != nil {
-		return netip.Addr{}, fmt.Errorf("invalid IP address, skipping firewall rule")
-	}
-	return addr.Unmap(), nil
-}
-
-func convertToFirewallProtocol(protocol mgmProto.RuleProtocol) (firewall.Protocol, error) {
+// ConvertToFirewallProtocol maps a management rule protocol to the
+// firewall protocol type.
+func ConvertToFirewallProtocol(protocol mgmProto.RuleProtocol) (firewall.Protocol, error) {
 	switch protocol {
 	case mgmProto.RuleProtocol_TCP:
 		return firewall.ProtocolTCP, nil

client/internal/acl/manager_test.go

@@ -10,6 +10,7 @@ import (
 	"github.com/stretchr/testify/require"
 
 	"github.com/netbirdio/netbird/client/firewall"
+	fwmanager "github.com/netbirdio/netbird/client/firewall/manager"
 	"github.com/netbirdio/netbird/client/iface"
 	"github.com/netbirdio/netbird/client/iface/wgaddr"
 	"github.com/netbirdio/netbird/client/internal/acl/mocks"
@@ -77,9 +78,9 @@ func TestDefaultManager(t *testing.T) {
 	})
 
 	t.Run("add extra rules", func(t *testing.T) {
-		existedPairs := map[string]struct{}{}
+		existedPairs := map[fwmanager.RuleID]struct{}{}
 		for id := range acl.peerRulesPairs {
-			existedPairs[id.ID()] = struct{}{}
+			existedPairs[id] = struct{}{}
 		}
 
 		// remove first rule
@@ -106,7 +107,7 @@ func TestDefaultManager(t *testing.T) {
 		// check that old rule was removed
 		previousCount := 0
 		for id := range acl.peerRulesPairs {
-			if _, ok := existedPairs[id.ID()]; ok {
+			if _, ok := existedPairs[id]; ok {
 				previousCount++
 			}
 		}

client/internal/conn_mgr.go

@@ -385,11 +385,20 @@ func inactivityThresholdEnv() *time.Duration {
 		return nil
 	}
 
-	parsedMinutes, err := strconv.Atoi(envValue)
-	if err != nil || parsedMinutes <= 0 {
-		return nil
+	// Documented format: a Go duration such as "30m" or "1h".
+	if d, err := time.ParseDuration(envValue); err == nil {
+		if d <= 0 {
+			return nil
+		}
+		return &d
 	}
 
-	d := time.Duration(parsedMinutes) * time.Minute
-	return &d
+	// Backwards compatibility: a bare integer used to be interpreted as minutes.
+	if parsedMinutes, err := strconv.Atoi(envValue); err == nil && parsedMinutes > 0 {
+		d := time.Duration(parsedMinutes) * time.Minute
+		return &d
+	}
+
+	log.Warnf("invalid %s value %q: expected a Go duration such as 30m or 1h", lazyconn.EnvInactivityThreshold, envValue)
+	return nil
 }

client/internal/conn_mgr_test.go

@@ -104,3 +104,38 @@ func TestConnMgr_ActivatePeerConcurrentWithLifecycle(t *testing.T) {
 	close(done)
 	wg.Wait()
 }
+
+func TestInactivityThresholdEnv(t *testing.T) {
+	tests := []struct {
+		name string
+		val  string
+		want *time.Duration
+	}{
+		{name: "unset", val: "", want: nil},
+		{name: "go duration minutes", val: "30m", want: durPtr(30 * time.Minute)},
+		{name: "go duration hours", val: "1h", want: durPtr(time.Hour)},
+		{name: "go duration seconds", val: "90s", want: durPtr(90 * time.Second)},
+		{name: "bare integer is minutes (backwards compat)", val: "5", want: durPtr(5 * time.Minute)},
+		{name: "zero duration", val: "0s", want: nil},
+		{name: "zero integer", val: "0", want: nil},
+		{name: "negative duration", val: "-5m", want: nil},
+		{name: "garbage", val: "abc", want: nil},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Setenv(lazyconn.EnvInactivityThreshold, tc.val)
+			got := inactivityThresholdEnv()
+			switch {
+			case tc.want == nil && got != nil:
+				t.Fatalf("want nil, got %v", *got)
+			case tc.want != nil && got == nil:
+				t.Fatalf("want %v, got nil", *tc.want)
+			case tc.want != nil && *got != *tc.want:
+				t.Fatalf("want %v, got %v", *tc.want, *got)
+			}
+		})
+	}
+}
+
+func durPtr(d time.Duration) *time.Duration { return &d }

client/internal/connect.go

@@ -34,6 +34,7 @@ import (
 	"github.com/netbirdio/netbird/client/internal/profilemanager"
 	"github.com/netbirdio/netbird/client/internal/statemanager"
 	"github.com/netbirdio/netbird/client/internal/stdnet"
+	"github.com/netbirdio/netbird/client/internal/tunnelnotifier"
 	"github.com/netbirdio/netbird/client/internal/updater"
 	"github.com/netbirdio/netbird/client/internal/updater/installer"
 	nbnet "github.com/netbirdio/netbird/client/net"
@@ -136,10 +137,13 @@ func (c *ConnectClient) RunOniOS(
 	// Set GC percent to 5% to reduce memory usage as iOS only allows 50MB of memory for the extension.
 	debug.SetGCPercent(5)
 
+	notifier := tunnelnotifier.New(networkChangeListener, dnsManager)
+	defer notifier.Close()
+
 	mobileDependency := MobileDependency{
 		FileDescriptor:        fileDescriptor,
-		NetworkChangeListener: networkChangeListener,
-		DnsManager:            dnsManager,
+		NetworkChangeListener: notifier,
+		DnsManager:            notifier,
 		StateFilePath:         stateFilePath,
 		TempDir:               cacheDir,
 	}