Preserve pre-existing ipsets and roll back partial route ACL installs

e2e/harness documents itself as feature-agnostic, but three details
assumed the caller lives in this repo, so the terraform provider's
acceptance suite would otherwise carry a second harness for the same
product.

repoRoot took the first module root above the working directory as the
Docker build context, which from another module is the caller's own
root, with no combined/Dockerfile.multistage in it. It now requires that
ancestor to be this module, and otherwise asks the go tool for the
source: for a dependent, the extracted directory of the version it pins,
so the server matches the client library it was compiled against. That
lookup uses -mod=readonly, since automatic vendor mode otherwise reports
an empty Dir.

Geolocation was disabled unconditionally. Agent-network ingest does not
use it, but location-based posture checks need the database, and a rule
management cannot evaluate fails rather than passing.
StartClient pinned one network alias and set no hostname, so a second
agent could not start and a peer's name was arbitrary. Management
records that hostname, making it the peer's name in the API.
The client entrypoint is copied with an explicit mode: git tracks it
100755, but the module cache extracts 0444, so a dependent's build
produced a container exiting with "permission denied".

Adds CombinedOption, WithGeolocation, WithServerEnv, ClientOption and
WithClientName.

.github/workflows/release.yml

@@ -475,6 +475,132 @@ jobs:
           path: dist/
           retention-days: 3
 
+  release_ui_gtk3:
+    # Legacy GTK3/WebKit2GTK 4.1 UI build for distros without WebKitGTK 6.0
+    # (Ubuntu 22.04, Debian 12, RHEL 9, Fedora <=39). Runs on ubuntu-22.04 so
+    # the binary links against the oldest supported glibc.
+    runs-on: ubuntu-22.04
+    outputs:
+      release_ui_gtk3_artifact_url: ${{ steps.upload_release_ui_gtk3.outputs.artifact-url }}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
+        with:
+          fetch-depth: 0 # It is required for GoReleaser to work properly
+          persist-credentials: false
+
+      - name: Parse semver string
+        id: semver_parser
+        uses: netbirdio/shared-actions/actions/parse-semver@be5df6047383da2236e02243cceb857d8567c27e # v0.0.2
+
+      - name: Set snapshot flag
+        if: ${{ !startsWith(github.ref, 'refs/tags/v') }}
+        run: |
+          echo "flags=--snapshot" >> $GITHUB_ENV
+
+      - name: Set build vars
+        if: ${{ startsWith(github.ref, 'refs/tags/v') }}
+        run: |
+          if [[ "x-${{ steps.semver_parser.outputs.prerelease }}" == "x-" && "x-${{ github.repository }}" == "x-netbirdio/netbird" ]]; then
+            echo "x-${{ github.repository }}"
+            echo "x-${{ steps.semver_parser.outputs.prerelease }}"
+            echo "SKIP_PUBLISH=false" >> $GITHUB_ENV
+          else
+            echo "x-${{ github.repository }}"
+            echo "x-${{ steps.semver_parser.outputs.prerelease }}"
+          fi
+
+      - name: Set up Go
+        uses: actions/setup-go@924ae3a1cded613372ab5595356fb5720e22ba16 # v6.5.0
+        with:
+          go-version-file: "go.mod"
+          cache: false
+      - name: Cache Go modules
+        # Restore-only from the release_ui cache written by trusted runs; the
+        # module cache is identical (same go.sum) and stale build-cache
+        # entries just miss.
+        uses: actions/cache/restore@2c8a9bd7457de244a408f35966fab2fb45fda9c8 # v6.0.0
+        with:
+          path: |
+            ~/go/pkg/mod
+            ~/.cache/go-build
+          key: ${{ runner.os }}-ui-go-releaser-${{ hashFiles('**/go.sum') }}
+          restore-keys: |
+            ${{ runner.os }}-ui-go-releaser-
+
+      - name: Install modules
+        run: go mod tidy
+
+      - name: check git status
+        run: git --no-pager diff --exit-code
+
+      - name: Set up Node.js
+        uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+        with:
+          node-version: '22'
+
+      - name: Set up pnpm
+        uses: pnpm/action-setup@a3252b78c470c02df07e9d59298aecedc3ccdd6d # v3.0.0
+        with:
+          version: 11
+
+      - name: Install dependencies
+        run: sudo apt update && sudo apt install -y -q libgtk-3-dev libwebkit2gtk-4.1-dev
+
+      - name: Decode GPG signing key
+        if: github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name == github.repository
+        env:
+          GPG_RPM_PRIVATE_KEY: ${{ secrets.GPG_RPM_PRIVATE_KEY }}
+        run: |
+          echo "$GPG_RPM_PRIVATE_KEY" | base64 -d > /tmp/gpg-rpm-signing-key.asc
+          echo "GPG_RPM_KEY_FILE=/tmp/gpg-rpm-signing-key.asc" >> $GITHUB_ENV
+
+      - name: Install wails3 CLI
+        # Version derived from go.mod so the binding generator always matches
+        # the wails runtime the binary links against.
+        # -tags gtk3: the CLI links the wails runtime's cgo packages, and the
+        # default tags request gtk4/webkitgtk-6.0 pkg-config entries that do
+        # not exist on ubuntu-22.04.
+        run: |
+          WAILS_VERSION=$(go list -m -f '{{.Version}}' github.com/wailsapp/wails/v3)
+          go install -tags gtk3 github.com/wailsapp/wails/v3/cmd/wails3@$WAILS_VERSION
+
+      - name: Run GoReleaser
+        uses: goreleaser/goreleaser-action@5daf1e915a5f0af01ddbcd89a43b8061ff4f1a89 # v7.2.2
+        with:
+          version: ${{ env.GORELEASER_VER }}
+          args: release --config .goreleaser_ui_gtk3.yaml --clean ${{ env.flags }}
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          UPLOAD_DEBIAN_SECRET: ${{ secrets.PKG_UPLOAD_SECRET }}
+          UPLOAD_YUM_SECRET: ${{ secrets.PKG_UPLOAD_SECRET }}
+          GPG_RPM_KEY_FILE: ${{ env.GPG_RPM_KEY_FILE }}
+          NFPM_NETBIRD_UI_RPM_GTK3_PASSPHRASE: ${{ secrets.GPG_RPM_PASSPHRASE }}
+          SKIP_PUBLISH: ${{ env.SKIP_PUBLISH }}
+      - name: Verify RPM signatures
+        run: |
+          docker run --rm -v $(pwd)/dist:/dist fedora:41 bash -c '
+            dnf install -y -q rpm-sign curl >/dev/null 2>&1
+            curl -sSL https://pkgs.netbird.io/yum/repodata/repomd.xml.key -o /tmp/rpm-pub.key
+            rpm --import /tmp/rpm-pub.key
+            echo "=== Verifying RPM signatures ==="
+            for rpm_file in /dist/*.rpm; do
+              [ -f "$rpm_file" ] || continue
+              echo "--- $(basename $rpm_file) ---"
+              rpm -K "$rpm_file"
+            done
+          '
+      - name: Clean up GPG key
+        if: always()
+        run: rm -f /tmp/gpg-rpm-signing-key.asc
+      - name: upload non tags for debug purposes
+        id: upload_release_ui_gtk3
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a #v7.0.1
+        with:
+          name: release-ui-gtk3
+          path: dist/
+          retention-days: 3
+
   release_ui_darwin:
     runs-on: macos-latest
     outputs:
@@ -688,7 +814,7 @@ jobs:
   comment_release_artifacts:
     name: Comment release artifacts
     runs-on: ubuntu-latest
-    needs: [release, release_ui, release_ui_darwin]
+    needs: [release, release_ui, release_ui_gtk3, release_ui_darwin]
     if: ${{ always() && github.event_name == 'pull_request' && github.event.pull_request.head.repo.full_name == github.repository }}
     permissions:
       contents: read
@@ -700,12 +826,14 @@ jobs:
         env:
           RELEASE_RESULT: ${{ needs.release.result }}
           RELEASE_UI_RESULT: ${{ needs.release_ui.result }}
+          RELEASE_UI_GTK3_RESULT: ${{ needs.release_ui_gtk3.result }}
           RELEASE_UI_DARWIN_RESULT: ${{ needs.release_ui_darwin.result }}
           RELEASE_ARTIFACT_URL: ${{ needs.release.outputs.release_artifact_url }}
           LINUX_PACKAGES_ARTIFACT_URL: ${{ needs.release.outputs.linux_packages_artifact_url }}
           WINDOWS_PACKAGES_ARTIFACT_URL: ${{ needs.release.outputs.windows_packages_artifact_url }}
           MACOS_PACKAGES_ARTIFACT_URL: ${{ needs.release.outputs.macos_packages_artifact_url }}
           RELEASE_UI_ARTIFACT_URL: ${{ needs.release_ui.outputs.release_ui_artifact_url }}
+          RELEASE_UI_GTK3_ARTIFACT_URL: ${{ needs.release_ui_gtk3.outputs.release_ui_gtk3_artifact_url }}
           RELEASE_UI_DARWIN_ARTIFACT_URL: ${{ needs.release_ui_darwin.outputs.release_ui_darwin_artifact_url }}
           GHCR_IMAGES_MARKDOWN: ${{ needs.release.outputs.ghcr_images }}
         with:
@@ -728,6 +856,7 @@ jobs:
               ['Windows packages', process.env.WINDOWS_PACKAGES_ARTIFACT_URL, process.env.RELEASE_RESULT],
               ['macOS packages', process.env.MACOS_PACKAGES_ARTIFACT_URL, process.env.RELEASE_RESULT],
               ['UI artifacts', process.env.RELEASE_UI_ARTIFACT_URL, process.env.RELEASE_UI_RESULT],
+              ['UI GTK3 artifacts', process.env.RELEASE_UI_GTK3_ARTIFACT_URL, process.env.RELEASE_UI_GTK3_RESULT],
               ['UI macOS artifacts', process.env.RELEASE_UI_DARWIN_ARTIFACT_URL, process.env.RELEASE_UI_DARWIN_RESULT],
             ];
 
@@ -784,7 +913,7 @@ jobs:
 
   trigger_signer:
     runs-on: ubuntu-latest
-    needs: [release, release_ui, release_ui_darwin, test_windows_installer]
+    needs: [release, release_ui, release_ui_gtk3, release_ui_darwin, test_windows_installer]
     if: startsWith(github.ref, 'refs/tags/')
     steps:
       - name: Trigger binaries sign pipelines

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

@@ -257,6 +257,15 @@ jobs:
         with:
           persist-credentials: false
 
+      - name: Verify fresh-install session cookie key hardening
+        run: |
+          grep -Fxq '  SESSION_COOKIE_ENCRYPTION_KEY=$(openssl rand -base64 32)' infrastructure_files/getting-started.sh
+          grep -Fxq '    sessionCookieEncryptionKey: "$SESSION_COOKIE_ENCRYPTION_KEY"' infrastructure_files/getting-started.sh
+          grep -Fxq '  install -m 600 /dev/null config.yaml' infrastructure_files/getting-started.sh
+          grep -Fxq '  openssl rand -base64 32' infrastructure_files/getting-started-enterprise.sh
+          grep -Fxq '  NETBIRD_SESSION_COOKIE_ENCRYPTION_KEY=$(rand_b64_key)' infrastructure_files/getting-started-enterprise.sh
+          grep -Fxq '    sessionCookieEncryptionKey: "${NETBIRD_SESSION_COOKIE_ENCRYPTION_KEY}"' infrastructure_files/getting-started-enterprise.sh
+
       - name: Verify Dex retirement notice
         run: |
           if infrastructure_files/getting-started-with-dex.sh >stdout.txt 2>stderr.txt; then

.goreleaser_ui.yaml

@@ -96,6 +96,7 @@ nfpms:
       - netbird (>= 0.75.0)
       - libgtk-4-1 (>= 4.14)
       - libwebkitgtk-6.0-4
+      - xdg-utils
 
   - maintainer: Netbird <dev@netbird.io>
     description: Netbird client UI.
@@ -119,6 +120,7 @@ nfpms:
       - netbird >= 0.75.0
       - (gtk4 >= 4.14 or libgtk-4-1 >= 4.14)
       - (webkitgtk6.0 or libwebkitgtk-6_0-4)
+      - xdg-utils
 
     rpm:
       signature:

.goreleaser_ui_gtk3.yaml

@@ -0,0 +1,136 @@
+version: 2
+env:
+  - SKIP_PUBLISH={{ if index .Env "SKIP_PUBLISH" }}{{ .Env.SKIP_PUBLISH }}{{ else }}true{{ end }}
+project_name: netbird-ui
+
+before:
+  hooks:
+    # Bindings are gitignored; regenerate before the frontend build so
+    # the @wailsio/runtime Vite plugin can resolve them (vite refuses to
+    # build without them).
+    # -f '-tags gtk3': the generator type-checks client/ui, whose cgo imports
+    # would otherwise resolve gtk4/webkitgtk-6.0 pkg-config entries that do
+    # not exist on ubuntu-22.04.
+    - sh -c 'cd client/ui && wails3 generate bindings -clean=true -ts -f "-tags gtk3"'
+    - sh -c 'cd client/ui/frontend && pnpm install --frozen-lockfile && pnpm build'
+
+builds:
+  # Legacy GTK3 / WebKit2GTK 4.1 build for distros without WebKitGTK 6.0
+  # (Ubuntu 22.04, Debian 12, RHEL 9, Fedora <=39). The gtk3 tag flips the
+  # Wails Linux backend to the GTK3 stack and swaps our GTK4-only XEmbed
+  # tray host for the pure-Go stub (client/ui/xembed_host_gtk3_linux.go).
+  # Must be built on the oldest supported glibc (ubuntu-22.04 runner).
+  - id: netbird-ui-gtk3
+    dir: client/ui
+    binary: netbird-ui
+    env:
+      - CGO_ENABLED=1
+    goos:
+      - linux
+    goarch:
+      - amd64
+    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
+      - gtk3
+
+archives:
+  - id: linux-gtk3-arch
+    name_template: "{{ .ProjectName }}-linux-gtk3_{{ .Version }}_{{ .Os }}_{{ .Arch }}"
+    builds:
+      - netbird-ui-gtk3
+
+nfpms:
+  # Mutually-exclusive alternative to the GTK4 netbird-ui package -- both
+  # ship the same /usr/bin/netbird-ui from the shared stable/yum repos, so
+  # this one carries its own name and conflicts with the GTK4 package.
+  - maintainer: Netbird <dev@netbird.io>
+    description: Netbird client UI.
+    homepage: https://netbird.io/
+    license: BSD-3-Clause
+    vendor: NetBird
+    id: netbird_ui_deb_gtk3
+    package_name: netbird-ui-gtk3
+    file_name_template: "{{ .PackageName }}_{{ .Version }}_{{ .Os }}_{{ .Arch }}"
+    builds:
+      - netbird-ui-gtk3
+    formats:
+      - deb
+    scripts:
+      postinstall: "release_files/ui-post-install.sh"
+    contents:
+      - src: client/ui/build/linux/netbird.desktop
+        dst: /usr/share/applications/org.wails.netbird.desktop
+      - src: client/ui/build/appicon.png
+        dst: /usr/share/pixmaps/netbird.png
+    conflicts:
+      - netbird-ui
+    replaces:
+      - netbird-ui
+    dependencies:
+      - netbird (>= 0.75.0)
+      - libgtk-3-0
+      - libwebkit2gtk-4.1-0
+      - xdg-utils
+
+  - maintainer: Netbird <dev@netbird.io>
+    description: Netbird client UI.
+    homepage: https://netbird.io/
+    license: BSD-3-Clause
+    vendor: NetBird
+    id: netbird_ui_rpm_gtk3
+    package_name: netbird-ui-gtk3
+    file_name_template: "{{ .PackageName }}_{{ .Version }}_{{ .Os }}_{{ .Arch }}"
+    builds:
+      - netbird-ui-gtk3
+    formats:
+      - rpm
+    scripts:
+      postinstall: "release_files/ui-post-install.sh"
+    contents:
+      - src: client/ui/build/linux/netbird.desktop
+        dst: /usr/share/applications/org.wails.netbird.desktop
+      - src: client/ui/build/appicon.png
+        dst: /usr/share/pixmaps/netbird.png
+    # No `replaces` here: nfpm maps it to rpm Obsoletes, which would make
+    # dnf swap installed GTK4 netbird-ui packages for this one on upgrade.
+    conflicts:
+      - netbird-ui
+    dependencies:
+      - netbird >= 0.75.0
+      - (gtk3 or libgtk-3-0)
+      - (webkit2gtk4.1 or libwebkit2gtk-4_1-0)
+      - xdg-utils
+
+    rpm:
+      signature:
+        key_file: '{{ if index .Env "GPG_RPM_KEY_FILE" }}{{ .Env.GPG_RPM_KEY_FILE }}{{ end }}'
+
+# The GTK4 UI job shares project_name, so the default checksum file name would
+# collide with it on the shared GitHub release.
+checksum:
+  name_template: "{{ .ProjectName }}_gtk3_checksums.txt"
+
+changelog:
+  disable: true
+
+uploads:
+  - name: debian
+    skip: "{{ .Env.SKIP_PUBLISH }}"
+    ids:
+      - netbird_ui_deb_gtk3
+    mode: archive
+    target: https://pkgs.wiretrustee.com/debian/pool/{{ .ArtifactName }};deb.distribution=stable;deb.component=main;deb.architecture={{ if .Arm }}armhf{{ else }}{{ .Arch }}{{ end }};deb.package=
+    username: dev@wiretrustee.com
+    method: PUT
+
+  - name: yum
+    skip: "{{ .Env.SKIP_PUBLISH }}"
+    ids:
+      - netbird_ui_rpm_gtk3
+    mode: archive
+    target: https://pkgs.wiretrustee.com/yum/{{ .Arch }}{{ if .Arm }}{{ .Arm }}{{ end }}
+    username: dev@wiretrustee.com
+    method: PUT

AGENTS.md

@@ -14,20 +14,22 @@ in this file, not duplicated there.
 
 ## Contents
 
-- [NetBird Agent Guidelines](#netbird-agent-guidelines)
-  - [Contents](#contents)
-  - [STOP and ask the user before](#stop-and-ask-the-user-before)
-  - [Quick reference](#quick-reference)
-  - [Structure](#structure)
-  - [Where to look](#where-to-look)
-  - [Repo-wide principles](#repo-wide-principles)
-  - [Error handling](#error-handling)
-  - [Comments](#comments)
-  - [Testing](#testing)
-  - [Pitfalls](#pitfalls)
-  - [Commits, PRs, releases](#commits-prs-releases)
-  - [After you push: CI and review bots](#after-you-push-ci-and-review-bots)
-  - [Discussion and support](#discussion-and-support)
+- [STOP and ask the user before](#stop-and-ask-the-user-before)
+- [Quick reference](#quick-reference)
+- [Structure](#structure)
+- [Where to look](#where-to-look)
+- [Security](#security)
+- [Agent conventions](#agent-conventions)
+- [Repo-wide principles](#repo-wide-principles)
+- [Type safety](#type-safety)
+- [Concurrency and lifecycle](#concurrency-and-lifecycle)
+- [Error handling](#error-handling)
+- [Comments](#comments)
+- [Testing](#testing)
+- [Pitfalls](#pitfalls)
+- [Commits, PRs, releases](#commits-prs-releases)
+- [After you push: CI and review bots](#after-you-push-ci-and-review-bots)
+- [Discussion and support](#discussion-and-support)
 
 ## STOP and ask the user before
 
@@ -157,11 +159,125 @@ netbird/
 | LLM routing / Agent Network | `proxy/internal/llm/`, `agent-network/`                      |
 | End-to-end tests            | `e2e/`                                                       |
 
+## Security
+
+### Never fail open
+
+When a security check — access control, an IP restriction, an auth decision —
+hits an error such as an unparseable value, an unavailable lookup, or a state it
+does not recognize, it must **deny**. Never skip the check or allow the request
+through because the check itself failed, and make the `default` and unknown cases
+of a security-related `switch` deny rather than fall through.
+
+### Daemon RPC input is untrusted
+
+The agent runs as root (LocalSystem on Windows), so a daemon RPC crosses a
+privilege boundary: treat every field as untrusted input rather than as something
+the UI or CLI validated on the way in.
+
+When you add or change an RPC, ask what the handler does with caller input while
+running as root. If the answer touches a filesystem path, a URL or host, or a
+privileged state change, it needs a gate **in the handler** — a check in the client
+that normally calls it is not a check at all.
+
+- **A caller-supplied path the daemon opens.** Never `os.Open` it as root.
+  Constrain it, then open it *as the caller* with `ipcauth.OpenOwnedFile`, which
+  opens `O_NOFOLLOW`, requires a regular file, and refuses a file the caller does
+  not own — so a symlink or hardlink aimed at a root-only file is rejected.
+- **A caller-supplied URL or host the daemon fetches.** Restrict the scheme and
+  allow only known hosts for unprivileged callers. Prefer a lexical host
+  allowlist plus TLS verification over "resolve the host, then reject private
+  IPs": the resolve-then-trust pattern has a DNS-rebinding race (public IP at
+  check time, attacker IP at connect time), while a name allowlist has no IP
+  check to race. Never accept `http://` where `https://` is expected.
+- **A privileged state change** (SSH root login, management URL, deregistration)
+  gates on the caller identity from `ipcauth.CallerIdentity(ctx)`.
+
+Caller identity comes from the kernel — `SO_PEERCRED`, `LOCAL_PEERCRED`, or the
+named-pipe client token — and never from an RPC field. When
+`ipcauth.CallerIdentity` reports that it could not determine an identity, **deny**;
+do not fall back to treating the caller as the transport peer.
+
+## Agent conventions
+
+### Three networking modes
+
+Where packets actually flow depends on the mode the agent is running in. The
+three are not interchangeable, so establish which one a change applies to — and
+what it should do in the other two — before you write it.
+
+- **kernel mode** (Linux only): in-kernel WireGuard®. The kernel handles both
+  peer-to-peer and routed traffic, and ACLs are iptables or nftables rules. The
+  client programs kernel facilities but never sees the traffic itself.
+- **userspace mode** (wireguard-go with a TUN): wireguard-go runs in-process. The
+  kernel handles peer-to-peer traffic once it leaves the TUN, while routed traffic
+  — exit nodes and network routes — goes through the userspace forwarder, which
+  terminates the connection and re-establishes it over OS sockets. Used on
+  platforms without kernel WireGuard® or when the user opts out.
+- **netstack mode**: wireguard-go in-process with no TUN and no kernel
+  networking. The forwarder does all routing by stitching userspace sockets, and
+  listeners such as the embedded SSH and DNS servers bind on a gVisor netstack.
+  Used where the process cannot create a TUN device, such as the embedded client
+  (`client/embed/`) and the WASM build.
+
+### The overlay interface is not "WireGuard"
+
+Do not put "WireGuard" in identifiers or comments unless the code is genuinely
+coupled to WireGuard® specifically — a wireguard-go call, a handshake field, a
+kernel WireGuard® netlink attribute. For the interface, the host, peers, or
+traffic in general, say "the NetBird interface", "the interface", or "the overlay".
+Most firewall, routing, and DNS code is transport-agnostic, so a WireGuard®
+reference there is simply inaccurate and rots as the transports change.
+
+### IPv6 is a soft feature
+
+The IPv6 overlay is opt-in dual-stack, and capability can change at runtime. Treat
+it as soft rather than a requirement:
+
+- Gate local v6 paths on the interface accessor (`wgIface.Address().HasIPv6()`),
+  not on raw state fields, and skip the v6 path when the host has no v6 rather
+  than returning an error.
+- Treat an empty or unparseable peer v6 address as "no v6 for that peer" and skip
+  it, keeping the v4 path working.
+- Never let a missing v6 break v4. Fail-closed is for security checks; a
+  capability mismatch skips the v6 work and carries on.
+
+### Environment variables
+
+Name the variable in a constant and parse booleans with `strconv.ParseBool` rather
+than comparing strings inline, so an unexpected value is logged instead of
+silently meaning false:
+
+```go
+const EnvDisableFeature = "NB_DISABLE_FEATURE"
+
+func isDisabledByEnv() bool {
+    val := os.Getenv(EnvDisableFeature)
+    if val == "" {
+        return false
+    }
+    disabled, err := strconv.ParseBool(val)
+    if err != nil {
+        log.Warnf("failed to parse %s: %v", EnvDisableFeature, err)
+        return false
+    }
+    return disabled
+}
+```
+
+### Validating against protocol specs
+
+When a change depends on what a protocol actually mandates, read the specification
+text from the [IETF datatracker](https://datatracker.ietf.org/) rather than a
+summary, and check that you have the current RFC — the widely cited one for a
+protocol is often superseded. Cite the section, not just the document, so a
+reviewer can jump straight to the rule.
+
 ## Repo-wide principles
 
 1. **Run `go fmt` on every modified Go file.** Formatting is not optional.
-2. **Zero unaddressed diagnostics.** Fix IDE and linter warnings on code you
-   touch, and delete imports, helpers, and parameters your refactor orphaned.
+2. **Zero unaddressed linter warnings.** Fix what `golangci-lint` reports on code
+   you touch, and delete imports, helpers, and parameters your refactor orphaned.
    Exception: unused parameters in shared code may be consumed by builds outside
    this repository — do not remove them, ask instead.
 3. **Function comments are mandatory for exported functions**, written as full
@@ -175,9 +291,12 @@ netbird/
 7. **Avoid LLM-slop tells:** em dashes, hedging narration, restating the diff in
    prose, trailing summaries. Defaults, not absolute bans. Applies to code,
    comments, commit messages, and PR descriptions alike.
-8. **Concurrency: do a two-pass race analysis after every change** that adds
-   shared state. Guard maps and slices with a mutex, keep critical sections
-   short, and run `go test -race` on the touched packages.
+8. **Concurrency: do a two-pass race analysis after every change** that touches
+   shared state, including reads of existing maps and slices. Guard them with a
+   mutex (or an atomic or channel where that fits better), keep critical
+   sections short, and run `go test -race` on the touched packages. See
+   [Concurrency and lifecycle](#concurrency-and-lifecycle) for the failure modes
+   to check for.
 9. **Cross-platform builds must keep working.** The agent targets Linux, macOS,
    Windows, FreeBSD, Android, and iOS. When you add a platform-specific file,
    add the counterpart or a build-tagged fallback for the others.
@@ -185,6 +304,93 @@ netbird/
 11. **Never log secrets** — private keys, setup keys, tokens, PAT values — and
     keep peer IPs and hostnames out of logs above debug level.
 
+## Type safety
+
+**No bare primitives for domain concepts.** A `string` parameter for an account
+ID next to a `string` parameter for a peer ID is two bugs waiting to happen,
+because the compiler cannot catch the swap. Declare the type once and use it
+throughout, converting only at the boundaries where data enters or leaves —
+protobuf, gRPC, HTTP, an external library.
+
+```go
+type ServiceID string
+type AccountID string
+
+// Internal: typed all the way through
+func (r *Router) RemoveRoute(host SNIHost, svcID ServiceID) { ... }
+
+// Proto boundary: convert once, on the way in and on the way out
+svcID := ServiceID(mapping.GetId())
+req.ServiceId = string(svcID)
+```
+
+- **IP addresses are `netip.Addr`**, not `string` and not `net.IP`. Parse at the
+  boundary and pass the typed value inward.
+- **Always `Unmap()`** after parsing an address, after converting from `net.IP`,
+  and after extracting one from `RemoteAddr()`. This normalizes a v4-mapped v6
+  address (`::ffff:10.1.2.3`) to plain v4 so IPv4 rules match it. A stored or
+  compared mapped address silently fails to match those rules.
+- **Ports are `uint16`** internally; use `int` only where a library forces it and
+  convert immediately.
+- **Enums are a typed string with constants**, so the valid set is discoverable
+  and a typo fails to compile.
+- **Map keys follow the same rule**, and must be a real type (`type ServiceID
+  string`) rather than an alias (`type serviceID = string`) — an alias silently
+  accepts bare strings.
+
+## Concurrency and lifecycle
+
+Beyond the mutex hygiene in the principles above, check for these failure
+modes.
+
+- **Never read a struct field inside a goroutine** when another goroutine may nil
+  or reassign it. Pass the value as a parameter, or capture it into a local before
+  launching. This matters most when `Stop()` nils a field without waiting for the
+  goroutine to finish.
+
+  ```go
+  go func(ifaceName string) {   // good: passed in, cannot be nilled underneath
+      m.Start(ctx, ifaceName)
+  }(iface.Name())
+  ```
+
+- **Never wait on a channel while holding a lock the sender needs.** Copy what you
+  need out from under the lock, release it, then wait.
+
+  ```go
+  func (m *Manager) Stop() {
+      m.mu.Lock()
+      cancel, done := m.cancel, m.done
+      m.mu.Unlock()
+      if cancel != nil {
+          cancel()
+          <-done
+      }
+  }
+  ```
+
+- **`Stop`/`Close` must be idempotent** — guard on an already-stopped flag or a
+  nil cancel — and must release the state they guarded. Clear maps and caches;
+  a cancelled goroutine holding a live map still pins that memory. Note that a
+  nil map only panics on writes; reads and iteration behave like an empty map,
+  so where post-close use must be rejected, check the stopped flag explicitly.
+- **Publish coupled state only after every fallible step succeeds.** When several
+  fields form an invariant, build them into locals and assign them to the receiver
+  at the end. Assigning as you go leaves the object half-initialized when a later
+  step fails, so a readiness predicate reports ready while a coupled field is nil.
+  If an earlier step already had an external side effect — a created chain, an
+  opened handle, an inserted rule — roll it back before returning the error.
+- **Clean up what you own on constructor error paths.** Once a constructor has
+  started something, every later error path must undo it: cancel a goroutine and
+  wait for it to exit, stop a ticker, close a watcher. The object is never
+  returned, so its `Close` will never run.
+- **A failed `Start` must undo everything it started.** When a component brings up
+  several subsystems in sequence — connection manager, watchers, routing, DNS,
+  flow, persisted state — a failure partway through has to tear down the ones
+  already running, not just close the handle the error came from. Put the
+  already-started guard *before* that teardown path, so a rejected second `Start`
+  cannot dismantle the one that is running.
+
 ## Error handling
 
 Use single-assignment form when the error is only needed inside the `if`:
@@ -248,6 +454,45 @@ Log the errors you choose not to act on:
 - Close errors may be ignored for read-only operations; log them at debug for
   writes.
 
+**Do not log and return the same error.** It gets reported twice, from two places,
+and the second reader cannot tell whether it happened once or twice. Return it and
+let the caller decide. The exception is an API handler that has already written a
+response. Internal helpers return errors rather than logging and swallowing them.
+
+**Never return a typed nil as an error.** A nil `*MyError` stored in an `error`
+interface is not nil, so `err != nil` is true and callers take the failure path on
+success. Return the error only where it is actually set:
+
+```go
+if _, err := conn.Write(buf); err != nil {   // good
+    return err
+}
+return nil
+```
+
+**Accumulate with `multierror` when an operation should continue past individual
+failures** — teardown, cleanup, or setup where partial success is acceptable.
+`client/errors.FormatErrorOrNil` returns nil for an empty accumulator, so callers
+still see a plain nil on full success:
+
+```go
+func (m *Manager) Cleanup() error {
+    var merr *multierror.Error
+    for _, r := range m.resources {
+        if err := r.Close(); err != nil {
+            merr = multierror.Append(merr, fmt.Errorf("close %s: %w", r.Name, err))
+        }
+    }
+    return nberrors.FormatErrorOrNil(merr)
+}
+```
+
+| Scenario              | Approach              | Why                                       |
+| --------------------- | --------------------- | ----------------------------------------- |
+| Cleanup / teardown    | Accumulate            | Clean up as much as possible              |
+| Setup with rollback   | Abort on first error  | Partial state is invalid; undo what stuck |
+| Setup with partial OK | Accumulate            | Degraded operation is still useful        |
+
 ## Comments
 
 Comment the **why**, never the **what**. Default to no comment, and add one only
@@ -269,10 +514,14 @@ checksum = updateChecksum(checksum, oldPort, newPort)
 
 ### Length budget
 
-- **90 characters per line.** Wrap the comment, do not run past it.
-- **250 characters per comment**, roughly three wrapped lines. Doc comments on
-  exported identifiers may exceed it when the API genuinely needs the
-  explanation; inline comments inside a function body may not.
+Neither of these is linter-enforced, so they are conventions the surrounding code
+mostly follows rather than hard limits:
+
+- **Around 90 characters per line.** Wrap the comment rather than running well past
+  it.
+- **Roughly 250 characters per comment**, about three wrapped lines. Doc comments
+  on exported identifiers may exceed it when the API genuinely needs the
+  explanation; inline comments inside a function body rarely should.
 
 The budget is a smell detector, not a rule to game. Do not compress a needed
 explanation into cryptic shorthand to fit — if a block of code needs more than
@@ -329,6 +578,19 @@ up, and the 250-character budget does not apply to them.
   otherwise.
 - **Message guidance:** optional for `NoError`/`Error`; always give context for
   comparison, boolean, and collection assertions.
+- **Reproduce a bug before fixing it.** Write the test, watch it fail *for the
+  reason you expect* — a test that fails for an unrelated reason proves nothing —
+  then apply the fix and confirm it passes. Add the thin surrounding cases while
+  you are there.
+- **Use `t.Setenv`** rather than `os.Setenv` so the previous value is restored on
+  cleanup. To test the unset case, call `t.Setenv` first to register the restore,
+  then `os.Unsetenv`.
+- **Prefer `t.Cleanup` over `defer`** in any test with parallel subtests: the
+  parent function returns, running its `defer`s, while parallel subtests are
+  still suspended. Sequential subtests finish inside `t.Run`, so `defer` is safe
+  there, but `t.Cleanup` works in both cases.
+- **Explanatory comments in tests are welcome.** Describe the scenario being set
+  up; the comment budget below does not apply to them.
 
 ```go
 server, err := StartTestServer()
@@ -380,7 +642,8 @@ assert.Equal(t, expectedResult, result, "Result should match expected")
   than replacing it with your own summary: describe the change, link the issue,
   tick the checklist honestly (including "ran locally" and "single purpose"),
   and complete the documentation section. Do not tick a box you have not
-  verified, and do not delete rows that do not apply.
+  verified, and do not delete rows that do not apply — the docs gate in CI reads
+  that section and fails when it is missing.
 
 - **Keep the PR description short.** Under 1000 words on top of the template's
   own text, and usually far less — a few paragraphs. Reviewers read the diff;
@@ -439,6 +702,12 @@ assert.Equal(t, expectedResult, result, "Result should match expected")
   on their own. Propose that split to the user rather than opening one large PR
   and hoping.
 
+  Prefer GitHub's stacked pull requests for such a sequence, rather than
+  hand-managing base branches: open each PR against the branch below it instead of
+  `main`, so every PR's diff shows only its own change. Merging a layer retargets
+  the PRs above it, and branch protections and required checks on the base branch
+  still apply to each one.
+
 - **User-facing changes need a docs PR** in
   [netbirdio/docs](https://github.com/netbirdio/docs), linked from the PR
   description.

CONTRIBUTING.md

@@ -112,6 +112,7 @@ aligns with our security standards and design expectations.
         - [Test suite](#test-suite)
     - [Checklist before submitting a PR](#checklist-before-submitting-a-pr)
     - [When we close a PR](#when-we-close-a-pr)
+    - [Translations](#translations)
     - [Other project repositories](#other-project-repositories)
     - [Contributor License Agreement](#contributor-license-agreement)
 
@@ -612,6 +613,17 @@ 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.
 
+## Translations
+
+Desktop UI translations are not contributed through pull requests. Translate on
+[Crowdin](https://crowdin.com/project/netbird) instead: no ticket needed, just
+join the project and pick your language. Crowdin syncs with this repository and
+opens the service PRs itself, so hand-edited locale files would conflict with
+the next sync. Style, terminology, and review guidance live in
+[client/ui/i18n/TRANSLATING.md](client/ui/i18n/TRANSLATING.md). To request a
+language the project does not offer yet, ask on the Crowdin project page or in
+a [discussion](https://github.com/netbirdio/netbird/discussions).
+
 ## Other project repositories
 
 NetBird project is composed of 3 main repositories:

client/android/client.go

@@ -15,6 +15,7 @@ import (
 
 	log "github.com/sirupsen/logrus"
 
+	nbAnonymize "github.com/netbirdio/netbird/client/anonymize"
 	"github.com/netbirdio/netbird/client/iface/device"
 	"github.com/netbirdio/netbird/client/internal"
 	"github.com/netbirdio/netbird/client/internal/debug"
@@ -32,6 +33,13 @@ import (
 	types "github.com/netbirdio/netbird/upload-server/types"
 )
 
+// AnonymizeLevelDefault and AnonymizeLevelStrict are the accepted
+// anonymizeLevel values for DebugBundle.
+const (
+	AnonymizeLevelDefault = nbAnonymize.LevelDefaultString
+	AnonymizeLevelStrict  = nbAnonymize.LevelStrictString
+)
+
 // ConnectionListener export internal Listener for mobile
 type ConnectionListener interface {
 	peer.Listener
@@ -278,8 +286,10 @@ func (c *Client) GetTunSettings() (*TunSettings, error) {
 }
 
 // DebugBundle generates a debug bundle, uploads it, and returns the upload key.
-// It works both with and without a running engine.
-func (c *Client) DebugBundle(platformFiles PlatformFiles, anonymize bool) (string, error) {
+// It works both with and without a running engine. anonymizeLevel is "default"
+// or "strict"; strict also anonymizes internal IP ranges, peer names, and
+// WireGuard public keys, and implies anonymize.
+func (c *Client) DebugBundle(platformFiles PlatformFiles, anonymize bool, anonymizeLevel string) (string, error) {
 	cfg, cacheDir, cc := c.stateSnapshot()
 
 	// If the engine hasn't been started, load config from disk
@@ -298,6 +308,7 @@ func (c *Client) DebugBundle(platformFiles PlatformFiles, anonymize bool) (strin
 		InternalConfig: cfg,
 		StatusRecorder: c.recorder,
 		TempDir:        cacheDir,
+		StatePath:      platformFiles.StateFilePath(),
 	}
 
 	if cc != nil {
@@ -321,6 +332,7 @@ func (c *Client) DebugBundle(platformFiles PlatformFiles, anonymize bool) (strin
 		deps,
 		debug.BundleConfig{
 			Anonymize:         anonymize,
+			AnonymizeLevel:    nbAnonymize.ParseLevel(anonymizeLevel),
 			IncludeSystemInfo: true,
 		},
 	)

client/anonymize/anonymize.go

@@ -2,6 +2,7 @@ package anonymize
 
 import (
 	"crypto/rand"
+	"encoding/base64"
 	"fmt"
 	"math/big"
 	"net"
@@ -15,13 +16,88 @@ import (
 
 const anonTLD = ".domain"
 
+// Level selects how much the anonymizer redacts. Levels are ordered: a higher
+// level redacts strictly more. On the wire (protos, flags) levels travel as
+// their string form.
+type Level int
+
+const (
+	// LevelDefault anonymizes public IP addresses, IPv6 ULA, domains, and MAC
+	// addresses. Internal IPv4 ranges (RFC 1918, CGNAT, link-local) are
+	// preserved so support can reason about the real topology.
+	LevelDefault Level = iota
+	// LevelStrict additionally anonymizes internal IP ranges, peer names, and
+	// WireGuard public keys.
+	LevelStrict
+)
+
+// LevelDefaultString and LevelStrictString are the wire forms of the levels,
+// for boundaries that pass levels as strings (flags, protos, mobile bindings).
+const (
+	LevelDefaultString = "default"
+	LevelStrictString  = "strict"
+)
+
+// ParseLevel maps s to a Level. Empty means LevelDefault; anything
+// unrecognized maps to LevelStrict so an unknown request never yields less
+// anonymization than intended.
+func ParseLevel(s string) Level {
+	switch strings.ToLower(s) {
+	case "", LevelDefaultString:
+		return LevelDefault
+	default:
+		return LevelStrict
+	}
+}
+
+// String returns the wire form of the level: "default" or "strict".
+func (l Level) String() string {
+	if l >= LevelStrict {
+		return LevelStrictString
+	}
+	return LevelDefaultString
+}
+
+// protectedDomains are NetBird-operated suffixes that stay recognizable in an
+// anonymized bundle. At LevelStrict the labels in front of them (the peer
+// name) are still replaced, except under netbird.io, which only hosts
+// NetBird infrastructure (api, signal, flow), never peer names.
+var protectedDomains = []string{"netbird.io", "netbird.selfhosted", "netbird.cloud", "netbird.stage"}
+
+const infraDomain = "netbird.io"
+
+var (
+	macColonRegex = regexp.MustCompile(`\b[0-9a-fA-F]{2}(?::[0-9a-fA-F]{2}){5}\b`)
+	macDashRegex  = regexp.MustCompile(`\b[0-9a-fA-F]{2}(?:-[0-9a-fA-F]{2}){5}\b`)
+	wgKeyRegex    = regexp.MustCompile(`\b[A-Za-z0-9+/]{43}=`)
+)
+
 type Anonymizer struct {
 	ipAnonymizer     map[netip.Addr]netip.Addr
 	domainAnonymizer map[string]string
-	currentAnonIPv4  netip.Addr
-	currentAnonIPv6  netip.Addr
-	startAnonIPv4    netip.Addr
-	startAnonIPv6    netip.Addr
+	// domainOrder caches the keys of domainAnonymizer sorted longest-first
+	// for AnonymizeString; it is rebuilt when the map gains entries.
+	domainOrder     []string
+	labelAnonymizer map[string]string
+	labelAnonymized map[string]struct{}
+	labelCounter    uint32
+	macAnonymizer   map[string]string
+	macCounter      uint32
+	wgKeyAnonymizer map[string]string
+	wgKeyAnonymized map[string]struct{}
+	currentAnonIPv4 netip.Addr
+	currentAnonIPv6 netip.Addr
+	startAnonIPv4   netip.Addr
+	startAnonIPv6   netip.Addr
+
+	// LevelStrict also anonymizes internal ranges (RFC 1918, CGNAT,
+	// link-local), replacing them from the dedicated internal pools below so
+	// a reader can still tell an internal address from a public one.
+	level                   Level
+	currentAnonInternalIPv4 netip.Addr
+	currentAnonInternalIPv6 netip.Addr
+	startAnonInternalIPv4   netip.Addr
+	startAnonInternalIPv6   netip.Addr
 
 	domainKeyRegex *regexp.Regexp
 }
@@ -32,25 +108,50 @@ func DefaultAddresses() (netip.Addr, netip.Addr) {
 	return netip.AddrFrom4([4]byte{198, 51, 100, 0}), netip.MustParseAddr("2001:db8:ffff::")
 }
 
+// InternalAddresses returns the pool starts used in strict mode for internal
+// ranges. Both are reserved ranges that cannot collide with real addressing:
+// 198.18.0.0 (RFC 2544 benchmarking), 2001:db8:1:: (RFC 3849 documentation).
+func InternalAddresses() (netip.Addr, netip.Addr) {
+	return netip.AddrFrom4([4]byte{198, 18, 0, 0}), netip.MustParseAddr("2001:db8:1::")
+}
+
 func NewAnonymizer(startIPv4, startIPv6 netip.Addr) *Anonymizer {
+	internalIPv4, internalIPv6 := InternalAddresses()
 	return &Anonymizer{
 		ipAnonymizer:     map[netip.Addr]netip.Addr{},
 		domainAnonymizer: map[string]string{},
+		labelAnonymizer:  map[string]string{},
+		labelAnonymized:  map[string]struct{}{},
+		macAnonymizer:    map[string]string{},
+		wgKeyAnonymizer:  map[string]string{},
+		wgKeyAnonymized:  map[string]struct{}{},
 		currentAnonIPv4:  startIPv4,
 		currentAnonIPv6:  startIPv6,
 		startAnonIPv4:    startIPv4,
 		startAnonIPv6:    startIPv6,
 
+		level:                   LevelDefault,
+		currentAnonInternalIPv4: internalIPv4,
+		currentAnonInternalIPv6: internalIPv6,
+		startAnonInternalIPv4:   internalIPv4,
+		startAnonInternalIPv6:   internalIPv6,
+
 		domainKeyRegex: regexp.MustCompile(`\bdomain=([^\s,:"]+)`),
 	}
 }
 
+// SetLevel selects the anonymization level. The zero value of a new
+// Anonymizer is LevelDefault.
+func (a *Anonymizer) SetLevel(level Level) {
+	a.level = level
+}
+
 func (a *Anonymizer) AnonymizeIP(ip netip.Addr) netip.Addr {
+	// Normalize 4-in-6 addresses so ::ffff:192.168.1.1 classifies and maps
+	// like 192.168.1.1.
+	ip = ip.Unmap()
+
 	if ip.IsLoopback() ||
-		ip.IsLinkLocalUnicast() ||
-		ip.IsLinkLocalMulticast() ||
-		ip.IsInterfaceLocalMulticast() ||
-		(ip.Is4() && ip.IsPrivate()) ||
 		ip.IsUnspecified() ||
 		ip.IsMulticast() ||
 		isWellKnown(ip) ||
@@ -59,18 +160,100 @@ func (a *Anonymizer) AnonymizeIP(ip netip.Addr) netip.Addr {
 		return ip
 	}
 
+	if isInternal(ip) && a.level < LevelStrict {
+		return ip
+	}
+
 	if _, ok := a.ipAnonymizer[ip]; !ok {
-		if ip.Is4() {
-			a.ipAnonymizer[ip] = a.currentAnonIPv4
-			a.currentAnonIPv4 = a.currentAnonIPv4.Next()
-		} else {
-			a.ipAnonymizer[ip] = a.currentAnonIPv6
-			a.currentAnonIPv6 = a.currentAnonIPv6.Next()
-		}
+		a.ipAnonymizer[ip] = a.nextAnonIP(ip)
 	}
 	return a.ipAnonymizer[ip]
 }
 
+func (a *Anonymizer) nextAnonIP(ip netip.Addr) netip.Addr {
+	// At the strict level, internal addresses (including IPv6 ULA, matched
+	// by IsPrivate) come from the internal pools so they remain recognizable
+	// as internal without disclosing the real values.
+	if a.level >= LevelStrict && (isInternal(ip) || ip.IsPrivate()) {
+		if ip.Is4() {
+			anon := a.currentAnonInternalIPv4
+			a.currentAnonInternalIPv4 = a.currentAnonInternalIPv4.Next()
+			return anon
+		}
+		anon := a.currentAnonInternalIPv6
+		a.currentAnonInternalIPv6 = a.currentAnonInternalIPv6.Next()
+		return anon
+	}
+
+	if ip.Is4() {
+		anon := a.currentAnonIPv4
+		a.currentAnonIPv4 = a.currentAnonIPv4.Next()
+		return anon
+	}
+	anon := a.currentAnonIPv6
+	a.currentAnonIPv6 = a.currentAnonIPv6.Next()
+	return anon
+}
+
+// AnonymizeMAC replaces a MAC address with a consistent placeholder from the
+// locally administered range starting at 02:00:00:00:00:01, at every
+// anonymization level. Broadcast, multicast, all-zero, and already assigned
+// placeholder addresses are preserved. The colon and dash spellings of the
+// same address share one placeholder; the output keeps the input's separator.
+func (a *Anonymizer) AnonymizeMAC(mac string) string {
+	hw, err := net.ParseMAC(mac)
+	if err != nil || len(hw) != 6 {
+		return mac
+	}
+
+	if isWellKnownMAC(hw) || a.isAnonymizedMAC(hw) {
+		return mac
+	}
+
+	key := hw.String()
+	anon, ok := a.macAnonymizer[key]
+	if !ok {
+		a.macCounter++
+		anon = fmt.Sprintf("02:00:00:%02x:%02x:%02x", byte(a.macCounter>>16), byte(a.macCounter>>8), byte(a.macCounter))
+		a.macAnonymizer[key] = anon
+	}
+
+	if strings.Contains(mac, "-") {
+		anon = strings.ReplaceAll(anon, ":", "-")
+	}
+	return anon
+}
+
+// isAnonymizedMAC reports whether hw is a placeholder this anonymizer already
+// handed out, so a second pass over anonymized output leaves it unchanged.
+func (a *Anonymizer) isAnonymizedMAC(hw net.HardwareAddr) bool {
+	if hw[0] != 0x02 || hw[1] != 0 || hw[2] != 0 {
+		return false
+	}
+	value := uint32(hw[3])<<16 | uint32(hw[4])<<8 | uint32(hw[5])
+	return value <= a.macCounter
+}
+
+// AnonymizeWGKey replaces a WireGuard public key with a consistent random
+// placeholder of the same shape. Keys are only anonymized at LevelStrict;
+// placeholders already handed out pass through unchanged.
+func (a *Anonymizer) AnonymizeWGKey(key string) string {
+	if a.level < LevelStrict || !looksLikeWGKey(key) {
+		return key
+	}
+	if _, ok := a.wgKeyAnonymized[key]; ok {
+		return key
+	}
+
+	anon, ok := a.wgKeyAnonymizer[key]
+	if !ok {
+		anon = generateAnonymousKey()
+		a.wgKeyAnonymizer[key] = anon
+		a.wgKeyAnonymized[anon] = struct{}{}
+	}
+	return anon
+}
+
 func (a *Anonymizer) AnonymizeUDPAddr(addr net.UDPAddr) net.UDPAddr {
 	// Convert IP to netip.Addr
 	ip, ok := netip.AddrFromSlice(addr.IP)
@@ -89,12 +272,12 @@ func (a *Anonymizer) AnonymizeUDPAddr(addr net.UDPAddr) net.UDPAddr {
 
 // isInAnonymizedRange checks if an IP is within the range of already assigned anonymized IPs
 func (a *Anonymizer) isInAnonymizedRange(ip netip.Addr) bool {
-	if ip.Is4() && ip.Compare(a.startAnonIPv4) >= 0 && ip.Compare(a.currentAnonIPv4) <= 0 {
-		return true
-	} else if !ip.Is4() && ip.Compare(a.startAnonIPv6) >= 0 && ip.Compare(a.currentAnonIPv6) <= 0 {
-		return true
+	if ip.Is4() {
+		return inPoolRange(ip, a.startAnonIPv4, a.currentAnonIPv4) ||
+			inPoolRange(ip, a.startAnonInternalIPv4, a.currentAnonInternalIPv4)
 	}
-	return false
+	return inPoolRange(ip, a.startAnonIPv6, a.currentAnonIPv6) ||
+		inPoolRange(ip, a.startAnonInternalIPv6, a.currentAnonInternalIPv6)
 }
 
 func (a *Anonymizer) AnonymizeIPString(ip string) string {
@@ -118,14 +301,17 @@ func (a *Anonymizer) AnonymizeDomain(domain string) string {
 		baseDomain = domain[:len(domain)-1]
 	}
 
-	if strings.HasSuffix(baseDomain, "netbird.io") ||
-		strings.HasSuffix(baseDomain, "netbird.selfhosted") ||
-		strings.HasSuffix(baseDomain, "netbird.cloud") ||
-		strings.HasSuffix(baseDomain, "netbird.stage") ||
-		strings.HasSuffix(baseDomain, anonTLD) {
+	if strings.HasSuffix(baseDomain, anonTLD) {
 		return domain
 	}
 
+	if suffix := protectedSuffix(baseDomain); suffix != "" {
+		if a.level < LevelStrict || baseDomain == suffix || suffix == infraDomain {
+			return domain
+		}
+		return withTrailingDot(a.anonymizePeerName(baseDomain, suffix), hasDot)
+	}
+
 	parts := strings.Split(baseDomain, ".")
 	if len(parts) < 2 {
 		return domain
@@ -141,12 +327,53 @@ func (a *Anonymizer) AnonymizeDomain(domain string) string {
 	}
 
 	result := strings.Replace(baseDomain, baseForLookup, anonymized, 1)
-	if hasDot {
-		result += "."
+	if a.level >= LevelStrict && len(parts) > 2 {
+		prefix := strings.TrimSuffix(baseDomain, "."+baseForLookup)
+		result = a.anonymizeLabels(prefix, "host") + "." + anonymized
+		// The full mapping feeds AnonymizeString so seeded FQDNs are caught
+		// in log lines as a whole, labels included.
+		a.domainAnonymizer[baseDomain] = result
+	}
+	return withTrailingDot(result, hasDot)
+}
+
+// anonymizePeerName replaces the labels in front of a protected suffix with
+// numbered peer placeholders, keeping the suffix, and records the full
+// mapping for string replacement in logs. The numbering keeps a peer
+// recognizable across the whole bundle without disclosing its name.
+func (a *Anonymizer) anonymizePeerName(baseDomain, suffix string) string {
+	prefix := strings.TrimSuffix(baseDomain, "."+suffix)
+	result := a.anonymizeLabels(prefix, "peer") + "." + suffix
+	if result != baseDomain {
+		a.domainAnonymizer[baseDomain] = result
 	}
 	return result
 }
 
+// anonymizeLabels replaces each dot-separated label with a consistent
+// numbered placeholder ("<placeholder>-<n>"). Wildcard labels and
+// placeholders already handed out pass through unchanged.
+func (a *Anonymizer) anonymizeLabels(prefix, placeholder string) string {
+	labels := strings.Split(prefix, ".")
+	for i, label := range labels {
+		if label == "*" {
+			continue
+		}
+		if _, ok := a.labelAnonymized[label]; ok {
+			continue
+		}
+		anon, ok := a.labelAnonymizer[label]
+		if !ok {
+			a.labelCounter++
+			anon = fmt.Sprintf("%s-%d", placeholder, a.labelCounter)
+			a.labelAnonymizer[label] = anon
+			a.labelAnonymized[anon] = struct{}{}
+		}
+		labels[i] = anon
+	}
+	return strings.Join(labels, ".")
+}
+
 func (a *Anonymizer) AnonymizeURI(uri string) string {
 	u, err := url.Parse(uri)
 	if err != nil {
@@ -181,16 +408,70 @@ func (a *Anonymizer) AnonymizeString(str string) string {
 	str = ipv4Regex.ReplaceAllStringFunc(str, a.AnonymizeIPString)
 	str = ipv6Regex.ReplaceAllStringFunc(str, a.AnonymizeIPString)
 
-	for domain, anonDomain := range a.domainAnonymizer {
-		str = strings.ReplaceAll(str, domain, anonDomain)
+	for _, domain := range a.sortedDomains() {
+		str = strings.ReplaceAll(str, domain, a.domainAnonymizer[domain])
 	}
 
 	str = a.AnonymizeSchemeURI(str)
 	str = a.AnonymizeDNSLogLine(str)
 
+	// MAC handling runs after the IP passes so preserved IPv6 addresses are
+	// already out of the way; the separator guard skips matches embedded in a
+	// longer colon- or dash-separated sequence (such as an IPv6 tail).
+	str = a.anonymizeMACsInString(str, macColonRegex, ':')
+	str = a.anonymizeMACsInString(str, macDashRegex, '-')
+
+	if a.level >= LevelStrict {
+		str = wgKeyRegex.ReplaceAllStringFunc(str, a.AnonymizeWGKey)
+	}
+
 	return str
 }
 
+// sortedDomains returns the domain mappings longest-first, so a full-FQDN
+// mapping (strict level) is applied before the base-domain mapping it
+// contains. The order is rebuilt only when domainAnonymizer has grown.
+func (a *Anonymizer) sortedDomains() []string {
+	if len(a.domainOrder) == len(a.domainAnonymizer) {
+		return a.domainOrder
+	}
+
+	a.domainOrder = a.domainOrder[:0]
+	for domain := range a.domainAnonymizer {
+		a.domainOrder = append(a.domainOrder, domain)
+	}
+	slices.SortFunc(a.domainOrder, func(x, y string) int {
+		if d := len(y) - len(x); d != 0 {
+			return d
+		}
+		return strings.Compare(x, y)
+	})
+	return a.domainOrder
+}
+
+// anonymizeMACsInString replaces MAC addresses matched by re, skipping
+// matches that directly adjoin another sep so a six-group run inside a longer
+// separated sequence is left alone.
+func (a *Anonymizer) anonymizeMACsInString(str string, re *regexp.Regexp, sep byte) string {
+	matches := re.FindAllStringIndex(str, -1)
+	if len(matches) == 0 {
+		return str
+	}
+
+	var b strings.Builder
+	last := 0
+	for _, m := range matches {
+		if (m[0] > 0 && str[m[0]-1] == sep) || (m[1] < len(str) && str[m[1]] == sep) {
+			continue
+		}
+		b.WriteString(str[last:m[0]])
+		b.WriteString(a.AnonymizeMAC(str[m[0]:m[1]]))
+		last = m[1]
+	}
+	b.WriteString(str[last:])
+	return b.String()
+}
+
 // AnonymizeSchemeURI finds and anonymizes URIs with ws, wss, rel, rels, stun, stuns, turn, and turns schemes.
 func (a *Anonymizer) AnonymizeSchemeURI(text string) string {
 	re := regexp.MustCompile(`(?i)\b(wss?://|rels?://|stuns?:|turns?:|https?://)\S+\b`)
@@ -239,10 +520,79 @@ func isWellKnown(addr netip.Addr) bool {
 		"128.0.0.0", "8000::", // 2nd split subnet for default routes
 	}
 
-	if slices.Contains(wellKnown, addr.String()) {
+	return slices.Contains(wellKnown, addr.String())
+}
+
+// isInternal reports whether ip identifies a host only within the local
+// network: IPv4 private (RFC 1918), CGNAT (RFC 6598), and link-local (v4 and
+// v6). These are preserved at the default level so support can reason about
+// the real topology, and replaced from the internal pools at the strict
+// level. IPv6 ULA is deliberately not internal: its random global ID uniquely
+// fingerprints the network, so it is anonymized at every level.
+func isInternal(ip netip.Addr) bool {
+	return (ip.Is4() && ip.IsPrivate()) ||
+		ip.IsLinkLocalUnicast() ||
+		isCGNAT(ip)
+}
+
+func inPoolRange(ip, start, current netip.Addr) bool {
+	return ip.Compare(start) >= 0 && ip.Compare(current) <= 0
+}
+
+// isWellKnownMAC reports whether hw carries no stable host identity: all-zero
+// or a group address (broadcast and multicast).
+func isWellKnownMAC(hw net.HardwareAddr) bool {
+	if hw[0]&1 == 1 {
 		return true
 	}
+	for _, b := range hw {
+		if b != 0 {
+			return false
+		}
+	}
+	return true
+}
 
+// looksLikeWGKey reports whether s has the shape of a WireGuard key:
+// 44 base64 characters decoding to 32 bytes.
+func looksLikeWGKey(s string) bool {
+	if len(s) != 44 || s[43] != '=' {
+		return false
+	}
+	decoded, err := base64.StdEncoding.DecodeString(s)
+	return err == nil && len(decoded) == 32
+}
+
+func generateAnonymousKey() string {
+	buf := make([]byte, 32)
+	if _, err := rand.Read(buf); err != nil {
+		return strings.Repeat("A", 43) + "="
+	}
+	return base64.StdEncoding.EncodeToString(buf)
+}
+
+// protectedSuffix returns the protected NetBird suffix baseDomain ends with,
+// or empty. The match is label-anchored so an unrelated domain that merely
+// ends in the same characters is not preserved.
+func protectedSuffix(baseDomain string) string {
+	for _, d := range protectedDomains {
+		if baseDomain == d || strings.HasSuffix(baseDomain, "."+d) {
+			return d
+		}
+	}
+	return ""
+}
+
+func withTrailingDot(domain string, hasDot bool) string {
+	if hasDot {
+		return domain + "."
+	}
+	return domain
+}
+
+// isCGNAT reports whether addr is in 100.64.0.0/10 (RFC 6598), the range
+// NetBird assigns overlay peer addresses from.
+func isCGNAT(addr netip.Addr) bool {
 	cgnatRangeStart := netip.AddrFrom4([4]byte{100, 64, 0, 0})
 	cgnatRange := netip.PrefixFrom(cgnatRangeStart, 10)
 

client/anonymize/anonymize_test.go

@@ -1,8 +1,11 @@
 package anonymize_test
 
 import (
+	"bytes"
+	"encoding/base64"
 	"net/netip"
 	"regexp"
+	"strings"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -44,6 +47,301 @@ func TestAnonymizeIP(t *testing.T) {
 	}
 }
 
+func TestParseLevel(t *testing.T) {
+	tests := []struct {
+		input  string
+		expect anonymize.Level
+	}{
+		{"", anonymize.LevelDefault},
+		{"default", anonymize.LevelDefault},
+		{"DEFAULT", anonymize.LevelDefault},
+		{"strict", anonymize.LevelStrict},
+		{"STRICT", anonymize.LevelStrict},
+		// Unknown values must never yield less anonymization than requested.
+		{"garbage", anonymize.LevelStrict},
+	}
+
+	for _, tc := range tests {
+		t.Run("input="+tc.input, func(t *testing.T) {
+			assert.Equal(t, tc.expect, anonymize.ParseLevel(tc.input), "parsed level should match")
+		})
+	}
+}
+
+func TestAnonymizeIP_DefaultLevelInternalRanges(t *testing.T) {
+	anonymizer := anonymize.NewAnonymizer(anonymize.DefaultAddresses())
+
+	tests := []struct {
+		name   string
+		ip     string
+		expect string
+	}{
+		{"RFC1918 10/8", "10.1.2.3", "10.1.2.3"},
+		{"RFC1918 172.16/12", "172.16.5.5", "172.16.5.5"},
+		{"RFC1918 192.168/16", "192.168.1.1", "192.168.1.1"},
+		{"CGNAT", "100.64.0.5", "100.64.0.5"},
+		{"IPv4 link-local", "169.254.1.1", "169.254.1.1"},
+		{"IPv6 link-local", "fe80::1", "fe80::1"},
+		// ULA is anonymized even at the default level: its random global ID
+		// uniquely fingerprints the network, unlike shared RFC 1918 space.
+		{"IPv6 ULA", "fd12:3456:789a::1", "2001:db8:ffff::"},
+		// 4-in-6 addresses classify like their unmapped IPv4 form.
+		{"4-in-6 RFC1918", "::ffff:192.168.1.1", "192.168.1.1"},
+		{"4-in-6 CGNAT", "::ffff:100.64.0.5", "100.64.0.5"},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			result := anonymizer.AnonymizeIP(netip.MustParseAddr(tc.ip))
+			assert.Equal(t, tc.expect, result.String(), "default level should preserve internal ranges except ULA")
+		})
+	}
+}
+
+func TestAnonymizeIP_StrictLevel(t *testing.T) {
+	anonymizer := anonymize.NewAnonymizer(anonymize.DefaultAddresses())
+	anonymizer.SetLevel(anonymize.LevelStrict)
+
+	// Order matters: internal pool addresses are assigned sequentially.
+	tests := []struct {
+		name   string
+		ip     string
+		expect string
+	}{
+		{"RFC1918 192.168/16", "192.168.1.1", "198.18.0.0"},
+		{"Second RFC1918", "192.168.1.2", "198.18.0.1"},
+		{"Repeated RFC1918", "192.168.1.1", "198.18.0.0"},
+		{"RFC1918 10/8", "10.1.2.3", "198.18.0.2"},
+		{"RFC1918 172.16/12", "172.16.5.5", "198.18.0.3"},
+		{"CGNAT", "100.64.0.5", "198.18.0.4"},
+		{"IPv4 link-local", "169.254.1.1", "198.18.0.5"},
+		{"Public IPv4 uses public pool", "1.2.3.4", "198.51.100.0"},
+		{"IPv6 link-local", "fe80::1", "2001:db8:1::"},
+		{"IPv6 ULA", "fd12:3456:789a::1", "2001:db8:1::1"},
+		{"Public IPv6 uses public pool", "2607:f8b0:4005:805::200e", "2001:db8:ffff::"},
+		{"Loopback IPv4", "127.0.0.1", "127.0.0.1"},
+		{"Loopback IPv6", "::1", "::1"},
+		{"Unspecified", "0.0.0.0", "0.0.0.0"},
+		{"Multicast", "224.0.0.251", "224.0.0.251"},
+		{"Well known resolver", "8.8.8.8", "8.8.8.8"},
+		{"Well known split marker", "128.0.0.0", "128.0.0.0"},
+		{"In internal pool range", "198.18.0.3", "198.18.0.3"},
+		{"In public pool range", "198.51.100.0", "198.51.100.0"},
+		{"4-in-6 repeated RFC1918", "::ffff:192.168.1.1", "198.18.0.0"},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			result := anonymizer.AnonymizeIP(netip.MustParseAddr(tc.ip))
+			assert.Equal(t, tc.expect, result.String(), "strict level should replace internal ranges from the internal pools")
+		})
+	}
+}
+
+func TestAnonymizeString_StrictInternalIPs(t *testing.T) {
+	anonymizer := anonymize.NewAnonymizer(anonymize.DefaultAddresses())
+	anonymizer.SetLevel(anonymize.LevelStrict)
+
+	input := "route 10.20.30.0/24 via 192.168.1.1 dev eth0 src 100.64.0.7"
+	firstPass := anonymizer.AnonymizeString(input)
+	secondPass := anonymizer.AnonymizeString(firstPass)
+
+	assert.NotContains(t, firstPass, "10.20.30.0", "private network address should be anonymized")
+	assert.NotContains(t, firstPass, "192.168.1.1", "private gateway should be anonymized")
+	assert.NotContains(t, firstPass, "100.64.0.7", "CGNAT address should be anonymized")
+	assert.Contains(t, firstPass, "/24", "prefix length should be preserved")
+	assert.Equal(t, firstPass, secondPass, "second pass should not further anonymize the string")
+}
+
+func TestAnonymizeMAC(t *testing.T) {
+	anonymizer := anonymize.NewAnonymizer(anonymize.DefaultAddresses())
+
+	first := anonymizer.AnonymizeMAC("aa:bb:cc:dd:ee:0f")
+	assert.Equal(t, "02:00:00:00:00:01", first, "first MAC should get the first placeholder")
+	assert.Equal(t, first, anonymizer.AnonymizeMAC("aa:bb:cc:dd:ee:0f"), "repeated MAC should map to the same placeholder")
+	assert.Equal(t, first, anonymizer.AnonymizeMAC("AA:BB:CC:DD:EE:0F"), "case should not affect the mapping")
+	assert.Equal(t, "02-00-00-00-00-01", anonymizer.AnonymizeMAC("AA-BB-CC-DD-EE-0F"), "dash form should keep its separator but share the mapping")
+
+	second := anonymizer.AnonymizeMAC("10:22:33:44:55:66")
+	assert.Equal(t, "02:00:00:00:00:02", second, "second distinct MAC should get the next placeholder")
+
+	tests := []struct {
+		name string
+		mac  string
+	}{
+		{"Broadcast", "ff:ff:ff:ff:ff:ff"},
+		{"IPv4 multicast", "01:00:5e:00:00:fb"},
+		{"IPv6 multicast", "33:33:00:00:00:01"},
+		{"All zero", "00:00:00:00:00:00"},
+		{"Assigned placeholder", "02:00:00:00:00:01"},
+		{"Invalid", "not-a-mac"},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			assert.Equal(t, tc.mac, anonymizer.AnonymizeMAC(tc.mac), "should be preserved")
+		})
+	}
+}
+
+func TestAnonymizeString_MACAddresses(t *testing.T) {
+	anonymizer := anonymize.NewAnonymizer(anonymize.DefaultAddresses())
+
+	tests := []struct {
+		name   string
+		input  string
+		expect string
+	}{
+		{
+			name:   "nftables ether rule",
+			input:  "ether saddr aa:bb:cc:dd:ee:ff drop",
+			expect: "ether saddr 02:00:00:00:00:01 drop",
+		},
+		{
+			name:   "Windows dash form",
+			input:  "Physical Address : AA-BB-CC-DD-EE-FF",
+			expect: "Physical Address : 02-00-00-00-00-01",
+		},
+		{
+			name:   "IPv6 address tail is not treated as MAC",
+			input:  "addr fe80:0:11:22:33:44:55:66 scope link",
+			expect: "addr fe80:0:11:22:33:44:55:66 scope link",
+		},
+		{
+			name:   "broadcast MAC preserved",
+			input:  "dst ff:ff:ff:ff:ff:ff type ARP",
+			expect: "dst ff:ff:ff:ff:ff:ff type ARP",
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			result := anonymizer.AnonymizeString(tc.input)
+			assert.Equal(t, tc.expect, result, "MAC addresses should be anonymized at every level")
+			assert.Equal(t, result, anonymizer.AnonymizeString(result), "second pass should not change the result")
+		})
+	}
+}
+
+func TestAnonymizeWGKey(t *testing.T) {
+	key := base64.StdEncoding.EncodeToString(bytes.Repeat([]byte{0x42}, 32))
+
+	t.Run("default level preserves keys", func(t *testing.T) {
+		anonymizer := anonymize.NewAnonymizer(anonymize.DefaultAddresses())
+		assert.Equal(t, key, anonymizer.AnonymizeWGKey(key), "default level should not touch WireGuard keys")
+	})
+
+	t.Run("strict level replaces keys", func(t *testing.T) {
+		anonymizer := anonymize.NewAnonymizer(anonymize.DefaultAddresses())
+		anonymizer.SetLevel(anonymize.LevelStrict)
+
+		anon := anonymizer.AnonymizeWGKey(key)
+		assert.NotEqual(t, key, anon, "strict level should replace the key")
+		assert.Regexp(t, `^[A-Za-z0-9+/]{43}=$`, anon, "placeholder should keep the WireGuard key shape")
+		assert.Equal(t, anon, anonymizer.AnonymizeWGKey(key), "repeated key should map to the same placeholder")
+		assert.Equal(t, anon, anonymizer.AnonymizeWGKey(anon), "an assigned placeholder should pass through unchanged")
+
+		assert.Equal(t, "not-a-key", anonymizer.AnonymizeWGKey("not-a-key"), "non-key values should be preserved")
+	})
+}
+
+func TestAnonymizeString_WGKeys(t *testing.T) {
+	key := base64.StdEncoding.EncodeToString(bytes.Repeat([]byte{0x42}, 32))
+	input := "peer " + key + " handshake completed"
+
+	t.Run("default level preserves keys", func(t *testing.T) {
+		anonymizer := anonymize.NewAnonymizer(anonymize.DefaultAddresses())
+		assert.Equal(t, input, anonymizer.AnonymizeString(input), "default level should not touch WireGuard keys in strings")
+	})
+
+	t.Run("strict level replaces keys", func(t *testing.T) {
+		anonymizer := anonymize.NewAnonymizer(anonymize.DefaultAddresses())
+		anonymizer.SetLevel(anonymize.LevelStrict)
+
+		firstPass := anonymizer.AnonymizeString(input)
+		assert.NotContains(t, firstPass, key, "the key should not survive strict anonymization")
+		assert.Equal(t, anonymizer.AnonymizeWGKey(key), extractKey(t, firstPass), "string replacement should be consistent with AnonymizeWGKey")
+		assert.Equal(t, firstPass, anonymizer.AnonymizeString(firstPass), "second pass should not change the result")
+	})
+}
+
+func extractKey(t *testing.T, logLine string) string {
+	t.Helper()
+	fields := strings.Fields(logLine)
+	require.Len(t, fields, 4, "log line should keep its structure")
+	return fields[1]
+}
+
+func TestAnonymizeDomain_StrictLevel(t *testing.T) {
+	anonymizer := anonymize.NewAnonymizer(anonymize.DefaultAddresses())
+	anonymizer.SetLevel(anonymize.LevelStrict)
+
+	t.Run("netbird peer name", func(t *testing.T) {
+		result := anonymizer.AnonymizeDomain("my-laptop.netbird.cloud")
+		assert.Regexp(t, `^peer-\d+\.netbird\.cloud$`, result, "peer name should be anonymized, suffix kept")
+		assert.NotContains(t, result, "my-laptop", "the peer name should not survive")
+		assert.Equal(t, result, anonymizer.AnonymizeDomain("my-laptop.netbird.cloud"), "repeated domain should map consistently")
+		assert.Equal(t, result, anonymizer.AnonymizeDomain(result), "an anonymized domain should pass through unchanged")
+	})
+
+	t.Run("bare netbird domain", func(t *testing.T) {
+		assert.Equal(t, "netbird.cloud", anonymizer.AnonymizeDomain("netbird.cloud"), "the bare protected suffix should be preserved")
+	})
+
+	t.Run("netbird infrastructure preserved", func(t *testing.T) {
+		assert.Equal(t, "api.netbird.io", anonymizer.AnonymizeDomain("api.netbird.io"),
+			"netbird.io hosts infrastructure, not peer names, and should stay readable")
+	})
+
+	t.Run("leading labels of other domains", func(t *testing.T) {
+		result := anonymizer.AnonymizeDomain("host1.corp.example.com")
+		assert.Regexp(t, `^host-\d+\.host-\d+\.anon-[a-zA-Z0-9]+\.domain$`, result, "every label should be anonymized")
+		for _, label := range []string{"host1", "corp", "example"} {
+			assert.NotContains(t, result, label, "no original label should survive")
+		}
+		assert.Equal(t, result, anonymizer.AnonymizeDomain("host1.corp.example.com"), "repeated domain should map consistently")
+	})
+
+	t.Run("same label maps consistently across domains", func(t *testing.T) {
+		first := anonymizer.AnonymizeDomain("shared.one.com")
+		second := anonymizer.AnonymizeDomain("shared.two.com")
+		assert.Equal(t, strings.Split(first, ".")[0], strings.Split(second, ".")[0], "the shared host label should get one placeholder")
+	})
+
+	t.Run("wildcard label preserved", func(t *testing.T) {
+		result := anonymizer.AnonymizeDomain("*.example.com")
+		assert.Regexp(t, `^\*\.anon-[a-zA-Z0-9]+\.domain$`, result, "the wildcard label should stay a wildcard")
+	})
+}
+
+func TestAnonymizeDomain_DefaultLevelKeepsPeerNames(t *testing.T) {
+	anonymizer := anonymize.NewAnonymizer(anonymize.DefaultAddresses())
+
+	assert.Equal(t, "my-laptop.netbird.cloud", anonymizer.AnonymizeDomain("my-laptop.netbird.cloud"),
+		"default level should preserve netbird FQDNs including the peer name")
+	assert.Regexp(t, `^sub\.anon-[a-zA-Z0-9]+\.domain$`, anonymizer.AnonymizeDomain("sub.example.com"),
+		"default level should keep subdomain labels")
+}
+
+func TestAnonymizeString_StrictPeerNames(t *testing.T) {
+	anonymizer := anonymize.NewAnonymizer(anonymize.DefaultAddresses())
+	anonymizer.SetLevel(anonymize.LevelStrict)
+
+	// Seed like the bundle generator does from the status: base first, then
+	// the full FQDN, so replacement must prefer the longer mapping.
+	anonBase := anonymizer.AnonymizeDomain("example.com")
+	anonPeer := anonymizer.AnonymizeDomain("peer1.netbird.cloud")
+	anonHost := anonymizer.AnonymizeDomain("host1.example.com")
+
+	logLine := "connected to peer1.netbird.cloud via host1.example.com endpoint"
+	firstPass := anonymizer.AnonymizeString(logLine)
+	assert.NotContains(t, firstPass, "peer1", "the peer name should not survive in logs")
+	assert.NotContains(t, firstPass, "host1", "the host label should not survive in logs")
+	assert.Contains(t, firstPass, anonPeer, "the seeded peer mapping should be applied")
+	assert.Contains(t, firstPass, anonHost, "the seeded host mapping should be applied, not just the base mapping")
+	assert.NotContains(t, firstPass, "host1."+anonBase, "the base mapping must not preempt the longer FQDN mapping")
+	assert.Equal(t, firstPass, anonymizer.AnonymizeString(firstPass), "second pass should not change the result")
+}
+
 func TestAnonymizeDNSLogLine(t *testing.T) {
 	anonymizer := anonymize.NewAnonymizer(netip.Addr{}, netip.Addr{})
 	tests := []struct {

client/cmd/debug.go

@@ -27,8 +27,8 @@ import (
 const errCloseConnection = "Failed to close connection: %v"
 
 var (
-	logFileCount        uint32
-	systemInfoFlag      bool
+	logFileCount             uint32
+	systemInfoFlag           bool
 	uploadBundleFlag         bool
 	uploadBundleURLFlag      string
 	uploadBundleInsecureFlag bool
@@ -156,6 +156,11 @@ func debugConfigDump(cmd *cobra.Command, _ []string) error {
 // request. Returns an error if the RPC fails or if the daemon reports
 // an upload failure reason.
 func debugBundle(cmd *cobra.Command, _ []string) error {
+	anonymizeEnabled, anonymizeLevel, err := effectiveAnonymize()
+	if err != nil {
+		return err
+	}
+
 	conn, err := getClient(cmd)
 	if err != nil {
 		return err
@@ -168,10 +173,11 @@ func debugBundle(cmd *cobra.Command, _ []string) error {
 
 	client := proto.NewDaemonServiceClient(conn)
 	request := &proto.DebugBundleRequest{
-		Anonymize:    anonymizeFlag,
-		SystemInfo:   systemInfoFlag,
-		LogFileCount: logFileCount,
-		CliVersion:   version.NetbirdVersion(),
+		Anonymize:      anonymizeEnabled,
+		AnonymizeLevel: anonymizeLevel.String(),
+		SystemInfo:     systemInfoFlag,
+		LogFileCount:   logFileCount,
+		CliVersion:     version.NetbirdVersion(),
 	}
 	if uploadBundleFlag {
 		request.UploadURL = uploadBundleURLFlag
@@ -229,6 +235,11 @@ func runForDuration(cmd *cobra.Command, args []string) error {
 		return fmt.Errorf("invalid duration format: %v", err)
 	}
 
+	anonymizeEnabled, anonymizeLevel, err := effectiveAnonymize()
+	if err != nil {
+		return err
+	}
+
 	conn, err := getClient(cmd)
 	if err != nil {
 		return err
@@ -368,10 +379,11 @@ func runForDuration(cmd *cobra.Command, args []string) error {
 	cmd.Println("Creating debug bundle...")
 
 	request := &proto.DebugBundleRequest{
-		Anonymize:    anonymizeFlag,
-		SystemInfo:   systemInfoFlag,
-		LogFileCount: logFileCount,
-		CliVersion:   version.NetbirdVersion(),
+		Anonymize:      anonymizeEnabled,
+		AnonymizeLevel: anonymizeLevel.String(),
+		SystemInfo:     systemInfoFlag,
+		LogFileCount:   logFileCount,
+		CliVersion:     version.NetbirdVersion(),
 	}
 	if uploadBundleFlag {
 		request.UploadURL = uploadBundleURLFlag

client/cmd/root.go

@@ -21,6 +21,7 @@ import (
 	"github.com/spf13/pflag"
 	"google.golang.org/grpc"
 
+	"github.com/netbirdio/netbird/client/anonymize"
 	daddr "github.com/netbirdio/netbird/client/internal/daemonaddr"
 	"github.com/netbirdio/netbird/client/internal/profilemanager"
 )
@@ -69,6 +70,7 @@ var (
 	autoConnectDisabled     bool
 	extraIFaceBlackList     []string
 	anonymizeFlag           bool
+	anonymizeLevelFlag      string
 	dnsRouteInterval        time.Duration
 	// lazyConnEnabled is the parse target for the deprecated --enable-lazy-connection
 	// flag. The flag is inert; the value is no longer read (use NB_LAZY_CONN instead).
@@ -156,7 +158,8 @@ func init() {
 	rootCmd.MarkFlagsMutuallyExclusive("setup-key", "setup-key-file")
 	rootCmd.PersistentFlags().StringVar(&preSharedKey, preSharedKeyFlag, "", "Sets WireGuard PreSharedKey property. If set, then only peers that have the same key can communicate.")
 	rootCmd.PersistentFlags().StringVarP(&hostName, "hostname", "n", "", "Sets a custom hostname for the device")
-	rootCmd.PersistentFlags().BoolVarP(&anonymizeFlag, "anonymize", "A", false, "anonymize IP addresses and non-netbird.io domains in logs and status output")
+	rootCmd.PersistentFlags().BoolVarP(&anonymizeFlag, "anonymize", "A", false, "anonymize public IP addresses, MAC addresses, and non-netbird.io domains in logs and status output; private, CGNAT, and link-local IP ranges are kept (see --anonymize-level strict)")
+	rootCmd.PersistentFlags().StringVar(&anonymizeLevelFlag, "anonymize-level", "", "anonymization level: \"default\" or \"strict\"; strict also anonymizes private, CGNAT, and link-local IP ranges, peer names, and WireGuard public keys. Setting this flag implies --anonymize")
 	rootCmd.PersistentFlags().StringVarP(&configPath, "config", "c", profilemanager.DefaultConfigPath, "Overrides the default profile file location")
 
 	rootCmd.AddCommand(upCmd)
@@ -293,6 +296,19 @@ var CLIBackOffSettings = &backoff.ExponentialBackOff{
 	Clock:               backoff.SystemClock,
 }
 
+// effectiveAnonymize resolves the --anonymize and --anonymize-level flags:
+// setting a level implies anonymization, and an invalid level is rejected.
+func effectiveAnonymize() (bool, anonymize.Level, error) {
+	if anonymizeLevelFlag == "" {
+		return anonymizeFlag, anonymize.LevelDefault, nil
+	}
+	level := anonymize.ParseLevel(anonymizeLevelFlag)
+	if !strings.EqualFold(anonymizeLevelFlag, level.String()) {
+		return false, anonymize.LevelDefault, fmt.Errorf("invalid anonymize level %q: use %q or %q", anonymizeLevelFlag, anonymize.LevelDefault.String(), anonymize.LevelStrict.String())
+	}
+	return true, level, nil
+}
+
 func getSetupKey() (string, error) {
 	if setupKeyPath != "" && setupKey == "" {
 		return getSetupKeyFromFile(setupKeyPath)

client/cmd/status.go

@@ -121,8 +121,14 @@ func statusFunc(cmd *cobra.Command, args []string) error {
 		sessionExpiresAt = ts.AsTime().UTC()
 	}
 
+	anonymizeEnabled, anonymizeLevel, err := effectiveAnonymize()
+	if err != nil {
+		return err
+	}
+
 	var outputInformationHolder = nbstatus.ConvertToStatusOutputOverview(resp.GetFullStatus(), nbstatus.ConvertOptions{
-		Anonymize:            anonymizeFlag,
+		Anonymize:            anonymizeEnabled,
+		AnonymizeLevel:       anonymizeLevel,
 		DaemonVersion:        resp.GetDaemonVersion(),
 		DaemonStatus:         nbstatus.ParseDaemonStatus(status),
 		StatusFilter:         statusFilter,

client/firewall/firewalld/firewalld.go

@@ -2,8 +2,8 @@
 // its wg interface into firewalld's "trusted" zone. This is required because
 // firewalld's nftables chains are created with NFT_CHAIN_OWNER on recent
 // versions, which returns EPERM to any other process that tries to insert
-// rules into them. The workaround mirrors what Tailscale does: let firewalld
-// itself add the accept rules to its own chains by trusting the interface.
+// rules into them. Trusting the interface makes firewalld itself add the
+// accept rules to its own chains instead.
 package firewalld
 
 // TrustedZone is the firewalld zone name used for interfaces whose traffic

client/firewall/iptables/acl_linux.go

@@ -42,11 +42,12 @@ type aclManager struct {
 	optionalEntries map[string][]entry
 	ipsetStore      *ipsetStore
 	v6              bool
+	ipsetSupport    *ipsetSupport
 
 	stateManager *statemanager.Manager
 }
 
-func newAclManager(iptablesClient *iptables.IPTables, wgIface iFaceMapper) (*aclManager, error) {
+func newAclManager(iptablesClient *iptables.IPTables, wgIface iFaceMapper, ipsetSupport *ipsetSupport) (*aclManager, error) {
 	return &aclManager{
 		iptablesClient:  iptablesClient,
 		wgIface:         wgIface,
@@ -54,6 +55,7 @@ func newAclManager(iptablesClient *iptables.IPTables, wgIface iFaceMapper) (*acl
 		optionalEntries: make(map[string][]entry),
 		ipsetStore:      newIpsetStore(),
 		v6:              iptablesClient.Proto() == iptables.ProtocolIPv6,
+		ipsetSupport:    ipsetSupport,
 	}, nil
 }
 
@@ -85,12 +87,77 @@ func (m *aclManager) AddPeerFiltering(
 	action firewall.Action,
 	ipsetName string,
 ) ([]firewall.Rule, error) {
-	chain := chainNameInputRules
+	ipsetName = m.resolveIPSetName(ipsetName, sPort, dPort, action)
+	if ipsetName == "" {
+		return m.addPeerRule(ip, protocol, sPort, dPort, action, "")
+	}
 
+	// A set that is already in the store backs rules installed earlier, so it must
+	// survive this call's failure.
+	_, preexisting := m.ipsetStore.ipset(ipsetName)
+
+	rules, err := m.addPeerRule(ip, protocol, sPort, dPort, action, ipsetName)
+	if err == nil {
+		return rules, nil
+	}
+
+	var unusable *ipsetUnusableError
+	if !errors.As(err, &unusable) {
+		return nil, err
+	}
+
+	// The set could not be created or matched. Drop the one this call created and
+	// retry the rule matching the IP directly; only if that succeeds do we know
+	// ipset was to blame and latch it off for subsequent rules.
+	if !preexisting {
+		m.discardIPSet(ipsetName)
+	}
+
+	rules, retryErr := m.addPeerRule(ip, protocol, sPort, dPort, action, "")
+	if retryErr != nil {
+		return nil, fmt.Errorf("add peer rule (ipset: %w): %w", unusable.cause, retryErr)
+	}
+
+	m.ipsetSupport.markUnsupported(unusable.cause)
+
+	return rules, nil
+}
+
+// resolveIPSetName derives the ipset name for a rule, returning "" when the rule
+// must match the IP directly: either no set was requested or ipset is unusable.
+func (m *aclManager) resolveIPSetName(ipsetName string, sPort, dPort *firewall.Port, action firewall.Action) string {
 	ipsetName = transformIPsetName(ipsetName, sPort, dPort, action)
-	if m.v6 && ipsetName != "" {
+	if ipsetName == "" || !m.ipsetSupport.supported() {
+		return ""
+	}
+
+	if m.v6 {
 		ipsetName += "-v6"
 	}
+
+	return ipsetName
+}
+
+// discardIPSet removes a set that turned out to be unusable, so a later rule
+// does not find it in the store and assume it works.
+func (m *aclManager) discardIPSet(ipsetName string) {
+	m.ipsetStore.deleteIpset(ipsetName)
+
+	if err := m.destroyIPSet(ipsetName); err != nil {
+		log.Debugf("destroy unusable ipset %s: %v", ipsetName, err)
+	}
+}
+
+func (m *aclManager) addPeerRule(
+	ip net.IP,
+	protocol firewall.Protocol,
+	sPort *firewall.Port,
+	dPort *firewall.Port,
+	action firewall.Action,
+	ipsetName string,
+) ([]firewall.Rule, error) {
+	chain := chainNameInputRules
+
 	proto := protoForFamily(protocol, m.v6)
 	specs := filterRuleSpecs(ip, proto, sPort, dPort, action, ipsetName)
 
@@ -105,7 +172,7 @@ func (m *aclManager) AddPeerFiltering(
 	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)
+				return nil, ipsetUnusable(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.
@@ -128,10 +195,10 @@ func (m *aclManager) AddPeerFiltering(
 			}
 		}
 		if err := m.createIPSet(ipsetName); err != nil {
-			return nil, fmt.Errorf("create ipset: %w", err)
+			return nil, ipsetUnusable(fmt.Errorf("create ipset: %w", err))
 		}
 		if err := m.addToIPSet(ipsetName, ip); err != nil {
-			return nil, fmt.Errorf("add IP to ipset: %w", err)
+			return nil, ipsetUnusable(fmt.Errorf("add IP to ipset: %w", err))
 		}
 
 		ipList := newIpList(ip.String())
@@ -140,7 +207,7 @@ func (m *aclManager) AddPeerFiltering(
 
 	ok, err := m.iptablesClient.Exists(tableFilter, chain, specs...)
 	if err != nil {
-		return nil, fmt.Errorf("failed to check rule: %w", err)
+		return nil, maybeIPSetUnusable(ipsetName, fmt.Errorf("check rule: %w", err))
 	}
 	if ok {
 		return nil, fmt.Errorf("rule already exists")
@@ -154,7 +221,7 @@ func (m *aclManager) AddPeerFiltering(
 		err = m.iptablesClient.Append(tableFilter, chain, specs...)
 	}
 	if err != nil {
-		return nil, err
+		return nil, maybeIPSetUnusable(ipsetName, err)
 	}
 
 	if err := m.iptablesClient.Append(tableMangle, chainRTPRE, mangleSpecs...); err != nil {

client/firewall/iptables/dnat_refcount_linux_test.go

@@ -0,0 +1,240 @@
+//go:build privileged
+
+package iptables
+
+import (
+	"net/netip"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"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/wgaddr"
+)
+
+func iptRefcountIfaceV4() *iFaceMock {
+	return &iFaceMock{
+		NameFunc: func() string { return "wt-refcount" },
+		AddressFunc: func() wgaddr.Address {
+			return wgaddr.Address{
+				IP:      netip.MustParseAddr("10.20.0.1"),
+				Network: netip.MustParsePrefix("10.20.0.0/24"),
+			}
+		},
+	}
+}
+
+func iptRefcountIfaceDual() *iFaceMock {
+	return &iFaceMock{
+		NameFunc: func() string { return "wt-refcount" },
+		AddressFunc: func() wgaddr.Address {
+			return wgaddr.Address{
+				IP:      netip.MustParseAddr("10.20.0.1"),
+				Network: netip.MustParsePrefix("10.20.0.0/24"),
+				IPv6:    netip.MustParseAddr("fd00::1"),
+				IPv6Net: netip.MustParsePrefix("fd00::/64"),
+			}
+		},
+	}
+}
+
+func newIptRefcountManager(t *testing.T, dual bool) *Manager {
+	t.Helper()
+	var ifMock *iFaceMock
+	if dual {
+		ifMock = iptRefcountIfaceDual()
+	} else {
+		ifMock = iptRefcountIfaceV4()
+	}
+	m, err := Create(ifMock, iface.DefaultMTU)
+	require.NoError(t, err, "create manager")
+	require.NoError(t, m.Init(nil), "init manager")
+	t.Cleanup(func() {
+		require.NoError(t, m.Close(nil), "close manager")
+	})
+	return m
+}
+
+func iptDnatV4(port uint16) fw.ForwardRule {
+	return fw.ForwardRule{
+		Protocol:          fw.ProtocolTCP,
+		DestinationPort:   fw.Port{Values: []uint16{port}},
+		TranslatedAddress: netip.MustParseAddr("10.20.0.2"),
+		TranslatedPort:    fw.Port{Values: []uint16{80}},
+	}
+}
+
+func iptDnatV6(port uint16) fw.ForwardRule {
+	return fw.ForwardRule{
+		Protocol:          fw.ProtocolTCP,
+		DestinationPort:   fw.Port{Values: []uint16{port}},
+		TranslatedAddress: netip.MustParseAddr("fd00::2"),
+		TranslatedPort:    fw.Port{Values: []uint16{80}},
+	}
+}
+
+// TestIptablesRouting_RepeatedEnableSingleReference verifies that EnableRouting
+// (called on every network-map update) holds at most one reference per family
+// and a single DisableRouting drops both back to zero.
+func TestIptablesRouting_RepeatedEnableSingleReference(t *testing.T) {
+	m := newIptRefcountManager(t, true)
+	state := m.router.ipFwdState
+
+	require.NoError(t, m.EnableRouting(), "first enable")
+	require.NoError(t, m.EnableRouting(), "second enable")
+	require.NoError(t, m.EnableRouting(), "third enable")
+	v4, v6 := state.Counts()
+	assert.Equal(t, 1, v4, "repeated enable holds a single v4 reference")
+	assert.Equal(t, 1, v6, "repeated enable holds a single v6 reference")
+
+	require.NoError(t, m.DisableRouting(), "disable")
+	v4, v6 = state.Counts()
+	assert.Equal(t, 0, v4, "single disable releases the v4 reference")
+	assert.Equal(t, 0, v6, "single disable releases the v6 reference")
+}
+
+// TestIptablesRouting_DisableKeepsDNATReference verifies that an unpaired
+// DisableRouting does not release references held by active DNAT rules.
+func TestIptablesRouting_DisableKeepsDNATReference(t *testing.T) {
+	m := newIptRefcountManager(t, true)
+	state := m.router.ipFwdState
+
+	r1, err := m.AddDNATRule(iptDnatV6(9095))
+	require.NoError(t, err, "add v6 dnat")
+
+	require.NoError(t, m.DisableRouting(), "unpaired disable")
+	_, v6 := state.Counts()
+	assert.Equal(t, 1, v6, "DNAT-held reference survives unpaired DisableRouting")
+
+	require.NoError(t, m.DeleteDNATRule(r1), "delete v6 dnat")
+	_, v6 = state.Counts()
+	assert.Equal(t, 0, v6, "delete releases the DNAT reference")
+}
+
+// TestIptablesDNAT_RefcountBalancedV4 covers a Balanced Add/Delete pair on v4.
+func TestIptablesDNAT_RefcountBalancedV4(t *testing.T) {
+	m := newIptRefcountManager(t, false)
+	state := m.router.ipFwdState
+
+	r1, err := m.AddDNATRule(iptDnatV4(7081))
+	require.NoError(t, err, "add v4 dnat 1")
+	v4, v6 := state.Counts()
+	assert.Equal(t, 1, v4, "v4 refcount after first add")
+	assert.Equal(t, 0, v6, "v6 refcount unchanged")
+
+	r2, err := m.AddDNATRule(iptDnatV4(7082))
+	require.NoError(t, err, "add v4 dnat 2")
+	v4, v6 = state.Counts()
+	assert.Equal(t, 2, v4, "v4 refcount after second add")
+	assert.Equal(t, 0, v6, "v6 refcount unchanged")
+
+	require.NoError(t, m.DeleteDNATRule(r1))
+	v4, v6 = state.Counts()
+	assert.Equal(t, 1, v4, "v4 refcount after first delete")
+	assert.Equal(t, 0, v6, "v6 refcount unchanged")
+
+	require.NoError(t, m.DeleteDNATRule(r2))
+	v4, v6 = state.Counts()
+	assert.Equal(t, 0, v4, "v4 refcount after second delete")
+	assert.Equal(t, 0, v6, "v6 refcount unchanged")
+}
+
+// TestIptablesDNAT_RefcountBalancedV6 checks the v6 path increments v6 only and
+// decrements back to zero.
+func TestIptablesDNAT_RefcountBalancedV6(t *testing.T) {
+	m := newIptRefcountManager(t, true)
+	require.NotNil(t, m.router6, "v6 router")
+	require.Same(t, m.router.ipFwdState, m.router6.ipFwdState, "shared state")
+	state := m.router.ipFwdState
+
+	r1, err := m.AddDNATRule(iptDnatV6(9081))
+	require.NoError(t, err, "add v6 dnat 1")
+	v4, v6 := state.Counts()
+	assert.Equal(t, 0, v4)
+	assert.Equal(t, 1, v6, "v6 refcount after first add")
+
+	r2, err := m.AddDNATRule(iptDnatV6(9082))
+	require.NoError(t, err, "add v6 dnat 2")
+	v4, v6 = state.Counts()
+	assert.Equal(t, 0, v4, "v4 refcount unchanged")
+	assert.Equal(t, 2, v6, "v6 refcount after second add")
+
+	require.NoError(t, m.DeleteDNATRule(r1))
+	v4, v6 = state.Counts()
+	assert.Equal(t, 0, v4, "v4 refcount unchanged")
+	assert.Equal(t, 1, v6, "v6 refcount after first delete")
+
+	require.NoError(t, m.DeleteDNATRule(r2))
+	v4, v6 = state.Counts()
+	assert.Equal(t, 0, v4)
+	assert.Equal(t, 0, v6, "v6 refcount after second delete")
+}
+
+// TestIptablesDNAT_DuplicateAddNoLeak verifies the duplicate-rule path returns
+// without bumping the refcount.
+func TestIptablesDNAT_DuplicateAddNoLeak(t *testing.T) {
+	m := newIptRefcountManager(t, true)
+	state := m.router.ipFwdState
+
+	rule := iptDnatV4(7083)
+	r1, err := m.AddDNATRule(rule)
+	require.NoError(t, err)
+	v4, _ := state.Counts()
+	assert.Equal(t, 1, v4)
+
+	_, err = m.AddDNATRule(rule)
+	require.NoError(t, err, "duplicate add")
+	v4, _ = state.Counts()
+	assert.Equal(t, 1, v4, "duplicate add must not increment")
+
+	require.NoError(t, m.DeleteDNATRule(r1))
+	v4, _ = state.Counts()
+	assert.Equal(t, 0, v4, "single delete must drop to zero")
+}
+
+// TestIptablesDNAT_DeleteMissingNoUnderflow verifies Delete on an unknown rule
+// neither errors nor releases the refcount.
+func TestIptablesDNAT_DeleteMissingNoUnderflow(t *testing.T) {
+	m := newIptRefcountManager(t, true)
+	state := m.router.ipFwdState
+
+	phantom := iptDnatV4(7099)
+	require.NoError(t, m.DeleteDNATRule(&phantom), "delete missing v4")
+	v4, v6 := state.Counts()
+	assert.Equal(t, 0, v4)
+	assert.Equal(t, 0, v6)
+
+	phantom6 := iptDnatV6(9099)
+	require.NoError(t, m.DeleteDNATRule(&phantom6), "delete missing v6")
+	v4, v6 = state.Counts()
+	assert.Equal(t, 0, v4)
+	assert.Equal(t, 0, v6)
+
+	r1, err := m.AddDNATRule(iptDnatV4(7100))
+	require.NoError(t, err)
+	v4, _ = state.Counts()
+	assert.Equal(t, 1, v4, "real add still increments after phantom delete")
+	require.NoError(t, m.DeleteDNATRule(r1))
+}
+
+// TestIptablesDNAT_DoubleDeleteNoUnderflow verifies a second Delete on the same
+// rule is a no-op.
+func TestIptablesDNAT_DoubleDeleteNoUnderflow(t *testing.T) {
+	m := newIptRefcountManager(t, true)
+	state := m.router.ipFwdState
+
+	r1, err := m.AddDNATRule(iptDnatV6(9083))
+	require.NoError(t, err)
+	_, v6 := state.Counts()
+	assert.Equal(t, 1, v6)
+
+	require.NoError(t, m.DeleteDNATRule(r1), "first delete")
+	_, v6 = state.Counts()
+	assert.Equal(t, 0, v6)
+
+	require.NoError(t, m.DeleteDNATRule(r1), "second delete must be no-op")
+	_, v6 = state.Counts()
+	assert.Equal(t, 0, v6, "double delete must not underflow")
+}

client/firewall/iptables/ipset_support_linux.go

@@ -0,0 +1,75 @@
+package iptables
+
+import (
+	"sync"
+
+	log "github.com/sirupsen/logrus"
+)
+
+// ipsetSupport tracks whether ipset-backed firewall rules can be installed.
+//
+// It starts optimistic and latches to unsupported the first time the kernel
+// proves otherwise: either the hash:net set type is missing (ip_set_hash_net) or
+// iptables cannot match against a set (xt_set). Callers then emit per-IP and
+// per-prefix rules instead. Without the fallback, a rule referencing an unusable
+// set is never installed and the catch-all DROP silently blocks traffic the
+// policy permits.
+//
+// One instance is shared by the ACL managers and routers of both address
+// families, because ipset availability is a property of the kernel rather than
+// of any single table.
+type ipsetSupport struct {
+	mu          sync.RWMutex
+	unsupported bool
+}
+
+func newIPSetSupport() *ipsetSupport {
+	return &ipsetSupport{}
+}
+
+func (s *ipsetSupport) supported() bool {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+
+	return !s.unsupported
+}
+
+// markUnsupported records that ipset cannot be used, logging the reason once.
+func (s *ipsetSupport) markUnsupported(cause error) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	if s.unsupported {
+		return
+	}
+	s.unsupported = true
+
+	log.Warnf("ipset is unavailable (%v); falling back to per-IP firewall rules. "+
+		"Ensure the kernel provides ip_set_hash_net and xt_set; without them rule "+
+		"sets are larger and slower to converge on networks with many peers", cause)
+}
+
+// ipsetUnusableError marks a failure attributable to ipset, so the caller can
+// retry the same rule in its per-IP form before latching the capability off.
+type ipsetUnusableError struct {
+	cause error
+}
+
+func (e *ipsetUnusableError) Error() string { return e.cause.Error() }
+
+func (e *ipsetUnusableError) Unwrap() error { return e.cause }
+
+func ipsetUnusable(cause error) error {
+	return &ipsetUnusableError{cause: cause}
+}
+
+// maybeIPSetUnusable marks an iptables failure as ipset-attributable only when the
+// rule actually carried a set match, since the same call can fail for unrelated
+// reasons on a rule that matches addresses directly.
+func maybeIPSetUnusable(ipsetName string, err error) error {
+	if ipsetName == "" {
+		return err
+	}
+
+	return ipsetUnusable(err)
+}

client/firewall/iptables/manager_linux.go

@@ -33,6 +33,10 @@ type Manager struct {
 	router       *router
 	rawSupported bool
 
+	// ipsetSupport is shared by the ACL managers and routers of both families,
+	// so a kernel without usable ipset support degrades them together.
+	ipsetSupport *ipsetSupport
+
 	// IPv6 counterparts, nil when no v6 overlay
 	ipv6Client *iptables.IPTables
 	aclMgr6    *aclManager
@@ -53,16 +57,17 @@ func Create(wgIface iFaceMapper, mtu uint16) (*Manager, error) {
 	}
 
 	m := &Manager{
-		wgIface:    wgIface,
-		ipv4Client: iptablesClient,
+		wgIface:      wgIface,
+		ipv4Client:   iptablesClient,
+		ipsetSupport: newIPSetSupport(),
 	}
 
-	m.router, err = newRouter(iptablesClient, wgIface, mtu)
+	m.router, err = newRouter(iptablesClient, wgIface, mtu, m.ipsetSupport)
 	if err != nil {
 		return nil, fmt.Errorf("create router: %w", err)
 	}
 
-	m.aclMgr, err = newAclManager(iptablesClient, wgIface)
+	m.aclMgr, err = newAclManager(iptablesClient, wgIface, m.ipsetSupport)
 	if err != nil {
 		return nil, fmt.Errorf("create acl manager: %w", err)
 	}
@@ -83,16 +88,16 @@ func (m *Manager) createIPv6Components(wgIface iFaceMapper, mtu uint16) error {
 	}
 	m.ipv6Client = ip6Client
 
-	m.router6, err = newRouter(ip6Client, wgIface, mtu)
+	m.router6, err = newRouter(ip6Client, wgIface, mtu, m.ipsetSupport)
 	if err != nil {
 		return fmt.Errorf("create v6 router: %w", err)
 	}
 
 	// Share the same IP forwarding state with the v4 router, since
-	// EnableIPForwarding controls both v4 and v6 sysctls.
+	// Forwarding refcounter is per-family but shared between v4 and v6 routers.
 	m.router6.ipFwdState = m.router.ipFwdState
 
-	m.aclMgr6, err = newAclManager(ip6Client, wgIface)
+	m.aclMgr6, err = newAclManager(ip6Client, wgIface, m.ipsetSupport)
 	if err != nil {
 		return fmt.Errorf("create v6 acl manager: %w", err)
 	}
@@ -402,17 +407,12 @@ func (m *Manager) SetLogLevel(log.Level) {
 }
 
 func (m *Manager) EnableRouting() error {
-	if err := m.router.ipFwdState.RequestForwarding(); err != nil {
-		return fmt.Errorf("enable IP forwarding: %w", err)
-	}
-	return nil
+	// v6 only when the overlay actually has v6.
+	return m.router.ipFwdState.RequestRouting(m.router6 != nil)
 }
 
 func (m *Manager) DisableRouting() error {
-	if err := m.router.ipFwdState.ReleaseForwarding(); err != nil {
-		return fmt.Errorf("disable IP forwarding: %w", err)
-	}
-	return nil
+	return m.router.ipFwdState.ReleaseRouting()
 }
 
 // AddDNATRule adds a DNAT rule

client/firewall/iptables/manager_linux_test.go

@@ -291,3 +291,98 @@ func TestIptablesCreatePerformance(t *testing.T) {
 		})
 	}
 }
+
+// newACLTestManager returns a started manager. Create()/Init() is used so the
+// router-owned chains (chainRTFWDIN/OUT) exist before the ACL manager's
+// createDefaultChains() references them.
+func newACLTestManager(t *testing.T) *Manager {
+	t.Helper()
+
+	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))
+	})
+
+	return manager
+}
+
+// TestIptablesACLUsesIPSetOnHealthyKernel guards the default: on a kernel that
+// does have ipset, rules must keep matching a set. A regression that reported
+// ipset as unusable would silently move every Linux client to per-IP rules.
+func TestIptablesACLUsesIPSetOnHealthyKernel(t *testing.T) {
+	ipv4Client, err := iptables.NewWithProtocol(iptables.ProtocolIPv4)
+	require.NoError(t, err)
+
+	manager := newACLTestManager(t)
+
+	ip := netip.MustParseAddr("10.20.0.42")
+	port := &fw.Port{Values: []uint16{22}}
+
+	rules, err := manager.aclMgr.AddPeerFiltering(nil, ip.AsSlice(), "tcp", nil, port, fw.ActionAccept, "nb0000001")
+	require.NoError(t, err)
+	require.NotEmpty(t, rules)
+
+	rule := rules[0].(*Rule)
+	require.Equal(t, "nb0000001-dport", rule.ipsetName, "healthy kernel must use an ipset")
+	require.Contains(t, rule.specs, "--match-set")
+	require.True(t, manager.ipsetSupport.supported(), "ipset must not be latched off on a healthy kernel")
+
+	checkRuleSpecs(t, ipv4Client, rule.chain, true, rule.specs...)
+}
+
+// TestIptablesACLFallsBackWhenIPSetUnusable drives the real failure path: an
+// oversized set name is rejected by the kernel, which stands in for a kernel
+// without ip_set_hash_net or xt_set. The rule must still land in the chain,
+// matching the IP directly, and the capability must latch off so later rules skip
+// ipset. Before the fallback existed, the rule was dropped and the catch-all DROP
+// silently blocked traffic the policy permits.
+func TestIptablesACLFallsBackWhenIPSetUnusable(t *testing.T) {
+	ipv4Client, err := iptables.NewWithProtocol(iptables.ProtocolIPv4)
+	require.NoError(t, err)
+
+	manager := newACLTestManager(t)
+
+	// ipset names are limited to 31 characters, so creating this set fails.
+	unusableName := strings.Repeat("a", 40)
+
+	ip := netip.MustParseAddr("10.20.0.42")
+	port := &fw.Port{Values: []uint16{22}}
+
+	rules, err := manager.aclMgr.AddPeerFiltering(nil, ip.AsSlice(), "tcp", nil, port, fw.ActionAccept, unusableName)
+	require.NoError(t, err, "AddPeerFiltering must succeed by falling back")
+	require.NotEmpty(t, rules)
+
+	rule := rules[0].(*Rule)
+	require.Empty(t, rule.ipsetName, "fallback rule must not reference an ipset")
+	require.Contains(t, strings.Join(rule.specs, " "), "-s 10.20.0.42", "fallback rule must match the source IP")
+	require.NotContains(t, strings.Join(rule.specs, " "), "--match-set")
+
+	// The rule must actually be present, not silently missing.
+	checkRuleSpecs(t, ipv4Client, rule.chain, true, rule.specs...)
+
+	require.False(t, manager.ipsetSupport.supported(), "failure must latch ipset off")
+
+	// A subsequent rule with a perfectly valid set name now skips ipset too.
+	next, err := manager.aclMgr.AddPeerFiltering(nil, netip.MustParseAddr("10.20.0.43").AsSlice(), "tcp", nil, port, fw.ActionAccept, "nb0000001")
+	require.NoError(t, err)
+	require.NotEmpty(t, next)
+	require.Empty(t, next[0].(*Rule).ipsetName, "later rules must skip ipset once latched")
+}
+
+// TestIptablesACLLeavesNoIPSetAfterFallback verifies the set created before the
+// failure is destroyed, so a later rule does not find a half-built set and assume
+// ipset works.
+func TestIptablesACLLeavesNoIPSetAfterFallback(t *testing.T) {
+	manager := newACLTestManager(t)
+
+	port := &fw.Port{Values: []uint16{22}}
+	ip := netip.MustParseAddr("10.20.0.42")
+
+	_, err := manager.aclMgr.AddPeerFiltering(nil, ip.AsSlice(), "tcp", nil, port, fw.ActionAccept, strings.Repeat("a", 40))
+	require.NoError(t, err)
+
+	_, exists := manager.aclMgr.ipsetStore.ipset(strings.Repeat("a", 40) + "-dport")
+	require.False(t, exists, "unusable set must not stay in the store")
+}

client/firewall/iptables/router_linux.go

@@ -3,6 +3,7 @@
 package iptables
 
 import (
+	"errors"
 	"fmt"
 	"maps"
 	"net/netip"
@@ -51,6 +52,10 @@ const (
 	markManglePost = "mark-mangle-post"
 	matchSet       = "--match-set"
 
+	// routeSourceSuffix names the extra rules a route ACL needs when ipset is
+	// unusable and each source prefix has to be matched by its own rule.
+	routeSourceSuffix = "_src"
+
 	dnatSuffix = "_dnat"
 	snatSuffix = "_snat"
 	fwdSuffix  = "_fwd"
@@ -68,7 +73,6 @@ type ruleInfo struct {
 }
 
 type routeFilteringRuleParams struct {
-	Source      firewall.Network
 	Destination firewall.Network
 	Proto       firewall.Protocol
 	SPort       *firewall.Port
@@ -90,19 +94,21 @@ type router struct {
 	legacyManagement bool
 	mtu              uint16
 	v6               bool
+	ipsetSupport     *ipsetSupport
 
 	stateManager *statemanager.Manager
 	ipFwdState   *ipfwdstate.IPForwardingState
 }
 
-func newRouter(iptablesClient *iptables.IPTables, wgIface iFaceMapper, mtu uint16) (*router, error) {
+func newRouter(iptablesClient *iptables.IPTables, wgIface iFaceMapper, mtu uint16, ipsetSupport *ipsetSupport) (*router, error) {
 	r := &router{
 		iptablesClient: iptablesClient,
 		rules:          make(map[string][]string),
 		wgIface:        wgIface,
 		mtu:            mtu,
 		v6:             iptablesClient.Proto() == iptables.ProtocolIPv6,
-		ipFwdState:     ipfwdstate.NewIPForwardingState(),
+		ipFwdState:     ipfwdstate.NewIPForwardingState(wgIface.Name()),
+		ipsetSupport:   ipsetSupport,
 	}
 
 	r.ipsetCounter = refcounter.New(
@@ -151,15 +157,7 @@ func (r *router) AddRouteFiltering(
 		return ruleKey, nil
 	}
 
-	var source firewall.Network
-	if len(sources) > 1 {
-		source.Set = firewall.NewPrefixSet(sources)
-	} else if len(sources) > 0 {
-		source.Prefix = sources[0]
-	}
-
 	params := routeFilteringRuleParams{
-		Source:      source,
 		Destination: destination,
 		Proto:       proto,
 		SPort:       sPort,
@@ -167,30 +165,156 @@ func (r *router) AddRouteFiltering(
 		Action:      action,
 	}
 
-	rule, err := r.genRouteRuleSpec(params, sources)
-	if err != nil {
-		return nil, fmt.Errorf("generate route rule spec: %w", err)
-	}
+	err := r.installRouteRules(string(ruleKey), params, sources, r.ipsetSupport.supported())
 
-	// Insert DROP rules at the beginning, append ACCEPT rules at the end
-	if action == firewall.ActionDrop {
-		// after the established rule
-		err = r.iptablesClient.Insert(tableFilter, chainRTFWDIN, 2, rule...)
-	} else {
-		err = r.iptablesClient.Append(tableFilter, chainRTFWDIN, rule...)
+	var unusable *ipsetUnusableError
+	if errors.As(err, &unusable) {
+		// The set could not be created or matched. Retry matching each source
+		// prefix on its own; only if that works do we know ipset was to blame.
+		r.removeRouteRules(string(ruleKey))
+
+		if retryErr := r.installRouteRules(string(ruleKey), params, sources, false); retryErr != nil {
+			r.removeRouteRules(string(ruleKey))
+			return nil, fmt.Errorf("add route rule (ipset: %w): %w", unusable.cause, retryErr)
+		}
+
+		r.ipsetSupport.markUnsupported(unusable.cause)
+		err = nil
 	}
 
 	if err != nil {
-		return nil, fmt.Errorf("add route rule: %v", err)
-	}
+		// Leave nothing half-installed: a later call finding the rule key would
+		// report success while some sources were never installed, which for a
+		// drop rule would leave them unblocked.
+		r.removeRouteRules(string(ruleKey))
 
-	r.rules[string(ruleKey)] = rule
+		return nil, fmt.Errorf("add route rule: %w", err)
+	}
 
 	r.updateState()
 
 	return ruleKey, nil
 }
 
+// installRouteRules installs every rule needed for one route ACL and records them
+// under ruleKey. It is more than one rule only when useIPSet is false and the
+// sources have to be matched one prefix at a time.
+func (r *router) installRouteRules(ruleKey string, params routeFilteringRuleParams, sources []netip.Prefix, useIPSet bool) error {
+	specs, err := r.genRouteRuleSpecs(params, sources, useIPSet)
+	if err != nil {
+		return fmt.Errorf("generate route rule spec: %w", err)
+	}
+
+	for i, spec := range specs {
+		if err := r.insertRouteRule(params.Action, spec); err != nil {
+			if len(r.findSets(spec)) > 0 {
+				return ipsetUnusable(err)
+			}
+			return err
+		}
+		r.rules[routeRuleKey(ruleKey, i)] = spec
+	}
+
+	return nil
+}
+
+// genRouteRuleSpecs builds the rules for one route ACL. With ipset available that
+// is a single rule matching a set of sources; without it, one rule per source
+// prefix, which is the only form a stripped kernel can express.
+func (r *router) genRouteRuleSpecs(params routeFilteringRuleParams, sources []netip.Prefix, useIPSet bool) ([][]string, error) {
+	destExp, err := r.applyNetwork("-d", params.Destination, nil)
+	if err != nil {
+		return nil, fmt.Errorf("apply network -d: %w", err)
+	}
+
+	specs, err := r.genSourceRules(params, sources, useIPSet, destExp)
+	if err != nil {
+		// The destination match may have taken a set reference already.
+		if decErr := r.decrementSetCounter(destExp); decErr != nil {
+			log.Debugf("release destination set after failed rule generation: %v", decErr)
+		}
+
+		return nil, err
+	}
+
+	return specs, nil
+}
+
+func (r *router) genSourceRules(params routeFilteringRuleParams, sources []netip.Prefix, useIPSet bool, destExp []string) ([][]string, error) {
+	if useIPSet || len(sources) <= 1 {
+		sourceExp, err := r.applyNetwork("-s", sourceNetwork(sources), sources)
+		if err != nil {
+			return nil, fmt.Errorf("apply network -s: %w", err)
+		}
+
+		return [][]string{assembleRouteRule(sourceExp, destExp, params, r.v6)}, nil
+	}
+
+	specs := make([][]string, 0, len(sources))
+	for _, source := range sources {
+		sourceExp, err := r.applyNetwork("-s", firewall.Network{Prefix: source}, nil)
+		if err != nil {
+			return nil, fmt.Errorf("apply network -s: %w", err)
+		}
+
+		specs = append(specs, assembleRouteRule(sourceExp, destExp, params, r.v6))
+	}
+
+	return specs, nil
+}
+
+func sourceNetwork(sources []netip.Prefix) firewall.Network {
+	var source firewall.Network
+	if len(sources) > 1 {
+		source.Set = firewall.NewPrefixSet(sources)
+	} else if len(sources) > 0 {
+		source.Prefix = sources[0]
+	}
+
+	return source
+}
+
+func (r *router) insertRouteRule(action firewall.Action, spec []string) error {
+	// Insert DROP rules at the beginning, append ACCEPT rules at the end
+	if action == firewall.ActionDrop {
+		// after the established rule
+		return r.iptablesClient.Insert(tableFilter, chainRTFWDIN, 2, spec...)
+	}
+
+	return r.iptablesClient.Append(tableFilter, chainRTFWDIN, spec...)
+}
+
+// removeRouteRules deletes the rules recorded for ruleKey, used to undo a partial
+// install before retrying without ipset.
+func (r *router) removeRouteRules(ruleKey string) {
+	for i := 0; ; i++ {
+		key := routeRuleKey(ruleKey, i)
+		spec, exists := r.rules[key]
+		if !exists {
+			return
+		}
+
+		if err := r.iptablesClient.DeleteIfExists(tableFilter, chainRTFWDIN, spec...); err != nil {
+			log.Debugf("delete partial route rule %s: %v", key, err)
+		}
+		delete(r.rules, key)
+
+		if err := r.decrementSetCounter(spec); err != nil {
+			log.Debugf("decrement ipset counter for %s: %v", key, err)
+		}
+	}
+}
+
+// routeRuleKey names the i-th rule of a route ACL. The first keeps the plain rule
+// key so single-rule ACLs, which is every ACL when ipset works, are unaffected.
+func routeRuleKey(ruleKey string, i int) string {
+	if i == 0 {
+		return ruleKey
+	}
+
+	return fmt.Sprintf("%s%s%d", ruleKey, routeSourceSuffix, i)
+}
+
 func (r *router) hasRule(id string) bool {
 	_, ok := r.rules[id]
 	return ok
@@ -199,17 +323,29 @@ func (r *router) hasRule(id string) bool {
 func (r *router) DeleteRouteRule(rule firewall.Rule) error {
 	ruleKey := rule.ID()
 
-	if rule, exists := r.rules[ruleKey]; exists {
+	if _, exists := r.rules[ruleKey]; !exists {
+		log.Debugf("route rule %s not found", ruleKey)
+		r.updateState()
+
+		return nil
+	}
+
+	// In the ipset fallback one ACL is several rules, one per source prefix.
+	for i := 0; ; i++ {
+		key := routeRuleKey(ruleKey, i)
+		rule, exists := r.rules[key]
+		if !exists {
+			break
+		}
+
 		if err := r.iptablesClient.Delete(tableFilter, chainRTFWDIN, rule...); err != nil {
 			return fmt.Errorf("delete route rule: %v", err)
 		}
-		delete(r.rules, ruleKey)
+		delete(r.rules, key)
 
 		if err := r.decrementSetCounter(rule); err != nil {
 			return fmt.Errorf("decrement ipset counter: %w", err)
 		}
-	} else {
-		log.Debugf("route rule %s not found", ruleKey)
 	}
 
 	r.updateState()
@@ -770,10 +906,6 @@ func (r *router) updateState() {
 }
 
 func (r *router) AddDNATRule(rule firewall.ForwardRule) (firewall.Rule, error) {
-	if err := r.ipFwdState.RequestForwarding(); err != nil {
-		return nil, err
-	}
-
 	ruleKey := rule.ID()
 	if _, exists := r.rules[ruleKey+dnatSuffix]; exists {
 		return rule, nil
@@ -840,18 +972,34 @@ func (r *router) AddDNATRule(rule firewall.ForwardRule) (firewall.Rule, error) {
 
 	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.cleanupFailedDNATAdd(rules)
 			return nil, fmt.Errorf("add rule %s: %w", key, err)
 		}
 		r.rules[key] = ruleInfo.rule
 	}
 
+	if err := r.ipFwdState.RequestForwarding(r.v6); err != nil {
+		r.cleanupFailedDNATAdd(rules)
+		return nil, fmt.Errorf("enable forwarding: %w", err)
+	}
+
 	r.updateState()
 	return rule, nil
 }
 
+// cleanupFailedDNATAdd removes the bookkeeping written by a partially applied
+// AddDNATRule before rolling back the kernel rules, so no entries remain that
+// never got a forwarding refcount. rollbackRules re-adds entries it failed to
+// remove from the kernel.
+func (r *router) cleanupFailedDNATAdd(rules map[string]ruleInfo) {
+	for key := range rules {
+		delete(r.rules, key)
+	}
+	if err := r.rollbackRules(rules); err != nil {
+		log.Errorf("rollback failed: %v", err)
+	}
+}
+
 func (r *router) rollbackRules(rules map[string]ruleInfo) error {
 	var merr *multierror.Error
 	for key, ruleInfo := range rules {
@@ -868,63 +1016,70 @@ func (r *router) rollbackRules(rules map[string]ruleInfo) error {
 }
 
 func (r *router) DeleteDNATRule(rule firewall.Rule) error {
-	if err := r.ipFwdState.ReleaseForwarding(); err != nil {
-		log.Errorf("%v", err)
-	}
-
 	ruleKey := rule.ID()
 
+	_, hadDNAT := r.rules[ruleKey+dnatSuffix]
+	_, hadSNAT := r.rules[ruleKey+snatSuffix]
+	_, hadFWD := r.rules[ruleKey+fwdSuffix]
+	if !hadDNAT && !hadSNAT && !hadFWD {
+		return nil
+	}
+
 	var merr *multierror.Error
 	if dnatRule, exists := r.rules[ruleKey+dnatSuffix]; exists {
 		if err := r.iptablesClient.Delete(tableNat, chainRTRDR, dnatRule...); err != nil {
 			merr = multierror.Append(merr, fmt.Errorf("delete DNAT rule: %w", err))
+		} else {
+			delete(r.rules, ruleKey+dnatSuffix)
 		}
-		delete(r.rules, ruleKey+dnatSuffix)
 	}
 
 	if snatRule, exists := r.rules[ruleKey+snatSuffix]; exists {
 		if err := r.iptablesClient.Delete(tableNat, chainRTNAT, snatRule...); err != nil {
 			merr = multierror.Append(merr, fmt.Errorf("delete SNAT rule: %w", err))
+		} else {
+			delete(r.rules, ruleKey+snatSuffix)
 		}
-		delete(r.rules, ruleKey+snatSuffix)
 	}
 
 	if fwdRule, exists := r.rules[ruleKey+fwdSuffix]; exists {
 		if err := r.iptablesClient.Delete(tableFilter, chainRTFWDOUT, fwdRule...); err != nil {
 			merr = multierror.Append(merr, fmt.Errorf("delete forward rule: %w", err))
+		} else {
+			delete(r.rules, ruleKey+fwdSuffix)
+		}
+	}
+
+	// Release the refcount only once all rules are gone from the kernel. On
+	// partial failure the failed entries stay in r.rules so a retry can remove
+	// them and release then.
+	if merr == nil {
+		if err := r.ipFwdState.ReleaseForwarding(r.v6); err != nil {
+			log.Errorf("%v", err)
 		}
-		delete(r.rules, ruleKey+fwdSuffix)
 	}
 
 	r.updateState()
 	return nberrors.FormatErrorOrNil(merr)
 }
 
-func (r *router) genRouteRuleSpec(params routeFilteringRuleParams, sources []netip.Prefix) ([]string, error) {
+// assembleRouteRule joins the pre-built source and destination matches with the
+// protocol, ports and target of a route ACL.
+func assembleRouteRule(sourceExp, destExp []string, params routeFilteringRuleParams, v6 bool) []string {
 	var rule []string
 
-	sourceExp, err := r.applyNetwork("-s", params.Source, sources)
-	if err != nil {
-		return nil, fmt.Errorf("apply network -s: %w", err)
-
-	}
-	destExp, err := r.applyNetwork("-d", params.Destination, nil)
-	if err != nil {
-		return nil, fmt.Errorf("apply network -d: %w", err)
-	}
-
 	rule = append(rule, sourceExp...)
 	rule = append(rule, destExp...)
 
 	if params.Proto != firewall.ProtocolALL {
-		rule = append(rule, "-p", strings.ToLower(protoForFamily(params.Proto, r.v6)))
+		rule = append(rule, "-p", strings.ToLower(protoForFamily(params.Proto, v6)))
 		rule = append(rule, applyPort("--sport", params.SPort)...)
 		rule = append(rule, applyPort("--dport", params.DPort)...)
 	}
 
 	rule = append(rule, "-j", actionToStr(params.Action))
 
-	return rule, nil
+	return rule
 }
 
 func (r *router) applyNetwork(flag string, network firewall.Network, prefixes []netip.Prefix) ([]string, error) {
@@ -934,9 +1089,17 @@ func (r *router) applyNetwork(flag string, network firewall.Network, prefixes []
 	}
 
 	if network.IsSet() {
+		// A destination set is populated later from DNS results, so unlike a
+		// source set it cannot be expanded into per-prefix rules here. Without
+		// ipset such a rule is not expressible; report it instead of installing
+		// something broader than the policy allows.
+		if flag == "-d" && !r.ipsetSupport.supported() {
+			return nil, fmt.Errorf("destination set %s requires ipset (ip_set_hash_net and xt_set)", network.Set.HashedName())
+		}
+
 		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 nil, ipsetUnusable(fmt.Errorf("create or get ipset: %w", err))
 		}
 
 		return []string{"-m", "set", matchSet, name, direction}, nil

client/firewall/iptables/router_linux_test.go

@@ -3,9 +3,11 @@
 package iptables
 
 import (
+	"errors"
 	"fmt"
 	"net/netip"
 	"os/exec"
+	"strings"
 	"testing"
 
 	"github.com/coreos/go-iptables/iptables"
@@ -15,7 +17,9 @@ import (
 	firewall "github.com/netbirdio/netbird/client/firewall/manager"
 	"github.com/netbirdio/netbird/client/firewall/test"
 	"github.com/netbirdio/netbird/client/iface"
+	nbid "github.com/netbirdio/netbird/client/internal/acl/id"
 	nbnet "github.com/netbirdio/netbird/client/net"
+	"github.com/netbirdio/netbird/shared/management/domain"
 )
 
 func isIptablesSupported() bool {
@@ -31,7 +35,7 @@ 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 := newRouter(iptablesClient, ifaceMock, iface.DefaultMTU, newIPSetSupport())
 	require.NoError(t, err, "should return a valid iptables manager")
 	require.NoError(t, manager.init(nil))
 
@@ -84,7 +88,7 @@ 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 := newRouter(iptablesClient, ifaceMock, iface.DefaultMTU, newIPSetSupport())
 			require.NoError(t, err, "shouldn't return error")
 			require.NoError(t, manager.init(nil))
 
@@ -157,7 +161,7 @@ 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 := newRouter(iptablesClient, ifaceMock, iface.DefaultMTU, newIPSetSupport())
 			require.NoError(t, err, "shouldn't return error")
 			require.NoError(t, manager.init(nil))
 			defer func() {
@@ -219,7 +223,7 @@ 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)
+	r, err := newRouter(iptablesClient, ifaceMock, iface.DefaultMTU, newIPSetSupport())
 	require.NoError(t, err, "Failed to create router manager")
 	require.NoError(t, r.init(nil))
 
@@ -337,27 +341,26 @@ func TestRouter_AddRouteFiltering(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")
 
-			// 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")
+			// A kernel without usable ipset splits a multi-source ACL into one
+			// rule per source, so compare against whichever form is in effect.
+			useIPSet := r.ipsetSupport.supported()
 
-			// Log the internal rule
-			t.Logf("Internal rule: %v", rule)
+			// Check if the rules are in the internal map
+			rules := routeRuleSpecs(t, r, ruleKey.ID())
+			require.NotEmpty(t, rules, "Rule not found in internal map")
 
-			// Check if the rule exists in iptables
-			exists, err := iptablesClient.Exists(tableFilter, chainRTFWDIN, rule...)
-			assert.NoError(t, err, "Failed to check rule existence")
-			assert.True(t, exists, "Rule not found in iptables")
+			// Log the internal rules
+			t.Logf("Internal rules: %v", rules)
 
-			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]
+			// Check if the rules exist in iptables
+			for _, rule := range rules {
+				exists, err := iptablesClient.Exists(tableFilter, chainRTFWDIN, rule...)
+				assert.NoError(t, err, "Failed to check rule existence")
+				assert.True(t, exists, "Rule not found in iptables")
 			}
+
 			// Verify rule content
 			params := routeFilteringRuleParams{
-				Source:      source,
 				Destination: firewall.Network{Prefix: tt.destination},
 				Proto:       tt.proto,
 				SPort:       tt.sPort,
@@ -365,20 +368,18 @@ func TestRouter_AddRouteFiltering(t *testing.T) {
 				Action:      tt.action,
 			}
 
-			expectedRule, err := r.genRouteRuleSpec(params, nil)
+			expectedRules, err := r.genRouteRuleSpecs(params, tt.sources, useIPSet)
 			require.NoError(t, err, "Failed to generate expected rule spec")
 
-			if tt.expectSet {
+			if tt.expectSet && useIPSet {
 				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.Equal(t, expectedRule, rule, "Rule content mismatch")
+			assert.Equal(t, expectedRules, rules, "Rule content mismatch")
 
 			// Clean up
 			err = r.DeleteRouteRule(ruleKey)
@@ -445,3 +446,145 @@ func TestFindSetNameInRule(t *testing.T) {
 		})
 	}
 }
+
+// TestRouter_AddRouteFilteringIPSetFallback covers a kernel that cannot use ipset:
+// a multi-source route ACL must become one rule per source prefix, all present in
+// the chain, and deleting the ACL must remove every one of them. Without the
+// fallback the rule was never installed and the interface-wide DROP in FORWARD
+// silently dropped routed traffic.
+func TestRouter_AddRouteFilteringIPSetFallback(t *testing.T) {
+	if !isIptablesSupported() {
+		t.Skip("iptables not supported on this system")
+	}
+
+	iptablesClient, err := iptables.NewWithProtocol(iptables.ProtocolIPv4)
+	require.NoError(t, err)
+
+	support := newIPSetSupport()
+	support.markUnsupported(errors.New("test: pretend the kernel has no ipset"))
+
+	r, err := newRouter(iptablesClient, ifaceMock, iface.DefaultMTU, support)
+	require.NoError(t, err)
+	require.NoError(t, r.init(nil))
+	t.Cleanup(func() {
+		require.NoError(t, r.Reset())
+	})
+
+	sources := []netip.Prefix{
+		netip.MustParsePrefix("172.16.0.0/16"),
+		netip.MustParsePrefix("192.168.0.0/16"),
+	}
+	destination := firewall.Network{Prefix: netip.MustParsePrefix("10.0.0.0/8")}
+
+	rule, err := r.AddRouteFiltering(nil, sources, destination, firewall.ProtocolTCP, nil,
+		&firewall.Port{Values: []uint16{443}}, firewall.ActionAccept)
+	require.NoError(t, err, "route ACL must install without ipset")
+
+	specs := routeRuleSpecs(t, r, rule.ID())
+	require.Len(t, specs, len(sources), "each source prefix needs its own rule")
+
+	for i, spec := range specs {
+		joined := strings.Join(spec, " ")
+		require.Contains(t, joined, "-s "+sources[i].String(), "rule must match the source prefix directly")
+		require.NotContains(t, joined, matchSet, "fallback rule must not reference a set")
+
+		exists, err := iptablesClient.Exists(tableFilter, chainRTFWDIN, spec...)
+		require.NoError(t, err)
+		require.True(t, exists, "rule %d must be present in %s", i, chainRTFWDIN)
+	}
+
+	require.NoError(t, r.DeleteRouteRule(rule))
+
+	for i, spec := range specs {
+		exists, err := iptablesClient.Exists(tableFilter, chainRTFWDIN, spec...)
+		require.NoError(t, err)
+		require.False(t, exists, "rule %d must be removed", i)
+	}
+	require.Empty(t, routeRuleSpecs(t, r, rule.ID()), "no rule may be left recorded")
+}
+
+// TestRouter_DestinationSetRequiresIPSet documents that a dynamic (domain)
+// destination cannot be expressed without ipset: its prefixes are only known
+// after DNS resolution, so there is nothing to expand into per-prefix rules. The
+// call must report that rather than install a broader rule than the policy allows.
+func TestRouter_DestinationSetRequiresIPSet(t *testing.T) {
+	if !isIptablesSupported() {
+		t.Skip("iptables not supported on this system")
+	}
+
+	iptablesClient, err := iptables.NewWithProtocol(iptables.ProtocolIPv4)
+	require.NoError(t, err)
+
+	support := newIPSetSupport()
+	support.markUnsupported(errors.New("test: pretend the kernel has no ipset"))
+
+	r, err := newRouter(iptablesClient, ifaceMock, iface.DefaultMTU, support)
+	require.NoError(t, err)
+	require.NoError(t, r.init(nil))
+	t.Cleanup(func() {
+		require.NoError(t, r.Reset())
+	})
+
+	destination := firewall.Network{Set: firewall.NewDomainSet(domain.List{"example.com"})}
+
+	_, err = r.AddRouteFiltering(nil, []netip.Prefix{netip.MustParsePrefix("172.16.0.0/16")},
+		destination, firewall.ProtocolALL, nil, nil, firewall.ActionAccept)
+	require.Error(t, err, "a domain destination is not expressible without ipset")
+	require.ErrorContains(t, err, "requires ipset")
+}
+
+// TestRouter_RouteFilteringRollsBackPartialInstall covers a fallback ACL whose
+// second rule cannot be installed. Nothing may be left behind: if the rule key
+// survived, a later call would short-circuit on it and report success while some
+// sources were never installed, leaving them unblocked for a drop rule.
+func TestRouter_RouteFilteringRollsBackPartialInstall(t *testing.T) {
+	if !isIptablesSupported() {
+		t.Skip("iptables not supported on this system")
+	}
+
+	iptablesClient, err := iptables.NewWithProtocol(iptables.ProtocolIPv4)
+	require.NoError(t, err)
+
+	support := newIPSetSupport()
+	support.markUnsupported(errors.New("test: pretend the kernel has no ipset"))
+
+	r, err := newRouter(iptablesClient, ifaceMock, iface.DefaultMTU, support)
+	require.NoError(t, err)
+	require.NoError(t, r.init(nil))
+	t.Cleanup(func() {
+		require.NoError(t, r.Reset())
+	})
+
+	// The v6 prefix is rejected by the v4 iptables binary, so the second rule of
+	// the expansion fails after the first has been installed.
+	good := netip.MustParsePrefix("172.16.0.0/16")
+	sources := []netip.Prefix{good, netip.MustParsePrefix("2001:db8::/32")}
+	destination := firewall.Network{Prefix: netip.MustParsePrefix("10.0.0.0/8")}
+
+	_, err = r.AddRouteFiltering(nil, sources, destination, firewall.ProtocolALL, nil, nil, firewall.ActionDrop)
+	require.Error(t, err, "a source that iptables rejects must fail the whole ACL")
+
+	ruleKey := nbid.GenerateRouteRuleKey(sources, destination, firewall.ProtocolALL, nil, nil, firewall.ActionDrop)
+	require.Empty(t, routeRuleSpecs(t, r, string(ruleKey)), "no rule may stay recorded")
+
+	// The rule that did get installed must be gone from the chain.
+	installed := []string{"-s", good.String(), "-d", "10.0.0.0/8", "-j", "DROP"}
+	exists, err := iptablesClient.Exists(tableFilter, chainRTFWDIN, installed...)
+	require.NoError(t, err)
+	require.False(t, exists, "the already-installed rule must be rolled back")
+}
+
+// routeRuleSpecs collects the rules recorded for one route ACL, which is more than
+// one when the ipset fallback splits it per source prefix.
+func routeRuleSpecs(t *testing.T, r *router, ruleKey string) [][]string {
+	t.Helper()
+
+	var specs [][]string
+	for i := 0; ; i++ {
+		spec, exists := r.rules[routeRuleKey(ruleKey, i)]
+		if !exists {
+			return specs
+		}
+		specs = append(specs, spec)
+	}
+}

client/firewall/nftables/dnat_refcount_linux_test.go

@@ -0,0 +1,249 @@
+//go:build privileged
+
+package nftables
+
+import (
+	"net/netip"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"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/wgaddr"
+)
+
+func nftRefcountIfaceV4() *iFaceMock {
+	return &iFaceMock{
+		NameFunc: func() string { return "wt-refcount" },
+		AddressFunc: func() wgaddr.Address {
+			return wgaddr.Address{
+				IP:      netip.MustParseAddr("100.96.0.1"),
+				Network: netip.MustParsePrefix("100.96.0.0/16"),
+			}
+		},
+	}
+}
+
+func nftRefcountIfaceDual() *iFaceMock {
+	return &iFaceMock{
+		NameFunc: func() string { return "wt-refcount" },
+		AddressFunc: func() wgaddr.Address {
+			return wgaddr.Address{
+				IP:      netip.MustParseAddr("100.96.0.1"),
+				Network: netip.MustParsePrefix("100.96.0.0/16"),
+				IPv6:    netip.MustParseAddr("fd00::1"),
+				IPv6Net: netip.MustParsePrefix("fd00::/64"),
+			}
+		},
+	}
+}
+
+func newNftRefcountManager(t *testing.T, dual bool) *Manager {
+	t.Helper()
+	if check() != NFTABLES {
+		t.Skip("nftables not supported on this system")
+	}
+	var ifMock *iFaceMock
+	if dual {
+		ifMock = nftRefcountIfaceDual()
+	} else {
+		ifMock = nftRefcountIfaceV4()
+	}
+	m, err := Create(ifMock, iface.DefaultMTU)
+	require.NoError(t, err, "create manager")
+	require.NoError(t, m.Init(nil), "init manager")
+	t.Cleanup(func() {
+		require.NoError(t, m.Close(nil), "close manager")
+	})
+	return m
+}
+
+func dnatV4(port uint16) fw.ForwardRule {
+	return fw.ForwardRule{
+		Protocol:          fw.ProtocolTCP,
+		DestinationPort:   fw.Port{Values: []uint16{port}},
+		TranslatedAddress: netip.MustParseAddr("100.96.0.2"),
+		TranslatedPort:    fw.Port{Values: []uint16{80}},
+	}
+}
+
+func dnatV6(port uint16) fw.ForwardRule {
+	return fw.ForwardRule{
+		Protocol:          fw.ProtocolTCP,
+		DestinationPort:   fw.Port{Values: []uint16{port}},
+		TranslatedAddress: netip.MustParseAddr("fd00::2"),
+		TranslatedPort:    fw.Port{Values: []uint16{80}},
+	}
+}
+
+// TestNftablesDNAT_RefcountBalancedV4 verifies that Add/Delete pairs leave the
+// v4 refcount at zero.
+func TestNftablesDNAT_RefcountBalancedV4(t *testing.T) {
+	m := newNftRefcountManager(t, false)
+	state := m.router.ipFwdState
+
+	r1, err := m.AddDNATRule(dnatV4(8081))
+	require.NoError(t, err, "add v4 dnat 1")
+	v4, v6 := state.Counts()
+	assert.Equal(t, 1, v4, "v4 refcount after first add")
+	assert.Equal(t, 0, v6, "v6 refcount unchanged")
+
+	r2, err := m.AddDNATRule(dnatV4(8082))
+	require.NoError(t, err, "add v4 dnat 2")
+	v4, v6 = state.Counts()
+	assert.Equal(t, 2, v4, "v4 refcount after second add")
+	assert.Equal(t, 0, v6, "v6 refcount unchanged")
+
+	require.NoError(t, m.DeleteDNATRule(r1), "delete v4 dnat 1")
+	v4, v6 = state.Counts()
+	assert.Equal(t, 1, v4, "v4 refcount after first delete")
+	assert.Equal(t, 0, v6, "v6 refcount unchanged")
+
+	require.NoError(t, m.DeleteDNATRule(r2), "delete v4 dnat 2")
+	v4, v6 = state.Counts()
+	assert.Equal(t, 0, v4, "v4 refcount after second delete")
+	assert.Equal(t, 0, v6, "v6 refcount unchanged")
+}
+
+// TestNftablesDNAT_RefcountBalancedV6 verifies the v6 path increments v6 only
+// and decrements back to zero on Delete.
+func TestNftablesDNAT_RefcountBalancedV6(t *testing.T) {
+	m := newNftRefcountManager(t, true)
+	require.NotNil(t, m.router6, "v6 router")
+	require.Same(t, m.router.ipFwdState, m.router6.ipFwdState, "shared state")
+	state := m.router.ipFwdState
+
+	r1, err := m.AddDNATRule(dnatV6(9091))
+	require.NoError(t, err, "add v6 dnat 1")
+	v4, v6 := state.Counts()
+	assert.Equal(t, 0, v4, "v4 refcount unchanged")
+	assert.Equal(t, 1, v6, "v6 refcount after first add")
+
+	r2, err := m.AddDNATRule(dnatV6(9092))
+	require.NoError(t, err, "add v6 dnat 2")
+	v4, v6 = state.Counts()
+	assert.Equal(t, 0, v4)
+	assert.Equal(t, 2, v6, "v6 refcount after second add")
+
+	require.NoError(t, m.DeleteDNATRule(r1), "delete v6 dnat 1")
+	v4, v6 = state.Counts()
+	assert.Equal(t, 0, v4, "v4 refcount unchanged")
+	assert.Equal(t, 1, v6, "v6 refcount after first delete")
+
+	require.NoError(t, m.DeleteDNATRule(r2), "delete v6 dnat 2")
+	v4, v6 = state.Counts()
+	assert.Equal(t, 0, v4)
+	assert.Equal(t, 0, v6, "v6 refcount after second delete")
+}
+
+// TestNftablesDNAT_DuplicateAddNoLeak verifies that a duplicate Add (same
+// ForwardRule) does not double-increment the refcount.
+func TestNftablesDNAT_DuplicateAddNoLeak(t *testing.T) {
+	m := newNftRefcountManager(t, true)
+	state := m.router.ipFwdState
+
+	rule := dnatV4(8083)
+	r1, err := m.AddDNATRule(rule)
+	require.NoError(t, err, "add v4 dnat")
+	v4, _ := state.Counts()
+	assert.Equal(t, 1, v4)
+
+	// duplicate add: same rule ID, must be a no-op for the refcount.
+	_, err = m.AddDNATRule(rule)
+	require.NoError(t, err, "duplicate add")
+	v4, _ = state.Counts()
+	assert.Equal(t, 1, v4, "duplicate add must not increment")
+
+	require.NoError(t, m.DeleteDNATRule(r1), "delete v4 dnat")
+	v4, _ = state.Counts()
+	assert.Equal(t, 0, v4, "single delete must drop to zero")
+}
+
+// TestNftablesDNAT_DeleteMissingNoUnderflow verifies deleting a rule that was
+// never added does not underflow the refcount.
+func TestNftablesDNAT_DeleteMissingNoUnderflow(t *testing.T) {
+	m := newNftRefcountManager(t, true)
+	state := m.router.ipFwdState
+
+	// Construct a Rule reference for something never added. The router stores
+	// rules by ID(), and DeleteDNATRule looks them up in r.rules; a missing
+	// entry must be a no-op rather than calling Release.
+	phantom := dnatV4(8099)
+	require.NoError(t, m.DeleteDNATRule(&phantom), "delete missing v4 dnat")
+	v4, v6 := state.Counts()
+	assert.Equal(t, 0, v4, "v4 refcount unaffected by missing delete")
+	assert.Equal(t, 0, v6, "v6 refcount unaffected")
+
+	phantom6 := dnatV6(9099)
+	require.NoError(t, m.DeleteDNATRule(&phantom6), "delete missing v6 dnat")
+	v4, v6 = state.Counts()
+	assert.Equal(t, 0, v4)
+	assert.Equal(t, 0, v6, "v6 refcount unaffected by missing delete")
+
+	// And after a phantom delete, a real add still results in count=1.
+	r1, err := m.AddDNATRule(dnatV4(8100))
+	require.NoError(t, err, "add v4 dnat after phantom delete")
+	v4, _ = state.Counts()
+	assert.Equal(t, 1, v4, "real add still increments after phantom delete")
+	require.NoError(t, m.DeleteDNATRule(r1))
+}
+
+// TestNftablesRouting_RepeatedEnableSingleReference verifies that EnableRouting
+// (called on every network-map update) holds at most one reference per family
+// and a single DisableRouting drops both back to zero.
+func TestNftablesRouting_RepeatedEnableSingleReference(t *testing.T) {
+	m := newNftRefcountManager(t, true)
+	state := m.router.ipFwdState
+
+	require.NoError(t, m.EnableRouting(), "first enable")
+	require.NoError(t, m.EnableRouting(), "second enable")
+	require.NoError(t, m.EnableRouting(), "third enable")
+	v4, v6 := state.Counts()
+	assert.Equal(t, 1, v4, "repeated enable holds a single v4 reference")
+	assert.Equal(t, 1, v6, "repeated enable holds a single v6 reference")
+
+	require.NoError(t, m.DisableRouting(), "disable")
+	v4, v6 = state.Counts()
+	assert.Equal(t, 0, v4, "single disable releases the v4 reference")
+	assert.Equal(t, 0, v6, "single disable releases the v6 reference")
+}
+
+// TestNftablesRouting_DisableKeepsDNATReference verifies that an unpaired
+// DisableRouting does not release references held by active DNAT rules.
+func TestNftablesRouting_DisableKeepsDNATReference(t *testing.T) {
+	m := newNftRefcountManager(t, true)
+	state := m.router.ipFwdState
+
+	r1, err := m.AddDNATRule(dnatV6(9095))
+	require.NoError(t, err, "add v6 dnat")
+
+	require.NoError(t, m.DisableRouting(), "unpaired disable")
+	_, v6 := state.Counts()
+	assert.Equal(t, 1, v6, "DNAT-held reference survives unpaired DisableRouting")
+
+	require.NoError(t, m.DeleteDNATRule(r1), "delete v6 dnat")
+	_, v6 = state.Counts()
+	assert.Equal(t, 0, v6, "delete releases the DNAT reference")
+}
+
+// TestNftablesDNAT_DoubleDeleteNoUnderflow verifies that deleting the same rule
+// twice does not underflow the refcount (the second delete is a no-op).
+func TestNftablesDNAT_DoubleDeleteNoUnderflow(t *testing.T) {
+	m := newNftRefcountManager(t, true)
+	state := m.router.ipFwdState
+
+	r1, err := m.AddDNATRule(dnatV6(9093))
+	require.NoError(t, err)
+	_, v6 := state.Counts()
+	assert.Equal(t, 1, v6)
+
+	require.NoError(t, m.DeleteDNATRule(r1), "first delete")
+	_, v6 = state.Counts()
+	assert.Equal(t, 0, v6)
+
+	require.NoError(t, m.DeleteDNATRule(r1), "second delete must be no-op")
+	_, v6 = state.Counts()
+	assert.Equal(t, 0, v6, "double delete must not underflow")
+}

client/firewall/nftables/manager_linux.go

@@ -105,8 +105,8 @@ func (m *Manager) createIPv6Components(tableName string, wgIface iFaceMapper, mt
 		return fmt.Errorf("create v6 router: %w", err)
 	}
 
-	// Share the same IP forwarding state with the v4 router, since
-	// EnableIPForwarding controls both v4 and v6 sysctls.
+	// Share the per-family forwarding refcounter with the v4 router so a v4
+	// rule and a v6 rule against the same state machine cooperate cleanly.
 	m.router6.ipFwdState = m.router.ipFwdState
 
 	m.aclManager6, err = newAclManager(workTable6, wgIface, chainNameRoutingFw)
@@ -530,17 +530,12 @@ func (m *Manager) SetLogLevel(log.Level) {
 }
 
 func (m *Manager) EnableRouting() error {
-	if err := m.router.ipFwdState.RequestForwarding(); err != nil {
-		return fmt.Errorf("enable IP forwarding: %w", err)
-	}
-	return nil
+	// v6 only when the overlay actually has v6.
+	return m.router.ipFwdState.RequestRouting(m.router6 != nil)
 }
 
 func (m *Manager) DisableRouting() error {
-	if err := m.router.ipFwdState.ReleaseForwarding(); err != nil {
-		return fmt.Errorf("disable IP forwarding: %w", err)
-	}
-	return nil
+	return m.router.ipFwdState.ReleaseRouting()
 }
 
 // Flush rule/chain/set operations from the buffer

client/firewall/nftables/router_linux.go

@@ -93,7 +93,7 @@ func newRouter(workTable *nftables.Table, wgIface iFaceMapper, mtu uint16) (*rou
 		rules:      make(map[string]*nftables.Rule),
 		af:         familyForAddr(workTable.Family == nftables.TableFamilyIPv4),
 		wgIface:    wgIface,
-		ipFwdState: ipfwdstate.NewIPForwardingState(),
+		ipFwdState: ipfwdstate.NewIPForwardingState(wgIface.Name()),
 		mtu:        mtu,
 	}
 
@@ -1553,10 +1553,6 @@ func (r *router) refreshRulesMap() error {
 }
 
 func (r *router) AddDNATRule(rule firewall.ForwardRule) (firewall.Rule, error) {
-	if err := r.ipFwdState.RequestForwarding(); err != nil {
-		return nil, err
-	}
-
 	ruleKey := rule.ID()
 	if _, exists := r.rules[ruleKey+dnatSuffix]; exists {
 		return rule, nil
@@ -1567,7 +1563,18 @@ func (r *router) AddDNATRule(rule firewall.ForwardRule) (firewall.Rule, error) {
 		return nil, fmt.Errorf("convert protocol to number: %w", err)
 	}
 
+	// Request forwarding before queueing rules: addDnatRedirect/addDnatMasq
+	// buffer netlink messages on r.conn that the next caller's Flush would
+	// commit if we returned without flushing them ourselves.
+	v6 := r.af.tableFamily == nftables.TableFamilyIPv6
+	if err := r.ipFwdState.RequestForwarding(v6); err != nil {
+		return nil, fmt.Errorf("enable forwarding: %w", err)
+	}
+
 	if err := r.addDnatRedirect(rule, protoNum, ruleKey); err != nil {
+		if rerr := r.ipFwdState.ReleaseForwarding(v6); rerr != nil {
+			log.Warnf("rollback forwarding refcount: %v", rerr)
+		}
 		return nil, err
 	}
 
@@ -1579,6 +1586,11 @@ func (r *router) AddDNATRule(rule firewall.ForwardRule) (firewall.Rule, error) {
 	// TODO: find chains with drop policies and add rules there
 
 	if err := r.conn.Flush(); err != nil {
+		if rerr := r.ipFwdState.ReleaseForwarding(v6); rerr != nil {
+			log.Warnf("rollback forwarding refcount: %v", rerr)
+		}
+		delete(r.rules, ruleKey+dnatSuffix)
+		delete(r.rules, ruleKey+snatSuffix)
 		return nil, fmt.Errorf("flush rules: %w", err)
 	}
 
@@ -1781,16 +1793,18 @@ func (r *router) addDnatMasq(rule firewall.ForwardRule, protoNum uint8, ruleKey
 }
 
 func (r *router) DeleteDNATRule(rule firewall.Rule) error {
-	if err := r.ipFwdState.ReleaseForwarding(); err != nil {
-		log.Errorf("%v", err)
-	}
-
 	ruleKey := rule.ID()
 
 	if err := r.refreshRulesMap(); err != nil {
 		return fmt.Errorf(refreshRulesMapError, err)
 	}
 
+	_, hadDNAT := r.rules[ruleKey+dnatSuffix]
+	_, hadSNAT := r.rules[ruleKey+snatSuffix]
+	if !hadDNAT && !hadSNAT {
+		return nil
+	}
+
 	var merr *multierror.Error
 	var needsFlush bool
 
@@ -1822,9 +1836,16 @@ func (r *router) DeleteDNATRule(rule firewall.Rule) error {
 		}
 	}
 
+	// Release the refcount only once the rules are gone from the kernel. On
+	// failure (including the refreshRulesMap error above) the rules and their
+	// map entries remain, keeping forwarding on until a retry removes them.
 	if merr == nil {
 		delete(r.rules, ruleKey+dnatSuffix)
 		delete(r.rules, ruleKey+snatSuffix)
+
+		if err := r.ipFwdState.ReleaseForwarding(r.af.tableFamily == nftables.TableFamilyIPv6); err != nil {
+			log.Errorf("%v", err)
+		}
 	}
 
 	return nberrors.FormatErrorOrNil(merr)

client/iface/bind/ice_bind.go

@@ -22,6 +22,16 @@ import (
 	nbnet "github.com/netbirdio/netbird/client/net"
 )
 
+const (
+	// wgMsgTypeHandshakeInitiation is the lowest WireGuard message type.
+	wgMsgTypeHandshakeInitiation uint32 = 1
+	// wgMsgTypeTransport is the highest WireGuard message type.
+	wgMsgTypeTransport uint32 = 4
+	// wgMinMsgSize is the smallest WireGuard message: transport data with an empty
+	// payload, which is what a keepalive is.
+	wgMinMsgSize = 32
+)
+
 type receiverCreator struct {
 	iceBind *ICEBind
 }
@@ -216,8 +226,15 @@ func (s *ICEBind) createReceiverFn(pc wgConn.BatchReader, conn *net.UDPConn, rxO
 		for i := 0; i < numMsgs; i++ {
 			msg := &(*msgs)[i]
 
-			// todo: handle err
-			if ok, _ := s.filterOutStunMessages(msg.Buffers, msg.N, msg.Addr); ok {
+			if ok, err := s.filterOutStunMessages(msg.Buffers, msg.N, msg.Addr); ok {
+				if err != nil {
+					log.Debugf("failed to handle STUN packet from %s: %v", msg.Addr, err)
+				}
+				// WireGuard reuses sizes and eps across reads and only skips a slot
+				// whose size is below the minimum message size. Leaving a consumed
+				// slot untouched makes it process this buffer again under the
+				// previous packet's length and endpoint.
+				sizes[i] = 0
 				continue
 			}
 			sizes[i] = msg.N
@@ -271,11 +288,16 @@ func (s *ICEBind) createOrUpdateMux() {
 
 func (s *ICEBind) filterOutStunMessages(buffers [][]byte, n int, addr net.Addr) (bool, error) {
 	for i := range buffers {
-		if !stun.IsMessage(buffers[i]) {
+		if n > len(buffers[i]) {
+			continue
+		}
+		pkt := buffers[i][:n]
+
+		if isWireGuardMsg(pkt) || !stun.IsMessage(pkt) {
 			continue
 		}
 
-		msg, err := s.parseSTUNMessage(buffers[i][:n])
+		msg, err := s.parseSTUNMessage(pkt)
 		if err != nil {
 			buffers[i] = []byte{}
 			return true, err
@@ -347,18 +369,34 @@ func putMessages(msgs *[]ipv6.Message, msgsPool *sync.Pool) {
 	msgsPool.Put(msgs)
 }
 
-func isTransportPkg(buffers [][]byte, n int) bool {
-	// The first buffer should contain at least 4 bytes for type
-	if len(buffers[0]) < 4 {
-		return true
+// isWireGuardMsg reports whether the packet carries a WireGuard message header: a
+// little-endian uint32 message type in the range 1..4, which leaves the three bytes
+// after the type byte zero, in a packet long enough to hold any WireGuard message.
+//
+// A well formed STUN message cannot take that shape. Its length field sits in the two
+// bytes the type must leave zero, and for a message of at least wgMinMsgSize bytes that
+// field holds at least 12, so the two framings do not overlap. The test has to be this
+// tight because stun.IsMessage only looks at the magic cookie, which in a WireGuard
+// message overlaps the receiver index: a session whose index happens to equal the cookie
+// would otherwise have all of its inbound data misrouted to the STUN handler until the
+// next rekey.
+func isWireGuardMsg(pkt []byte) bool {
+	if len(pkt) < wgMinMsgSize {
+		return false
 	}
 
-	// WireGuard packet type is a little-endian uint32 at start
-	packetType := binary.LittleEndian.Uint32(buffers[0][:4])
-
-	// Check if packetType matches known WireGuard message types
-	if packetType == 4 && n > 32 {
-		return true
-	}
-	return false
+	msgType := binary.LittleEndian.Uint32(pkt[:4])
+	return msgType >= wgMsgTypeHandshakeInitiation && msgType <= wgMsgTypeTransport
+}
+
+// isTransportPkg reports whether the packet is WireGuard transport data carrying a
+// payload, which is what counts as peer activity. A keepalive holds no payload and is
+// exactly wgMinMsgSize bytes.
+func isTransportPkg(buffers [][]byte, n int) bool {
+	if n < 4 || n > len(buffers[0]) {
+		return false
+	}
+
+	msgType := binary.LittleEndian.Uint32(buffers[0][:4])
+	return msgType == wgMsgTypeTransport && n > wgMinMsgSize
 }

client/iface/bind/stun_filter_test.go

@@ -0,0 +1,215 @@
+//go:build !js
+
+package bind
+
+import (
+	"encoding/binary"
+	"net"
+	"testing"
+	"time"
+
+	"github.com/pion/stun/v3"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"golang.org/x/net/ipv4"
+	wgConn "golang.zx2c4.com/wireguard/conn"
+)
+
+// magicCookieBytes is the STUN magic cookie as it appears on the wire. In a
+// WireGuard message the same offset holds the receiver (or sender) index, which is
+// a random uint32, so a session can draw exactly this value.
+var magicCookieBytes = []byte{0x21, 0x12, 0xA4, 0x42}
+
+const testBufSize = 1500
+
+// wgMsg builds a WireGuard message of the given type and size, with the index field
+// at bytes 4:8 set to index.
+func wgMsg(msgType uint32, size int, index []byte) []byte {
+	pkt := make([]byte, size)
+	binary.LittleEndian.PutUint32(pkt[:4], msgType)
+	copy(pkt[4:8], index)
+	return pkt
+}
+
+// intoBuffer copies pkt into a full-size receive buffer, the way the kernel read
+// does, so tests see the same buffer/length split as the hot path.
+func intoBuffer(pkt []byte) [][]byte {
+	buf := make([]byte, testBufSize)
+	copy(buf, pkt)
+	return [][]byte{buf}
+}
+
+func TestFilterOutStunMessages_PassesWireGuardWithCookieShapedIndex(t *testing.T) {
+	tests := []struct {
+		name    string
+		msgType uint32
+		size    int
+	}{
+		{"transport data", wgMsgTypeTransport, 128},
+		{"keepalive", wgMsgTypeTransport, wgMinMsgSize},
+		{"handshake initiation", wgMsgTypeHandshakeInitiation, 148},
+		{"handshake response", 2, 92},
+		{"cookie reply", 3, 64},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			pkt := wgMsg(tc.msgType, tc.size, magicCookieBytes)
+			require.True(t, stun.IsMessage(pkt), "precondition: pion sees this as STUN")
+
+			buffers := intoBuffer(pkt)
+			bind := &ICEBind{}
+
+			filtered, err := bind.filterOutStunMessages(buffers, tc.size, &net.UDPAddr{})
+			assert.NoError(t, err)
+			assert.False(t, filtered, "WireGuard message must be handed to WireGuard, not the STUN handler")
+			assert.Len(t, buffers[0], testBufSize, "buffer must be left intact for WireGuard")
+		})
+	}
+}
+
+func TestFilterOutStunMessages_FiltersRealSTUNMessage(t *testing.T) {
+	msg, err := stun.Build(stun.BindingRequest, stun.TransactionID, stun.Fingerprint)
+	require.NoError(t, err)
+
+	buffers := intoBuffer(msg.Raw)
+	bind := &ICEBind{}
+
+	filtered, err := bind.filterOutStunMessages(buffers, len(msg.Raw), &net.UDPAddr{})
+	assert.NoError(t, err)
+	assert.True(t, filtered, "STUN message must be consumed by the STUN handler")
+	assert.Empty(t, buffers[0], "consumed buffer must be emptied so WireGuard does not see it")
+}
+
+// TestIsWireGuardMsg_DisjointFromSTUN locks the invariant the filter relies on: a
+// well formed STUN message long enough to be a WireGuard message always has a
+// non-zero length field, so it cannot be mistaken for a WireGuard header.
+func TestIsWireGuardMsg_DisjointFromSTUN(t *testing.T) {
+	types := []stun.MessageType{
+		stun.BindingRequest,
+		stun.BindingSuccess,
+		stun.BindingError,
+		{Method: stun.MethodBinding, Class: stun.ClassIndication},
+	}
+
+	for _, msgType := range types {
+		// Long enough that the length guard is not what makes this pass.
+		msg, err := stun.Build(msgType, stun.TransactionID,
+			stun.NewUsername("remoteUfrag:localUfrag"), stun.Fingerprint)
+		require.NoError(t, err)
+		require.GreaterOrEqual(t, len(msg.Raw), wgMinMsgSize, "precondition: %s", msgType)
+		assert.False(t, isWireGuardMsg(msg.Raw),
+			"%s must not look like a WireGuard message", msgType)
+	}
+}
+
+func TestIsWireGuardMsg(t *testing.T) {
+	tests := []struct {
+		name string
+		pkt  []byte
+		want bool
+	}{
+		{"transport data", wgMsg(wgMsgTypeTransport, 128, nil), true},
+		{"handshake initiation", wgMsg(wgMsgTypeHandshakeInitiation, 148, nil), true},
+		{"unknown type 5", wgMsg(5, 128, nil), false},
+		{"type 0", wgMsg(0, 128, nil), false},
+		{"non-zero reserved byte", []byte{0x04, 0x00, 0x01, 0x00}, false},
+		{"too short", []byte{0x04, 0x00, 0x00}, false},
+		{"empty", nil, false},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			assert.Equal(t, tc.want, isWireGuardMsg(tc.pkt), "wrong classification for %s", tc.name)
+		})
+	}
+}
+
+// TestFilterOutStunMessages_IgnoresBytesBeyondPacket guards against classifying on
+// buffer contents left over from an earlier, longer packet.
+func TestFilterOutStunMessages_IgnoresBytesBeyondPacket(t *testing.T) {
+	buf := make([]byte, testBufSize)
+	copy(buf[4:8], magicCookieBytes)
+	buffers := [][]byte{buf}
+	bind := &ICEBind{}
+
+	filtered, err := bind.filterOutStunMessages(buffers, 2, &net.UDPAddr{})
+	assert.NoError(t, err)
+	assert.False(t, filtered, "a 2 byte packet must not be classified from stale buffer bytes")
+}
+
+// TestReceiveFn_ClearsSizeOfConsumedPacket covers the accounting WireGuard relies
+// on: sizes is reused across reads, so a slot whose packet was consumed as STUN must
+// be reported as empty. Otherwise WireGuard reprocesses the same buffer under the
+// previous packet's length, which for a WireGuard-shaped packet means it is handled
+// twice.
+func TestReceiveFn_ClearsSizeOfConsumedPacket(t *testing.T) {
+	conn := listenUDP(t, "udp4", "127.0.0.1:0")
+	defer conn.Close()
+
+	recvFn := receiverCreator{setupICEBind(t)}.CreateReceiverFn(
+		ipv4.NewPacketConn(conn), conn, false, createMsgPool(),
+	)
+
+	msg, err := stun.Build(stun.BindingRequest, stun.TransactionID, stun.Fingerprint)
+	require.NoError(t, err)
+
+	sender := listenUDP(t, "udp4", "127.0.0.1:0")
+	defer sender.Close()
+	_, err = sender.WriteTo(msg.Raw, conn.LocalAddr())
+	require.NoError(t, err)
+
+	require.NoError(t, conn.SetReadDeadline(time.Now().Add(3*time.Second)))
+
+	bufs := [][]byte{make([]byte, 1500)}
+	// A leftover size from an earlier read, which is what makes the missing reset
+	// observable.
+	sizes := []int{148}
+	eps := make([]wgConn.Endpoint, 1)
+
+	n, err := recvFn(bufs, sizes, eps)
+	require.NoError(t, err)
+	require.Equal(t, 1, n)
+	assert.Zero(t, sizes[0], "consumed STUN packet must not leave a size behind for WireGuard")
+}
+
+func TestIsTransportPkg(t *testing.T) {
+	tests := []struct {
+		name string
+		pkt  []byte
+		n    int
+		want bool
+	}{
+		{"transport data with payload", wgMsg(wgMsgTypeTransport, 128, nil), 128, true},
+		{"keepalive", wgMsg(wgMsgTypeTransport, wgMinMsgSize, nil), wgMinMsgSize, false},
+		{"handshake initiation", wgMsg(wgMsgTypeHandshakeInitiation, 148, nil), 148, false},
+		{"stale type bytes beyond packet", wgMsg(wgMsgTypeTransport, 128, nil), 2, false},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			assert.Equal(t, tc.want, isTransportPkg(intoBuffer(tc.pkt), tc.n),
+				"wrong activity classification for %s", tc.name)
+		})
+	}
+}
+
+// TestFilterOutStunMessages_ConsumesSTUNWithWireGuardShapedType covers the one STUN
+// encoding whose leading bytes collide with a WireGuard message type: method 0x080 as a
+// request encodes to 0x0200, so the type byte reads as a handshake response and the byte
+// after it is zero. Only the length check keeps such a message out of WireGuard's hands.
+// pion implements no method in that range, so this is a synthetic worst case rather than
+// traffic ICE produces.
+func TestFilterOutStunMessages_ConsumesSTUNWithWireGuardShapedType(t *testing.T) {
+	msg, err := stun.Build(stun.NewType(stun.Method(0x080), stun.ClassRequest), stun.TransactionID)
+	require.NoError(t, err)
+	require.Equal(t, []byte{0x02, 0x00, 0x00, 0x00}, msg.Raw[:4],
+		"precondition: the leading bytes read as a WireGuard message type")
+
+	buffers := intoBuffer(msg.Raw)
+	bind := &ICEBind{}
+
+	filtered, err := bind.filterOutStunMessages(buffers, len(msg.Raw), &net.UDPAddr{})
+	assert.NoError(t, err)
+	assert.True(t, filtered, "STUN message must be consumed despite its WireGuard-shaped type")
+}

client/internal/debug/debug.go

@@ -34,9 +34,8 @@ import (
 	"github.com/netbirdio/netbird/shared/netiputil"
 )
 
-const readmeContent = `Netbird debug bundle
-This debug bundle contains the following files.
-If the --anonymize flag is set, the files are anonymized to protect sensitive information.
+const readmeContent = `This debug bundle contains the following files.
+If anonymization is enabled (--anonymize / --anonymize-level), the files are anonymized to protect sensitive information.
 
 status.txt: Anonymized status information of the NetBird client.
 client.log: Most recent, anonymized client log file of the NetBird client.
@@ -70,21 +69,34 @@ capture.pcap: Packet capture in pcap format. Only present when capture was runni
 
 
 Anonymization Process
-The files in this bundle have been anonymized to protect sensitive information. Here's how the anonymization was applied:
+The files in this bundle have been anonymized to protect sensitive information. The level applied to this bundle is recorded at the top of this file. Here's how the anonymization was applied:
 
 IP Addresses
 
-IPv4 addresses are replaced with addresses starting from 198.51.100.0
-IPv6 addresses are replaced with addresses starting from 100::
+Default level:
+- Public IPv4 addresses are replaced with addresses starting from 198.51.100.0
+- Public IPv6 addresses are replaced with addresses starting from 2001:db8:ffff::
+- IPv6 unique local addresses (fc00::/7) are anonymized as well: their random global ID uniquely identifies the network.
+- IP addresses from internal IPv4 ranges and well-known addresses are not anonymized (e.g. 8.8.8.8, 100.64.0.0/10, addresses starting with 192.168., 172.16., 10., 169.254., fe80::).
+
+Strict level (--anonymize-level strict), in addition to the default level:
+- Private (RFC 1918), CGNAT (100.64.0.0/10), and link-local (169.254.0.0/16, fe80::/10) addresses are anonymized too.
+- Internal IPv4 addresses are replaced with addresses starting from 198.18.0.0 and internal IPv6 addresses with addresses starting from 2001:db8:1::, so internal addresses remain distinguishable from public ones.
+- Addresses are mapped in order of first appearance: subnet structure, allocation scheme, and gateway conventions are not preserved. Prefix lengths of networks are preserved.
+- Peer names in front of NetBird domains are replaced with numbered placeholders (e.g. peer-1.netbird.cloud), and subdomain labels of other domains with host-N placeholders.
+- WireGuard public keys are replaced with consistent placeholder keys.
 
-IP addresses from non public ranges and well known addresses are not anonymized (e.g. 8.8.8.8, 100.64.0.0/10, addresses starting with 192.168., 172.16., 10., etc.).
 Reoccuring IP addresses are replaced with the same anonymized address.
 
 Note: The anonymized IP addresses in the status file do not match those in the log and routes files. However, the anonymized IP addresses are consistent within the status file and across the routes and log files.
 
+MAC Addresses
+MAC addresses are replaced at every anonymization level with consistent placeholders counting up from 02:00:00:00:00:01. Broadcast, multicast, and all-zero addresses are kept. At the default level a preserved IPv6 link-local address may still embed a MAC address (EUI-64); the strict level anonymizes those addresses.
+
 Domains
 All domain names (except for the netbird domains) are replaced with randomly generated strings ending in ".domain". Anonymized domains are consistent across all files in the bundle.
 Reoccuring domain names are replaced with the same anonymized domain.
+At the strict level, the peer name labels in front of netbird domains are anonymized as well.
 
 Sync Response
 The network_map.json file contains the following anonymized information:
@@ -281,6 +293,7 @@ type BundleGenerator struct {
 	cliVersion     string
 
 	anonymize         bool
+	anonymizeLevel    anonymize.Level
 	includeSystemInfo bool
 	logFileCount      uint32
 
@@ -288,7 +301,10 @@ type BundleGenerator struct {
 }
 
 type BundleConfig struct {
-	Anonymize         bool
+	Anonymize bool
+	// AnonymizeLevel selects how much the anonymizer redacts.
+	// anonymize.LevelStrict implies Anonymize.
+	AnonymizeLevel    anonymize.Level
 	IncludeSystemInfo bool
 	LogFileCount      uint32
 }
@@ -327,8 +343,11 @@ func NewBundleGenerator(deps GeneratorDependencies, cfg BundleConfig) *BundleGen
 		uiLogOpener = openLogFile
 	}
 
+	anonymizer := anonymize.NewAnonymizer(anonymize.DefaultAddresses())
+	anonymizer.SetLevel(cfg.AnonymizeLevel)
+
 	return &BundleGenerator{
-		anonymizer: anonymize.NewAnonymizer(anonymize.DefaultAddresses()),
+		anonymizer: anonymizer,
 
 		internalConfig: deps.InternalConfig,
 		statusRecorder: deps.StatusRecorder,
@@ -345,7 +364,8 @@ func NewBundleGenerator(deps GeneratorDependencies, cfg BundleConfig) *BundleGen
 		daemonVersion:  deps.DaemonVersion,
 		cliVersion:     deps.CliVersion,
 
-		anonymize:         cfg.Anonymize,
+		anonymize:         cfg.Anonymize || cfg.AnonymizeLevel >= anonymize.LevelStrict,
+		anonymizeLevel:    cfg.AnonymizeLevel,
 		includeSystemInfo: cfg.IncludeSystemInfo,
 		logFileCount:      logFileCount,
 	}
@@ -485,7 +505,13 @@ func (g *BundleGenerator) addSystemInfo() {
 }
 
 func (g *BundleGenerator) addReadme() error {
-	readmeReader := strings.NewReader(readmeContent)
+	level := "none (anonymization disabled)"
+	if g.anonymize {
+		level = g.anonymizeLevel.String()
+	}
+	header := fmt.Sprintf("Netbird debug bundle\nAnonymization level applied to this bundle: %s\n", level)
+
+	readmeReader := strings.NewReader(header + readmeContent)
 	if err := g.addFileToZip(readmeReader, "README.txt"); err != nil {
 		return fmt.Errorf("add README file to zip: %w", err)
 	}
@@ -507,9 +533,10 @@ func (g *BundleGenerator) addStatus() error {
 		fullStatus := g.statusRecorder.GetFullStatus()
 		protoFullStatus := nbstatus.ToProtoFullStatus(fullStatus)
 		overview := nbstatus.ConvertToStatusOutputOverview(protoFullStatus, nbstatus.ConvertOptions{
-			Anonymize:     g.anonymize,
-			ProfileName:   profName,
-			DaemonVersion: g.daemonVersion,
+			Anonymize:      g.anonymize,
+			AnonymizeLevel: g.anonymizeLevel,
+			ProfileName:    profName,
+			DaemonVersion:  g.daemonVersion,
 		})
 		overview.CliVersion = g.cliVersion
 		statusOutput := overview.FullDetailSummary()
@@ -662,7 +689,7 @@ func (g *BundleGenerator) addCommonConfigFields(configContent *strings.Builder)
 	configContent.WriteString("NetBird Client Configuration:\n\n")
 
 	if key, err := wgtypes.ParseKey(g.internalConfig.PrivateKey); err == nil {
-		configContent.WriteString(fmt.Sprintf("PublicKey: %s\n", key.PublicKey().String()))
+		configContent.WriteString(fmt.Sprintf("PublicKey: %s\n", g.anonymizer.AnonymizeWGKey(key.PublicKey().String())))
 	}
 	configContent.WriteString(fmt.Sprintf("WgIface: %s\n", g.internalConfig.WgIface))
 	configContent.WriteString(fmt.Sprintf("WgPort: %d\n", g.internalConfig.WgPort))
@@ -952,6 +979,11 @@ func (g *BundleGenerator) addUpdateLogs() error {
 		}
 
 		baseName := filepath.Base(logFile)
+		data, err = g.anonymizeBytes(data)
+		if err != nil {
+			log.Warnf("skipping update log file %s: %v", baseName, err)
+			continue
+		}
 		if err := g.addFileToZip(bytes.NewReader(data), filepath.Join("update-logs", baseName)); err != nil {
 			return fmt.Errorf("add update log file %s to zip: %w", baseName, err)
 		}
@@ -979,6 +1011,13 @@ func (g *BundleGenerator) addCorruptedStateFiles() error {
 		}
 
 		fileName := filepath.Base(match)
+		// Corrupted state files usually fail structured JSON anonymization,
+		// so run them through the string anonymizer instead.
+		data, err = g.anonymizeBytes(data)
+		if err != nil {
+			log.Warnf("skipping corrupted state file %s: %v", fileName, err)
+			continue
+		}
 		if err := g.addFileToZip(bytes.NewReader(data), "corrupted_states/"+fileName); err != nil {
 			log.Warnf("Failed to add corrupted state file %s to zip: %v", fileName, err)
 			continue
@@ -990,6 +1029,27 @@ func (g *BundleGenerator) addCorruptedStateFiles() error {
 	return nil
 }
 
+// anonymizeBytes runs raw file content through the string anonymizer line by
+// line when anonymization is enabled. It errors instead of returning partial
+// content, so a caller never adds an unanonymized fallback to the bundle.
+func (g *BundleGenerator) anonymizeBytes(data []byte) ([]byte, error) {
+	if !g.anonymize {
+		return data, nil
+	}
+
+	var buf bytes.Buffer
+	scanner := bufio.NewScanner(bytes.NewReader(data))
+	scanner.Buffer(make([]byte, 1024*1024), 1024*1024)
+	for scanner.Scan() {
+		buf.WriteString(g.anonymizer.AnonymizeString(scanner.Text()))
+		buf.WriteByte('\n')
+	}
+	if err := scanner.Err(); err != nil {
+		return nil, fmt.Errorf("anonymize content: %w", err)
+	}
+	return buf.Bytes(), nil
+}
+
 func (g *BundleGenerator) addMetrics() error {
 	if g.clientMetrics == nil {
 		log.Debugf("skipping metrics in debug bundle: no metrics collector")
@@ -1462,6 +1522,7 @@ func anonymizeRemotePeer(peer *mgmProto.RemotePeerConfig, anonymizer *anonymize.
 	}
 
 	peer.Fqdn = anonymizer.AnonymizeDomain(peer.Fqdn)
+	peer.WgPubKey = anonymizer.AnonymizeWGKey(peer.WgPubKey)
 
 	anonymizeSSHConfig(peer.SshConfig)
 }

client/internal/debug/debug_linux.go

@@ -844,6 +844,10 @@ func collectSysctls() string {
 		[]string{"net.ipv4.conf.all.src_valid_mark", "net.ipv4.conf.default.src_valid_mark"},
 		listInterfaceSysctls("ipv4", "src_valid_mark")...,
 	))
+	writeSysctlGroup(&builder, "accept_ra", append(
+		[]string{"net.ipv6.conf.all.accept_ra", "net.ipv6.conf.default.accept_ra"},
+		listInterfaceSysctls("ipv6", "accept_ra")...,
+	))
 	writeSysctlGroup(&builder, "conntrack", []string{
 		"net.netfilter.nf_conntrack_acct",
 		"net.netfilter.nf_conntrack_tcp_loose",

client/internal/debug/wgshow.go

@@ -35,14 +35,14 @@ func (g *BundleGenerator) toWGShowFormat(s *configurer.Stats) string {
 	var sb strings.Builder
 
 	sb.WriteString(fmt.Sprintf("interface: %s\n", s.DeviceName))
-	sb.WriteString(fmt.Sprintf("  public key: %s\n", s.PublicKey))
+	sb.WriteString(fmt.Sprintf("  public key: %s\n", g.anonymizer.AnonymizeWGKey(s.PublicKey)))
 	sb.WriteString(fmt.Sprintf("  listen port: %d\n", s.ListenPort))
 	if s.FWMark != 0 {
 		sb.WriteString(fmt.Sprintf("  fwmark: %#x\n", s.FWMark))
 	}
 
 	for _, peer := range s.Peers {
-		sb.WriteString(fmt.Sprintf("\npeer: %s\n", peer.PublicKey))
+		sb.WriteString(fmt.Sprintf("\npeer: %s\n", g.anonymizer.AnonymizeWGKey(peer.PublicKey)))
 		if peer.Endpoint.IP != nil {
 			if g.anonymize {
 				anonEndpoint := g.anonymizer.AnonymizeUDPAddr(peer.Endpoint)
@@ -54,7 +54,11 @@ func (g *BundleGenerator) toWGShowFormat(s *configurer.Stats) string {
 		if len(peer.AllowedIPs) > 0 {
 			var ipStrings []string
 			for _, ipnet := range peer.AllowedIPs {
-				ipStrings = append(ipStrings, ipnet.String())
+				ipStr := ipnet.String()
+				if g.anonymize {
+					ipStr = g.anonymizer.AnonymizeIPString(ipStr)
+				}
+				ipStrings = append(ipStrings, ipStr)
 			}
 			sb.WriteString(fmt.Sprintf("  allowed ips: %s\n", strings.Join(ipStrings, ", ")))
 		}

client/internal/dns/host_darwin.go

@@ -267,18 +267,38 @@ func (s *systemConfigurator) getSystemDNSSettings() (SystemDNSSettings, error) {
 		return SystemDNSSettings{}, fmt.Errorf("sending the command: %w", err)
 	}
 
-	var dnsSettings SystemDNSSettings
+	dnsSettings, serverAddresses, err := parseSystemDNSSettings(b)
+	if err != nil {
+		return dnsSettings, err
+	}
+
+	s.mu.Lock()
+	s.origNameservers = serverAddresses
+	s.mu.Unlock()
+
+	return dnsSettings, nil
+}
+
+// parseSystemDNSSettings parses the output of `scutil show State:/Network/Service/<id>/DNS`.
+// Lines that don't match the expected "index : value" shape are skipped: hosts with unusual
+// network services (e.g. orphaned hardware ports) can produce entries without a value.
+func parseSystemDNSSettings(out []byte) (SystemDNSSettings, []netip.Addr, error) {
+	// port is not exposed by scutil, default to 53
+	dnsSettings := SystemDNSSettings{ServerPort: DefaultPort}
 	var serverAddresses []netip.Addr
 	inSearchDomainsArray := false
 	inServerAddressesArray := false
 
-	scanner := bufio.NewScanner(bytes.NewReader(b))
+	scanner := bufio.NewScanner(bytes.NewReader(out))
 	for scanner.Scan() {
 		line := strings.TrimSpace(scanner.Text())
 		switch {
 		case strings.HasPrefix(line, "DomainName :"):
-			domainName := strings.TrimSpace(strings.Split(line, ":")[1])
-			dnsSettings.Domains = append(dnsSettings.Domains, domainName)
+			domainName := strings.TrimSpace(strings.TrimPrefix(line, "DomainName :"))
+			if domainName != "" {
+				dnsSettings.Domains = append(dnsSettings.Domains, domainName)
+			}
+			continue
 		case line == "SearchDomains : <array> {":
 			inSearchDomainsArray = true
 			continue
@@ -288,36 +308,45 @@ func (s *systemConfigurator) getSystemDNSSettings() (SystemDNSSettings, error) {
 		case line == "}":
 			inSearchDomainsArray = false
 			inServerAddressesArray = false
+			continue
+		}
+
+		if !inSearchDomainsArray && !inServerAddressesArray {
+			continue
+		}
+
+		parts := strings.SplitN(line, " : ", 2)
+		if len(parts) != 2 {
+			log.Debugf("skipping unexpected scutil DNS line %q", line)
+			continue
+		}
+		value := strings.TrimSpace(parts[1])
+		if value == "" {
+			continue
 		}
 
 		if inSearchDomainsArray {
-			searchDomain := strings.Split(line, " : ")[1]
-			dnsSettings.Domains = append(dnsSettings.Domains, searchDomain)
-		} else if inServerAddressesArray {
-			address := strings.Split(line, " : ")[1]
-			if ip, err := netip.ParseAddr(address); err == nil && !ip.IsUnspecified() {
-				ip = ip.Unmap()
-				serverAddresses = append(serverAddresses, ip)
-				// Prefer the first IPv4 server as ServerIP since our DNS listener is IPv4.
-				if !dnsSettings.ServerIP.IsValid() && ip.Is4() {
-					dnsSettings.ServerIP = ip
-				}
-			}
+			dnsSettings.Domains = append(dnsSettings.Domains, value)
+			continue
+		}
+
+		ip, err := netip.ParseAddr(value)
+		if err != nil || ip.IsUnspecified() {
+			continue
+		}
+		ip = ip.Unmap()
+		serverAddresses = append(serverAddresses, ip)
+		// Prefer the first IPv4 server as ServerIP since our DNS listener is IPv4.
+		if !dnsSettings.ServerIP.IsValid() && ip.Is4() {
+			dnsSettings.ServerIP = ip
 		}
 	}
 
 	if err := scanner.Err(); err != nil {
-		return dnsSettings, err
+		return dnsSettings, serverAddresses, err
 	}
 
-	// default to 53 port
-	dnsSettings.ServerPort = DefaultPort
-
-	s.mu.Lock()
-	s.origNameservers = serverAddresses
-	s.mu.Unlock()
-
-	return dnsSettings, nil
+	return dnsSettings, serverAddresses, nil
 }
 
 func (s *systemConfigurator) getOriginalNameservers() []netip.Addr {
@@ -435,11 +464,15 @@ func (s *systemConfigurator) getPrimaryService() (string, string, error) {
 	router := ""
 	for scanner.Scan() {
 		text := scanner.Text()
+		parts := strings.SplitN(text, ":", 2)
+		if len(parts) != 2 {
+			continue
+		}
 		if strings.Contains(text, "PrimaryService") {
-			primaryService = strings.TrimSpace(strings.Split(text, ":")[1])
+			primaryService = strings.TrimSpace(parts[1])
 		}
 		if strings.Contains(text, "Router") {
-			router = strings.TrimSpace(strings.Split(text, ":")[1])
+			router = strings.TrimSpace(parts[1])
 		}
 	}
 	if err := scanner.Err(); err != nil && err != io.EOF {

client/internal/dns/host_darwin_test.go

@@ -328,6 +328,120 @@ func removeTestDNSKey(key string) error {
 	return err
 }
 
+func TestParseSystemDNSSettings(t *testing.T) {
+	tests := []struct {
+		name            string
+		output          string
+		expectedDomains []string
+		expectedServers []netip.Addr
+		expectedIP      netip.Addr
+	}{
+		{
+			name: "well_formed",
+			output: `<dictionary> {
+  DomainName : example.com
+  SearchDomains : <array> {
+    0 : example.com
+    1 : corp.example.com
+  }
+  ServerAddresses : <array> {
+    0 : 192.168.1.1
+    1 : fd00::53
+  }
+}
+`,
+			expectedDomains: []string{"example.com", "example.com", "corp.example.com"},
+			expectedServers: []netip.Addr{netip.MustParseAddr("192.168.1.1"), netip.MustParseAddr("fd00::53")},
+			expectedIP:      netip.MustParseAddr("192.168.1.1"),
+		},
+		{
+			// entries without a value after the separator used to panic with
+			// "index out of range [1] with length 1"
+			name: "malformed_array_entries_skipped",
+			output: `<dictionary> {
+  SearchDomains : <array> {
+    0 :
+    (null)
+
+    1 : corp.example.com
+  }
+  ServerAddresses : <array> {
+    0 :
+    1 : 192.168.1.1
+  }
+}
+`,
+			expectedDomains: []string{"corp.example.com"},
+			expectedServers: []netip.Addr{netip.MustParseAddr("192.168.1.1")},
+			expectedIP:      netip.MustParseAddr("192.168.1.1"),
+		},
+		{
+			name: "domain_name_without_value_skipped",
+			output: `<dictionary> {
+  DomainName :
+  ServerAddresses : <array> {
+    0 : 192.168.1.1
+  }
+}
+`,
+			expectedServers: []netip.Addr{netip.MustParseAddr("192.168.1.1")},
+			expectedIP:      netip.MustParseAddr("192.168.1.1"),
+		},
+		{
+			name: "ipv6_first_prefers_ipv4_server_ip",
+			output: `<dictionary> {
+  ServerAddresses : <array> {
+    0 : fd00::53
+    1 : 192.168.1.1
+  }
+}
+`,
+			expectedServers: []netip.Addr{netip.MustParseAddr("fd00::53"), netip.MustParseAddr("192.168.1.1")},
+			expectedIP:      netip.MustParseAddr("192.168.1.1"),
+		},
+		{
+			name: "invalid_and_unspecified_addresses_skipped",
+			output: `<dictionary> {
+  ServerAddresses : <array> {
+    0 : (null)
+    1 : 0.0.0.0
+    2 : 192.168.1.1
+  }
+}
+`,
+			expectedServers: []netip.Addr{netip.MustParseAddr("192.168.1.1")},
+			expectedIP:      netip.MustParseAddr("192.168.1.1"),
+		},
+		{
+			name: "v4_mapped_address_unmapped",
+			output: `<dictionary> {
+  ServerAddresses : <array> {
+    0 : ::ffff:192.168.1.1
+  }
+}
+`,
+			expectedServers: []netip.Addr{netip.MustParseAddr("192.168.1.1")},
+			expectedIP:      netip.MustParseAddr("192.168.1.1"),
+		},
+		{
+			name:   "empty_output",
+			output: "",
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			settings, servers, err := parseSystemDNSSettings([]byte(tc.output))
+			require.NoError(t, err, "parsing should not fail")
+
+			assert.Equal(t, tc.expectedDomains, settings.Domains, "domains should match")
+			assert.Equal(t, tc.expectedServers, servers, "server addresses should match")
+			assert.Equal(t, tc.expectedIP, settings.ServerIP, "server IP should match")
+			assert.Equal(t, DefaultPort, settings.ServerPort, "server port should default to 53")
+		})
+	}
+}
+
 func TestGetOriginalNameservers(t *testing.T) {
 	configurator := &systemConfigurator{
 		createdKeys: make(map[string]struct{}),

client/internal/engine.go

@@ -23,6 +23,7 @@ import (
 	"golang.zx2c4.com/wireguard/tun/netstack"
 	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
 
+	"github.com/netbirdio/netbird/client/anonymize"
 	nberrors "github.com/netbirdio/netbird/client/errors"
 	"github.com/netbirdio/netbird/client/firewall"
 	"github.com/netbirdio/netbird/client/firewall/firewalld"
@@ -1385,6 +1386,7 @@ func (e *Engine) handleBundle(params *mgmProto.BundleParameters) (*mgmProto.JobR
 
 	bundleJobParams := debug.BundleConfig{
 		Anonymize:         params.Anonymize,
+		AnonymizeLevel:    anonymize.ParseLevel(params.AnonymizeLevel),
 		IncludeSystemInfo: true,
 		LogFileCount:      uint32(params.LogFileCount),
 	}

client/internal/metrics/connection_type.go

@@ -4,11 +4,17 @@ package metrics
 type ConnectionType string
 
 const (
-	// ConnectionTypeICE represents a direct peer-to-peer connection using ICE
-	ConnectionTypeICE ConnectionType = "ice"
+	// ConnectionTypeICEP2P represents a direct peer-to-peer connection using ICE
+	ConnectionTypeICEP2P ConnectionType = "ice_p2p"
+
+	// ConnectionTypeICETurn represents an ICE connection through a TURN server
+	ConnectionTypeICETurn ConnectionType = "ice_turn"
 
 	// ConnectionTypeRelay represents a relayed connection
 	ConnectionTypeRelay ConnectionType = "relay"
+
+	// ConnectionTypeUnknown represents a connection with no active transport. It is not pushed.
+	ConnectionTypeUnknown ConnectionType = "unknown"
 )
 
 // String returns the string representation of the connection type

client/internal/metrics/influxdb_test.go

@@ -28,7 +28,7 @@ func TestInfluxDBMetrics_RecordAndExport(t *testing.T) {
 		WgHandshakeSuccess: time.Now().Add(-1 * time.Second),
 	}
 
-	m.RecordConnectionStages(context.Background(), agentInfo, "pair123", ConnectionTypeICE, false, ts)
+	m.RecordConnectionStages(context.Background(), agentInfo, "pair123", ConnectionTypeICEP2P, false, ts)
 
 	var buf bytes.Buffer
 	err := m.Export(&buf)
@@ -60,7 +60,7 @@ func TestInfluxDBMetrics_ExportDeterministicFieldOrder(t *testing.T) {
 
 	// Record multiple times and verify consistent field order
 	for i := 0; i < 10; i++ {
-		m.RecordConnectionStages(context.Background(), agentInfo, "pair123", ConnectionTypeICE, false, ts)
+		m.RecordConnectionStages(context.Background(), agentInfo, "pair123", ConnectionTypeICEP2P, false, ts)
 	}
 
 	var buf bytes.Buffer

client/internal/metrics/infra/README.md

@@ -56,14 +56,33 @@ Measurement: `netbird_peer_connection`
 
 Tags:
 - `deployment_type`: "cloud" | "selfhosted" | "unknown"
-- `connection_type`: "ice" | "relay"
+- `connection_type`: "ice_p2p" | "ice_turn" | "relay" (see below)
 - `attempt_type`: "initial" | "reconnection"
 - `version`: NetBird version string
 - `os`: Operating system (linux, darwin, windows, android, ios, etc.)
 - `arch`: CPU architecture (amd64, arm64, etc.)
+- `peer_id`: anonymised peer identifier (truncated SHA-256 of the WireGuard public key)
+- `connection_pair_id`: deterministic identifier for the peer pair, identical on both sides
 
 **Note:** `SignalingReceived` is set when the first offer or answer arrives from the remote peer (in both initial and reconnection paths). It excludes the potentially unbounded wait for the remote peer to come online.
 
+#### `connection_type` values
+
+Derived from the connection priority (`conntype.ConnPriority`) by `metricsConnType` in `client/internal/peer/conn.go`:
+
+| Value | Priority | Traffic is |
+|-------|----------|------------|
+| `ice_p2p` | `ICEP2P` | direct peer-to-peer |
+| `ice_turn` | `ICETurn` | relayed, through a TURN server |
+| `relay` | `Relay` | relayed, through a NetBird relay |
+| `unknown` | `None` or unrecognised | no active transport — **the sample is not pushed** |
+
+**Direct traffic is `ice_p2p` only.** `ice_turn` is relayed despite being negotiated by ICE, matching `Conn.isRelayed`.
+
+`None` means no transport is active: not established yet, or reset after a relay drop or a peer-state reset. Such a sample cannot be attributed to a transport, so `recordConnectionMetrics` drops it instead of pushing it — `unknown` therefore never appears in the bucket. Connection counts are counts of connections whose transport was known at sampling time.
+
+**Samples recorded before 0.77 used a single `ice` value** which covered `ICEP2P`, `ICETurn` *and* `None`, so historical `ice` samples overstate direct connections by an unknown amount and must not be compared with `ice_p2p`.
+
 ### Sync Duration
 
 Measurement: `netbird_sync`

client/internal/peer/conn.go

@@ -307,6 +307,8 @@ func (conn *Conn) Close(signalToRemote bool) {
 
 	if conn.wgWatcherCancel != nil {
 		conn.wgWatcherCancel()
+		conn.wgWatcher = nil
+		conn.wgWatcherCancel = nil
 	}
 	conn.workerRelay.CloseConn()
 	if conn.workerICE != nil {
@@ -959,12 +961,9 @@ func (conn *Conn) recordConnectionMetrics() {
 	priority := conn.currentConnPriority
 	conn.mu.Unlock()
 
-	var connType metrics.ConnectionType
-	switch priority {
-	case conntype.Relay:
-		connType = metrics.ConnectionTypeRelay
-	default:
-		connType = metrics.ConnectionTypeICE
+	connType := metricsConnType(priority)
+	if connType == metrics.ConnectionTypeUnknown {
+		return
 	}
 
 	// Record metrics with timestamps - duration calculation happens in metrics package
@@ -1065,3 +1064,16 @@ func boolToConnStatus(connected bool) guard.ConnStatus {
 	}
 	return guard.ConnStatusDisconnected
 }
+
+func metricsConnType(priority conntype.ConnPriority) metrics.ConnectionType {
+	switch priority {
+	case conntype.Relay:
+		return metrics.ConnectionTypeRelay
+	case conntype.ICETurn:
+		return metrics.ConnectionTypeICETurn
+	case conntype.ICEP2P:
+		return metrics.ConnectionTypeICEP2P
+	default:
+		return metrics.ConnectionTypeUnknown
+	}
+}

client/internal/peer/conn_test.go

@@ -11,6 +11,8 @@ import (
 	"github.com/stretchr/testify/assert"
 
 	"github.com/netbirdio/netbird/client/iface"
+	"github.com/netbirdio/netbird/client/internal/metrics"
+	"github.com/netbirdio/netbird/client/internal/peer/conntype"
 	"github.com/netbirdio/netbird/client/internal/peer/dispatcher"
 	"github.com/netbirdio/netbird/client/internal/peer/guard"
 	"github.com/netbirdio/netbird/client/internal/peer/ice"
@@ -386,3 +388,33 @@ func TestConn_onWGDisconnected_NoEscalationWithoutRosenpass(t *testing.T) {
 	}
 	assert.Empty(t, disconnected, "escalation must be limited to rosenpass connections")
 }
+
+func TestMetricsConnType(t *testing.T) {
+	tests := []struct {
+		name     string
+		priority conntype.ConnPriority
+		expected metrics.ConnectionType
+	}{
+		{"relay", conntype.Relay, metrics.ConnectionTypeRelay},
+		{"ice over turn is relayed, not p2p", conntype.ICETurn, metrics.ConnectionTypeICETurn},
+		{"direct p2p", conntype.ICEP2P, metrics.ConnectionTypeICEP2P},
+		{"unset priority is unknown, not p2p", conntype.None, metrics.ConnectionTypeUnknown},
+		{"unrecognised priority is unknown", conntype.ConnPriority(99), metrics.ConnectionTypeUnknown},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			assert.Equal(t, tc.expected, metricsConnType(tc.priority))
+		})
+	}
+}
+
+func TestMetricsConnType_RelayedMatchesIsRelayed(t *testing.T) {
+	for _, priority := range []conntype.ConnPriority{conntype.None, conntype.Relay, conntype.ICETurn, conntype.ICEP2P} {
+		conn := &Conn{currentConnPriority: priority}
+		tag := metricsConnType(priority)
+		relayedTag := tag == metrics.ConnectionTypeRelay || tag == metrics.ConnectionTypeICETurn
+		assert.Equal(t, conn.isRelayed(), relayedTag,
+			"priority %s: isRelayed and the %q metric tag must agree", priority, tag)
+	}
+}

client/internal/routemanager/ipfwdstate/ipfwdstate.go

@@ -2,54 +2,183 @@ package ipfwdstate
 
 import (
 	"fmt"
+	"sync"
 
 	log "github.com/sirupsen/logrus"
 
 	"github.com/netbirdio/netbird/client/internal/routemanager/systemops"
 )
 
-// IPForwardingState is a struct that keeps track of the IP forwarding state.
-// todo: read initial state of the IP forwarding from the system and reset the state based on it.
-// todo: separate v4/v6 forwarding state, since the sysctls are independent
-// (net.ipv4.ip_forward vs net.ipv6.conf.all.forwarding). Currently the nftables
-// manager shares one instance between both routers, which works only because
-// EnableIPForwarding enables both sysctls in a single call.
+// IPForwardingState tracks v4 and v6 IP-forwarding sysctl enables with
+// independent refcounts so a v4-only routing setup doesn't flip v6 sysctls.
 type IPForwardingState struct {
-	enabledCounter int
+	mu sync.Mutex
+
+	v4Count int
+	v6Count int
+
+	// routingV4/routingV6 track whether the routing path currently holds a
+	// reference, so repeated EnableRouting calls (one per network-map update)
+	// hold at most one reference per family and an unpaired DisableRouting
+	// can't release references held by DNAT rules.
+	routingV4 bool
+	routingV6 bool
+
+	wgIfaceName string
+	v6Saved     map[string]int
 }
 
-func NewIPForwardingState() *IPForwardingState {
-	return &IPForwardingState{}
+// NewIPForwardingState returns a state tracker for the IP-forwarding sysctls.
+// wgIfaceName is excluded from the per-interface accept_ra handling.
+func NewIPForwardingState(wgIfaceName string) *IPForwardingState {
+	return &IPForwardingState{wgIfaceName: wgIfaceName}
 }
 
-func (f *IPForwardingState) RequestForwarding() error {
-	if f.enabledCounter != 0 {
-		f.enabledCounter++
+// Counts returns the current v4 and v6 refcounts. Intended for diagnostics
+// and tests.
+func (f *IPForwardingState) Counts() (v4, v6 int) {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	return f.v4Count, f.v6Count
+}
+
+// RequestRouting takes the forwarding references for the routing path. It is
+// idempotent: while routing already holds a reference, further calls don't
+// increment the refcounts, and a v4-only request releases a previously held v6
+// reference. A v6 sysctl failure is logged and not returned so it can't take
+// down v4 routing (the sysctl may be unwritable, e.g. read-only /proc/sys or
+// IPv6 disabled on the kernel command line); v6 is retried on the next call.
+func (f *IPForwardingState) RequestRouting(v6 bool) error {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+
+	if !f.routingV4 {
+		if err := f.requestV4(); err != nil {
+			return err
+		}
+		f.routingV4 = true
+	}
+
+	if !v6 {
+		if !f.routingV6 {
+			return nil
+		}
+		f.routingV6 = false
+		return f.releaseV6()
+	}
+
+	if f.routingV6 {
 		return nil
 	}
-
-	if err := systemops.EnableIPForwarding(); err != nil {
-		return fmt.Errorf("failed to enable IP forwarding with sysctl: %w", err)
+	if err := f.requestV6(); err != nil {
+		log.Warnf("enable IPv6 forwarding for routing: %v", err)
+		return nil
 	}
-	f.enabledCounter = 1
-	log.Info("IP forwarding enabled")
-
+	f.routingV6 = true
 	return nil
 }
 
-func (f *IPForwardingState) ReleaseForwarding() error {
-	if f.enabledCounter == 0 {
-		return nil
+// ReleaseRouting releases the references RequestRouting holds. Calls without a
+// held reference are no-ops.
+func (f *IPForwardingState) ReleaseRouting() error {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+
+	if f.routingV4 {
+		f.routingV4 = false
+		f.releaseV4()
 	}
-
-	if f.enabledCounter > 1 {
-		f.enabledCounter--
-		return nil
+	if f.routingV6 {
+		f.routingV6 = false
+		return f.releaseV6()
 	}
-
-	// if failed to disable IP forwarding we anyway decrement the counter
-	f.enabledCounter = 0
-
-	// todo call systemops.DisableIPForwarding()
+	return nil
+}
+
+// RequestForwarding enables the family's forwarding sysctl on first request.
+func (f *IPForwardingState) RequestForwarding(v6 bool) error {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+
+	if v6 {
+		return f.requestV6()
+	}
+	return f.requestV4()
+}
+
+// ReleaseForwarding decrements the family counter. The last v6 release restores
+// what enable captured. v4 stays on: net.ipv4.ip_forward is co-owned by other
+// tooling (docker, k8s, libvirt).
+func (f *IPForwardingState) ReleaseForwarding(v6 bool) error {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+
+	if v6 {
+		return f.releaseV6()
+	}
+	f.releaseV4()
+	return nil
+}
+
+func (f *IPForwardingState) requestV4() error {
+	if f.v4Count == 0 {
+		if err := systemops.EnableV4IPForwarding(); err != nil {
+			return fmt.Errorf("enable IPv4 forwarding: %w", err)
+		}
+		log.Info("IPv4 forwarding enabled")
+	}
+	f.v4Count++
+	return nil
+}
+
+func (f *IPForwardingState) releaseV4() {
+	if f.v4Count > 0 {
+		f.v4Count--
+	}
+}
+
+func (f *IPForwardingState) requestV6() error {
+	if f.v6Count == 0 {
+		saved, err := systemops.EnableV6IPForwarding(f.wgIfaceName)
+		if err != nil {
+			if rerr := systemops.DisableV6IPForwarding(saved); rerr != nil {
+				log.Warnf("rollback partial v6 sysctls: %v", rerr)
+			}
+			return fmt.Errorf("enable IPv6 forwarding: %w", err)
+		}
+		// A failed restore on a previous release keeps its saved values; those
+		// are the true originals, so keep them over what this enable captured.
+		if f.v6Saved == nil {
+			f.v6Saved = saved
+		} else {
+			for k, v := range saved {
+				if _, ok := f.v6Saved[k]; !ok {
+					f.v6Saved[k] = v
+				}
+			}
+		}
+		log.Info("IPv6 forwarding enabled")
+	}
+	f.v6Count++
+	return nil
+}
+
+func (f *IPForwardingState) releaseV6() error {
+	if f.v6Count == 0 {
+		return nil
+	}
+	f.v6Count--
+	if f.v6Count > 0 {
+		return nil
+	}
+
+	// Keep the saved values on failure so a later release or enable/release
+	// cycle can still restore them; re-restoring an already-restored key is a
+	// no-op since the sysctl already holds the desired value.
+	if err := systemops.DisableV6IPForwarding(f.v6Saved); err != nil {
+		return fmt.Errorf("disable IPv6 forwarding: %w", err)
+	}
+	f.v6Saved = nil
+	log.Info("IPv6 forwarding disabled")
 	return nil
 }

client/internal/routemanager/ipfwdstate/ipfwdstate_privileged_linux_test.go

@@ -0,0 +1,39 @@
+//go:build privileged
+
+package ipfwdstate
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// TestRequestRoutingV6ToV4Transition verifies that a v4-only routing request
+// releases a previously held routing-owned v6 reference without touching
+// references held by DNAT rules.
+func TestRequestRoutingV6ToV4Transition(t *testing.T) {
+	f := NewIPForwardingState("wt-fwd-test")
+
+	require.NoError(t, f.RequestRouting(true), "request routing with v6")
+	v4, v6 := f.Counts()
+	assert.Equal(t, 1, v4, "v4 reference held")
+	assert.Equal(t, 1, v6, "v6 reference held")
+
+	require.NoError(t, f.RequestRouting(false), "request routing v4-only")
+	v4, v6 = f.Counts()
+	assert.Equal(t, 1, v4, "v4 reference kept")
+	assert.Equal(t, 0, v6, "routing-owned v6 reference released")
+
+	// A DNAT-held reference survives a v4-only routing request.
+	require.NoError(t, f.RequestForwarding(true), "dnat v6 reference")
+	require.NoError(t, f.RequestRouting(false), "repeat v4-only request")
+	_, v6 = f.Counts()
+	assert.Equal(t, 1, v6, "dnat-held v6 reference survives")
+	require.NoError(t, f.ReleaseForwarding(true), "release dnat v6 reference")
+
+	require.NoError(t, f.ReleaseRouting(), "release routing")
+	v4, v6 = f.Counts()
+	assert.Equal(t, 0, v4, "all v4 references released")
+	assert.Equal(t, 0, v6, "all v6 references released")
+}

client/internal/routemanager/sysctl/sysctl_linux.go

@@ -58,11 +58,7 @@ func Setup(wgIface iface) (map[string]int, error) {
 			continue
 		}
 
-		// Escape '%' and '.' so they survive the dot-to-slash conversion in Set()
-		safeName := strings.ReplaceAll(intf.Name, "%", percentEscape)
-		safeName = strings.ReplaceAll(safeName, ".", dotEscape)
-
-		i := fmt.Sprintf(rpFilterInterfacePath, safeName)
+		i := fmt.Sprintf(rpFilterInterfacePath, EscapeInterfaceName(intf.Name))
 		oldVal, err := Set(i, 2, true)
 		if err != nil {
 			result = multierror.Append(result, err)
@@ -74,6 +70,13 @@ func Setup(wgIface iface) (map[string]int, error) {
 	return keys, nberrors.FormatErrorOrNil(result)
 }
 
+// EscapeInterfaceName escapes '%' and '.' in an interface name (e.g. VLANs
+// like eth0.100) so the name survives the dot-to-slash conversion in Set.
+func EscapeInterfaceName(name string) string {
+	safe := strings.ReplaceAll(name, "%", percentEscape)
+	return strings.ReplaceAll(safe, ".", dotEscape)
+}
+
 // Set sets a sysctl configuration, if onlyIfOne is true it will only set the new value if it's set to 1
 func Set(key string, desiredValue int, onlyIfOne bool) (int, error) {
 	path := strings.ReplaceAll(key, ".", "/")

client/internal/routemanager/systemops/systemops_android.go

@@ -32,8 +32,17 @@ func (r *SysOps) removeFromRouteTable(netip.Prefix, Nexthop) error {
 	return nil
 }
 
-func EnableIPForwarding() error {
-	log.Infof("Enable IP forwarding is not implemented on %s", runtime.GOOS)
+func EnableV4IPForwarding() error {
+	log.Infof("Enable IPv4 forwarding is not implemented on %s", runtime.GOOS)
+	return nil
+}
+
+func EnableV6IPForwarding(string) (map[string]int, error) {
+	log.Infof("Enable IPv6 forwarding is not implemented on %s", runtime.GOOS)
+	return map[string]int{}, nil
+}
+
+func DisableV6IPForwarding(map[string]int) error {
 	return nil
 }
 

client/internal/routemanager/systemops/systemops_ios.go

@@ -58,8 +58,17 @@ func (r *SysOps) removeFromRouteTable(netip.Prefix, Nexthop) error {
 	return nil
 }
 
-func EnableIPForwarding() error {
-	log.Infof("Enable IP forwarding is not implemented on %s", runtime.GOOS)
+func EnableV4IPForwarding() error {
+	log.Infof("Enable IPv4 forwarding is not implemented on %s", runtime.GOOS)
+	return nil
+}
+
+func EnableV6IPForwarding(string) (map[string]int, error) {
+	log.Infof("Enable IPv6 forwarding is not implemented on %s", runtime.GOOS)
+	return map[string]int{}, nil
+}
+
+func DisableV6IPForwarding(map[string]int) error {
 	return nil
 }
 

client/internal/routemanager/systemops/systemops_linux.go

@@ -763,13 +763,10 @@ func flushRoutes(tableID, family int) error {
 	return nberrors.FormatErrorOrNil(result)
 }
 
-func EnableIPForwarding() error {
+func EnableV4IPForwarding() error {
 	if _, err := sysctl.Set(ipv4ForwardingPath, 1, false); err != nil {
 		return err
 	}
-	if _, err := sysctl.Set(ipv6ForwardingPath, 1, false); err != nil {
-		log.Warnf("failed to enable IPv6 forwarding: %v", err)
-	}
 	return nil
 }
 

client/internal/routemanager/systemops/systemops_nonlinux.go

@@ -43,8 +43,17 @@ func (r *SysOps) RemoveVPNRoute(prefix netip.Prefix, intf *net.Interface) error
 	return r.genericRemoveVPNRoute(prefix, intf)
 }
 
-func EnableIPForwarding() error {
-	log.Infof("Enable IP forwarding is not implemented on %s", runtime.GOOS)
+func EnableV4IPForwarding() error {
+	log.Infof("Enable IPv4 forwarding is not implemented on %s", runtime.GOOS)
+	return nil
+}
+
+func EnableV6IPForwarding(string) (map[string]int, error) {
+	log.Infof("Enable IPv6 forwarding is not implemented on %s", runtime.GOOS)
+	return map[string]int{}, nil
+}
+
+func DisableV6IPForwarding(map[string]int) error {
 	return nil
 }
 

client/internal/routemanager/systemops/v6forwarding_linux.go

@@ -0,0 +1,92 @@
+//go:build !android
+
+package systemops
+
+import (
+	"fmt"
+	"net"
+	"os"
+
+	"github.com/hashicorp/go-multierror"
+	log "github.com/sirupsen/logrus"
+
+	nberrors "github.com/netbirdio/netbird/client/errors"
+	"github.com/netbirdio/netbird/client/internal/routemanager/sysctl"
+)
+
+const (
+	// 1 (default) accepts RAs only while forwarding is off; 2 keeps RA
+	// acceptance on regardless, so RA-installed host defaults survive our
+	// v6 forwarding flip.
+	acceptRAInterfacePath  = "net.ipv6.conf.%s.accept_ra"
+	acceptRADefaultPath    = "net.ipv6.conf.default.accept_ra"
+	acceptRAProcPathFormat = "/proc/sys/net/ipv6/conf/%s/accept_ra"
+)
+
+// EnableV6IPForwarding bumps accept_ra=2 on host v6 interfaces before flipping
+// forwarding=1, so RA-installed host defaults survive. Returns the prior values
+// of sysctls we actually changed; entries already at the target are omitted.
+func EnableV6IPForwarding(wgIfaceName string) (map[string]int, error) {
+	saved := map[string]int{}
+	bumpAcceptRA(saved, wgIfaceName)
+
+	oldVal, err := sysctl.Set(ipv6ForwardingPath, 1, false)
+	if err != nil {
+		return saved, err
+	}
+	if oldVal != 1 {
+		saved[ipv6ForwardingPath] = oldVal
+	}
+	return saved, nil
+}
+
+// DisableV6IPForwarding restores what EnableV6IPForwarding captured.
+func DisableV6IPForwarding(saved map[string]int) error {
+	var result *multierror.Error
+	for key, value := range saved {
+		if _, err := sysctl.Set(key, value, false); err != nil {
+			result = multierror.Append(result, fmt.Errorf("restore %s: %w", key, err))
+		}
+	}
+	return nberrors.FormatErrorOrNil(result)
+}
+
+func bumpAcceptRA(saved map[string]int, wgIfaceName string) {
+	// Also bump conf.default so interfaces created while forwarding is on
+	// (hotplug, new Wi-Fi/dock) inherit accept_ra=2 and keep accepting RAs.
+	bumpAcceptRAKey(saved, acceptRADefaultPath)
+
+	interfaces, err := net.Interfaces()
+	if err != nil {
+		log.Warnf("list interfaces for accept_ra: %v", err)
+		return
+	}
+	for _, intf := range interfaces {
+		if intf.Name == "lo" || intf.Name == wgIfaceName {
+			continue
+		}
+		bumpAcceptRAForInterface(saved, intf.Name)
+	}
+}
+
+func bumpAcceptRAForInterface(saved map[string]int, name string) {
+	// Build procfs path from name, not the dotted key: VLAN names like eth0.100.
+	if _, err := os.Stat(fmt.Sprintf(acceptRAProcPathFormat, name)); err != nil {
+		return
+	}
+	bumpAcceptRAKey(saved, fmt.Sprintf(acceptRAInterfacePath, sysctl.EscapeInterfaceName(name)))
+}
+
+func bumpAcceptRAKey(saved map[string]int, key string) {
+	// onlyIfOne=true: leave admin overrides (0, 2) alone.
+	oldVal, err := sysctl.Set(key, 2, true)
+	if err != nil {
+		log.Warnf("bump %s: %v", key, err)
+		return
+	}
+	// With onlyIfOne, a write only happened when the old value was 1; values
+	// left untouched (0, 2) must not be recorded for restore.
+	if oldVal == 1 {
+		saved[key] = oldVal
+	}
+}

client/ios/NetBirdSDK/client.go

@@ -14,6 +14,7 @@ import (
 
 	log "github.com/sirupsen/logrus"
 
+	nbAnonymize "github.com/netbirdio/netbird/client/anonymize"
 	"github.com/netbirdio/netbird/client/internal"
 	"github.com/netbirdio/netbird/client/internal/auth"
 	"github.com/netbirdio/netbird/client/internal/debug"
@@ -28,6 +29,13 @@ import (
 	types "github.com/netbirdio/netbird/upload-server/types"
 )
 
+// AnonymizeLevelDefault and AnonymizeLevelStrict are the accepted
+// anonymizeLevel values for DebugBundle.
+const (
+	AnonymizeLevelDefault = nbAnonymize.LevelDefaultString
+	AnonymizeLevelStrict  = nbAnonymize.LevelStrictString
+)
+
 // ConnectionListener export internal Listener for mobile
 type ConnectionListener interface {
 	peer.Listener
@@ -200,8 +208,10 @@ func (c *Client) Stop() {
 // DebugBundle generates a debug bundle, uploads it and returns the upload key.
 // It works with or without a running engine: when the engine is up it reuses
 // the live config, sync response and client metrics; otherwise it loads the
-// config from disk (or the preloaded tvOS config).
-func (c *Client) DebugBundle(anonymize bool) (string, error) {
+// config from disk (or the preloaded tvOS config). anonymizeLevel is "default"
+// or "strict"; strict also anonymizes internal IP ranges, peer names, and
+// WireGuard public keys, and implies anonymize.
+func (c *Client) DebugBundle(anonymize bool, anonymizeLevel string) (string, error) {
 	cfg, cc := c.stateSnapshot()
 
 	// If the engine hasn't been started, load config so we can reach management.
@@ -251,6 +261,7 @@ func (c *Client) DebugBundle(anonymize bool) (string, error) {
 		deps,
 		debug.BundleConfig{
 			Anonymize:         anonymize,
+			AnonymizeLevel:    nbAnonymize.ParseLevel(anonymizeLevel),
 			IncludeSystemInfo: true,
 		},
 	)

client/proto/daemon.pb.go

@@ -2781,6 +2781,11 @@ type DebugBundleRequest struct {
 	// untrusted TLS certificate. Restricted to privileged callers; for
 	// self-hosted upload servers.
 	UploadInsecure bool `protobuf:"varint,7,opt,name=uploadInsecure,proto3" json:"uploadInsecure,omitempty"`
+	// anonymizeLevel selects how much the anonymizer redacts: "default"
+	// (or empty) keeps internal IP ranges, "strict" also anonymizes them.
+	// Unknown values are treated as "strict". Only meaningful with anonymize;
+	// "strict" implies it.
+	AnonymizeLevel string `protobuf:"bytes,8,opt,name=anonymizeLevel,proto3" json:"anonymizeLevel,omitempty"`
 	unknownFields  protoimpl.UnknownFields
 	sizeCache      protoimpl.SizeCache
 }
@@ -2857,6 +2862,13 @@ func (x *DebugBundleRequest) GetUploadInsecure() bool {
 	return false
 }
 
+func (x *DebugBundleRequest) GetAnonymizeLevel() string {
+	if x != nil {
+		return x.AnonymizeLevel
+	}
+	return ""
+}
+
 type DebugBundleResponse struct {
 	state               protoimpl.MessageState `protogen:"open.v1"`
 	Path                string                 `protobuf:"bytes,1,opt,name=path,proto3" json:"path,omitempty"`
@@ -7253,7 +7265,7 @@ const file_daemon_proto_rawDesc = "" +
 	"\x12translatedHostname\x18\x04 \x01(\tR\x12translatedHostname\x128\n" +
 	"\x0etranslatedPort\x18\x05 \x01(\v2\x10.daemon.PortInfoR\x0etranslatedPort\"G\n" +
 	"\x17ForwardingRulesResponse\x12,\n" +
-	"\x05rules\x18\x01 \x03(\v2\x16.daemon.ForwardingRuleR\x05rules\"\xdc\x01\n" +
+	"\x05rules\x18\x01 \x03(\v2\x16.daemon.ForwardingRuleR\x05rules\"\x84\x02\n" +
 	"\x12DebugBundleRequest\x12\x1c\n" +
 	"\tanonymize\x18\x01 \x01(\bR\tanonymize\x12\x1e\n" +
 	"\n" +
@@ -7264,7 +7276,8 @@ const file_daemon_proto_rawDesc = "" +
 	"\n" +
 	"cliVersion\x18\x06 \x01(\tR\n" +
 	"cliVersion\x12&\n" +
-	"\x0euploadInsecure\x18\a \x01(\bR\x0euploadInsecure\"}\n" +
+	"\x0euploadInsecure\x18\a \x01(\bR\x0euploadInsecure\x12&\n" +
+	"\x0eanonymizeLevel\x18\b \x01(\tR\x0eanonymizeLevel\"}\n" +
 	"\x13DebugBundleResponse\x12\x12\n" +
 	"\x04path\x18\x01 \x01(\tR\x04path\x12 \n" +
 	"\vuploadedKey\x18\x02 \x01(\tR\vuploadedKey\x120\n" +

client/proto/daemon.proto

@@ -540,6 +540,11 @@ message DebugBundleRequest {
   // untrusted TLS certificate. Restricted to privileged callers; for
   // self-hosted upload servers.
   bool uploadInsecure = 7;
+  // anonymizeLevel selects how much the anonymizer redacts: "default"
+  // (or empty) keeps internal IP ranges, "strict" also anonymizes them.
+  // Unknown values are treated as "strict". Only meaningful with anonymize;
+  // "strict" implies it.
+  string anonymizeLevel = 8;
 }
 
 message DebugBundleResponse {

client/server/debug.go

@@ -16,6 +16,7 @@ import (
 	"google.golang.org/grpc/codes"
 	gstatus "google.golang.org/grpc/status"
 
+	"github.com/netbirdio/netbird/client/anonymize"
 	"github.com/netbirdio/netbird/client/internal/debug"
 	"github.com/netbirdio/netbird/client/internal/ipcauth"
 	"github.com/netbirdio/netbird/client/proto"
@@ -122,6 +123,7 @@ func (s *Server) generateDebugBundle(req *proto.DebugBundleRequest, uiOpener deb
 		},
 		debug.BundleConfig{
 			Anonymize:         req.GetAnonymize(),
+			AnonymizeLevel:    anonymize.ParseLevel(req.GetAnonymizeLevel()),
 			IncludeSystemInfo: req.GetSystemInfo(),
 			LogFileCount:      req.GetLogFileCount(),
 		},

client/ssh/server/command_execution_windows.go

@@ -243,7 +243,7 @@ func (s *Server) setUserEnvironmentVariables(envMap map[string]string, userProfi
 
 // prepareCommandEnv prepares environment variables for command execution on Windows
 func (s *Server) prepareCommandEnv(logger *log.Entry, localUser *user.User, session ssh.Session) []string {
-	username, domain := s.parseUsername(localUser.Username)
+	username, domain := parseUsername(localUser.Username)
 	userEnv, err := s.getUserEnvironment(logger, username, domain)
 	if err != nil {
 		log.Debugf("failed to get user environment for %s\\%s, using fallback: %v", domain, username, err)
@@ -383,7 +383,7 @@ func (s *Server) executeCommandWithPty(logger *log.Entry, session ssh.Session, _
 		return false
 	}
 
-	username, domain := s.parseUsername(localUser.Username)
+	username, domain := parseUsername(localUser.Username)
 	shell := getUserShell(localUser.Uid)
 
 	req := PtyExecutionRequest{

client/ssh/server/port_forwarding.go

@@ -133,7 +133,12 @@ func (s *Server) checkPrivilegedPortAccess(forwardType string, port uint32, resu
 		return nil
 	}
 
-	if result.User != nil && isPrivilegedUsername(result.User.Username) {
+	// Only uid 0 may bind below the threshold, which is the kernel's own rule and
+	// is asked directly rather than through isPrivilegedOrUnknown: that helper
+	// reports an account it cannot evaluate as privileged, which is safe for a
+	// refusal and unsafe for a grant such as this one. Windows has returned
+	// above, so Uid here is a Unix uid and never a SID.
+	if result.User != nil && result.User.Uid == "0" {
 		return nil
 	}
 

client/ssh/server/privileges_other.go

@@ -0,0 +1,16 @@
+//go:build !windows
+
+package server
+
+// isProcessElevated is only meaningful on Windows; other platforms use the
+// effective UID check in isCurrentProcessPrivileged.
+func isProcessElevated() bool {
+	return false
+}
+
+// isWindowsAccountPrivilegedOrUnknown is only reachable on Windows. Report
+// privileged on other platforms so a caller refusing privileged accounts fails
+// closed.
+func isWindowsAccountPrivilegedOrUnknown(string) bool {
+	return true
+}

client/ssh/server/privileges_windows.go

@@ -0,0 +1,228 @@
+//go:build windows
+
+package server
+
+import (
+	"fmt"
+	"strings"
+	"unsafe"
+
+	log "github.com/sirupsen/logrus"
+	"golang.org/x/sys/windows"
+)
+
+var (
+	netapi32                  = windows.NewLazySystemDLL("netapi32.dll")
+	procNetUserGetLocalGroups = netapi32.NewProc("NetUserGetLocalGroups")
+)
+
+const (
+	// lgIncludeIndirect makes NetUserGetLocalGroups also return local groups
+	// the user belongs to through a global group.
+	lgIncludeIndirect  = 0x1
+	maxPreferredLength = 0xFFFFFFFF
+)
+
+// localGroupUsersInfo0 mirrors LOCALGROUP_USERS_INFO_0.
+type localGroupUsersInfo0 struct {
+	name *uint16
+}
+
+// isProcessElevated reports whether the current process token is elevated
+// (TokenElevation): true for elevated administrators, the built-in
+// Administrator, administrators with UAC disabled, and SYSTEM; false for
+// standard users and administrators running with a UAC-filtered token.
+func isProcessElevated() bool {
+	return windows.GetCurrentProcessToken().IsElevated()
+}
+
+// isWindowsAccountPrivilegedOrUnknown reports whether the account is privileged
+// on this machine: a well-known service account, a built-in Administrator
+// (RID 500), or a member of the local Administrators group, directly or through
+// nested groups.
+//
+// An account whose privilege cannot be determined counts as privileged, which
+// is why the name says "or unknown". That is fail-closed for a caller that
+// refuses privileged accounts, and fail-open for a caller that grants something
+// to them, so only the former may use this.
+func isWindowsAccountPrivilegedOrUnknown(username string) bool {
+	sid, _, _, err := windows.LookupSID("", username)
+	if err != nil {
+		log.Warnf("privilege check: SID lookup for %q failed, treating as privileged: %v", username, err)
+		return true
+	}
+
+	if isPrivilegedUserSID(sid) {
+		return true
+	}
+
+	member, err := isLocalAdminsMember(username)
+	if err != nil {
+		log.Warnf("privilege check: cannot determine Administrators membership for %q, treating as privileged: %v", username, err)
+		return true
+	}
+	return member
+}
+
+// isPrivilegedUserSID reports whether the SID itself identifies a privileged
+// principal, without consulting group membership.
+func isPrivilegedUserSID(sid *windows.SID) bool {
+	wellKnown := []windows.WELL_KNOWN_SID_TYPE{
+		windows.WinLocalSystemSid,
+		windows.WinLocalServiceSid,
+		windows.WinNetworkServiceSid,
+		windows.WinBuiltinAdministratorsSid,
+	}
+	for _, sidType := range wellKnown {
+		if sid.IsWellKnown(sidType) {
+			return true
+		}
+	}
+	return isBuiltinAdministratorSID(sid)
+}
+
+// isBuiltinAdministratorSID reports whether the SID is a machine or domain
+// built-in Administrator account (S-1-5-21-...-500). RID 500 is reserved for
+// that account; it can be renamed but cannot be removed from the
+// Administrators group.
+func isBuiltinAdministratorSID(sid *windows.SID) bool {
+	if sid.IdentifierAuthority() != windows.SECURITY_NT_AUTHORITY {
+		return false
+	}
+	count := sid.SubAuthorityCount()
+	if count < 2 || sid.SubAuthority(0) != 21 {
+		return false
+	}
+	return sid.SubAuthority(uint32(count-1)) == 500
+}
+
+// isLocalAdminsMember reports whether the account is a member of the local
+// Administrators group.
+//
+// Local accounts are checked against the local SAM, which is authoritative for
+// them and, unlike a token, cannot under-report: UAC filters the tokens of
+// local administrators, and a filtered token carries Administrators as
+// deny-only, which a membership check on the token would read as "not a
+// member". Domain accounts are exempt from that filtering, so for them an S4U
+// token is preferred because its group list is LSA's transitive expansion and
+// therefore covers nested and universal groups plus the machine's own local
+// groups. NetUserGetLocalGroups expands only one global-group hop but needs no
+// logon, so it serves as the fallback when no token can be obtained.
+func isLocalAdminsMember(username string) (bool, error) {
+	adminSid, err := windows.CreateWellKnownSid(windows.WinBuiltinAdministratorsSid)
+	if err != nil {
+		return false, fmt.Errorf("create Administrators SID: %w", err)
+	}
+
+	account, domain := parseUsername(username)
+	if NewPrivilegeDropper().isLocalUser(domain) {
+		return localGroupsContainSID(account, adminSid)
+	}
+
+	member, s4uErr := s4uTokenIsMember(account, domain, adminSid)
+	if s4uErr == nil {
+		return member, nil
+	}
+	log.Debugf("privilege check: S4U membership check for %q failed, falling back to local group enumeration: %v", username, s4uErr)
+
+	member, err = localGroupsContainSID(buildUserCpn(account, domain), adminSid)
+	if err != nil {
+		return false, fmt.Errorf("S4U check: %w; local group enumeration: %w", s4uErr, err)
+	}
+	return member, nil
+}
+
+// s4uTokenIsMember obtains an S4U token for the account and checks whether the
+// given SID is enabled in it.
+func s4uTokenIsMember(account, domain string, sid *windows.SID) (bool, error) {
+	token, err := generateS4UUserToken(log.NewEntry(log.StandardLogger()), account, domain)
+	if err != nil {
+		return false, err
+	}
+	defer func() {
+		if err := windows.CloseHandle(token); err != nil {
+			log.Debugf("close S4U token: %v", err)
+		}
+	}()
+	return windows.Token(token).IsMember(sid)
+}
+
+// localGroupsContainSID reports whether the wanted group is among the local
+// groups the account belongs to, directly or through a global group.
+//
+// The wanted SID is resolved to its group name once and compared against the
+// enumerated names. Well-known SIDs resolve from a static table, so that lookup
+// needs no domain controller, and it keeps the comparison correct for a renamed
+// or localized group because both sides then carry the new name. Resolving each
+// enumerated name back to a SID instead would add a lookup per group that can
+// block until it times out while a domain controller is unreachable, and cannot
+// change the outcome: the names enumerated here are local groups of this
+// machine, whose names are unique, so a name match identifies the group.
+//
+// A failure to resolve the wanted SID is returned rather than reported as
+// "not a member", so a privilege check built on this fails closed.
+func localGroupsContainSID(username string, want *windows.SID) (bool, error) {
+	wantName, _, _, err := want.LookupAccount("")
+	if err != nil {
+		return false, fmt.Errorf("resolve group SID %s to a name: %w", want, err)
+	}
+
+	groups, err := netUserGetLocalGroups(username)
+	if err != nil {
+		return false, err
+	}
+
+	for _, group := range groups {
+		if strings.EqualFold(group, wantName) {
+			return true, nil
+		}
+	}
+	return false, nil
+}
+
+// netUserGetLocalGroups returns the names of the local groups the account is a
+// member of, including indirect membership through global groups.
+func netUserGetLocalGroups(username string) ([]string, error) {
+	name16, err := windows.UTF16PtrFromString(username)
+	if err != nil {
+		return nil, fmt.Errorf("convert username: %w", err)
+	}
+
+	var buf *byte
+	var entriesRead, totalEntries uint32
+	status, _, _ := procNetUserGetLocalGroups.Call(
+		0, // local server
+		uintptr(unsafe.Pointer(name16)),
+		0, // level 0: LOCALGROUP_USERS_INFO_0
+		lgIncludeIndirect,
+		uintptr(unsafe.Pointer(&buf)),
+		maxPreferredLength,
+		uintptr(unsafe.Pointer(&entriesRead)),
+		uintptr(unsafe.Pointer(&totalEntries)),
+	)
+	if status != 0 {
+		return nil, fmt.Errorf("NetUserGetLocalGroups for %q: status %d", username, status)
+	}
+	if buf == nil {
+		return nil, nil
+	}
+	defer func() {
+		if err := windows.NetApiBufferFree(buf); err != nil {
+			log.Debugf("free NetApi buffer: %v", err)
+		}
+	}()
+
+	// MAX_PREFERRED_LENGTH makes the API allocate as much as it needs, so a
+	// short read is not expected. Report it rather than silently returning a
+	// subset of the account's groups.
+	if entriesRead != totalEntries {
+		return nil, fmt.Errorf("NetUserGetLocalGroups for %q returned %d of %d groups", username, entriesRead, totalEntries)
+	}
+
+	entries := unsafe.Slice((*localGroupUsersInfo0)(unsafe.Pointer(buf)), entriesRead)
+	groups := make([]string, 0, entriesRead)
+	for _, entry := range entries {
+		groups = append(groups, windows.UTF16PtrToString(entry.name))
+	}
+	return groups, nil
+}

client/ssh/server/privileges_windows_test.go

@@ -0,0 +1,293 @@
+//go:build windows
+
+package server
+
+import (
+	"os/user"
+	"testing"
+	"unsafe"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"golang.org/x/sys/windows"
+)
+
+// filterNormalAccount limits NetUserEnum to normal user accounts.
+const filterNormalAccount = 0x2
+
+// TOKEN_ELEVATION_TYPE values.
+const (
+	tokenElevationTypeDefault = 1
+	tokenElevationTypeFull    = 2
+	tokenElevationTypeLimited = 3
+)
+
+// tokenElevationType reads TokenElevationType from a token.
+func tokenElevationType(token windows.Token) (uint32, error) {
+	var elevationType, returnedLen uint32
+	err := windows.GetTokenInformation(token, windows.TokenElevationType,
+		(*byte)(unsafe.Pointer(&elevationType)), uint32(unsafe.Sizeof(elevationType)), &returnedLen)
+	if err != nil {
+		return 0, err
+	}
+	return elevationType, nil
+}
+
+// userInfo0 mirrors USER_INFO_0.
+type userInfo0 struct {
+	name *uint16
+}
+
+func mustParseSID(t *testing.T, s string) *windows.SID {
+	t.Helper()
+	sid, err := windows.StringToSid(s)
+	require.NoError(t, err, "parse SID %s", s)
+	return sid
+}
+
+// localAccountNames returns the names of the local user accounts.
+func localAccountNames(t *testing.T) []string {
+	t.Helper()
+
+	var buf *byte
+	var entriesRead, totalEntries, resume uint32
+	err := windows.NetUserEnum(nil, 0, filterNormalAccount, &buf, maxPreferredLength,
+		&entriesRead, &totalEntries, &resume)
+	require.NoError(t, err, "enumerate local users")
+	t.Cleanup(func() {
+		require.NoError(t, windows.NetApiBufferFree(buf), "free NetApi buffer")
+	})
+
+	entries := unsafe.Slice((*userInfo0)(unsafe.Pointer(buf)), entriesRead)
+	names := make([]string, 0, entriesRead)
+	for _, entry := range entries {
+		names = append(names, windows.UTF16PtrToString(entry.name))
+	}
+	return names
+}
+
+// localAccountNameByRID returns the name of the local account carrying the
+// given RID. Accounts such as Administrator and Guest can be renamed and are
+// localized, so tests must not name them literally.
+func localAccountNameByRID(t *testing.T, rid uint32) string {
+	t.Helper()
+
+	for _, name := range localAccountNames(t) {
+		sid, _, _, err := windows.LookupSID("", name)
+		if err != nil {
+			continue
+		}
+		if sid.IdentifierAuthority() != windows.SECURITY_NT_AUTHORITY {
+			continue
+		}
+		count := sid.SubAuthorityCount()
+		if count < 2 || sid.SubAuthority(0) != 21 {
+			continue
+		}
+		if sid.SubAuthority(uint32(count-1)) == rid {
+			return name
+		}
+	}
+
+	t.Fatalf("no local account with RID %d", rid)
+	return ""
+}
+
+// wellKnownAccountName resolves a well-known SID to the qualified account name
+// the local system uses for it, which is localized.
+func wellKnownAccountName(t *testing.T, sidType windows.WELL_KNOWN_SID_TYPE) string {
+	t.Helper()
+
+	sid, err := windows.CreateWellKnownSid(sidType)
+	require.NoError(t, err, "create well-known SID")
+	name, domain, _, err := sid.LookupAccount("")
+	require.NoError(t, err, "resolve %s to an account name", sid)
+	if domain == "" {
+		return name
+	}
+	return domain + `\` + name
+}
+
+func TestIsBuiltinAdministratorSID(t *testing.T) {
+	tests := []struct {
+		name string
+		sid  string
+		want bool
+	}{
+		{"machine_administrator", "S-1-5-21-1111111111-2222222222-3333333333-500", true},
+		{"domain_administrator", "S-1-5-21-3390233681-4087452608-412898826-500", true},
+		{"regular_user", "S-1-5-21-1111111111-2222222222-3333333333-1001", false},
+		{"guest_account", "S-1-5-21-1111111111-2222222222-3333333333-501", false},
+		{"domain_admins_group", "S-1-5-21-1111111111-2222222222-3333333333-512", false},
+		{"system", "S-1-5-18", false},
+		{"administrators_group", "S-1-5-32-544", false},
+		{"non_nt_authority", "S-1-1-0", false},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := isBuiltinAdministratorSID(mustParseSID(t, tt.sid))
+			assert.Equal(t, tt.want, result, "RID 500 detection for %s", tt.sid)
+		})
+	}
+}
+
+func TestIsPrivilegedUserSID(t *testing.T) {
+	tests := []struct {
+		name string
+		sid  string
+		want bool
+	}{
+		{"local_system", "S-1-5-18", true},
+		{"local_service", "S-1-5-19", true},
+		{"network_service", "S-1-5-20", true},
+		{"administrators_group", "S-1-5-32-544", true},
+		{"builtin_administrator", "S-1-5-21-1111111111-2222222222-3333333333-500", true},
+		{"regular_user", "S-1-5-21-1111111111-2222222222-3333333333-1001", false},
+		{"users_group", "S-1-5-32-545", false},
+		{"everyone", "S-1-1-0", false},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := isPrivilegedUserSID(mustParseSID(t, tt.sid))
+			assert.Equal(t, tt.want, result, "SID privilege classification for %s", tt.sid)
+		})
+	}
+}
+
+func TestIsWindowsAccountPrivilegedOrUnknown(t *testing.T) {
+	tests := []struct {
+		name     string
+		username string
+		want     bool
+	}{
+		{"system", wellKnownAccountName(t, windows.WinLocalSystemSid), true},
+		{"local_service", wellKnownAccountName(t, windows.WinLocalServiceSid), true},
+		{"network_service", wellKnownAccountName(t, windows.WinNetworkServiceSid), true},
+		{"administrators_group", wellKnownAccountName(t, windows.WinBuiltinAdministratorsSid), true},
+		// The built-in Administrator (RID 500) and Guest (RID 501) accounts
+		// exist on every Windows installation, though they may be disabled.
+		{"builtin_administrator", localAccountNameByRID(t, 500), true},
+		{"guest", localAccountNameByRID(t, 501), false},
+		// Unresolvable accounts fail closed.
+		{"nonexistent_user", "netbird-no-such-user", true},
+		{"empty_username", "", true},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := isWindowsAccountPrivilegedOrUnknown(tt.username)
+			assert.Equal(t, tt.want, result, "account privilege classification for %q", tt.username)
+		})
+	}
+}
+
+func TestIsProcessElevated(t *testing.T) {
+	elevated := isProcessElevated()
+
+	// TokenElevationType is a second, independent view of the same token:
+	// Full means elevated and Limited means a filtered administrator, while
+	// Default covers both a standard user and an administrator with no linked
+	// token (UAC off, the built-in Administrator, SYSTEM), so it implies nothing.
+	elevationType, err := tokenElevationType(windows.GetCurrentProcessToken())
+	require.NoError(t, err, "read token elevation type")
+
+	adminSid, err := windows.CreateWellKnownSid(windows.WinBuiltinAdministratorsSid)
+	require.NoError(t, err, "create Administrators SID")
+
+	// Token(0) makes CheckTokenMembership evaluate the caller's own token. It
+	// counts only enabled SIDs, so a filtered administrator reports false here.
+	member, err := windows.Token(0).IsMember(adminSid)
+	require.NoError(t, err, "check own Administrators membership")
+
+	t.Logf("elevated=%v elevationType=%d memberOfAdministrators=%v", elevated, elevationType, member)
+
+	switch elevationType {
+	case tokenElevationTypeFull:
+		assert.True(t, elevated, "a token of elevation type Full must report elevated")
+	case tokenElevationTypeLimited:
+		assert.False(t, elevated, "a filtered administrator token must not report elevated")
+	}
+
+	// Administrators enabled in the token means the token wields administrative
+	// rights, which is what elevation reports.
+	if member {
+		assert.True(t, elevated, "token with enabled Administrators membership must report elevated")
+	}
+}
+
+// TestS4UMembershipAgreesWithLocalGroups exercises the S4U token path used
+// for domain accounts. S4U logons need the TCB privilege, so the test runs
+// only as SYSTEM (which is how CI executes the suite). For local accounts the
+// token's Administrators membership must agree with the SAM enumeration.
+func TestS4UMembershipAgreesWithLocalGroups(t *testing.T) {
+	system, err := windows.CreateWellKnownSid(windows.WinLocalSystemSid)
+	require.NoError(t, err, "create SYSTEM SID")
+	current, err := user.Current()
+	require.NoError(t, err, "get current user")
+	if current.Uid != system.String() {
+		t.Skipf("S4U logon requires SYSTEM (running as %s)", current.Username)
+	}
+
+	adminSid, err := windows.CreateWellKnownSid(windows.WinBuiltinAdministratorsSid)
+	require.NoError(t, err, "create Administrators SID")
+
+	checked := 0
+	for _, name := range localAccountNames(t) {
+		viaToken, err := s4uTokenIsMember(name, ".", adminSid)
+		if err != nil {
+			// Disabled or logon-restricted accounts cannot get an S4U logon.
+			t.Logf("skipping %s: %v", name, err)
+			continue
+		}
+		viaSAM, err := localGroupsContainSID(name, adminSid)
+		require.NoError(t, err, "enumerate local groups for %s", name)
+
+		assert.Equal(t, viaSAM, viaToken, "S4U token and SAM enumeration must agree on Administrators membership for %s", name)
+		checked++
+	}
+	// Ineligible accounts are skipped, so without this the test could report
+	// success while comparing nothing at all.
+	require.Positive(t, checked, "no local account completed an S4U logon, so nothing was compared")
+	t.Logf("checked %d local accounts via S4U", checked)
+}
+
+// TestLocalGroupsContainSID_Administrator checks the positive case against the
+// built-in Administrator, a member of Administrators on every installation.
+func TestLocalGroupsContainSID_Administrator(t *testing.T) {
+	adminSid, err := windows.CreateWellKnownSid(windows.WinBuiltinAdministratorsSid)
+	require.NoError(t, err, "create Administrators SID")
+
+	administrator := localAccountNameByRID(t, 500)
+	member, err := localGroupsContainSID(administrator, adminSid)
+	require.NoError(t, err, "enumerate local groups for %s", administrator)
+	assert.True(t, member, "%s is a member of the Administrators group", administrator)
+}
+
+// TestLocalGroupsContainSID_UnresolvableGroupFailsClosed covers a wanted SID
+// that resolves to no group: the error must surface rather than being reported
+// as "not a member", so the privilege check treats the account as privileged.
+func TestLocalGroupsContainSID_UnresolvableGroupFailsClosed(t *testing.T) {
+	unknown := mustParseSID(t, "S-1-5-21-1111111111-2222222222-3333333333-4444")
+
+	_, err := localGroupsContainSID(localAccountNameByRID(t, 500), unknown)
+	require.Error(t, err, "must report an error when the wanted group cannot be identified")
+}
+
+func TestLocalGroupsContainSID_Guest(t *testing.T) {
+	guestsSid, err := windows.CreateWellKnownSid(windows.WinBuiltinGuestsSid)
+	require.NoError(t, err, "create Guests SID")
+	adminsSid, err := windows.CreateWellKnownSid(windows.WinBuiltinAdministratorsSid)
+	require.NoError(t, err, "create Administrators SID")
+
+	guest := localAccountNameByRID(t, 501)
+
+	inGuests, err := localGroupsContainSID(guest, guestsSid)
+	require.NoError(t, err, "enumerate local groups for %s", guest)
+	assert.True(t, inGuests, "%s is a member of the Guests group", guest)
+
+	inAdmins, err := localGroupsContainSID(guest, adminsSid)
+	require.NoError(t, err, "enumerate local groups for %s", guest)
+	assert.False(t, inAdmins, "%s is not a member of the Administrators group", guest)
+}

client/ssh/server/server_config_test.go

@@ -239,6 +239,7 @@ func TestServer_PrivilegedPortAccess(t *testing.T) {
 		forwardType   string
 		port          uint32
 		username      string
+		uid           string
 		expectError   bool
 		errorMsg      string
 		skipOnWindows bool
@@ -248,6 +249,7 @@ func TestServer_PrivilegedPortAccess(t *testing.T) {
 			forwardType:   "remote",
 			port:          80,
 			username:      "testuser",
+			uid:           "1000",
 			expectError:   true,
 			errorMsg:      "cannot bind to privileged port",
 			skipOnWindows: true,
@@ -257,6 +259,7 @@ func TestServer_PrivilegedPortAccess(t *testing.T) {
 			forwardType:   "tcpip-forward",
 			port:          443,
 			username:      "testuser",
+			uid:           "1000",
 			expectError:   true,
 			errorMsg:      "cannot bind to privileged port",
 			skipOnWindows: true,
@@ -266,6 +269,7 @@ func TestServer_PrivilegedPortAccess(t *testing.T) {
 			forwardType: "remote",
 			port:        8080,
 			username:    "testuser",
+			uid:         "1000",
 			expectError: false,
 		},
 		{
@@ -273,6 +277,7 @@ func TestServer_PrivilegedPortAccess(t *testing.T) {
 			forwardType: "remote",
 			port:        0,
 			username:    "testuser",
+			uid:         "1000",
 			expectError: false,
 		},
 		{
@@ -280,13 +285,35 @@ func TestServer_PrivilegedPortAccess(t *testing.T) {
 			forwardType: "remote",
 			port:        22,
 			username:    "root",
+			uid:         "0",
 			expectError: false,
 		},
+		{
+			// Only uid 0 is privileged, whatever the account is called.
+			name:          "uid 0 under another name may bind a privileged port",
+			forwardType:   "remote",
+			port:          22,
+			username:      "toor",
+			uid:           "0",
+			expectError:   false,
+			skipOnWindows: true,
+		},
+		{
+			name:          "account named root without uid 0 may not",
+			forwardType:   "remote",
+			port:          22,
+			username:      "root",
+			uid:           "1000",
+			expectError:   true,
+			errorMsg:      "cannot bind to privileged port",
+			skipOnWindows: true,
+		},
 		{
 			name:        "local forward privileged port allowed for non-root",
 			forwardType: "local",
 			port:        80,
 			username:    "testuser",
+			uid:         "1000",
 			expectError: false,
 		},
 	}
@@ -299,7 +326,7 @@ func TestServer_PrivilegedPortAccess(t *testing.T) {
 
 			result := PrivilegeCheckResult{
 				Allowed: true,
-				User:    &user.User{Username: tt.username},
+				User:    &user.User{Username: tt.username, Uid: tt.uid},
 			}
 
 			err := server.checkPrivilegedPortAccess(tt.forwardType, tt.port, result)
@@ -420,6 +447,13 @@ func TestServer_PortConflictHandling(t *testing.T) {
 
 func TestServer_IsPrivilegedUser(t *testing.T) {
 
+	// Windows classification depends on account SIDs and group membership, and
+	// the accounts involved carry localized, renameable names. It is covered by
+	// TestIsWindowsAccountPrivileged, which resolves them from well-known SIDs.
+	if runtime.GOOS == "windows" {
+		t.Skip("covered by TestIsWindowsAccountPrivileged")
+	}
+
 	tests := []struct {
 		username    string
 		expected    bool
@@ -440,44 +474,16 @@ func TestServer_IsPrivilegedUser(t *testing.T) {
 			expected:    false,
 			description: "empty username should not be privileged",
 		},
-	}
-
-	// Add Windows-specific tests
-	if runtime.GOOS == "windows" {
-		tests = append(tests, []struct {
-			username    string
-			expected    bool
-			description string
-		}{
-			{
-				username:    "Administrator",
-				expected:    true,
-				description: "Administrator should be considered privileged on Windows",
-			},
-			{
-				username:    "administrator",
-				expected:    true,
-				description: "administrator should be considered privileged on Windows (case insensitive)",
-			},
-		}...)
-	} else {
-		// On non-Windows systems, Administrator should not be privileged
-		tests = append(tests, []struct {
-			username    string
-			expected    bool
-			description string
-		}{
-			{
-				username:    "Administrator",
-				expected:    false,
-				description: "Administrator should not be privileged on non-Windows systems",
-			},
-		}...)
+		{
+			username:    "Administrator",
+			expected:    false,
+			description: "Administrator should not be privileged on non-Windows systems",
+		},
 	}
 
 	for _, tt := range tests {
 		t.Run(tt.description, func(t *testing.T) {
-			result := isPrivilegedUsername(tt.username)
+			result := isPrivilegedOrUnknown(tt.username)
 			assert.Equal(t, tt.expected, result, tt.description)
 		})
 	}

client/ssh/server/sftp_windows.go

@@ -17,7 +17,7 @@ import (
 // createSftpCommand creates a Windows SFTP command with user switching.
 // The caller must close the returned token handle after starting the process.
 func (s *Server) createSftpCommand(targetUser *user.User, sess ssh.Session) (*exec.Cmd, windows.Token, error) {
-	username, domain := s.parseUsername(targetUser.Username)
+	username, domain := parseUsername(targetUser.Username)
 
 	netbirdPath, err := os.Executable()
 	if err != nil {

client/ssh/server/user_utils.go

@@ -16,11 +16,6 @@ var (
 	ErrPrivilegedUserSwitch = errors.New("cannot switch to privileged user - current user lacks required privileges")
 )
 
-// isPlatformUnix returns true for Unix-like platforms (Linux, macOS, etc.)
-func isPlatformUnix() bool {
-	return getCurrentOS() != "windows"
-}
-
 // Dependency injection variables for testing - allows mocking dynamic runtime checks
 var (
 	getCurrentUser         = currentUserWithGetent
@@ -29,6 +24,9 @@ var (
 	getIsProcessPrivileged = isCurrentProcessPrivileged
 
 	getEuid = os.Geteuid
+
+	getProcessElevated                   = isProcessElevated
+	getWindowsAccountPrivilegedOrUnknown = isWindowsAccountPrivilegedOrUnknown
 )
 
 const (
@@ -65,6 +63,13 @@ type PrivilegeCheckResult struct {
 	RequiresUserSwitching bool
 }
 
+// privilegeCheckContext holds all context needed for privilege checking
+type privilegeCheckContext struct {
+	currentUser           *user.User
+	currentUserPrivileged bool
+	allowRoot             bool
+}
+
 // CheckPrivileges performs comprehensive privilege checking for all SSH features.
 // This is the single source of truth for privilege decisions across the SSH server.
 func (s *Server) CheckPrivileges(req PrivilegeCheckRequest) PrivilegeCheckResult {
@@ -75,7 +80,7 @@ func (s *Server) CheckPrivileges(req PrivilegeCheckRequest) PrivilegeCheckResult
 
 	// Handle empty username case - but still check root access controls
 	if req.RequestedUsername == "" {
-		if isPrivilegedUsername(context.currentUser.Username) && !context.allowRoot {
+		if isPrivilegedOrUnknown(context.currentUser.Username) && !context.allowRoot {
 			return PrivilegeCheckResult{
 				Allowed: false,
 				Error:   &PrivilegedUserError{Username: context.currentUser.Username},
@@ -135,7 +140,7 @@ func (s *Server) checkUserRequest(ctx *privilegeCheckContext, req PrivilegeCheck
 
 	needsUserSwitching := !isSameResolvedUser(resolvedUser, ctx.currentUser)
 
-	if isPrivilegedUsername(resolvedUser.Username) && !ctx.allowRoot {
+	if isPrivilegedOrUnknown(resolvedUser.Username) && !ctx.allowRoot {
 		return PrivilegeCheckResult{
 			Allowed:               false,
 			Error:                 &PrivilegedUserError{Username: resolvedUser.Username},
@@ -175,6 +180,42 @@ func (s *Server) resolveRequestedUser(requestedUsername string) (*user.User, err
 	return u, nil
 }
 
+// SetAllowRootLogin configures root login access
+func (s *Server) SetAllowRootLogin(allow bool) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.allowRootLogin = allow
+}
+
+// userNameLookup performs user lookup with root login permission check
+func (s *Server) userNameLookup(username string) (*user.User, error) {
+	result, err := s.userPrivilegeCheck(username)
+	if err != nil {
+		return nil, err
+	}
+	return result.User, nil
+}
+
+// userPrivilegeCheck performs user lookup with full privilege check result
+func (s *Server) userPrivilegeCheck(username string) (PrivilegeCheckResult, error) {
+	result := s.CheckPrivileges(PrivilegeCheckRequest{
+		RequestedUsername:         username,
+		FeatureSupportsUserSwitch: true,
+		FeatureName:               FeatureSSHLogin,
+	})
+
+	if !result.Allowed {
+		return result, result.Error
+	}
+
+	return result, nil
+}
+
+// isPlatformUnix returns true for Unix-like platforms (Linux, macOS, etc.)
+func isPlatformUnix() bool {
+	return getCurrentOS() != "windows"
+}
+
 // isSameResolvedUser compares two resolved user identities
 func isSameResolvedUser(user1, user2 *user.User) bool {
 	if user1 == nil || user2 == nil {
@@ -183,13 +224,6 @@ func isSameResolvedUser(user1, user2 *user.User) bool {
 	return user1.Uid == user2.Uid
 }
 
-// privilegeCheckContext holds all context needed for privilege checking
-type privilegeCheckContext struct {
-	currentUser           *user.User
-	currentUserPrivileged bool
-	allowRoot             bool
-}
-
 // isSameUser checks if two usernames refer to the same user
 // SECURITY: This function must be conservative - it should only return true
 // when we're certain both usernames refer to the exact same user identity
@@ -253,159 +287,30 @@ func isWindowsSameUser(requestedUsername, currentUsername string) bool {
 	return strings.EqualFold(reqDomain, curDomain)
 }
 
-// SetAllowRootLogin configures root login access
-func (s *Server) SetAllowRootLogin(allow bool) {
-	s.mu.Lock()
-	defer s.mu.Unlock()
-	s.allowRootLogin = allow
-}
-
-// userNameLookup performs user lookup with root login permission check
-func (s *Server) userNameLookup(username string) (*user.User, error) {
-	result := s.CheckPrivileges(PrivilegeCheckRequest{
-		RequestedUsername:         username,
-		FeatureSupportsUserSwitch: true,
-		FeatureName:               FeatureSSHLogin,
-	})
-
-	if !result.Allowed {
-		return nil, result.Error
-	}
-
-	return result.User, nil
-}
-
-// userPrivilegeCheck performs user lookup with full privilege check result
-func (s *Server) userPrivilegeCheck(username string) (PrivilegeCheckResult, error) {
-	result := s.CheckPrivileges(PrivilegeCheckRequest{
-		RequestedUsername:         username,
-		FeatureSupportsUserSwitch: true,
-		FeatureName:               FeatureSSHLogin,
-	})
-
-	if !result.Allowed {
-		return result, result.Error
-	}
-
-	return result, nil
-}
-
-// isPrivilegedUsername checks if the given username represents a privileged user across platforms.
-// On Unix: root
-// On Windows: Administrator, SYSTEM (case-insensitive)
-// Handles domain-qualified usernames like "DOMAIN\Administrator" or "user@domain.com"
-func isPrivilegedUsername(username string) bool {
+// isPrivilegedOrUnknown reports whether the given username represents a
+// privileged user, or on Windows an account whose privilege could not be
+// determined.
+// On Unix: root.
+// On Windows: well-known service accounts, built-in Administrator accounts,
+// and members of the local Administrators group; handles domain-qualified
+// usernames like "DOMAIN\user" or "user@domain.com". An account that cannot be
+// resolved or evaluated is reported as privileged.
+//
+// Use this to refuse privileged accounts, never to grant them anything: the
+// undetermined case is safe for a refusal and unsafe for a grant.
+func isPrivilegedOrUnknown(username string) bool {
 	if getCurrentOS() != "windows" {
 		return username == "root"
 	}
-
-	bareUsername := username
-	// Handle Windows domain format: DOMAIN\username
-	if idx := strings.LastIndex(username, `\`); idx != -1 {
-		bareUsername = username[idx+1:]
-	}
-	// Handle email-style format: username@domain.com
-	if idx := strings.Index(bareUsername, "@"); idx != -1 {
-		bareUsername = bareUsername[:idx]
-	}
-
-	return isWindowsPrivilegedUser(bareUsername)
-}
-
-// isWindowsPrivilegedUser checks if a bare username (domain already stripped) represents a Windows privileged account
-func isWindowsPrivilegedUser(bareUsername string) bool {
-	// common privileged usernames (case insensitive)
-	privilegedNames := []string{
-		"administrator",
-		"admin",
-		"root",
-		"system",
-		"localsystem",
-		"networkservice",
-		"localservice",
-	}
-
-	usernameLower := strings.ToLower(bareUsername)
-	for _, privilegedName := range privilegedNames {
-		if usernameLower == privilegedName {
-			return true
-		}
-	}
-
-	// computer accounts (ending with $) are not privileged by themselves
-	// They only gain privileges through group membership or specific SIDs
-
-	if targetUser, err := lookupUser(bareUsername); err == nil {
-		return isWindowsPrivilegedSID(targetUser.Uid)
-	}
-
-	return false
-}
-
-// isWindowsPrivilegedSID checks if a Windows SID represents a privileged account
-func isWindowsPrivilegedSID(sid string) bool {
-	privilegedSIDs := []string{
-		"S-1-5-18",     // Local System (SYSTEM)
-		"S-1-5-19",     // Local Service (NT AUTHORITY\LOCAL SERVICE)
-		"S-1-5-20",     // Network Service (NT AUTHORITY\NETWORK SERVICE)
-		"S-1-5-32-544", // Administrators group (BUILTIN\Administrators)
-		"S-1-5-500",    // Built-in Administrator account (local machine RID 500)
-	}
-
-	for _, privilegedSID := range privilegedSIDs {
-		if sid == privilegedSID {
-			return true
-		}
-	}
-
-	// Check for domain administrator accounts (RID 500 in any domain)
-	// Format: S-1-5-21-domain-domain-domain-500
-	// This is reliable as RID 500 is reserved for the domain Administrator account
-	if strings.HasPrefix(sid, "S-1-5-21-") && strings.HasSuffix(sid, "-500") {
-		return true
-	}
-
-	// Check for other well-known privileged RIDs in domain contexts
-	// RID 512 = Domain Admins group, RID 516 = Domain Controllers group
-	if strings.HasPrefix(sid, "S-1-5-21-") {
-		if strings.HasSuffix(sid, "-512") || // Domain Admins group
-			strings.HasSuffix(sid, "-516") || // Domain Controllers group
-			strings.HasSuffix(sid, "-519") { // Enterprise Admins group
-			return true
-		}
-	}
-
-	return false
+	return getWindowsAccountPrivilegedOrUnknown(username)
 }
 
 // isCurrentProcessPrivileged checks if the current process is running with elevated privileges.
 // On Unix systems, this means running as root (UID 0).
-// On Windows, this means running as Administrator or SYSTEM.
+// On Windows, this means the process token is elevated (administrators, SYSTEM).
 func isCurrentProcessPrivileged() bool {
 	if getCurrentOS() == "windows" {
-		return isWindowsElevated()
+		return getProcessElevated()
 	}
 	return getEuid() == 0
 }
-
-// isWindowsElevated checks if the current process is running with elevated privileges on Windows
-func isWindowsElevated() bool {
-	currentUser, err := getCurrentUser()
-	if err != nil {
-		log.Errorf("failed to get current user for privilege check, assuming non-privileged: %v", err)
-		return false
-	}
-
-	if isWindowsPrivilegedSID(currentUser.Uid) {
-		log.Debugf("Windows user switching supported: running as privileged SID %s", currentUser.Uid)
-		return true
-	}
-
-	if isPrivilegedUsername(currentUser.Username) {
-		log.Debugf("Windows user switching supported: running as privileged username %s", currentUser.Username)
-		return true
-	}
-
-	log.Debugf("Windows user switching not supported: not running as privileged user (current: %s)", currentUser.Uid)
-	return false
-}

client/ssh/server/user_utils_test.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"os/user"
 	"runtime"
+	"strings"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -27,8 +28,8 @@ func setupTestDependencies(currentUser *user.User, currentUserErr error, os stri
 	originalLookupUser := lookupUser
 	originalGetCurrentOS := getCurrentOS
 	originalGetEuid := getEuid
-
-	// Reset caches to ensure clean test state
+	originalGetProcessElevated := getProcessElevated
+	originalGetWindowsAccountPrivilegedOrUnknown := getWindowsAccountPrivilegedOrUnknown
 
 	// Set test values - inject platform dependencies
 	getCurrentUser = func() (*user.User, error) {
@@ -53,16 +54,31 @@ func setupTestDependencies(currentUser *user.User, currentUserErr error, os stri
 		return euid
 	}
 
-	// Mock privilege detection based on the test user
-	getIsProcessPrivileged = func() bool {
+	// Simulate the Windows token elevation check based on the fixture user:
+	// the built-in Administrator (RID 500) and SYSTEM run elevated.
+	getProcessElevated = func() bool {
 		if currentUser == nil {
 			return false
 		}
-		// Check both username and SID for Windows systems
-		if os == "windows" && isWindowsPrivilegedSID(currentUser.Uid) {
+		return currentUser.Uid == "S-1-5-18" || strings.HasSuffix(currentUser.Uid, "-500")
+	}
+
+	// Simulate the Windows account classifier for the fixture accounts.
+	// "root" does not exist on Windows; the real classifier fails closed on
+	// unresolvable accounts, so it counts as privileged here too.
+	getWindowsAccountPrivilegedOrUnknown = func(username string) bool {
+		bare := username
+		if idx := strings.LastIndex(bare, `\`); idx != -1 {
+			bare = bare[idx+1:]
+		}
+		if idx := strings.Index(bare, "@"); idx != -1 {
+			bare = bare[:idx]
+		}
+		switch strings.ToLower(bare) {
+		case "administrator", "system", "root":
 			return true
 		}
-		return isPrivilegedUsername(currentUser.Username)
+		return false
 	}
 
 	// Return cleanup function
@@ -71,10 +87,8 @@ func setupTestDependencies(currentUser *user.User, currentUserErr error, os stri
 		lookupUser = originalLookupUser
 		getCurrentOS = originalGetCurrentOS
 		getEuid = originalGetEuid
-
-		getIsProcessPrivileged = isCurrentProcessPrivileged
-
-		// Reset caches after test
+		getProcessElevated = originalGetProcessElevated
+		getWindowsAccountPrivilegedOrUnknown = originalGetWindowsAccountPrivilegedOrUnknown
 	}
 }
 
@@ -421,6 +435,9 @@ func TestUsedFallback_MeansNoPrivilegeDropping(t *testing.T) {
 }
 
 func TestPrivilegedUsernameDetection(t *testing.T) {
+	// Windows classification is syscall-backed (SID resolution, group
+	// membership) and is covered by privileges_windows_test.go; here only the
+	// Unix logic and the platform dispatch are exercised.
 	tests := []struct {
 		name       string
 		username   string
@@ -432,25 +449,9 @@ func TestPrivilegedUsernameDetection(t *testing.T) {
 		{"unix_regular_user", "alice", "linux", false},
 		{"unix_root_capital", "Root", "linux", false}, // Case-sensitive
 
-		// Windows tests
+		// Windows dispatch to the (mocked) account classifier
 		{"windows_administrator", "Administrator", "windows", true},
-		{"windows_system", "SYSTEM", "windows", true},
-		{"windows_admin", "admin", "windows", true},
-		{"windows_admin_lowercase", "administrator", "windows", true}, // Case-insensitive
-		{"windows_domain_admin", "DOMAIN\\Administrator", "windows", true},
-		{"windows_email_admin", "admin@domain.com", "windows", true},
 		{"windows_regular_user", "alice", "windows", false},
-		{"windows_domain_user", "DOMAIN\\alice", "windows", false},
-		{"windows_localsystem", "localsystem", "windows", true},
-		{"windows_networkservice", "networkservice", "windows", true},
-		{"windows_localservice", "localservice", "windows", true},
-
-		// Computer accounts (these depend on current user context in real implementation)
-		{"windows_computer_account", "WIN2K19-C2$", "windows", false},      // Computer account by itself not privileged
-		{"windows_domain_computer", "DOMAIN\\COMPUTER$", "windows", false}, // Domain computer account
-
-		// Cross-platform
-		{"root_on_windows", "root", "windows", true}, // Root should be privileged everywhere
 	}
 
 	for _, tt := range tests {
@@ -459,50 +460,8 @@ func TestPrivilegedUsernameDetection(t *testing.T) {
 			cleanup := setupTestDependencies(nil, nil, tt.platform, 1000, nil, nil)
 			defer cleanup()
 
-			result := isPrivilegedUsername(tt.username)
-			assert.Equal(t, tt.privileged, result)
-		})
-	}
-}
-
-func TestWindowsPrivilegedSIDDetection(t *testing.T) {
-	tests := []struct {
-		name        string
-		sid         string
-		privileged  bool
-		description string
-	}{
-		// Well-known system accounts
-		{"system_account", "S-1-5-18", true, "Local System (SYSTEM)"},
-		{"local_service", "S-1-5-19", true, "Local Service"},
-		{"network_service", "S-1-5-20", true, "Network Service"},
-		{"administrators_group", "S-1-5-32-544", true, "Administrators group"},
-		{"builtin_administrator", "S-1-5-500", true, "Built-in Administrator"},
-
-		// Domain accounts
-		{"domain_administrator", "S-1-5-21-1234567890-1234567890-1234567890-500", true, "Domain Administrator (RID 500)"},
-		{"domain_admins_group", "S-1-5-21-1234567890-1234567890-1234567890-512", true, "Domain Admins group"},
-		{"domain_controllers_group", "S-1-5-21-1234567890-1234567890-1234567890-516", true, "Domain Controllers group"},
-		{"enterprise_admins_group", "S-1-5-21-1234567890-1234567890-1234567890-519", true, "Enterprise Admins group"},
-
-		// Regular users
-		{"regular_user", "S-1-5-21-1234567890-1234567890-1234567890-1001", false, "Regular domain user"},
-		{"another_regular_user", "S-1-5-21-1234567890-1234567890-1234567890-1234", false, "Another regular user"},
-		{"local_user", "S-1-5-21-1234567890-1234567890-1234567890-1000", false, "Local regular user"},
-
-		// Groups that are not privileged
-		{"domain_users", "S-1-5-21-1234567890-1234567890-1234567890-513", false, "Domain Users group"},
-		{"power_users", "S-1-5-32-547", false, "Power Users group"},
-
-		// Invalid SIDs
-		{"malformed_sid", "S-1-5-invalid", false, "Malformed SID"},
-		{"empty_sid", "", false, "Empty SID"},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			result := isWindowsPrivilegedSID(tt.sid)
-			assert.Equal(t, tt.privileged, result, "Failed for %s: %s", tt.description, tt.sid)
+			result := isPrivilegedOrUnknown(tt.username)
+			assert.Equal(t, tt.privileged, result, "privilege classification for %s on %s", tt.username, tt.platform)
 		})
 	}
 }

client/ssh/server/userswitching_windows.go

@@ -91,7 +91,7 @@ func validateUsernameFormat(username string) error {
 func (s *Server) createExecutorCommand(logger *log.Entry, session ssh.Session, localUser *user.User, hasPty bool) (*exec.Cmd, func(), error) {
 	logger.Debugf("creating Windows executor command for user %s (Pty: %v)", localUser.Username, hasPty)
 
-	username, _ := s.parseUsername(localUser.Username)
+	username, _ := parseUsername(localUser.Username)
 	if err := validateUsername(username); err != nil {
 		return nil, nil, fmt.Errorf("invalid username %q: %w", username, err)
 	}
@@ -102,7 +102,7 @@ func (s *Server) createExecutorCommand(logger *log.Entry, session ssh.Session, l
 // createUserSwitchCommand creates a command with Windows user switching.
 // Returns the command and a cleanup function that must be called after starting the process.
 func (s *Server) createUserSwitchCommand(logger *log.Entry, session ssh.Session, localUser *user.User) (*exec.Cmd, func(), error) {
-	username, domain := s.parseUsername(localUser.Username)
+	username, domain := parseUsername(localUser.Username)
 
 	shell := getUserShell(localUser.Uid)
 
@@ -138,7 +138,7 @@ func (s *Server) createUserSwitchCommand(logger *log.Entry, session ssh.Session,
 }
 
 // parseUsername extracts username and domain from a Windows username
-func (s *Server) parseUsername(fullUsername string) (username, domain string) {
+func parseUsername(fullUsername string) (username, domain string) {
 	// Handle DOMAIN\username format
 	if idx := strings.LastIndex(fullUsername, `\`); idx != -1 {
 		domain = fullUsername[:idx]

client/status/status.go

@@ -46,7 +46,10 @@ func ParseDaemonStatus(s string) DaemonStatus {
 
 // ConvertOptions holds parameters for ConvertToStatusOutputOverview.
 type ConvertOptions struct {
-	Anonymize            bool
+	Anonymize bool
+	// AnonymizeLevel selects how much the anonymizer redacts. Only
+	// meaningful when Anonymize is set.
+	AnonymizeLevel       anonymize.Level
 	DaemonVersion        string
 	DaemonStatus         DaemonStatus
 	StatusFilter         string
@@ -217,6 +220,7 @@ func ConvertToStatusOutputOverview(pbFullStatus *proto.FullStatus, opts ConvertO
 
 	if opts.Anonymize {
 		anonymizer := anonymize.NewAnonymizer(anonymize.DefaultAddresses())
+		anonymizer.SetLevel(opts.AnonymizeLevel)
 		anonymizeOverview(anonymizer, &overview)
 	}
 
@@ -976,6 +980,7 @@ func timeAgo(t time.Time) string {
 
 func anonymizePeerDetail(a *anonymize.Anonymizer, peer *PeerStateDetailOutput) {
 	peer.FQDN = a.AnonymizeDomain(peer.FQDN)
+	peer.PubKey = a.AnonymizeWGKey(peer.PubKey)
 	if localIP, port, err := net.SplitHostPort(peer.IceCandidateEndpoint.Local); err == nil {
 		peer.IceCandidateEndpoint.Local = fmt.Sprintf("%s:%s", a.AnonymizeIPString(localIP), port)
 	}
@@ -1007,6 +1012,7 @@ func anonymizeOverview(a *anonymize.Anonymizer, overview *OutputOverview) {
 	overview.SignalState.URL = a.AnonymizeURI(overview.SignalState.URL)
 	overview.SignalState.Error = a.AnonymizeString(overview.SignalState.Error)
 
+	overview.PubKey = a.AnonymizeWGKey(overview.PubKey)
 	overview.IP = a.AnonymizeIPString(overview.IP)
 	overview.IPv6 = a.AnonymizeIPString(overview.IPv6)
 	for i, detail := range overview.Relays.Details {

client/ui/frontend/src/contexts/DebugBundleContext.tsx

@@ -71,10 +71,12 @@ type BundleOptions = {
     hasWindow: boolean;
     totalSec: number;
     uploadUrl: string;
-    anonymize: boolean;
+    anonymizeLevel: AnonymizeLevel;
     systemInfo: boolean;
 };
 
+export type AnonymizeLevel = "none" | "default" | "strict";
+
 const startCaptureBestEffort = async (totalSec: number, pcap: CaptureState) => {
     try {
         // Mirror the CLI's safety margin: window + 30s, server caps at 10m.
@@ -187,7 +189,10 @@ const runBundleFlow = async (
 
     if (opts.uploadUrl) setStage({ kind: "uploading" });
     const result = await DebugSvc.Bundle({
-        anonymize: opts.anonymize,
+        anonymize: opts.anonymizeLevel !== "none",
+        // The daemon only knows "default" and "strict"; "none" is expressed
+        // through the anonymize flag being off.
+        anonymizeLevel: opts.anonymizeLevel === "strict" ? "strict" : "default",
         systemInfo: opts.systemInfo,
         uploadUrl: opts.uploadUrl,
         logFileCount,
@@ -198,7 +203,7 @@ const runBundleFlow = async (
 };
 
 const useDebugBundle = () => {
-    const [anonymize, setAnonymize] = useState(false);
+    const [anonymizeLevel, setAnonymizeLevel] = useState<AnonymizeLevel>("none");
     const [systemInfo, setSystemInfo] = useState(true);
     const [upload, setUpload] = useState(true);
     const [trace, setTrace] = useState(true);
@@ -240,7 +245,7 @@ const useDebugBundle = () => {
             hasWindow: capture && totalSec > 0,
             totalSec,
             uploadUrl: upload ? NETBIRD_UPLOAD_URL : "",
-            anonymize,
+            anonymizeLevel,
             systemInfo,
         };
 
@@ -272,8 +277,8 @@ const useDebugBundle = () => {
     };
 
     return {
-        anonymize,
-        setAnonymize,
+        anonymizeLevel,
+        setAnonymizeLevel,
         systemInfo,
         setSystemInfo,
         upload,

client/ui/frontend/src/hooks/useKeepConnectedOnQuit.ts

@@ -0,0 +1,35 @@
+import { useCallback, useEffect, useState } from "react";
+import { Preferences } from "@bindings/services";
+
+export const useKeepConnectedOnQuit = () => {
+    const [keepConnected, setKeepConnected] = useState<boolean | null>(null);
+
+    useEffect(() => {
+        let cancelled = false;
+        Preferences.Get()
+            .then((prefs) => {
+                if (cancelled) return;
+                setKeepConnected(prefs?.keepConnectedOnQuit ?? false);
+            })
+            .catch((err: unknown) => {
+                if (cancelled) return;
+                console.warn("[useKeepConnectedOnQuit] load preferences failed", err);
+                setKeepConnected(false);
+            });
+        return () => {
+            cancelled = true;
+        };
+    }, []);
+
+    const setKeepConnectedOnQuit = useCallback(async (keep: boolean) => {
+        setKeepConnected(keep);
+        try {
+            await Preferences.SetKeepConnectedOnQuit(keep);
+        } catch (err: unknown) {
+            setKeepConnected(!keep);
+            console.error("[useKeepConnectedOnQuit] SetKeepConnectedOnQuit failed", err);
+        }
+    }, []);
+
+    return { keepConnected, setKeepConnectedOnQuit };
+};

client/ui/frontend/src/modules/settings/SettingsGeneral.tsx

@@ -11,6 +11,7 @@ import { ManagementServerSwitch } from "@/components/ManagementServerSwitch.tsx"
 import { ManagementMode, useManagementUrl } from "@/hooks/useManagementUrl.ts";
 import { LanguagePicker } from "@/components/LanguagePicker.tsx";
 import { useRestrictions } from "@/contexts/RestrictionsContext.tsx";
+import { useKeepConnectedOnQuit } from "@/hooks/useKeepConnectedOnQuit.ts";
 
 export function SettingsGeneral() {
     const { t } = useTranslation();
@@ -19,6 +20,7 @@ export function SettingsGeneral() {
     const { mode, setMode, setUrl, displayUrl, showError, canSave, save, checking, unreachable } =
         useManagementUrl();
     const { mdm, features } = useRestrictions();
+    const { keepConnected, setKeepConnectedOnQuit } = useKeepConnectedOnQuit();
 
     const inputRef = useRef<HTMLInputElement>(null);
     const managementUrlId = useId();
@@ -57,6 +59,15 @@ export function SettingsGeneral() {
                         helpText={t("settings.general.autostart.help")}
                     />
                 )}
+                <FancyToggleSwitch
+                    value={keepConnected ?? false}
+                    onChange={(v) => {
+                        void setKeepConnectedOnQuit(v);
+                    }}
+                    loading={keepConnected === null}
+                    label={t("settings.general.keepConnectedOnQuit.label")}
+                    helpText={t("settings.general.keepConnectedOnQuit.help")}
+                />
             </SectionGroup>
 
             {!mdm.managementURL && !features.disableUpdateSettings && (

client/ui/frontend/src/modules/settings/SettingsTroubleshooting.tsx

@@ -1,6 +1,6 @@
 import { useId, type ReactNode } from "react";
 import { Trans, useTranslation } from "react-i18next";
-import { CircleCheckBig, FolderOpen, Loader2 } from "lucide-react";
+import { ChevronDown, CircleCheckBig, FolderOpen, Info, Loader2 } from "lucide-react";
 import { Browser } from "@wailsio/runtime";
 import { Debug as DebugSvc } from "@bindings/services";
 import type { DebugBundleResult } from "@bindings/services/models.js";
@@ -8,13 +8,22 @@ import { Button } from "@/components/buttons/Button";
 import { DialogActions } from "@/components/dialog/DialogActions";
 import { DialogDescription } from "@/components/dialog/DialogDescription";
 import { DialogHeading } from "@/components/dialog/DialogHeading";
+import {
+    DropdownMenu,
+    DropdownMenuContent,
+    DropdownMenuRadioGroup,
+    DropdownMenuRadioItem,
+    DropdownMenuTrigger,
+} from "@/components/DropdownMenu";
 import FancyToggleSwitch from "@/components/switches/FancyToggleSwitch";
 import HelpText from "@/components/typography/HelpText.tsx";
 import { Input } from "@/components/inputs/Input";
 import { Label } from "@/components/typography/Label";
 import { SquareIcon } from "@/components/SquareIcon";
+import { Tooltip } from "@/components/Tooltip";
+import { cn } from "@/lib/cn";
 import { formatRemaining } from "@/lib/formatters";
-import type { DebugStage } from "@/contexts/DebugBundleContext";
+import type { AnonymizeLevel, DebugStage } from "@/contexts/DebugBundleContext";
 import { useDebugBundleContext } from "@/contexts/DebugBundleContext";
 import { SectionGroup, SettingsBottomBar } from "@/modules/settings/SettingsSection.tsx";
 
@@ -24,8 +33,8 @@ export function SettingsTroubleshooting() {
     const { t } = useTranslation();
     const durationId = useId();
     const {
-        anonymize,
-        setAnonymize,
+        anonymizeLevel,
+        setAnonymizeLevel,
         systemInfo,
         setSystemInfo,
         upload,
@@ -55,12 +64,71 @@ export function SettingsTroubleshooting() {
 
     return (
         <SectionGroup title={t("settings.troubleshooting.section.title")}>
-            <FancyToggleSwitch
-                value={anonymize}
-                onChange={setAnonymize}
-                label={t("settings.troubleshooting.anonymize.label")}
-                helpText={t("settings.troubleshooting.anonymize.help")}
-            />
+            <div className={"flex items-center justify-between gap-6"}>
+                <div className={"max-w-md flex-1"}>
+                    <Label as={"div"}>
+                        <span className={"inline-flex items-center gap-1.5"}>
+                            {t("settings.troubleshooting.anonymize.label")}
+                            <Tooltip
+                                content={
+                                    <div className={"max-w-xs whitespace-normal leading-relaxed"}>
+                                        {t("settings.troubleshooting.anonymize.info")}
+                                    </div>
+                                }
+                            >
+                                <Info
+                                    size={14}
+                                    aria-label={t("settings.troubleshooting.anonymize.label")}
+                                    className={"shrink-0 cursor-default text-nb-gray-400"}
+                                />
+                            </Tooltip>
+                        </span>
+                    </Label>
+                    <HelpText margin={false}>
+                        {t("settings.troubleshooting.anonymize.help")}
+                    </HelpText>
+                </div>
+                <div className={"shrink-0"}>
+                    <DropdownMenu>
+                        <DropdownMenuTrigger asChild>
+                            <button
+                                type={"button"}
+                                aria-label={t("settings.troubleshooting.anonymize.label")}
+                                className={cn(
+                                    "inline-flex h-[40px] min-w-[160px] items-center justify-between gap-2 px-3",
+                                    "rounded-md border bg-white dark:bg-nb-gray-900",
+                                    "border-neutral-200 dark:border-nb-gray-700",
+                                    "cursor-default text-xs font-semibold text-nb-gray-100 outline-none",
+                                    "hover:border-nb-gray-600 data-[state=open]:border-nb-gray-600",
+                                )}
+                            >
+                                {t(`settings.troubleshooting.anonymize.${anonymizeLevel}`)}
+                                <ChevronDown
+                                    size={16}
+                                    aria-hidden={"true"}
+                                    className={"shrink-0 text-nb-gray-200"}
+                                />
+                            </button>
+                        </DropdownMenuTrigger>
+                        <DropdownMenuContent align={"end"} className={"min-w-[160px]"}>
+                            <DropdownMenuRadioGroup
+                                value={anonymizeLevel}
+                                onValueChange={(v) => setAnonymizeLevel(v as AnonymizeLevel)}
+                            >
+                                <DropdownMenuRadioItem value={"none"}>
+                                    {t("settings.troubleshooting.anonymize.none")}
+                                </DropdownMenuRadioItem>
+                                <DropdownMenuRadioItem value={"default"}>
+                                    {t("settings.troubleshooting.anonymize.default")}
+                                </DropdownMenuRadioItem>
+                                <DropdownMenuRadioItem value={"strict"}>
+                                    {t("settings.troubleshooting.anonymize.strict")}
+                                </DropdownMenuRadioItem>
+                            </DropdownMenuRadioGroup>
+                        </DropdownMenuContent>
+                    </DropdownMenu>
+                </div>
+            </div>
             <FancyToggleSwitch
                 value={systemInfo}
                 onChange={setSystemInfo}

client/ui/i18n/TRANSLATING.md

@@ -2,9 +2,24 @@
 
 A short brief for translating the desktop UI — for any translator, human or AI agent (*"you"* = whoever's translating).
 
-**Drive an agent with:** *"Read `i18n/TRANSLATING.md` and translate the UI to Russian"* — or *"…and review the existing German translation."*
+**Translations are managed on Crowdin: <https://crowdin.com/project/netbird>.** Join the project, pick your language, and translate in the editor. Each string carries a context note (the `description` from the source file) telling you what it is and where it shows up, and the project's glossary, style guide, and QA checks mirror this document.
 
-> 💡 **The one habit that matters most:** read each key's `description` before translating it. Labels are terse and ambiguous on their own; the `description` tells you what the string is, where it shows up, what to keep verbatim, and what it actually means.
+> 💡 **The one habit that matters most:** read each string's context before translating it. Labels are terse and ambiguous on their own; the context tells you what the string is, where it shows up, what to keep verbatim, and what it actually means.
+
+---
+
+## How contributions flow
+
+```text
+i18n/locales/en/common.json ──sync──▶ Crowdin ──service PR──▶ i18n/locales/<code>/common.json
+```
+
+- `i18n/locales/en/common.json` is the source of truth. New and changed strings sync to Crowdin automatically (see `crowdin.yml` in the repository root).
+- Crowdin opens and updates a service pull request with the translated bundles, keeping the source's file shape and key order. Keys nobody has translated yet are left out of the export; the app falls back to English for them at runtime. Maintainers review and merge that PR.
+- Don't hand-edit `i18n/locales/<code>/common.json` in your own PRs: the next sync would conflict with or overwrite your changes. Translate on Crowdin instead.
+- Missing your language? Request it on the Crowdin project page or in a [GitHub discussion](https://github.com/netbirdio/netbird/discussions). When a language first ships, a maintainer adds its row to `i18n/locales/_index.json` with `code`, `displayName` (the native name), and `englishName`, which puts it in the app's language picker.
+
+**Prefer translating with an AI agent?** That still works: drive it with *"Read `i18n/TRANSLATING.md` and translate the UI to Russian"* as before, but deliver the result to Crowdin instead of a pull request. Download your language's file from the Crowdin editor, let the agent translate it, and upload it back (the editor's offline translation flow). Crowdin runs its QA checks on upload, and the next service PR carries the strings into the repo.
 
 ---
 
@@ -30,25 +45,6 @@ A **business zero-trust VPN** — an encrypted **overlay mesh** between a compan
 
 ---
 
-## The files
-
-```
-i18n/locales/_index.json         shipped-language list
-i18n/locales/en/common.json      source of truth — message + description
-i18n/locales/<code>/common.json  a target — message only
-```
-
-Chrome-extension JSON, each key → `{ "message", "description" }`. You translate the **`message`**.
-
-| ✅ Do | ❌ Don't |
-|---|---|
-| Keep **every key** from `en`, in the same order | Translate, rename, reorder, drop, or add keys (they're identifiers; the set grows over time) |
-| Put **only `message`** in target bundles | Copy `description` into a target bundle |
-| Give every key a non-empty `message` | Leave keys missing or empty |
-| Save valid UTF-8 JSON, no BOM | Add trailing commas or break the JSON |
-
----
-
 ## Hard rules — get these exactly right
 
 These are the usual ways a translation *breaks the app*, not just reads oddly.
@@ -58,7 +54,7 @@ These are the usual ways a translation *breaks the app*, not just reads oddly.
 | Copy `{placeholders}` verbatim — `{version}`, `{count}`, `{name}`… | Translate the word inside the braces (`{verbleibend}` breaks it) |
 | Reposition a placeholder so the sentence flows | Drop or duplicate a placeholder |
 | Preserve every `\n`, leading/trailing space, and trailing `...` | Trim "invisible" spaces or the `...` (they're load-bearing) |
-| Keep `®` in WireGuard® and quotes around `{name}` | Strip punctuation the description flags |
+| Keep `®` in WireGuard® and quotes around `{name}` | Strip punctuation the context flags |
 
 **Plurals:** the app has only a *one / other* split — the singular key fires only when `count == 1`; the `{count}` key covers everything else (0, 2, 5, 100…). Languages with more than two forms (ru, pl, uk) can't be fully correct here — use the form that fits the widest range (Russian genitive plural: `минут` / `часов` / `дней`). Don't invent extra keys or cram multiple forms into one string. When no single form fits every value — a unit label after a number field, say — reach for a number-agnostic form (an abbreviation, or wording that reads the same for 1 and 100) instead of forcing a plural the *one / other* split can't supply.
 
@@ -78,13 +74,15 @@ When a brand sits beside a common noun, keep its exact spelling but join them th
 
 > **Use the word that language's IT users actually say.** Translate when a natural, common term exists; keep the English term *only* when the literal translation would be awkward or no one in that field really uses it.
 
-Apply each term **consistently** — same English term → same translation everywhere — and keep a term once you've settled it. Whether a term stays English or takes a native word is **language-dependent**: a technical loanword (e.g. *Daemon*, *Handshake*) often stays, an everyday word (e.g. *Latency*, *Public key*) usually localizes, and some (*Exit Node*, *Peer*) go either way depending on the language. Decide per term with the rule above — a foreign origin alone is no reason to keep English. **Your main reference is the existing bundles:** match how a term was already rendered for your language rather than re-deciding it.
+Apply each term **consistently** — same English term → same translation everywhere — and keep a term once you've settled it. Whether a term stays English or takes a native word is **language-dependent**: a technical loanword (e.g. *Daemon*, *Handshake*) often stays, an everyday word (e.g. *Latency*, *Public key*) usually localizes, and some (*Exit Node*, *Peer*) go either way depending on the language. Decide per term with the rule above — a foreign origin alone is no reason to keep English. **Your main reference is the existing translation:** match how a term was already rendered for your language rather than re-deciding it.
 
 Two checks before you commit a term:
 
 - **Prefer established localized wording.** If a widely used tool in this space (for example WireGuard) ships your language, its wording for a shared term such as *handshake* is what users already expect — look at the translated app, not just English docs. For generic UI verbs and formal address, follow your OS vendor's style guide (Microsoft / Apple / Google).
 - **Watch for false friends.** A literal translation can collide with a *different* established term in your field — confirm your word doesn't already mean something else in this domain before using it.
 
+These tiers are mirrored in the Crowdin project glossary, so the editor highlights them inline. When you settle a new Tier C term for your language, add its translation to the glossary entry so it sticks for everyone who comes after you.
+
 ---
 
 ## Style
@@ -98,7 +96,7 @@ Two checks before you commit a term:
 
 Where it reads naturally, aim to keep each string **roughly the same length** as the English — the UI is tight and over-long strings can wrap or truncate. It's a soft preference, not a rule: if your language simply needs more words, use them.
 
-A few habits that keep a bundle reading like one product rather than a word-for-word port:
+A few habits that keep a translation reading like one product rather than a word-for-word port:
 
 - **Translate meaning, not words.** Render what a string *does*. An idiom or an awkward source phrase should become natural in your language, not a literal calque.
 - **Keep one voice within a family.** Sibling strings — the connection states, every settings *help* caption, every "… Failed" title — should share a grammatical form. If one member sounds wrong in that form, re-voice the whole family rather than leave one odd sibling.
@@ -107,27 +105,26 @@ A few habits that keep a bundle reading like one product rather than a word-for-
 
 ---
 
-## Procedure
+## Reviewing a language
 
-**New language** — read `en/common.json` *with* descriptions → settle your Tier C terms → write `i18n/locales/<code>/common.json` (same keys and order as `en`, `message` only, placeholders & brands preserved) → add a row to `_index.json` (`{"code","displayName"` = native name`,"englishName"}`) → run the QA list. Use the locale-code style the existing entries use (e.g. `fr`, `pt`, `zh-CN`).
+**On Crowdin:** proofread in the editor — context, glossary highlights, and QA flags sit inline next to each string.
 
-**Review (de / hu / …)** — read source and target side by side; for each key check glossary conformance (e.g. de `Exit-Node` → `Exit Node`, hu `Kilépő csomópont` → `Exit Node`), placeholder/`\n` integrity, consistency, tone, and that the meaning matches the English `description`. Fix in place, then report what you changed (especially term standardizations) so a native speaker can sanity-check.
+**In the repo** — e.g. driving an AI agent with *"Read `i18n/TRANSLATING.md` and review the existing German translation"* — read source and target side by side; for each key check glossary conformance (e.g. de `Exit-Node` → `Exit Node`, hu `Kilépő csomópont` → `Exit Node`), placeholder/`\n` integrity, consistency, tone, and that the meaning matches the English `description`. Report what you found, and apply the fixes **on Crowdin** — direct edits to the locale files are overwritten by the next sync.
 
 ---
 
 ## QA before you finish
 
-- [ ] Valid JSON · **every `en` key** present, same order · **no `description`** fields
 - [ ] Every `{placeholder}`, `\n`, and intentional space preserved · `...` / `… Failed` / `{name}` quotes kept
-- [ ] Tier A/B left intact · Tier C applied consistently (and matching the existing bundle for your language)
+- [ ] Tier A/B left intact · Tier C applied consistently (and matching the existing translation for your language)
 - [ ] Buttons & tray short · locale punctuation and capitalization applied
-- [ ] New language added to `_index.json`
+- [ ] Crowdin QA flags resolved (variables, glossary terms, punctuation)
 - [ ] **Tested in the running app** ↓
 
 ---
 
 ## Test it in the app
 
-A bundle can pass every check above and still read wrong on screen. **Run the app, switch to your language, and click through the real surfaces** — tray menu, main window, every Settings tab, the dialogs. Watch for text overflow or truncation, labels that are technically right but wrong *for what the control does*, leaked placeholders, and terms that drift between screens.
+A translation can pass every check above and still read wrong on screen. **Run the app, switch to your language, and click through the real surfaces** — tray menu, main window, every Settings tab, the dialogs. Watch for text overflow or truncation, labels that are technically right but wrong *for what the control does*, leaked placeholders, and terms that drift between screens.
 
 How to run the app and switch language: see the project README. Can't run it (e.g. a headless agent)? Say so in your summary — don't silently skip this step.

client/ui/i18n/locales/de/common.json

@@ -551,6 +551,14 @@
     "settings.general.autostart.errorTitle": {
         "message": "Ändern des Autostarts fehlgeschlagen"
     },
+    "settings.general.keepConnectedOnQuit.label": {
+        "message": "Nach dem Beenden verbunden bleiben",
+        "description": "Toggle label: keep the VPN connection up after quitting the UI."
+    },
+    "settings.general.keepConnectedOnQuit.help": {
+        "message": "Die Verbindung bleibt im Hintergrund bestehen, nachdem Sie NetBird schließen. Sie endet erst, wenn Sie sie selbst trennen.",
+        "description": "Helper text for the stay-connected-after-quitting toggle."
+    },
     "settings.general.language.label": {
         "message": "Anzeigesprache"
     },

client/ui/i18n/locales/en/common.json

@@ -735,6 +735,14 @@
         "message": "Autostart Change Failed",
         "description": "Error-dialog title when changing the autostart setting fails."
     },
+    "settings.general.keepConnectedOnQuit.label": {
+        "message": "Stay Connected After Quitting",
+        "description": "Toggle label: keep the VPN connection up after quitting the UI."
+    },
+    "settings.general.keepConnectedOnQuit.help": {
+        "message": "The connection stays up in the background after you close NetBird. It only stops when you disconnect it yourself.",
+        "description": "Helper text for the stay-connected-after-quitting toggle."
+    },
     "settings.general.language.label": {
         "message": "Display Language",
         "description": "Label for the display-language picker."
@@ -1005,11 +1013,27 @@
     },
     "settings.troubleshooting.anonymize.label": {
         "message": "Anonymize Sensitive Information",
-        "description": "Toggle label: anonymize sensitive information in the bundle."
+        "description": "Label for the anonymization level dropdown (None, Default, Strict)."
     },
     "settings.troubleshooting.anonymize.help": {
-        "message": "Hides public IP addresses and non-NetBird domains from logs.",
-        "description": "Helper text for anonymizing logs (hides public IPs and non-NetBird domains)."
+        "message": "Hides IP addresses, domains, and other sensitive values.",
+        "description": "Helper text under the anonymization dropdown. The level details live in the info tooltip."
+    },
+    "settings.troubleshooting.anonymize.info": {
+        "message": "Default keeps internal IPv4 addresses and peer names readable for support. Strict additionally anonymizes private (RFC 1918), CGNAT, and link-local IP addresses, peer names, and WireGuard public keys. Recurring values map to the same placeholder, so peers stay distinguishable. Use Strict when sharing the bundle outside your organization.",
+        "description": "Info tooltip explaining the anonymization levels. 'RFC 1918', 'CGNAT', 'link-local', and 'WireGuard' are technical terms — keep them."
+    },
+    "settings.troubleshooting.anonymize.none": {
+        "message": "None",
+        "description": "Dropdown option: no anonymization."
+    },
+    "settings.troubleshooting.anonymize.default": {
+        "message": "Default",
+        "description": "Dropdown option: default anonymization level."
+    },
+    "settings.troubleshooting.anonymize.strict": {
+        "message": "Strict",
+        "description": "Dropdown option: strict anonymization level."
     },
     "settings.troubleshooting.systemInfo.label": {
         "message": "Include System Information",

client/ui/i18n/locales/es/common.json

@@ -551,6 +551,14 @@
     "settings.general.autostart.errorTitle": {
         "message": "Error al cambiar el inicio automático"
     },
+    "settings.general.keepConnectedOnQuit.label": {
+        "message": "Permanecer conectado al salir",
+        "description": "Toggle label: keep the VPN connection up after quitting the UI."
+    },
+    "settings.general.keepConnectedOnQuit.help": {
+        "message": "La conexión sigue activa en segundo plano después de cerrar NetBird. Solo se detiene cuando la desconectas tú.",
+        "description": "Helper text for the stay-connected-after-quitting toggle."
+    },
     "settings.general.language.label": {
         "message": "Idioma de la interfaz"
     },

client/ui/i18n/locales/fr/common.json

@@ -551,6 +551,14 @@
     "settings.general.autostart.errorTitle": {
         "message": "Échec de la modification du démarrage automatique"
     },
+    "settings.general.keepConnectedOnQuit.label": {
+        "message": "Rester connecté après la fermeture",
+        "description": "Toggle label: keep the VPN connection up after quitting the UI."
+    },
+    "settings.general.keepConnectedOnQuit.help": {
+        "message": "La connexion reste active en arrière-plan après la fermeture de NetBird. Elle ne s'arrête que si vous la coupez vous-même.",
+        "description": "Helper text for the stay-connected-after-quitting toggle."
+    },
     "settings.general.language.label": {
         "message": "Langue d’affichage"
     },

client/ui/i18n/locales/hu/common.json

@@ -551,6 +551,14 @@
     "settings.general.autostart.errorTitle": {
         "message": "Az automatikus indítás módosítása sikertelen"
     },
+    "settings.general.keepConnectedOnQuit.label": {
+        "message": "Kapcsolat megtartása kilépéskor",
+        "description": "Toggle label: keep the VPN connection up after quitting the UI."
+    },
+    "settings.general.keepConnectedOnQuit.help": {
+        "message": "A kapcsolat a háttérben megmarad, miután bezárod a NetBirdöt. Csak akkor szakad meg, ha te magad bontod.",
+        "description": "Helper text for the stay-connected-after-quitting toggle."
+    },
     "settings.general.language.label": {
         "message": "Megjelenítési nyelv"
     },

client/ui/i18n/locales/it/common.json

@@ -551,6 +551,14 @@
     "settings.general.autostart.errorTitle": {
         "message": "Modifica avvio automatico non riuscita"
     },
+    "settings.general.keepConnectedOnQuit.label": {
+        "message": "Resta connesso dopo la chiusura",
+        "description": "Toggle label: keep the VPN connection up after quitting the UI."
+    },
+    "settings.general.keepConnectedOnQuit.help": {
+        "message": "La connessione resta attiva in background dopo la chiusura di NetBird. Si interrompe solo quando la disconnetti tu.",
+        "description": "Helper text for the stay-connected-after-quitting toggle."
+    },
     "settings.general.language.label": {
         "message": "Lingua dell'interfaccia"
     },

client/ui/i18n/locales/ja/common.json

@@ -551,6 +551,14 @@
     "settings.general.autostart.errorTitle": {
         "message": "自動起動の変更に失敗しました"
     },
+    "settings.general.keepConnectedOnQuit.label": {
+        "message": "終了後も接続を維持",
+        "description": "Toggle label: keep the VPN connection up after quitting the UI."
+    },
+    "settings.general.keepConnectedOnQuit.help": {
+        "message": "NetBird を閉じたあとも接続はバックグラウンドで維持されます。自分で切断したときにだけ停止します。",
+        "description": "Helper text for the stay-connected-after-quitting toggle."
+    },
     "settings.general.language.label": {
         "message": "表示言語"
     },

client/ui/i18n/locales/pt/common.json

@@ -551,6 +551,14 @@
     "settings.general.autostart.errorTitle": {
         "message": "Falha ao alterar o início automático"
     },
+    "settings.general.keepConnectedOnQuit.label": {
+        "message": "Permanecer conectado ao sair",
+        "description": "Toggle label: keep the VPN connection up after quitting the UI."
+    },
+    "settings.general.keepConnectedOnQuit.help": {
+        "message": "A conexão continua ativa em segundo plano depois de fechar o NetBird. Ela só para quando você mesmo a desconecta.",
+        "description": "Helper text for the stay-connected-after-quitting toggle."
+    },
     "settings.general.language.label": {
         "message": "Idioma de exibição"
     },

client/ui/i18n/locales/ru/common.json

@@ -551,6 +551,14 @@
     "settings.general.autostart.errorTitle": {
         "message": "Не удалось изменить автозапуск"
     },
+    "settings.general.keepConnectedOnQuit.label": {
+        "message": "Оставаться подключённым после выхода",
+        "description": "Toggle label: keep the VPN connection up after quitting the UI."
+    },
+    "settings.general.keepConnectedOnQuit.help": {
+        "message": "Соединение остаётся активным в фоне после закрытия NetBird. Оно прервётся, только когда вы отключите его сами.",
+        "description": "Helper text for the stay-connected-after-quitting toggle."
+    },
     "settings.general.language.label": {
         "message": "Язык интерфейса"
     },

client/ui/i18n/locales/zh-CN/common.json

@@ -551,6 +551,14 @@
     "settings.general.autostart.errorTitle": {
         "message": "更改自启动设置失败"
     },
+    "settings.general.keepConnectedOnQuit.label": {
+        "message": "退出后保持连接",
+        "description": "Toggle label: keep the VPN connection up after quitting the UI."
+    },
+    "settings.general.keepConnectedOnQuit.help": {
+        "message": "关闭 NetBird 后，连接会在后台保持。只有你自己断开时才会停止。",
+        "description": "Helper text for the stay-connected-after-quitting toggle."
+    },
     "settings.general.language.label": {
         "message": "显示语言"
     },

client/ui/main.go

@@ -180,6 +180,7 @@ func main() {
 		WindowManager:   windowManager,
 		Session:         authSession,
 		Localizer:       localizer,
+		Preferences:     prefStore,
 	})
 	listenForShowSignal(context.Background(), tray)
 

client/ui/preferences/store.go

@@ -58,6 +58,10 @@ type UIPreferences struct {
 	// decision has run for this OS user. It only ever transitions to true
 	// and is never reset, so the default-on flow runs at most once, ever.
 	AutostartInitialized bool `json:"autostartInitialized"`
+	// KeepConnectedOnQuit leaves the daemon connected when the GUI quits.
+	// Its false zero value preserves the historical disconnect-on-quit
+	// behaviour for preference files written before the field existed.
+	KeepConnectedOnQuit bool `json:"keepConnectedOnQuit"`
 }
 
 // LanguageValidator rejects SetLanguage inputs with no shipped bundle.
@@ -183,6 +187,26 @@ func (s *Store) SetAutostartInitialized(done bool) error {
 	return nil
 }
 
+// SetKeepConnectedOnQuit persists the disconnect-on-quit opt-out. No-op if unchanged.
+func (s *Store) SetKeepConnectedOnQuit(keep bool) error {
+	s.mu.Lock()
+	if s.current.KeepConnectedOnQuit == keep {
+		s.mu.Unlock()
+		return nil
+	}
+	next := s.current
+	next.KeepConnectedOnQuit = keep
+	if err := s.persistLocked(next); err != nil {
+		s.mu.Unlock()
+		return fmt.Errorf("persist preferences: %w", err)
+	}
+	s.current = next
+	s.mu.Unlock()
+
+	s.broadcast(next)
+	return nil
+}
+
 // SetLanguage validates, persists, and broadcasts. No-op if unchanged.
 func (s *Store) SetLanguage(lang i18n.LanguageCode) error {
 	if lang == "" {

client/ui/preferences/store_test.go

@@ -238,6 +238,42 @@ func TestStore_SetAutostartInitializedPersistsAcrossReload(t *testing.T) {
 	assert.True(t, reloaded.Get().AutostartInitialized, "marker must survive a reload from disk")
 }
 
+func TestStore_SetKeepConnectedOnQuitPersistsAcrossReload(t *testing.T) {
+	withTempConfigDir(t)
+	emitter := &recordingEmitter{}
+	s, err := NewStore(nil, emitter)
+	require.NoError(t, err)
+
+	assert.False(t, s.Get().KeepConnectedOnQuit, "quitting must disconnect by default")
+
+	require.NoError(t, s.SetKeepConnectedOnQuit(true))
+	assert.True(t, s.Get().KeepConnectedOnQuit, "Get should reflect the persisted opt-out")
+	require.Len(t, emitter.calledWith(EventPreferencesChanged), 1, "first write should broadcast")
+
+	require.NoError(t, s.SetKeepConnectedOnQuit(true))
+	assert.Len(t, emitter.calledWith(EventPreferencesChanged), 1, "idempotent write should not broadcast again")
+
+	reloaded, err := NewStore(nil, nil)
+	require.NoError(t, err)
+	assert.True(t, reloaded.Get().KeepConnectedOnQuit, "opt-out must survive a reload from disk")
+}
+
+func TestStore_KeepConnectedOnQuitDefaultsFalseForPreExistingFile(t *testing.T) {
+	withTempConfigDir(t)
+
+	// A preferences file written before the field existed must keep the
+	// historical disconnect-on-quit behaviour rather than silently opting out.
+	path, err := preferencesPath()
+	require.NoError(t, err)
+	require.NoError(t, os.MkdirAll(filepath.Dir(path), 0o755))
+	require.NoError(t, os.WriteFile(path, []byte(`{"language":"en","viewMode":"default"}`), 0o600))
+
+	s, err := NewStore(nil, nil)
+	require.NoError(t, err)
+	assert.False(t, s.Get().KeepConnectedOnQuit, "a file predating the field must not opt out of disconnect-on-quit")
+	assert.True(t, s.ExistedAtLoad(), "the pre-existing file must be seen on disk")
+}
+
 func TestStore_ExistedAtLoad(t *testing.T) {
 	withTempConfigDir(t)
 

client/ui/services/cursor_linux.go

@@ -49,5 +49,11 @@ func getCursorPosition(app *application.App) (application.Point, bool) {
 	if app == nil || app.Screen == nil {
 		return p, true
 	}
+	// The wails GTK3 backend caches screens from the active window; a tray app
+	// has none at startup, so the cache is empty and PhysicalToDipPoint would
+	// dereference a nil nearest screen. Raw pixels are correct there anyway.
+	if app.Screen.ScreenNearestPhysicalPoint(p) == nil {
+		return p, true
+	}
 	return app.Screen.PhysicalToDipPoint(p), true
 }

client/ui/services/debug.go

@@ -15,10 +15,13 @@ import (
 )
 
 type DebugBundleParams struct {
-	Anonymize    bool   `json:"anonymize"`
-	SystemInfo   bool   `json:"systemInfo"`
-	UploadURL    string `json:"uploadUrl"`
-	LogFileCount uint32 `json:"logFileCount"`
+	Anonymize bool `json:"anonymize"`
+	// AnonymizeLevel is "default" or "strict"; strict also anonymizes
+	// private IP ranges, peer names, and WireGuard public keys.
+	AnonymizeLevel string `json:"anonymizeLevel"`
+	SystemInfo     bool   `json:"systemInfo"`
+	UploadURL      string `json:"uploadUrl"`
+	LogFileCount   uint32 `json:"logFileCount"`
 }
 
 // DebugBundleResult: Path is set for local-only bundles, UploadedKey on upload
@@ -48,11 +51,12 @@ func (s *Debug) Bundle(ctx context.Context, p DebugBundleParams) (DebugBundleRes
 		return DebugBundleResult{}, err
 	}
 	resp, err := cli.DebugBundle(ctx, &proto.DebugBundleRequest{
-		Anonymize:    p.Anonymize,
-		SystemInfo:   p.SystemInfo,
-		UploadURL:    p.UploadURL,
-		LogFileCount: p.LogFileCount,
-		CliVersion:   version.NetbirdVersion(),
+		Anonymize:      p.Anonymize,
+		AnonymizeLevel: p.AnonymizeLevel,
+		SystemInfo:     p.SystemInfo,
+		UploadURL:      p.UploadURL,
+		LogFileCount:   p.LogFileCount,
+		CliVersion:     version.NetbirdVersion(),
 	})
 	if err != nil {
 		return DebugBundleResult{}, err

client/ui/services/preferences.go

@@ -34,3 +34,7 @@ func (s *Preferences) SetViewMode(_ context.Context, mode preferences.ViewMode)
 func (s *Preferences) SetOnboardingCompleted(_ context.Context, done bool) error {
 	return s.store.SetOnboardingCompleted(done)
 }
+
+func (s *Preferences) SetKeepConnectedOnQuit(_ context.Context, keep bool) error {
+	return s.store.SetKeepConnectedOnQuit(keep)
+}

client/ui/tray.go

@@ -16,6 +16,7 @@ import (
 
 	"github.com/netbirdio/netbird/client/ui/authsession"
 	"github.com/netbirdio/netbird/client/ui/i18n"
+	"github.com/netbirdio/netbird/client/ui/preferences"
 	"github.com/netbirdio/netbird/client/ui/services"
 	"github.com/netbirdio/netbird/version"
 )
@@ -50,8 +51,9 @@ type TrayServices struct {
 	WindowManager   *services.WindowManager
 	// Session is bound to authsession directly because the services wrapper
 	// only re-exposes the React subset.
-	Session   *authsession.Session
-	Localizer *Localizer
+	Session     *authsession.Session
+	Localizer   *Localizer
+	Preferences *preferences.Store
 }
 
 type Tray struct {
@@ -461,10 +463,12 @@ func (t *Tray) handleQuit() {
 	t.profileMu.Unlock()
 	t.svc.DaemonFeed.CancelProfileSwitch()
 
-	ctx, cancel := context.WithTimeout(context.Background(), quitDownTimeout)
-	defer cancel()
-	if err := t.svc.Connection.Down(ctx); err != nil {
-		log.Errorf("disconnect on quit: %v", err)
+	if t.svc.Preferences == nil || !t.svc.Preferences.Get().KeepConnectedOnQuit {
+		ctx, cancel := context.WithTimeout(context.Background(), quitDownTimeout)
+		defer cancel()
+		if err := t.svc.Connection.Down(ctx); err != nil {
+			log.Errorf("disconnect on quit: %v", err)
+		}
 	}
 	t.app.Quit()
 }

client/ui/xembed_host_gtk3_linux.go

@@ -0,0 +1,40 @@
+//go:build linux && gtk3 && !(linux && 386)
+
+package main
+
+import (
+	"errors"
+
+	"github.com/godbus/dbus/v5"
+)
+
+// The legacy GTK3 / WebKit2GTK 4.1 build (-tags gtk3) drops the in-process
+// XEmbed StatusNotifierWatcher entirely. The real implementation
+// (xembed_host_linux.go + xembed_tray_linux.c) links GTK4 and uses GTK4-only
+// popup-menu APIs that have no drop-in GTK3 equivalent, so rather than port the
+// C layer we stub the host out on gtk3 builds. The tray still works on every
+// desktop that ships its own StatusNotifierWatcher (KDE, GNOME+AppIndicator,
+// Cinnamon/xapp, XFCE, …); only the minimal-WM fallback (Fluxbox/OpenBox/i3/
+// dwm/vanilla GNOME) is unavailable on gtk3 packages. See LINUX-TRAY.md.
+
+// xembedHost is a placeholder so the package compiles on gtk3 builds; the real
+// type (with X11/GTK4 state) lives in xembed_host_linux.go. It is never
+// instantiated here because xembedTrayAvailable always reports false.
+type xembedHost struct{}
+
+// run satisfies the call in tray_watcher_linux.go; unreachable on gtk3 because
+// newXembedHost never returns a non-nil host.
+func (*xembedHost) run() {}
+
+// xembedTrayAvailable always reports false on gtk3 builds, so the watcher probe
+// loop in startStatusNotifierWatcher exits immediately and newXembedHost is
+// never reached. recenter_linux.go's predicate becomes a harmless no-op too.
+func xembedTrayAvailable() bool {
+	return false
+}
+
+// newXembedHost exists only to satisfy the reference in tray_watcher_linux.go;
+// it is unreachable because xembedTrayAvailable returns false on gtk3.
+func newXembedHost(conn *dbus.Conn, busName string, objPath dbus.ObjectPath) (*xembedHost, error) {
+	return nil, errors.New("xembed host unsupported on gtk3 build")
+}

client/ui/xembed_host_linux.go

@@ -1,4 +1,4 @@
-//go:build linux && !(linux && 386)
+//go:build linux && !gtk3 && !(linux && 386)
 
 package main
 

client/ui/xembed_tray_linux.c

@@ -1,3 +1,5 @@
+//go:build linux && !gtk3 && !(linux && 386)
+
 #include "xembed_tray_linux.h"
 
 #include <X11/Xatom.h>

crowdin.yml

@@ -0,0 +1,11 @@
+skip_untranslated_strings: true
+skip_untranslated_files: true
+import_eq_suggestions: true
+
+files:
+  - source: /client/ui/i18n/locales/en/common.json
+    translation: /client/ui/i18n/locales/%two_letters_code%/common.json
+    type: chrome
+    languages_mapping:
+      two_letters_code:
+        zh-CN: zh-CN

e2e/agentnetwork/chat_test.go

@@ -438,14 +438,10 @@ func TestProvidersMatrix(t *testing.T) {
 	// Create every provider, all enabled, each with a unique model string so the
 	// proxy's connect-time snapshot carries them all and model→provider routing
 	// is unambiguous (provider toggles after connect don't reconcile to the
-	// proxy, so we enable everything up front). The first create bootstraps the
-	// cluster.
+	// proxy, so we enable everything up front).
 	ids := make([]string, 0, len(matrix))
-	for i, pc := range matrix {
+	for _, pc := range matrix {
 		req := providerRequest(pc)
-		if i == 0 {
-			req.BootstrapCluster = ptr(harness.AgentNetworkCluster)
-		}
 		prov, perr := srv.CreateProvider(ctx, req)
 		require.NoError(t, perr, "create provider %s", pc.name)
 		ids = append(ids, prov.Id)

e2e/agentnetwork/custom_pricing_test.go

@@ -82,13 +82,12 @@ func provisionPricedProvider(t *testing.T, ctx context.Context, name string, mod
 	// need NOT be in the catalog — the operator names it and prices it here.
 	dummyKey := "sk-price-e2e"
 	prov, err := srv.CreateProvider(ctx, api.AgentNetworkProviderRequest{
-		Name:             name,
-		ProviderId:       "openai_api",
-		UpstreamUrl:      vllm.URL,
-		ApiKey:           &dummyKey,
-		Enabled:          ptr(true),
-		BootstrapCluster: ptr(harness.AgentNetworkCluster),
-		Models:           &models,
+		Name:        name,
+		ProviderId:  "openai_api",
+		UpstreamUrl: vllm.URL,
+		ApiKey:      &dummyKey,
+		Enabled:     ptr(true),
+		Models:      &models,
 	})
 	require.NoError(t, err, "create provider")
 	t.Cleanup(func() { _ = srv.DeleteProvider(context.Background(), prov.Id) })

e2e/agentnetwork/guardrail_block_test.go

@@ -113,15 +113,14 @@ func runPathRoutedGuardrailCase(t *testing.T, tc pathRoutedGuardrailCase) {
 
 	// Catch-all provider (no models) so the router forwards any model; a static
 	// bearer key means the router injects a static auth header instead of minting
-	// a GCP token. Bootstraps the cluster if it isn't already.
+	// a GCP token.
 	staticKey := "static-e2e-token"
 	prov, err := srv.CreateProvider(ctx, api.AgentNetworkProviderRequest{
-		Name:             tc.name,
-		ProviderId:       tc.catalogID,
-		UpstreamUrl:      vllm.URL,
-		ApiKey:           &staticKey,
-		Enabled:          ptr(true),
-		BootstrapCluster: ptr(harness.AgentNetworkCluster),
+		Name:        tc.name,
+		ProviderId:  tc.catalogID,
+		UpstreamUrl: vllm.URL,
+		ApiKey:      &staticKey,
+		Enabled:     ptr(true),
 	})
 	require.NoError(t, err, "create %s provider", tc.name)
 	t.Cleanup(func() { _ = srv.DeleteProvider(context.Background(), prov.Id) })

e2e/agentnetwork/guardrail_groupswitch_test.go

@@ -73,7 +73,6 @@ func TestGuardrailGroupSwitchTakesEffectAfterTTL(t *testing.T) {
 			{Id: modelA, InputPer1k: 0.001, OutputPer1k: 0.001},
 			{Id: modelB, InputPer1k: 0.001, OutputPer1k: 0.001},
 		},
-		BootstrapCluster: ptr(harness.AgentNetworkCluster),
 	})
 	require.NoError(t, err, "create provider")
 	t.Cleanup(func() { _ = srv.DeleteProvider(context.Background(), prov.Id) })

e2e/agentnetwork/guardrail_multipolicy_test.go

@@ -61,15 +61,14 @@ func TestGuardrailMultiPolicyModelAllowlist(t *testing.T) {
 	}
 
 	// pRestricted declares the two guardrailed models so routing is deterministic
-	// (model -> provider). Created first, so it carries the bootstrap cluster.
+	// (model -> provider).
 	pRestricted, err := srv.CreateProvider(ctx, api.AgentNetworkProviderRequest{
-		Name:             "restricted",
-		ProviderId:       "openai_api",
-		UpstreamUrl:      vllm.URL,
-		ApiKey:           &staticKey,
-		Enabled:          ptr(true),
-		Models:           models(modelSelected, modelOther),
-		BootstrapCluster: ptr(harness.AgentNetworkCluster),
+		Name:        "restricted",
+		ProviderId:  "openai_api",
+		UpstreamUrl: vllm.URL,
+		ApiKey:      &staticKey,
+		Enabled:     ptr(true),
+		Models:      models(modelSelected, modelOther),
 	})
 	require.NoError(t, err, "create restricted provider")
 	t.Cleanup(func() { _ = srv.DeleteProvider(context.Background(), pRestricted.Id) })

e2e/agentnetwork/guardrail_pergroup_providers_test.go

@@ -115,7 +115,7 @@ func TestGuardrailPerGroupAllowlist_AllProviders(t *testing.T) {
 	staticKey := "static-e2e-token"
 	enabled := true
 
-	for i, c := range cases {
+	for _, c := range cases {
 		req := api.AgentNetworkProviderRequest{
 			Name:        "e2e-pergroup-" + c.name,
 			ProviderId:  c.catalogID,
@@ -124,9 +124,6 @@ func TestGuardrailPerGroupAllowlist_AllProviders(t *testing.T) {
 			Enabled:     ptr(true),
 			Models:      c.models,
 		}
-		if i == 0 {
-			req.BootstrapCluster = ptr(harness.AgentNetworkCluster)
-		}
 		prov, perr := srv.CreateProvider(ctx, req)
 		require.NoError(t, perr, "create provider %s", c.name)
 		c.providerID = prov.Id
@@ -283,13 +280,12 @@ func TestGuardrailMultiGroupUser(t *testing.T) {
 
 	// P1 — union scenario: two restricting policies, one per group.
 	p1, err := srv.CreateProvider(ctx, api.AgentNetworkProviderRequest{
-		Name:             "e2e-mg-union",
-		ProviderId:       "openai_api",
-		UpstreamUrl:      vllm.URL,
-		ApiKey:           &staticKey,
-		Enabled:          ptr(true),
-		Models:           priced(unionA, unionB, unionC),
-		BootstrapCluster: ptr(harness.AgentNetworkCluster),
+		Name:        "e2e-mg-union",
+		ProviderId:  "openai_api",
+		UpstreamUrl: vllm.URL,
+		ApiKey:      &staticKey,
+		Enabled:     ptr(true),
+		Models:      priced(unionA, unionB, unionC),
 	})
 	require.NoError(t, err, "create union provider")
 	t.Cleanup(func() { _ = srv.DeleteProvider(context.Background(), p1.Id) })

e2e/agentnetwork/guardrail_test.go

@@ -115,14 +115,11 @@ func TestModelAllowlistEnforced(t *testing.T) {
 	})
 	require.NoError(t, err, "mint setup key")
 
-	// Providers with their configured (allowed) models; the first bootstraps the cluster.
+	// Providers with their configured (allowed) models
 	ids := make([]string, 0, len(providers))
 	allowed := make([]string, 0, len(providers))
-	for i, pc := range providers {
+	for _, pc := range providers {
 		req := providerRequest(pc)
-		if i == 0 {
-			req.BootstrapCluster = ptr(harness.AgentNetworkCluster)
-		}
 		prov, perr := srv.CreateProvider(ctx, req)
 		require.NoError(t, perr, "create provider %s", pc.name)
 		id := prov.Id

e2e/agentnetwork/main_test.go

@@ -14,6 +14,7 @@ import (
 	"time"
 
 	"github.com/netbirdio/netbird/e2e/harness"
+	"github.com/netbirdio/netbird/shared/management/http/api"
 )
 
 // srv is the shared combined server for the package, ready (PAT-authenticated)
@@ -42,5 +43,14 @@ func run(m *testing.M) int {
 		return 1
 	}
 
+	// Bootstrap the account's agent-network endpoint once for the package:
+	// providers no longer have settings side effects, and every data-plane
+	// test expects the shared account pinned to the combined proxy cluster.
+	cluster := harness.AgentNetworkCluster
+	if _, err := srv.CreateSettings(ctx, api.AgentNetworkSettingsCreateRequest{ProxyAddress: &cluster}); err != nil {
+		fmt.Fprintf(os.Stderr, "e2e: bootstrap agent-network endpoint: %v\n", err)
+		return 1
+	}
+
 	return m.Run()
 }

e2e/agentnetwork/management_test.go

@@ -21,11 +21,10 @@ func ptr[T any](v T) *T { return &v }
 func newProvider(t *testing.T, ctx context.Context, name string) api.AgentNetworkProvider {
 	t.Helper()
 	prov, err := srv.CreateProvider(ctx, api.AgentNetworkProviderRequest{
-		Name:             name,
-		ProviderId:       "openai_api",
-		UpstreamUrl:      "https://api.openai.com",
-		ApiKey:           ptr("sk-dummy-e2e-key"),
-		BootstrapCluster: ptr("eu.proxy.netbird.test"),
+		Name:        name,
+		ProviderId:  "openai_api",
+		UpstreamUrl: "https://api.openai.com",
+		ApiKey:      ptr("sk-dummy-e2e-key"),
 	})
 	require.NoError(t, err, "create provider %q", name)
 	t.Cleanup(func() { _ = srv.DeleteProvider(context.Background(), prov.Id) })
@@ -57,17 +56,11 @@ func TestProviderLifecycle(t *testing.T) {
 		}}
 	}
 
-	for i, pc := range cases {
-		i, pc := i, pc
+	for _, pc := range cases {
+		pc := pc
 		t.Run(pc.name, func(t *testing.T) {
 			req := providerRequest(pc)
 			req.Name = "lc-" + pc.name
-			// Bootstrap the cluster on the first create in case the matrix has
-			// not run (e.g. no provider keys → settings not yet bootstrapped).
-			if i == 0 {
-				req.BootstrapCluster = ptr(harness.AgentNetworkCluster)
-			}
-
 			prov, err := srv.CreateProvider(ctx, req)
 			require.NoError(t, err, "create %s provider", pc.name)
 			t.Cleanup(func() { _ = srv.DeleteProvider(context.Background(), prov.Id) })
@@ -137,45 +130,65 @@ func TestProviderValidation(t *testing.T) {
 	requireClientError(t, err)
 }
 
-// TestSettingsRoundTrip flips the collection toggles and confirms cluster /
-// subdomain stay immutable, then restores the original state.
+// TestSettingsRoundTrip flips the collection toggles and confirms the
+// endpoint and proxy address stay immutable, then restores the original
+// state. A second bootstrap attempt must be rejected as a conflict.
 func TestSettingsRoundTrip(t *testing.T) {
 	ctx := context.Background()
 
-	// Settings are bootstrapped on first provider create.
-	newProvider(t, ctx, "Settings Bootstrap")
-
+	// The package's TestMain bootstrapped the shared account's endpoint.
 	before, err := srv.GetSettings(ctx)
 	require.NoError(t, err, "get settings")
-	require.NotEmpty(t, before.Cluster, "settings must carry an assigned cluster")
+	require.NotEmpty(t, before.Endpoint, "settings must carry the bootstrapped endpoint")
+	require.NotEmpty(t, before.ProxyAddress, "settings must carry the bootstrapped proxy address")
+
+	require.NotNil(t, before.AccessLogRetentionDays, "bootstrapped settings must carry a retention")
+	beforeRetention := *before.AccessLogRetentionDays
 
 	flipped, err := srv.UpdateSettings(ctx, api.AgentNetworkSettingsRequest{
+		Endpoint:               before.Endpoint,
+		ProxyAddress:           before.ProxyAddress,
 		EnableLogCollection:    !before.EnableLogCollection,
 		EnablePromptCollection: !before.EnablePromptCollection,
 		RedactPii:              !before.RedactPii,
+		AccessLogRetentionDays: beforeRetention,
 	})
 	require.NoError(t, err, "update settings")
 	assert.Equal(t, !before.EnableLogCollection, flipped.EnableLogCollection, "log collection toggle must flip")
 	assert.Equal(t, !before.EnablePromptCollection, flipped.EnablePromptCollection, "prompt collection toggle must flip")
-	assert.Equal(t, before.Cluster, flipped.Cluster, "cluster must be immutable across updates")
-	assert.Equal(t, before.Subdomain, flipped.Subdomain, "subdomain must be immutable across updates")
+	require.NotNil(t, flipped.AccessLogRetentionDays)
+	assert.Equal(t, beforeRetention, *flipped.AccessLogRetentionDays,
+		"retention sent unchanged must round-trip, not reset to the zero value")
+	assert.Equal(t, before.Endpoint, flipped.Endpoint, "endpoint must be immutable across updates")
+	assert.Equal(t, before.ProxyAddress, flipped.ProxyAddress, "proxy address must be immutable across updates")
 
-	// A cluster different from the pinned one must be rejected; echoing the
-	// pinned one back is valid.
+	// The account is already bootstrapped: a second bootstrap is a conflict,
+	// whatever shape it asks for.
+	_, err = srv.CreateSettings(ctx, api.AgentNetworkSettingsCreateRequest{
+		Endpoint: ptr("attacker.cluster.invalid"),
+	})
+	requireClientError(t, err)
+
+	// The identity fields ride along on the PUT as a required echo: a request
+	// carrying a different endpoint is rejected without applying anything.
 	_, err = srv.UpdateSettings(ctx, api.AgentNetworkSettingsRequest{
-		Cluster:                ptr("attacker.cluster.invalid"),
+		Endpoint:               "other.cluster.invalid",
+		ProxyAddress:           before.ProxyAddress,
 		EnableLogCollection:    before.EnableLogCollection,
 		EnablePromptCollection: before.EnablePromptCollection,
 		RedactPii:              before.RedactPii,
+		AccessLogRetentionDays: beforeRetention,
 	})
 	requireClientError(t, err)
 
 	// Restore the original toggles.
 	_, err = srv.UpdateSettings(ctx, api.AgentNetworkSettingsRequest{
-		Cluster:                ptr(before.Cluster),
+		Endpoint:               before.Endpoint,
+		ProxyAddress:           before.ProxyAddress,
 		EnableLogCollection:    before.EnableLogCollection,
 		EnablePromptCollection: before.EnablePromptCollection,
 		RedactPii:              before.RedactPii,
+		AccessLogRetentionDays: beforeRetention,
 	})
 	require.NoError(t, err, "restore settings")
 }

e2e/agentnetwork/settings_bootstrap_test.go

@@ -4,6 +4,7 @@ package agentnetwork
 
 import (
 	"context"
+	"strings"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -14,7 +15,8 @@ import (
 )
 
 // harnessStartFresh boots a dedicated combined server with its own fresh
-// account and registers its teardown on t.
+// account and registers its teardown on t. Unlike the shared srv, the fresh
+// account has NOT had its agent-network endpoint bootstrapped.
 func harnessStartFresh(ctx context.Context, t *testing.T) (*harness.Combined, error) {
 	t.Helper()
 	fresh, err := harness.StartCombined(ctx)
@@ -28,16 +30,16 @@ func harnessStartFresh(ctx context.Context, t *testing.T) (*harness.Combined, er
 	return fresh, nil
 }
 
-// TestSettingsBootstrapViaPut covers the settings-first bootstrap path on an
+// TestSettingsBootstrapViaPost covers the explicit bootstrap contract on an
 // account that has never been bootstrapped: the GET reads as the defaults
-// with an empty cluster/subdomain/endpoint, a PUT without a cluster has
-// nothing to pin and fails, and a PUT carrying a cluster creates the row and
-// pins it immutably. The shared srv cannot provide that starting state (any
-// provider-creating test bootstraps it, and test order is deliberately not
-// relied on), so this boots a dedicated combined server — the image is
-// already built and cached by TestMain's StartCombined, so the extra cost is
-// one container start.
-func TestSettingsBootstrapViaPut(t *testing.T) {
+// with an empty endpoint/proxy_address, a PUT has no row to update and fails,
+// and a POST creates the row and assigns the immutable endpoint — labeled
+// beneath a proxy address here, with the toggle overrides from the same
+// request applied. The shared srv cannot provide that starting state
+// (TestMain bootstraps it), so this boots a dedicated combined server — the
+// image is already built and cached by TestMain's StartCombined, so the extra
+// cost is one container start.
+func TestSettingsBootstrapViaPost(t *testing.T) {
 	ctx := context.Background()
 
 	fresh, err := harnessStartFresh(ctx, t)
@@ -47,32 +49,35 @@ func TestSettingsBootstrapViaPut(t *testing.T) {
 	// as an error and not as a null body.
 	before, err := fresh.GetSettings(ctx)
 	require.NoError(t, err, "get settings on a fresh account must succeed")
-	assert.Empty(t, before.Cluster, "cluster must be empty before bootstrap")
-	assert.Empty(t, before.Subdomain, "subdomain must be empty before bootstrap")
-	assert.Empty(t, before.Endpoint, "endpoint must be empty before bootstrap, not a bare dot")
+	assert.Empty(t, before.Endpoint, "endpoint must be empty before bootstrap")
+	assert.Empty(t, before.ProxyAddress, "proxy address must be empty before bootstrap")
+	assert.False(t, before.Dedicated, "an unbootstrapped account has no serving shape")
 	assert.True(t, before.EnableLogCollection, "defaults must show log collection on, matching bootstrap")
 	assert.False(t, before.EnablePromptCollection, "defaults must show prompt collection off")
 
-	// A PUT without a cluster has nothing to pin the account to.
+	// A PUT has no row to update yet — bootstrap is the explicit POST.
 	_, err = fresh.UpdateSettings(ctx, api.AgentNetworkSettingsRequest{
-		EnableLogCollection: true,
+		EnableLogCollection:    true,
+		AccessLogRetentionDays: 30,
 	})
 	requireClientError(t, err)
 
-	// A PUT carrying a cluster bootstraps the account and applies the
-	// mutable fields from the same request. Every toggle is set away from
-	// its bootstrap default so each assertion can actually fail.
+	// A POST with a proxy address bootstraps a labeled endpoint and applies
+	// the toggles from the same request. Every toggle is set away from its
+	// bootstrap default so each assertion can actually fail.
 	const cluster = "e2e.bootstrap.netbird.selfhosted"
-	bootstrapped, err := fresh.UpdateSettings(ctx, api.AgentNetworkSettingsRequest{
-		Cluster:                ptr(cluster),
-		EnableLogCollection:    false,
-		EnablePromptCollection: true,
-		RedactPii:              true,
+	bootstrapped, err := fresh.CreateSettings(ctx, api.AgentNetworkSettingsCreateRequest{
+		ProxyAddress:           ptr(cluster),
+		EnableLogCollection:    ptr(false),
+		EnablePromptCollection: ptr(true),
+		RedactPii:              ptr(true),
 	})
-	require.NoError(t, err, "bootstrap settings via PUT must succeed")
-	assert.Equal(t, cluster, bootstrapped.Cluster, "cluster must be pinned from the request")
-	require.NotEmpty(t, bootstrapped.Subdomain, "subdomain must be assigned at bootstrap")
-	assert.Equal(t, bootstrapped.Subdomain+"."+cluster, bootstrapped.Endpoint, "endpoint must combine subdomain and cluster")
+	require.NoError(t, err, "bootstrap settings via POST must succeed")
+	assert.Equal(t, cluster, bootstrapped.ProxyAddress, "proxy address must be pinned from the request")
+	require.NotEmpty(t, bootstrapped.Endpoint, "endpoint must be assigned at bootstrap")
+	assert.True(t, strings.HasSuffix(bootstrapped.Endpoint, "."+cluster),
+		"labeled endpoint must hang one label beneath the proxy address: %s", bootstrapped.Endpoint)
+	assert.False(t, bootstrapped.Dedicated, "a labeled pin is not dedicated")
 	assert.False(t, bootstrapped.EnableLogCollection, "log collection from the bootstrap request must override the default")
 	assert.True(t, bootstrapped.EnablePromptCollection, "prompt collection from the bootstrap request must apply")
 	assert.True(t, bootstrapped.RedactPii, "redact toggle from the bootstrap request must apply")
@@ -85,30 +90,90 @@ func TestSettingsBootstrapViaPut(t *testing.T) {
 	assert.Equal(t, bootstrapped.EnablePromptCollection, after.EnablePromptCollection, "prompt collection must persist")
 	assert.Equal(t, bootstrapped.RedactPii, after.RedactPii, "redact toggle must persist")
 
-	// Once bootstrapped, later updates may omit the cluster entirely.
+	// Once bootstrapped, PUT updates the toggles. The identity fields ride
+	// along as a required echo of the assigned values; a matching echo is
+	// accepted and never written.
 	persisted, err := fresh.UpdateSettings(ctx, api.AgentNetworkSettingsRequest{
+		Endpoint:               bootstrapped.Endpoint,
+		ProxyAddress:           bootstrapped.ProxyAddress,
 		EnableLogCollection:    true,
 		EnablePromptCollection: false,
 		RedactPii:              true,
+		AccessLogRetentionDays: 21,
 	})
-	require.NoError(t, err, "post-bootstrap update without cluster must succeed")
-	assert.Equal(t, cluster, persisted.Cluster, "omitted cluster must keep the pinned value")
+	require.NoError(t, err, "post-bootstrap update must succeed")
+	require.NotNil(t, persisted.AccessLogRetentionDays)
+	assert.Equal(t, 21, *persisted.AccessLogRetentionDays, "retention from the update must apply")
+	assert.Equal(t, bootstrapped.Endpoint, persisted.Endpoint, "endpoint must survive updates untouched")
+	assert.Equal(t, cluster, persisted.ProxyAddress, "proxy address must survive updates untouched")
 	assert.True(t, persisted.EnableLogCollection, "post-bootstrap toggle must apply")
 	assert.False(t, persisted.EnablePromptCollection, "post-bootstrap toggle must apply")
 
-	// The cluster is immutable: a different value is rejected rather than
-	// silently ignored, and the rejected update must not disturb anything.
+	// The endpoint is immutable: a PUT carrying a different endpoint is
+	// rejected, and a second bootstrap is rejected as a conflict. Neither
+	// rejected write may disturb anything.
 	_, err = fresh.UpdateSettings(ctx, api.AgentNetworkSettingsRequest{
-		Cluster:             ptr("other.cluster.invalid"),
-		EnableLogCollection: false,
+		Endpoint:               "other.cluster.invalid",
+		ProxyAddress:           persisted.ProxyAddress,
+		EnableLogCollection:    persisted.EnableLogCollection,
+		EnablePromptCollection: persisted.EnablePromptCollection,
+		RedactPii:              persisted.RedactPii,
+		AccessLogRetentionDays: 21,
+	})
+	requireClientError(t, err)
+
+	_, err = fresh.CreateSettings(ctx, api.AgentNetworkSettingsCreateRequest{
+		Endpoint: ptr("other.cluster.invalid"),
 	})
 	requireClientError(t, err)
 
 	final, err := fresh.GetSettings(ctx)
-	require.NoError(t, err, "get settings after the rejected cluster change must succeed")
-	assert.Equal(t, persisted.Cluster, final.Cluster, "rejected update must not change the cluster")
-	assert.Equal(t, persisted.Endpoint, final.Endpoint, "rejected update must not change the endpoint")
-	assert.Equal(t, persisted.EnableLogCollection, final.EnableLogCollection, "rejected update must not apply its toggles")
-	assert.Equal(t, persisted.EnablePromptCollection, final.EnablePromptCollection, "rejected update must not apply its toggles")
-	assert.Equal(t, persisted.RedactPii, final.RedactPii, "rejected update must not apply its toggles")
+	require.NoError(t, err, "get settings after the rejected bootstrap must succeed")
+	assert.Equal(t, persisted.Endpoint, final.Endpoint, "rejected bootstrap must not change the endpoint")
+	assert.Equal(t, persisted.ProxyAddress, final.ProxyAddress, "rejected bootstrap must not change the proxy address")
+	assert.Equal(t, persisted.EnableLogCollection, final.EnableLogCollection, "rejected bootstrap must not apply its toggles")
+	assert.Equal(t, persisted.EnablePromptCollection, final.EnablePromptCollection, "rejected bootstrap must not apply its toggles")
+	assert.Equal(t, persisted.RedactPii, final.RedactPii, "rejected bootstrap must not apply its toggles")
+}
+
+// TestSettingsBootstrapSelfAddressed covers the dedicated shape end to end:
+// a POST carrying an endpoint claims the hostname verbatim, the proxy address
+// equals it, and the pin reads as dedicated — the address-first flow a
+// self-hosted operator uses before deploying the proxy that will declare it.
+// The tail covers the recovery path the guarded DELETE exists for: with no
+// providers and no proxy at the address, the claim can be released and a
+// fresh bootstrap succeeds — the fix for a typo'd immutable endpoint.
+func TestSettingsBootstrapSelfAddressed(t *testing.T) {
+	ctx := context.Background()
+
+	fresh, err := harnessStartFresh(ctx, t)
+	require.NoError(t, err, "start dedicated combined server")
+
+	created, err := fresh.CreateSettings(ctx, api.AgentNetworkSettingsCreateRequest{
+		Endpoint: ptr("gw.e2e.netbird.selfhosted"),
+	})
+	require.NoError(t, err, "self-addressed bootstrap must succeed")
+	assert.Equal(t, "gw.e2e.netbird.selfhosted", created.Endpoint, "endpoint must be claimed verbatim")
+	assert.Equal(t, created.Endpoint, created.ProxyAddress, "self-addressed: proxy address is the endpoint")
+	assert.True(t, created.Dedicated, "a self-addressed pin is dedicated")
+
+	// No providers exist and no proxy declares the address, so both delete
+	// guards are clear: the delete releases the claim and the account reads
+	// as unbootstrapped defaults again.
+	require.NoError(t, fresh.DeleteSettings(ctx), "guarded delete with both guards clear must succeed")
+
+	after, err := fresh.GetSettings(ctx)
+	require.NoError(t, err, "get settings after delete must succeed")
+	assert.Empty(t, after.Endpoint, "a deleted account must read as unbootstrapped")
+
+	// A second delete has nothing to remove.
+	requireClientError(t, fresh.DeleteSettings(ctx))
+
+	// Re-creating is a fresh bootstrap — the released hostname is free to be
+	// claimed again, or a different one chosen.
+	recreated, err := fresh.CreateSettings(ctx, api.AgentNetworkSettingsCreateRequest{
+		Endpoint: ptr("gw2.e2e.netbird.selfhosted"),
+	})
+	require.NoError(t, err, "bootstrap after delete must succeed")
+	assert.Equal(t, "gw2.e2e.netbird.selfhosted", recreated.Endpoint, "the fresh bootstrap claims the new hostname")
 }

e2e/agentnetwork/skiptls_test.go

@@ -66,9 +66,7 @@ func TestProviderSkipTLSVerification(t *testing.T) {
 		}
 	}
 
-	// First create bootstraps the account cluster.
 	insecureReq := newReq("skip-tls", insecureModel, true)
-	insecureReq.BootstrapCluster = ptr(harness.AgentNetworkCluster)
 	insecureProv, err := srv.CreateProvider(ctx, insecureReq)
 	require.NoError(t, err, "create skip-tls provider")
 	t.Cleanup(func() { _ = srv.DeleteProvider(context.Background(), insecureProv.Id) })

e2e/agentnetwork/vllm_test.go

@@ -57,12 +57,11 @@ func TestVLLMProvider(t *testing.T) {
 	// is enumerated so the router dispatches this model string to this provider.
 	dummyKey := "sk-vllm-e2e"
 	prov, err := srv.CreateProvider(ctx, api.AgentNetworkProviderRequest{
-		Name:             "vllm",
-		ProviderId:       "vllm",
-		UpstreamUrl:      vllm.URL,
-		ApiKey:           &dummyKey,
-		Enabled:          ptr(true),
-		BootstrapCluster: ptr(harness.AgentNetworkCluster),
+		Name:        "vllm",
+		ProviderId:  "vllm",
+		UpstreamUrl: vllm.URL,
+		ApiKey:      &dummyKey,
+		Enabled:     ptr(true),
 		Models: &[]api.AgentNetworkProviderModel{
 			{Id: harness.VLLMModel, InputPer1k: 0.001, OutputPer1k: 0.002},
 		},

e2e/harness/Dockerfile.client

@@ -20,5 +20,9 @@ ENV NETBIRD_BIN="/usr/local/bin/netbird" \
     NB_ENABLE_CAPTURE="false" \
     NB_ENTRYPOINT_SERVICE_TIMEOUT="30"
 ENTRYPOINT [ "/usr/local/bin/netbird-entrypoint.sh" ]
-COPY client/netbird-entrypoint.sh /usr/local/bin/netbird-entrypoint.sh
+# --chmod because the build context is not always a git checkout. A suite in
+# another module builds from this module's extracted copy in the module cache,
+# where every file is 0444 — the cache drops the executable bit git records — and
+# a bare COPY then produces an entrypoint the runtime cannot exec.
+COPY --chmod=0755 client/netbird-entrypoint.sh /usr/local/bin/netbird-entrypoint.sh
 COPY --from=builder /out/netbird /usr/local/bin/netbird

e2e/harness/agentnetwork.go

@@ -126,17 +126,33 @@ func (c *Combined) DeleteGuardrail(ctx context.Context, id string) error {
 	return anDelete(ctx, c, "/api/agent-network/guardrails/"+id)
 }
 
-// GetSettings returns the account's agent-network settings row. It exists only
-// after the first provider create bootstraps it.
+// CreateSettings bootstraps the account's agent-network settings row,
+// assigning the immutable endpoint. Exactly one of req.ProxyAddress (labeled
+// endpoint beneath that cluster) and req.Endpoint (self-addressed dedicated
+// endpoint) must be set; a second bootstrap returns a conflict.
+func (c *Combined) CreateSettings(ctx context.Context, req api.AgentNetworkSettingsCreateRequest) (api.AgentNetworkSettings, error) {
+	return anRequest[api.AgentNetworkSettings](ctx, c, http.MethodPost, "/api/agent-network/settings", req)
+}
+
+// GetSettings returns the account's agent-network settings row. Before the
+// CreateSettings bootstrap it reads as the defaults with an empty endpoint.
 func (c *Combined) GetSettings(ctx context.Context) (api.AgentNetworkSettings, error) {
 	return anRequest[api.AgentNetworkSettings](ctx, c, http.MethodGet, "/api/agent-network/settings", nil)
 }
 
-// UpdateSettings applies the mutable collection toggles.
+// UpdateSettings applies the mutable collection toggles. The request must
+// echo the assigned endpoint and proxy address unchanged — the server rejects
+// a PUT that tries to change them.
 func (c *Combined) UpdateSettings(ctx context.Context, req api.AgentNetworkSettingsRequest) (api.AgentNetworkSettings, error) {
 	return anRequest[api.AgentNetworkSettings](ctx, c, http.MethodPut, "/api/agent-network/settings", req)
 }
 
+// DeleteSettings removes the account's settings row, releasing the endpoint.
+// Refused while providers exist or a proxy is actively serving the endpoint.
+func (c *Combined) DeleteSettings(ctx context.Context) error {
+	return anDelete(ctx, c, "/api/agent-network/settings")
+}
+
 // ListConsumption returns the account's consumption rows (possibly empty).
 func (c *Combined) ListConsumption(ctx context.Context) ([]api.AgentNetworkConsumption, error) {
 	return anRequest[[]api.AgentNetworkConsumption](ctx, c, http.MethodGet, "/api/agent-network/consumption", nil)

e2e/harness/client.go

@@ -32,12 +32,36 @@ type Client struct {
 	container testcontainers.Container
 }
 
+// clientOptions is what the ClientOption values assemble.
+type clientOptions struct {
+	name string
+}
+
+// ClientOption adjusts how StartClient runs the agent.
+type ClientOption func(*clientOptions)
+
+// WithClientName names the agent, which sets both its network alias and its
+// container hostname. The hostname matters beyond addressing: the agent reports
+// it to management at registration, so it is the name the peer appears under in
+// the API.
+//
+// Required to run more than one agent against the same server — the default name
+// is shared, and two containers cannot hold the same alias on one network.
+func WithClientName(name string) ClientOption {
+	return func(o *clientOptions) { o.name = name }
+}
+
 // StartClient builds the client image and runs it on the combined server's
 // network, joining via the given setup key. The image entrypoint brings the
 // daemon up automatically; callers wait for connectivity with WaitConnected /
 // WaitProxyPeer.
-func StartClient(ctx context.Context, c *Combined, setupKey string) (*Client, error) {
-	root, err := repoRoot()
+func StartClient(ctx context.Context, c *Combined, setupKey string, opts ...ClientOption) (*Client, error) {
+	o := clientOptions{name: clientAlias}
+	for _, opt := range opts {
+		opt(&o)
+	}
+
+	root, err := repoRoot(ctx)
 	if err != nil {
 		return nil, err
 	}
@@ -47,9 +71,13 @@ func StartClient(ctx context.Context, c *Combined, setupKey string) (*Client, er
 	}
 
 	req := testcontainers.ContainerRequest{
-		Image:          clientImage,
+		Image: clientImage,
+		// The agent reports the container's hostname to management, so this is
+		// the name the peer is addressable by in the API as well as on the
+		// network. The entrypoint takes no hostname flag of its own.
+		Hostname:       o.name,
 		Networks:       []string{c.network.Name},
-		NetworkAliases: map[string][]string{c.network.Name: {clientAlias}},
+		NetworkAliases: map[string][]string{c.network.Name: {o.name}},
 		Env: map[string]string{
 			"NB_MANAGEMENT_URL": combinedExposedURL,
 			"NB_SETUP_KEY":      setupKey,