Reject port 0 in NB_DNS_FIREWALL_PORTS and roll back firewall on DNS setup failure

Address CodeRabbit nits: errors.As, defensive disable, port-aware filter name, log wording, provenance
Fix Windows lint: handle close error and exclude vendored WFP types from unused
2026-05-05 16:46:39 +00:00 · 2026-05-05 18:38:45 +02:00 · 2026-05-05 18:29:23 +02:00 · 2026-05-05 18:25:53 +02:00 · 2026-05-05 18:24:09 +02:00 · 2026-05-05 18:16:28 +02:00
32 changed files with 2478 additions and 174 deletions
--- a/.github/DISCUSSION_TEMPLATE/ideas-feature-requests.yml
+++ b/.github/DISCUSSION_TEMPLATE/ideas-feature-requests.yml
@@ -0,0 +1,130 @@
+body:
+  - type: markdown
+    attributes:
+      value: |
+        ## Ideas & Feature Requests
+
+        Use this category for feature requests, enhancements, integrations, and product ideas.
+
+        NetBird uses community traction in discussions — upvotes, replies, affected users, and use-case detail — as an input when deciding what should become a maintainer-curated issue or roadmap item. A clear problem statement is more useful than a solution-only request.
+
+        Please search first and add your use case to an existing discussion when one already exists.
+
+  - type: checkboxes
+    id: preflight
+    attributes:
+      label: Before posting
+      options:
+        - label: I searched existing discussions and issues for similar requests.
+          required: true
+        - label: I checked the documentation to confirm this is not already supported.
+          required: true
+        - label: This is a product idea or enhancement request, not a support question.
+          required: true
+        - label: I removed or anonymized sensitive details from examples and screenshots.
+          required: true
+
+  - type: dropdown
+    id: area
+    attributes:
+      label: Product area
+      description: Select every area this request touches.
+      multiple: true
+      options:
+        - Client / Agent
+        - CLI
+        - Desktop UI
+        - Mobile app
+        - Dashboard / Admin UI
+        - Management service / API
+        - Signal service
+        - Relay
+        - DNS
+        - Routes / Exit nodes
+        - NetBird SSH
+        - Access control policies
+        - Posture checks
+        - Identity provider / SSO
+        - Self-hosting / Deployment
+        - Kubernetes / Operator
+        - Terraform / Automation
+        - Documentation
+        - Other / not sure
+    validations:
+      required: true
+
+  - type: textarea
+    id: problem
+    attributes:
+      label: Problem or use case
+      description: What are you trying to accomplish, and what is difficult or impossible today?
+      placeholder: |
+        As a ...
+        I want to ...
+        Because ...
+    validations:
+      required: true
+
+  - type: textarea
+    id: proposal
+    attributes:
+      label: Proposed solution
+      description: Describe the behavior, workflow, API, UI, or integration you would like to see.
+    validations:
+      required: true
+
+  - type: textarea
+    id: alternatives
+    attributes:
+      label: Alternatives or workarounds considered
+      description: What have you tried today? Why is the current workaround not enough?
+
+  - type: textarea
+    id: impact
+    attributes:
+      label: Community impact and priority
+      description: Help us understand who benefits and how urgent this is.
+      placeholder: |
+        - Number of users/teams/peers affected:
+        - Deployment type: Cloud / self-hosted / both
+        - Frequency: daily / weekly / occasional
+        - Blocking production adoption? yes/no
+        - Related comments, discussions, or customer requests:
+    validations:
+      required: true
+
+  - type: textarea
+    id: examples
+    attributes:
+      label: Examples from other tools or products
+      description: If another tool solves this well, link or describe the behavior.
+
+  - type: textarea
+    id: security
+    attributes:
+      label: Security, privacy, and compatibility considerations
+      description: Note any access-control, audit, data retention, network, platform, or backward-compatibility concerns.
+
+  - type: textarea
+    id: implementation
+    attributes:
+      label: Implementation ideas
+      description: Optional. If you are familiar with the codebase or API, share possible implementation notes.
+
+  - type: dropdown
+    id: contribution
+    attributes:
+      label: Are you willing to help?
+      options:
+        - Yes, I can submit a PR if the approach is accepted.
+        - Yes, I can test or validate a proposed implementation.
+        - Yes, I can provide more use-case details.
+        - Not at this time.
+    validations:
+      required: true
+
+  - type: textarea
+    id: additional-context
+    attributes:
+      label: Additional context
+      description: Add screenshots, diagrams, links, or anything else that helps explain the request.
--- a/.github/DISCUSSION_TEMPLATE/issue-triage.yml
+++ b/.github/DISCUSSION_TEMPLATE/issue-triage.yml
@@ -0,0 +1,237 @@
+body:
+  - type: markdown
+    attributes:
+      value: |
+        ## Issue Triage
+
+        Use this category for reproducible bugs and regressions in NetBird.
+
+        The more context you include, the faster we can validate and act on your report. If you're not sure whether something is a bug, **Q&A / Support** is a good starting point — we can always move the conversation here once we've confirmed it's a product issue.
+
+        Intermittent issues are useful too. Include the trigger, frequency, timing, and any logs or debug evidence you have, and we'll work from there.
+
+        Please don't include secrets, tokens, private keys, internal hostnames, or public IPs. Security vulnerabilities should be reported through the repository security policy rather than a public discussion.
+
+  - type: checkboxes
+    id: preflight
+    attributes:
+      label: Before posting
+      options:
+        - label: I searched existing discussions and issues, including closed ones, and checked the relevant docs.
+          required: true
+        - label: I believe this is a product bug rather than a configuration or setup question.
+          required: true
+        - label: I can reproduce this issue, or for intermittent issues I've included trigger, frequency, and timing details below.
+          required: true
+        - label: I removed or anonymized sensitive data from logs, screenshots, and configuration.
+          required: true
+
+  - type: dropdown
+    id: area
+    attributes:
+      label: Affected area
+      description: Select every area this report touches.
+      multiple: true
+      options:
+        - Client / Agent
+        - Reverse Proxy
+        - CLI
+        - Desktop UI
+        - Mobile app
+        - Peer connectivity
+        - DNS
+        - Routes / Exit nodes
+        - NetBird SSH
+        - Relay / Signal / NAT traversal
+        - Login / Authentication / IdP
+        - Dashboard / Admin UI
+        - Management service / API
+        - Access control policies / Posture checks
+        - Self-hosting / Deployment
+        - Kubernetes / Operator
+        - Documentation
+        - Other / not sure
+    validations:
+      required: true
+
+  - type: dropdown
+    id: deployment
+    attributes:
+      label: Deployment type
+      options:
+        - NetBird Cloud
+        - Self-hosted - quickstart script
+        - Self-hosted - advanced/custom deployment
+        - Local development build
+        - Not sure / environment I do not fully control
+    validations:
+      required: true
+
+  - type: dropdown
+    id: platform
+    attributes:
+      label: Operating system or environment
+      description: Select every environment involved in the reproduction.
+      multiple: true
+      options:
+        - Linux
+        - macOS
+        - Windows
+        - Android
+        - iOS
+        - FreeBSD
+        - OpenWRT
+        - Docker
+        - Kubernetes
+        - Synology
+        - Browser
+        - Other / not sure
+    validations:
+      required: true
+
+  - type: textarea
+    id: version
+    attributes:
+      label: NetBird version and upgrade status
+      description: Run `netbird version` where applicable. For self-hosted deployments, include management, signal, relay, and dashboard versions if available. If you cannot test on a current/supported version, explain why.
+      placeholder: |
+        Example:
+        - Client: 0.30.2
+        - Management: 0.30.2
+        - Signal: 0.30.2
+        - Relay: 0.30.2
+        - Dashboard: 0.30.2
+        - Upgrade status: reproduced on current version / cannot upgrade because ...
+    validations:
+      required: true
+
+  - type: dropdown
+    id: regression
+    attributes:
+      label: Did this work before?
+      options:
+        - Yes, this worked before
+        - No, this never worked
+        - Not sure
+    validations:
+      required: true
+
+  - type: textarea
+    id: regression-details
+    attributes:
+      label: Regression details
+      description: If this worked before, include the last known working version, first known broken version, and any recent upgrade, configuration, network, or IdP changes.
+      placeholder: |
+        - Last known working version:
+        - First known broken version:
+        - Recent changes:
+
+  - type: textarea
+    id: summary
+    attributes:
+      label: Summary
+      description: Briefly describe the reproducible bug.
+      placeholder: What is broken?
+    validations:
+      required: true
+
+  - type: textarea
+    id: current-behavior
+    attributes:
+      label: Current behavior
+      description: What happens now? Include exact errors, timeouts, UI messages, or failed commands when possible.
+    validations:
+      required: true
+
+  - type: textarea
+    id: expected-behavior
+    attributes:
+      label: Expected behavior
+      description: What did you expect to happen instead?
+    validations:
+      required: true
+
+  - type: textarea
+    id: reproduction
+    attributes:
+      label: Steps to reproduce
+      description: Provide the smallest set of steps that reliably reproduces the bug. If the issue is intermittent, include the trigger, frequency, timing, and relevant timestamps.
+      placeholder: |
+        1. Configure ...
+        2. Run ...
+        3. Observe ...
+
+        For intermittent issues:
+        - Trigger:
+        - Frequency:
+        - Timing/timestamps:
+    validations:
+      required: true
+
+  - type: textarea
+    id: environment
+    attributes:
+      label: Environment and topology
+      description: Include the relevant topology and software involved in the reproduction. For UI/docs-only reports, write `N/A` if this does not apply. Use `None`, `Unknown`, or `N/A` where appropriate.
+      placeholder: |
+        - Peer A:
+        - Peer B:
+        - Same LAN or different networks:
+        - NAT/CGNAT/corporate firewall/mobile network:
+        - Other VPN software:
+        - Firewall, DNS, or endpoint security software:
+        - Routes, DNS, policies, posture checks, or SSH rules involved:
+        - IdP, reverse proxy, or browser involved:
+    validations:
+      required: true
+
+  - type: textarea
+    id: self-hosted-details
+    attributes:
+      label: Self-hosted details, if available
+      description: Optional. If you use self-hosting and have access to these details, include them. If you do not administer the environment, provide what you know and say what you cannot access.
+      placeholder: |
+        - Deployment method: quickstart / Docker Compose / Helm / operator / custom
+        - Management/signal/relay/dashboard versions:
+        - Reverse proxy:
+        - IdP/provider:
+        - STUN/TURN/coturn/relay details:
+        - Relevant component logs:
+
+  - type: textarea
+    id: logs
+    attributes:
+      label: Logs, status output, or debug evidence
+      description: |
+        For client, connectivity, DNS, route, relay/signal, or self-hosted reports, logs are essential — please include anonymized output from `netbird status -dA`, or a debug bundle via `netbird debug for 1m -AS -U`. Debug bundles are automatically deleted after 30 days.
+
+        For UI, dashboard, or documentation reports, leave the pre-filled `N/A`.
+      value: "N/A"
+      render: shell
+    validations:
+      required: true
+
+  - type: textarea
+    id: related-reports
+    attributes:
+      label: Related issues or discussions
+      description: Optional. Link similar reports you found while searching, if any.
+      placeholder: |
+        - Related issue/discussion:
+        - Why this may be the same or different:
+
+  - type: textarea
+    id: impact
+    attributes:
+      label: Impact
+      description: Optional. Help us understand priority. How many users, peers, environments, or workflows are affected? Is there a workaround?
+      placeholder: |
+        - Affected users/peers:
+        - Business or production impact:
+        - Workaround available:
+
+  - type: textarea
+    id: additional-context
+    attributes:
+      label: Additional context
+      description: Add links to related discussions, issues, docs, screenshots, recordings, or anything else that may help validation.
--- a/.github/DISCUSSION_TEMPLATE/q-a-support.yml
+++ b/.github/DISCUSSION_TEMPLATE/q-a-support.yml
@@ -0,0 +1,146 @@
+body:
+  - type: markdown
+    attributes:
+      value: |
+        ## Q&A / Support
+
+        Use this category for questions about configuration, setup, self-hosted deployments, troubleshooting, and general NetBird usage.
+
+        This is community support and does not provide an SLA. For NetBird Cloud support, use the official support channel linked from the issue creation page. Please do not post secrets, tokens, private keys, internal hostnames, or public IPs unless you intentionally want them public.
+
+        If your question turns into a reproducible product defect, DevRel or a maintainer may ask you to open or move the conversation to Issue Triage.
+
+  - type: checkboxes
+    id: preflight
+    attributes:
+      label: Before posting
+      options:
+        - label: I searched existing discussions and issues for similar questions.
+          required: true
+        - label: I reviewed the relevant NetBird documentation or troubleshooting guide.
+          required: true
+        - label: I removed or anonymized sensitive data from logs, screenshots, and configuration.
+          required: true
+
+  - type: dropdown
+    id: topic
+    attributes:
+      label: Topic
+      multiple: true
+      options:
+        - Getting started
+        - Self-hosting
+        - Client / Agent
+        - CLI
+        - Desktop UI
+        - Mobile app
+        - Dashboard / Admin UI
+        - DNS
+        - Routes / Exit nodes
+        - NetBird SSH
+        - Relay
+        - Access control policies
+        - Posture checks
+        - Identity provider / SSO
+        - API
+        - Kubernetes / Operator
+        - Terraform / Automation
+        - Documentation
+        - Other / not sure
+    validations:
+      required: true
+
+  - type: dropdown
+    id: deployment
+    attributes:
+      label: Deployment type
+      options:
+        - NetBird Cloud
+        - Self-hosted - quickstart script
+        - Self-hosted - advanced/custom deployment
+        - Local development build
+        - Not sure
+    validations:
+      required: true
+
+  - type: dropdown
+    id: platform
+    attributes:
+      label: Operating system or environment
+      multiple: true
+      options:
+        - Linux
+        - macOS
+        - Windows
+        - Android
+        - iOS
+        - FreeBSD
+        - OpenWRT
+        - Docker
+        - Kubernetes
+        - Synology
+        - Browser
+        - Other / not sure
+    validations:
+      required: true
+
+  - type: input
+    id: version
+    attributes:
+      label: NetBird version
+      description: Run `netbird version` where applicable. For self-hosted deployments, include component versions if relevant.
+      placeholder: "Example: client 0.30.2, management 0.30.2"
+
+  - type: textarea
+    id: question
+    attributes:
+      label: Question
+      description: What are you trying to understand or accomplish?
+      placeholder: Describe your question clearly.
+    validations:
+      required: true
+
+  - type: textarea
+    id: goal
+    attributes:
+      label: Desired outcome
+      description: What would a successful answer help you do?
+      placeholder: |
+        I want to configure ...
+        I expected ...
+        I need help deciding ...
+
+  - type: textarea
+    id: attempted
+    attributes:
+      label: What have you tried?
+      description: Include commands, documentation links, configuration attempts, or troubleshooting steps already tried.
+      placeholder: |
+        - Read ...
+        - Ran ...
+        - Changed ...
+        - Observed ...
+
+  - type: textarea
+    id: environment
+    attributes:
+      label: Relevant environment details
+      description: Include redacted topology, IdP/provider, reverse proxy, firewall, DNS, route, policy, or self-hosted setup details that may affect the answer.
+      placeholder: |
+        - Deployment:
+        - Components involved:
+        - Network/topology:
+        - Related config:
+
+  - type: textarea
+    id: logs
+    attributes:
+      label: Logs or output
+      description: Optional. Include anonymized logs, command output, screenshots, or `netbird status -dA` if relevant.
+      render: shell
+
+  - type: textarea
+    id: additional-context
+    attributes:
+      label: Additional context
+      description: Add links, diagrams, screenshots, or other details that may help the community answer.
--- a/.github/ISSUE_TEMPLATE/bug-issue-report.md
+++ b/.github/ISSUE_TEMPLATE/bug-issue-report.md
@@ -1,71 +0,0 @@
---
-name: Bug/Issue report
-about: Create a report to help us improve
-title: ''
-labels: ['triage-needed']
-assignees: ''
-
---
-
-**Describe the problem**
-
-A clear and concise description of what the problem is.
-
-**To Reproduce**
-
-Steps to reproduce the behavior:
-1. Go to '...'
-2. Click on '....'
-3. Scroll down to '....'
-4. See error
-
-**Expected behavior**
-
-A clear and concise description of what you expected to happen.
-
-**Are you using NetBird Cloud?**
-
-Please specify whether you use NetBird Cloud or self-host NetBird's control plane.
-
-**NetBird version**
-
-`netbird version`
-
-**Is any other VPN software installed?**
-
-If yes, which one?
-
-**Debug output**
-
-To help us resolve the problem, please attach the following anonymized status output
-
-  netbird status -dA
-
-Create and upload a debug bundle, and share the returned file key:
-
-  netbird debug for 1m -AS -U
-
-*Uploaded files are automatically deleted after 30 days.*
-
-
-Alternatively, create the file only and attach it here manually:
-
-  netbird debug for 1m -AS
-
-
-**Screenshots**
-
-If applicable, add screenshots to help explain your problem.
-
-**Additional context**
-
-Add any other context about the problem here.
-
-**Have you tried these troubleshooting steps?**
- [ ] Reviewed [client troubleshooting](https://docs.netbird.io/how-to/troubleshooting-client) (if applicable)
- [ ] Checked for newer NetBird versions
- [ ] Searched for similar issues on GitHub (including closed ones)
- [ ] Restarted the NetBird client
- [ ] Disabled other VPN software
- [ ] Checked firewall settings
-
--- a/.github/ISSUE_TEMPLATE/config.yml
+++ b/.github/ISSUE_TEMPLATE/config.yml
@@ -1,14 +1,26 @@
-blank_issues_enabled: true
+blank_issues_enabled: false
 contact_links:
-  - name: Community Support
+  - name: Start an Issue Triage discussion
+    url: https://github.com/netbirdio/netbird/discussions/new?category=issue-triage
+    about: Report a bug, regression, or unexpected behavior so DevRel can validate it before it becomes an issue.
+  - name: Propose an idea or feature request
+    url: https://github.com/netbirdio/netbird/discussions/new?category=ideas-feature-requests
+    about: Share feature requests, enhancements, and integration ideas for community feedback and prioritization.
+  - name: Ask a Q&A / Support question
+    url: https://github.com/netbirdio/netbird/discussions/new?category=q-a-support
+    about: Get help with setup, configuration, self-hosting, troubleshooting, and general usage.
+  - name: Security vulnerability disclosure
+    url: https://github.com/netbirdio/netbird/security/policy
+    about: Please do not report security vulnerabilities in public issues or discussions.
+  - name: Community Support Forum
    url: https://forum.netbird.io/
-    about: Community support forum
+    about: Community support forum.
  - name: Cloud Support
    url: https://docs.netbird.io/help/report-bug-issues
-    about: Contact us for support
-  - name: Client/Connection Troubleshooting
+    about: Contact NetBird for Cloud support.
+  - name: Client / Connection Troubleshooting
    url: https://docs.netbird.io/help/troubleshooting-client
-    about: See our client troubleshooting guide for help addressing common issues
+    about: See the client troubleshooting guide for common connectivity issues.
  - name: Self-host Troubleshooting
    url: https://docs.netbird.io/selfhosted/troubleshooting
-    about: See our self-host troubleshooting guide for help addressing common issues
+    about: See the self-host troubleshooting guide for common deployment issues.
--- a/.github/ISSUE_TEMPLATE/feature_request.md
+++ b/.github/ISSUE_TEMPLATE/feature_request.md
@@ -1,20 +0,0 @@
---
-name: Feature request
-about: Suggest an idea for this project
-title: ''
-labels: ['feature-request']
-assignees: ''
-
---
-
-**Is your feature request related to a problem? Please describe.**
-A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]
-
-**Describe the solution you'd like**
-A clear and concise description of what you want to happen.
-
-**Describe alternatives you've considered**
-A clear and concise description of any alternative solutions or features you've considered.
-
-**Additional context**
-Add any other context or screenshots about the feature request here.
--- a/.github/ISSUE_TEMPLATE/validated_issue.yml
+++ b/.github/ISSUE_TEMPLATE/validated_issue.yml
@@ -0,0 +1,128 @@
+name: Validated issue
+description: Maintainer/DevRel only. Create an issue after a discussion has been validated or for internally validated work.
+title: "[Validated]: "
+body:
+  - type: markdown
+    attributes:
+      value: |
+        ## Discussion-first issue policy
+
+        Issues are maintainer-curated work items. Community reports and feature requests should start in [Discussions](https://github.com/netbirdio/netbird/discussions) so DevRel can validate, reproduce, and route them before engineering time is committed.
+
+        Use this form when:
+        - A discussion has been validated and should become actionable work.
+        - A maintainer is opening internally validated work that can bypass the discussion-first flow.
+
+        Issues opened without a relevant validated discussion or maintainer context may be closed and redirected to Discussions.
+
+  - type: checkboxes
+    id: validation-checks
+    attributes:
+      label: Validation checklist
+      options:
+        - label: This issue is linked to a validated discussion, or it is being opened directly by a maintainer.
+          required: true
+        - label: The report has enough context for engineering to act on it without re-triaging from scratch.
+          required: true
+        - label: Sensitive data, secrets, private keys, internal hostnames, and public IPs have been removed or intentionally disclosed.
+          required: true
+
+  - type: dropdown
+    id: issue-type
+    attributes:
+      label: Issue type
+      options:
+        - Bug / Regression
+        - Feature / Enhancement
+        - Documentation
+        - Maintenance / Refactor
+        - Cross-repository coordination
+        - Other
+    validations:
+      required: true
+
+  - type: input
+    id: source-discussion
+    attributes:
+      label: Source discussion
+      description: Link the GitHub Discussion that was validated. Maintainers bypassing the flow can write "Maintainer-created" and explain why below.
+      placeholder: https://github.com/netbirdio/netbird/discussions/1234
+    validations:
+      required: true
+
+  - type: input
+    id: validation-owner
+    attributes:
+      label: Validation owner
+      description: GitHub handle of the DevRel team member or maintainer who validated this work.
+      placeholder: "@username"
+    validations:
+      required: true
+
+  - type: dropdown
+    id: target-repository
+    attributes:
+      label: Target repository
+      description: Where should the implementation work happen?
+      options:
+        - netbirdio/netbird
+        - netbirdio/dashboard
+        - netbirdio/kubernetes-operator
+        - netbirdio/docs
+        - Multiple repositories
+        - Unknown / needs routing
+    validations:
+      required: true
+
+  - type: textarea
+    id: summary
+    attributes:
+      label: Summary
+      description: Concise description of the validated work.
+      placeholder: What needs to be fixed, changed, documented, or built?
+    validations:
+      required: true
+
+  - type: textarea
+    id: evidence
+    attributes:
+      label: Validation evidence
+      description: For bugs, include reproduction status, affected versions, logs, and environment. For features, include community traction, affected users, and alignment notes.
+      placeholder: |
+        - Reproduced by:
+        - Affected versions / platforms:
+        - Community signal:
+        - Related logs or screenshots:
+    validations:
+      required: true
+
+  - type: textarea
+    id: scope
+    attributes:
+      label: Proposed scope
+      description: Describe what is in scope and, if helpful, what is explicitly out of scope.
+      placeholder: |
+        In scope:
+        - ...
+
+        Out of scope:
+        - ...
+    validations:
+      required: true
+
+  - type: textarea
+    id: acceptance-criteria
+    attributes:
+      label: Acceptance criteria
+      description: What must be true for this issue to be closed?
+      placeholder: |
+        - [ ] ...
+        - [ ] ...
+    validations:
+      required: true
+
+  - type: textarea
+    id: additional-context
+    attributes:
+      label: Additional context
+      description: Links to related PRs, docs, issues in other repositories, roadmap items, or implementation notes.
--- a/.golangci.yaml
+++ b/.golangci.yaml
@@ -92,6 +92,9 @@ linters:
      - linters:
          - unused
        path: client/firewall/iptables/rule\.go
+      - linters:
+          - unused
+        path: client/internal/dns/dnsfw/(types|syscall|zsyscall)_windows.*\.go
      - linters:
          - gosec
          - mirror
--- a/client/internal/dns/dnsfw/config.go
+++ b/client/internal/dns/dnsfw/config.go
@@ -0,0 +1,63 @@
+package dnsfw
+
+import (
+	"os"
+	"strconv"
+	"strings"
+
+	log "github.com/sirupsen/logrus"
+)
+
+const (
+	// EnvDisable disables the DNS firewall entirely when set to a truthy value.
+	EnvDisable = "NB_DISABLE_DNS_FIREWALL"
+	// EnvPorts overrides the comma-separated list of remote ports to block.
+	// Empty disables the firewall.
+	EnvPorts = "NB_DNS_FIREWALL_PORTS"
+	// EnvStrict enables strict mode: permit DNS only to the virtual DNS IP
+	// and the netbird daemon. Default mode also permits anything on the
+	// netbird tunnel interface, which is safer if NRPT is silently ignored
+	// by Windows but lets apps reach custom DNS servers via the tunnel.
+	EnvStrict = "NB_DNS_FIREWALL_STRICT"
+)
+
+// defaultBlockedPorts are the well-known DNS ports we block for non-netbird
+// processes: 53 (plain DNS) and 853 (DNS-over-TLS).
+var defaultBlockedPorts = []uint16{53, 853}
+
+// blockedPorts returns the effective port list, honoring env overrides.
+// A nil return means the firewall should not be installed.
+func blockedPorts() []uint16 {
+	if disabled, _ := strconv.ParseBool(os.Getenv(EnvDisable)); disabled {
+		log.Infof("dns firewall disabled via %s", EnvDisable)
+		return nil
+	}
+
+	override, ok := os.LookupEnv(EnvPorts)
+	if !ok {
+		return defaultBlockedPorts
+	}
+
+	var ports []uint16
+	for _, raw := range strings.Split(override, ",") {
+		raw = strings.TrimSpace(raw)
+		if raw == "" {
+			continue
+		}
+		port, err := strconv.ParseUint(raw, 10, 16)
+		if err != nil {
+			log.Warnf("dns firewall: ignoring invalid port %q in %s: %v", raw, EnvPorts, err)
+			continue
+		}
+		if port == 0 {
+			log.Warnf("dns firewall: ignoring port 0 in %s", EnvPorts)
+			continue
+		}
+		ports = append(ports, uint16(port))
+	}
+	if len(ports) == 0 {
+		log.Infof("dns firewall disabled: %s yielded no valid ports", EnvPorts)
+		return nil
+	}
+	return ports
+}
--- a/client/internal/dns/dnsfw/config_test.go
+++ b/client/internal/dns/dnsfw/config_test.go
@@ -0,0 +1,39 @@
+package dnsfw
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestBlockedPorts(t *testing.T) {
+	tests := []struct {
+		name     string
+		disable  string
+		ports    string
+		setPorts bool
+		want     []uint16
+	}{
+		{name: "default", want: defaultBlockedPorts},
+		{name: "disabled", disable: "true", want: nil},
+		{name: "disabled false keeps default", disable: "false", want: defaultBlockedPorts},
+		{name: "override single port", ports: "53", setPorts: true, want: []uint16{53}},
+		{name: "override multi", ports: "53, 853 ,5353", setPorts: true, want: []uint16{53, 853, 5353}},
+		{name: "override empty disables", ports: "", setPorts: true, want: nil},
+		{name: "override invalid skipped", ports: "53,not-a-port,853", setPorts: true, want: []uint16{53, 853}},
+		{name: "override zero skipped", ports: "53,0,853", setPorts: true, want: []uint16{53, 853}},
+		{name: "override only invalid disables", ports: "abc", setPorts: true, want: nil},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Setenv(EnvDisable, tc.disable)
+			if tc.setPorts {
+				t.Setenv(EnvPorts, tc.ports)
+			}
+			got := blockedPorts()
+			if !reflect.DeepEqual(got, tc.want) {
+				t.Fatalf("blockedPorts() = %v, want %v", got, tc.want)
+			}
+		})
+	}
+}
--- a/client/internal/dns/dnsfw/dnsfw.go
+++ b/client/internal/dns/dnsfw/dnsfw.go
@@ -0,0 +1,16 @@
+// Package dnsfw blocks DNS traffic from non-netbird processes when netbird is
+// managing the host's DNS, so that resolvers running on apps or libraries
+// outside netbird cannot bypass the configured DNS path.
+//
+// Implementation is Windows-only (uses WFP). On other platforms New returns
+// a no-op manager.
+package dnsfw
+
+import "net/netip"
+
+// Manager controls the per-tunnel DNS firewall. Both methods must be safe
+// to call multiple times.
+type Manager interface {
+	Enable(ifaceGUID string, virtualDNSIP netip.Addr) error
+	Disable() error
+}
--- a/client/internal/dns/dnsfw/dnsfw_other.go
+++ b/client/internal/dns/dnsfw/dnsfw_other.go
@@ -0,0 +1,15 @@
+//go:build !windows
+
+package dnsfw
+
+import "net/netip"
+
+type noopManager struct{}
+
+func (noopManager) Enable(string, netip.Addr) error { return nil }
+func (noopManager) Disable() error                  { return nil }
+
+// New returns a no-op manager on non-Windows platforms.
+func New() Manager {
+	return noopManager{}
+}
--- a/client/internal/dns/dnsfw/dnsfw_windows.go
+++ b/client/internal/dns/dnsfw/dnsfw_windows.go
@@ -0,0 +1,144 @@
+//go:build windows
+
+package dnsfw
+
+import (
+	"fmt"
+	"net/netip"
+	"os"
+	"strconv"
+	"sync"
+	"unsafe"
+
+	log "github.com/sirupsen/logrus"
+	"golang.org/x/sys/windows"
+)
+
+var (
+	modIphlpapi                    = windows.NewLazyDLL("iphlpapi.dll")
+	procConvertInterfaceGuidToLuid = modIphlpapi.NewProc("ConvertInterfaceGuidToLuid")
+)
+
+type windowsManager struct {
+	mu sync.Mutex
+	// session is the WFP engine handle. Zero when disabled.
+	session uintptr
+}
+
+// Enable installs the dns firewall. Strict mode propagates failures;
+// non-strict mode logs and returns nil so partial protection is preserved.
+func (m *windowsManager) Enable(ifaceGUID string, virtualDNSIP netip.Addr) error {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+	ports := blockedPorts()
+	if len(ports) == 0 {
+		return nil
+	}
+
+	if m.session != 0 {
+		if err := m.disableLocked(); err != nil {
+			return fmt.Errorf("reset existing dns firewall session: %w", err)
+		}
+	}
+
+	strict := strictMode()
+
+	luid, err := luidFromGUID(ifaceGUID)
+	if err != nil {
+		return m.failOrLog(strict, fmt.Errorf("resolve tun luid from guid %s: %w", ifaceGUID, err))
+	}
+
+	exe, err := os.Executable()
+	if err != nil {
+		return m.failOrLog(strict, fmt.Errorf("resolve daemon executable path: %w", err))
+	}
+
+	cfg := installConfig{
+		tunLUID:      luid,
+		daemonExe:    exe,
+		blockedPorts: ports,
+		strict:       strict,
+		virtualDNSIP: virtualDNSIP,
+	}
+	// session==0 signals a hard failure; non-zero with non-nil err is a partial install.
+	session, installErr := installFilters(cfg)
+	if session == 0 {
+		return m.failOrLog(strict, fmt.Errorf("install dns firewall filters: %w", installErr))
+	}
+
+	if installErr != nil && strict {
+		_ = closeSession(session)
+		return fmt.Errorf("strict dns firewall: partial install: %w", installErr)
+	}
+
+	m.session = session
+	log.Infof("dns firewall installed: iface=%s daemon=%s ports=%v strict=%v virtual_dns=%s",
+		ifaceGUID, exe, ports, strict, virtualDNSIP)
+	if installErr != nil {
+		log.Warnf("dns firewall partially installed (some filters failed): %v", installErr)
+	}
+	return nil
+}
+
+func (m *windowsManager) Disable() error {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	return m.disableLocked()
+}
+
+func (m *windowsManager) disableLocked() error {
+	if m.session == 0 {
+		return nil
+	}
+	session := m.session
+	m.session = 0
+	if err := closeSession(session); err != nil {
+		return fmt.Errorf("close wfp session: %w", err)
+	}
+	log.Info("dns firewall removed")
+	return nil
+}
+
+// failOrLog returns err unchanged in strict mode. In non-strict mode the
+// error is logged and nil is returned.
+func (m *windowsManager) failOrLog(strict bool, err error) error {
+	if strict {
+		return err
+	}
+	log.Errorf("dns firewall: %v", err)
+	return nil
+}
+
+// New returns a Windows DNS firewall manager backed by WFP.
+func New() Manager {
+	return &windowsManager{}
+}
+
+// strictMode reports whether strict mode is enabled via env.
+func strictMode() bool {
+	v, _ := strconv.ParseBool(os.Getenv(EnvStrict))
+	return v
+}
+
+// luidFromGUID converts a Windows interface GUID string to its LUID.
+func luidFromGUID(ifaceGUID string) (luid uint64, err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = fmt.Errorf("panic in luidFromGUID: %v", r)
+		}
+	}()
+
+	guid, err := windows.GUIDFromString(ifaceGUID)
+	if err != nil {
+		return 0, fmt.Errorf("parse guid: %w", err)
+	}
+	rc, _, _ := procConvertInterfaceGuidToLuid.Call(
+		uintptr(unsafe.Pointer(&guid)),
+		uintptr(unsafe.Pointer(&luid)),
+	)
+	if rc != 0 {
+		return 0, fmt.Errorf("ConvertInterfaceGuidToLuid returned %d", rc)
+	}
+	return luid, nil
+}
--- a/client/internal/dns/dnsfw/dnsfw_windows_test.go
+++ b/client/internal/dns/dnsfw/dnsfw_windows_test.go
@@ -0,0 +1,72 @@
+//go:build windows
+
+package dnsfw
+
+import (
+	"net/netip"
+	"os"
+	"testing"
+)
+
+func TestStrictMode(t *testing.T) {
+	tests := []struct {
+		name string
+		val  string
+		set  bool
+		want bool
+	}{
+		{name: "unset", want: false},
+		{name: "true", val: "true", set: true, want: true},
+		{name: "1", val: "1", set: true, want: true},
+		{name: "false", val: "false", set: true, want: false},
+		{name: "invalid is false", val: "garbage", set: true, want: false},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Setenv(EnvStrict, tc.val)
+			if !tc.set {
+				os.Unsetenv(EnvStrict)
+			}
+			if got := strictMode(); got != tc.want {
+				t.Fatalf("strictMode() = %v, want %v", got, tc.want)
+			}
+		})
+	}
+}
+
+func TestWindowsManagerDisableIdempotent(t *testing.T) {
+	m := &windowsManager{}
+	if err := m.Disable(); err != nil {
+		t.Fatalf("first Disable on fresh manager: %v", err)
+	}
+	if err := m.Disable(); err != nil {
+		t.Fatalf("second Disable on fresh manager: %v", err)
+	}
+	if m.session != 0 {
+		t.Fatalf("session should remain zero, got %d", m.session)
+	}
+}
+
+func TestWindowsManagerEnableNoOpWhenDisabledByEnv(t *testing.T) {
+	t.Setenv(EnvDisable, "true")
+
+	m := &windowsManager{}
+	if err := m.Enable("00000000-0000-0000-0000-000000000000", netip.Addr{}); err != nil {
+		t.Fatalf("Enable should be a no-op when firewall disabled by env: %v", err)
+	}
+	if m.session != 0 {
+		t.Fatalf("session must remain zero when env disables firewall, got %d", m.session)
+	}
+}
+
+func TestWindowsManagerEnableNoOpWhenPortsEmpty(t *testing.T) {
+	t.Setenv(EnvPorts, "")
+
+	m := &windowsManager{}
+	if err := m.Enable("00000000-0000-0000-0000-000000000000", netip.Addr{}); err != nil {
+		t.Fatalf("Enable should be a no-op when ports list is empty: %v", err)
+	}
+	if m.session != 0 {
+		t.Fatalf("session must remain zero when ports list is empty, got %d", m.session)
+	}
+}
--- a/client/internal/dns/dnsfw/helpers_windows.go
+++ b/client/internal/dns/dnsfw/helpers_windows.go
@@ -0,0 +1,53 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2019-2021 WireGuard LLC. All Rights Reserved.
+ *
+ * Adapted from wireguard-windows tunnel/firewall/helpers.go.
+ */
+
+package dnsfw
+
+import (
+	"errors"
+	"fmt"
+	"runtime"
+	"syscall"
+
+	"golang.org/x/sys/windows"
+)
+
+func createWtFwpmDisplayData0(name, description string) (*wtFwpmDisplayData0, error) {
+	namePtr, err := windows.UTF16PtrFromString(name)
+	if err != nil {
+		return nil, wrapErr(err)
+	}
+
+	descriptionPtr, err := windows.UTF16PtrFromString(description)
+	if err != nil {
+		return nil, wrapErr(err)
+	}
+
+	return &wtFwpmDisplayData0{
+		name:        namePtr,
+		description: descriptionPtr,
+	}, nil
+}
+
+func filterWeight(weight uint8) wtFwpValue0 {
+	return wtFwpValue0{
+		_type: cFWP_UINT8,
+		value: uintptr(weight),
+	}
+}
+
+func wrapErr(err error) error {
+	var errno syscall.Errno
+	if !errors.As(err, &errno) {
+		return err
+	}
+	_, file, line, ok := runtime.Caller(1)
+	if !ok {
+		return fmt.Errorf("wfp error at unknown location: %w", err)
+	}
+	return fmt.Errorf("wfp error at %s:%d: %w", file, line, err)
+}
--- a/client/internal/dns/dnsfw/rules_windows.go
+++ b/client/internal/dns/dnsfw/rules_windows.go
@@ -0,0 +1,249 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2019-2021 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2026 NetBird GmbH. All Rights Reserved.
+ *
+ * Filter installers adapted from wireguard-windows tunnel/firewall/rules.go.
+ * The block-DNS approach (port 53 + UDP/TCP) matches what wireguard-windows
+ * uses for its kill-switch DNS leak protection. We extend it with a
+ * configurable port set so we also cover :853 (DoT) and any future ports.
+ */
+
+package dnsfw
+
+import (
+	"encoding/binary"
+	"fmt"
+	"net/netip"
+	"unsafe"
+
+	"github.com/hashicorp/go-multierror"
+	"golang.org/x/sys/windows"
+
+	nberrors "github.com/netbirdio/netbird/client/errors"
+)
+
+// Filters install at outbound ALE_AUTH_CONNECT layers only; inbound replies
+// follow the authorized outbound flow.
+
+// permitTunInterface installs a permit filter for any traffic whose local
+// interface is the netbird tunnel.
+func permitTunInterface(session uintptr, base *baseObjects, weight uint8, ifLUID uint64) error {
+	cond := wtFwpmFilterCondition0{
+		fieldKey:  cFWPM_CONDITION_IP_LOCAL_INTERFACE,
+		matchType: cFWP_MATCH_EQUAL,
+		conditionValue: wtFwpConditionValue0{
+			_type: cFWP_UINT64,
+			value: uintptr(unsafe.Pointer(&ifLUID)),
+		},
+	}
+
+	filter := wtFwpmFilter0{
+		providerKey:         &base.provider,
+		subLayerKey:         base.filters,
+		weight:              filterWeight(weight),
+		numFilterConditions: 1,
+		filterCondition:     (*wtFwpmFilterCondition0)(unsafe.Pointer(&cond)),
+		action:              wtFwpmAction0{_type: cFWP_ACTION_PERMIT},
+	}
+
+	return addOutboundFilters(session, &filter, "Permit netbird tunnel")
+}
+
+// permitDaemonByAppID installs a permit filter matching the netbird daemon
+// executable by App-ID. App-ID alone is sufficient because netbird.exe is a
+// dedicated binary.
+func permitDaemonByAppID(session uintptr, base *baseObjects, daemonExe string, weight uint8) error {
+	appID, err := daemonAppID(daemonExe)
+	if err != nil {
+		return err
+	}
+	defer fwpmFreeMemory0(unsafe.Pointer(&appID))
+
+	cond := wtFwpmFilterCondition0{
+		fieldKey:  cFWPM_CONDITION_ALE_APP_ID,
+		matchType: cFWP_MATCH_EQUAL,
+		conditionValue: wtFwpConditionValue0{
+			_type: cFWP_BYTE_BLOB_TYPE,
+			value: uintptr(unsafe.Pointer(appID)),
+		},
+	}
+
+	filter := wtFwpmFilter0{
+		providerKey:         &base.provider,
+		subLayerKey:         base.filters,
+		weight:              filterWeight(weight),
+		numFilterConditions: 1,
+		filterCondition:     (*wtFwpmFilterCondition0)(unsafe.Pointer(&cond)),
+		action:              wtFwpmAction0{_type: cFWP_ACTION_PERMIT},
+	}
+
+	return addOutboundFilters(session, &filter, "Permit netbird daemon")
+}
+
+// permitVirtualDNSIP installs a permit filter for DNS-port traffic destined
+// for the in-tunnel virtual DNS IP. Used in strict mode in lieu of
+// permitTunInterface.
+func permitVirtualDNSIP(session uintptr, base *baseObjects, ip netip.Addr, ports []uint16, weight uint8) error {
+	var merr *multierror.Error
+	for _, port := range ports {
+		if err := permitDNSToHost(session, base, ip, port, weight); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("permit %s:%d: %w", ip, port, err))
+		}
+	}
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+func permitDNSToHost(session uintptr, base *baseObjects, ip netip.Addr, port uint16, weight uint8) error {
+	if !ip.IsValid() {
+		return fmt.Errorf("invalid address")
+	}
+
+	var addrCond wtFwpmFilterCondition0
+	var layer windows.GUID
+	// v6 backing must outlive fwpmFilterAdd0; keep it on this stack frame.
+	var v6 wtFwpByteArray16
+
+	if ip.Is4() {
+		v4 := ip.As4()
+		addrCond = wtFwpmFilterCondition0{
+			fieldKey:  cFWPM_CONDITION_IP_REMOTE_ADDRESS,
+			matchType: cFWP_MATCH_EQUAL,
+			conditionValue: wtFwpConditionValue0{
+				_type: cFWP_UINT32,
+				value: uintptr(binary.BigEndian.Uint32(v4[:])),
+			},
+		}
+		layer = cFWPM_LAYER_ALE_AUTH_CONNECT_V4
+	} else {
+		v6 = wtFwpByteArray16{byteArray16: ip.As16()}
+		addrCond = wtFwpmFilterCondition0{
+			fieldKey:  cFWPM_CONDITION_IP_REMOTE_ADDRESS,
+			matchType: cFWP_MATCH_EQUAL,
+			conditionValue: wtFwpConditionValue0{
+				_type: cFWP_BYTE_ARRAY16_TYPE,
+				value: uintptr(unsafe.Pointer(&v6)),
+			},
+		}
+		layer = cFWPM_LAYER_ALE_AUTH_CONNECT_V6
+	}
+
+	conditions := [2]wtFwpmFilterCondition0{
+		addrCond,
+		{
+			fieldKey:  cFWPM_CONDITION_IP_REMOTE_PORT,
+			matchType: cFWP_MATCH_EQUAL,
+			conditionValue: wtFwpConditionValue0{
+				_type: cFWP_UINT16,
+				value: uintptr(port),
+			},
+		},
+	}
+	filter := wtFwpmFilter0{
+		providerKey:         &base.provider,
+		subLayerKey:         base.filters,
+		weight:              filterWeight(weight),
+		numFilterConditions: uint32(len(conditions)),
+		filterCondition:     (*wtFwpmFilterCondition0)(unsafe.Pointer(&conditions[0])),
+		action:              wtFwpmAction0{_type: cFWP_ACTION_PERMIT},
+	}
+
+	display, err := createWtFwpmDisplayData0(fmt.Sprintf("Permit DNS to %s:%d", ip, port), "")
+	if err != nil {
+		return wrapErr(err)
+	}
+	filter.displayData = *display
+	filter.layerKey = layer
+
+	var filterID uint64
+	if err := fwpmFilterAdd0(session, &filter, 0, &filterID); err != nil {
+		return wrapErr(err)
+	}
+	_ = v6
+	return nil
+}
+
+// blockDNSPorts installs a deny filter for outbound traffic to each of the
+// given remote ports over UDP or TCP. Per-port and per-layer failures are
+// accumulated; partial coverage is preferred over zero coverage.
+func blockDNSPorts(session uintptr, base *baseObjects, ports []uint16, weight uint8) error {
+	var merr *multierror.Error
+	for _, port := range ports {
+		if err := blockDNSPort(session, base, port, weight); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("block port %d: %w", port, err))
+		}
+	}
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+func blockDNSPort(session uintptr, base *baseObjects, port uint16, weight uint8) error {
+	conditions := [3]wtFwpmFilterCondition0{
+		{
+			fieldKey:  cFWPM_CONDITION_IP_REMOTE_PORT,
+			matchType: cFWP_MATCH_EQUAL,
+			conditionValue: wtFwpConditionValue0{
+				_type: cFWP_UINT16,
+				value: uintptr(port),
+			},
+		},
+		{
+			fieldKey:  cFWPM_CONDITION_IP_PROTOCOL,
+			matchType: cFWP_MATCH_EQUAL,
+			conditionValue: wtFwpConditionValue0{
+				_type: cFWP_UINT8,
+				value: uintptr(cIPPROTO_UDP),
+			},
+		},
+		// Repeat the IP_PROTOCOL condition for logical OR with TCP.
+		{
+			fieldKey:  cFWPM_CONDITION_IP_PROTOCOL,
+			matchType: cFWP_MATCH_EQUAL,
+			conditionValue: wtFwpConditionValue0{
+				_type: cFWP_UINT8,
+				value: uintptr(cIPPROTO_TCP),
+			},
+		},
+	}
+
+	filter := wtFwpmFilter0{
+		providerKey:         &base.provider,
+		subLayerKey:         base.filters,
+		weight:              filterWeight(weight),
+		numFilterConditions: uint32(len(conditions)),
+		filterCondition:     (*wtFwpmFilterCondition0)(unsafe.Pointer(&conditions[0])),
+		action:              wtFwpmAction0{_type: cFWP_ACTION_BLOCK},
+	}
+
+	return addOutboundFilters(session, &filter, fmt.Sprintf("Block DNS port %d", port))
+}
+
+// addOutboundFilters installs the same filter on the v4 and v6 outbound ALE
+// connect layers. v4 and v6 are installed independently: failure on one
+// layer does not abort the other, and the accumulated errors are returned.
+// Partial coverage is preferred over zero coverage.
+func addOutboundFilters(session uintptr, filter *wtFwpmFilter0, name string) error {
+	layers := [...]struct {
+		layer windows.GUID
+		label string
+	}{
+		{cFWPM_LAYER_ALE_AUTH_CONNECT_V4, name + " (IPv4)"},
+		{cFWPM_LAYER_ALE_AUTH_CONNECT_V6, name + " (IPv6)"},
+	}
+
+	var merr *multierror.Error
+	for _, l := range layers {
+		display, err := createWtFwpmDisplayData0(l.label, "")
+		if err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("%s: %w", l.label, wrapErr(err)))
+			continue
+		}
+		filter.displayData = *display
+		filter.layerKey = l.layer
+
+		var filterID uint64
+		if err := fwpmFilterAdd0(session, filter, 0, &filterID); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("%s: %w", l.label, wrapErr(err)))
+		}
+	}
+	return nberrors.FormatErrorOrNil(merr)
+}
--- a/client/internal/dns/dnsfw/session_windows.go
+++ b/client/internal/dns/dnsfw/session_windows.go
@@ -0,0 +1,177 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2019-2021 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2026 NetBird GmbH. All Rights Reserved.
+ *
+ * Session lifecycle and the high-level Install/Close entry points adapted
+ * from wireguard-windows tunnel/firewall.
+ */
+
+package dnsfw
+
+import (
+	"errors"
+	"fmt"
+	"net/netip"
+	"unsafe"
+
+	"github.com/hashicorp/go-multierror"
+	"golang.org/x/sys/windows"
+
+	nberrors "github.com/netbirdio/netbird/client/errors"
+)
+
+// installConfig is the input to installFilters.
+type installConfig struct {
+	tunLUID      uint64
+	daemonExe    string
+	blockedPorts []uint16
+	// strict, when true, narrows the carve-out from "anything on tun" to
+	// "DNS only to virtualDNSIP". virtualDNSIP must be valid in this case.
+	strict       bool
+	virtualDNSIP netip.Addr
+}
+
+// baseObjects holds the GUIDs of the WFP provider and sublayer registered
+// for our session. Both are randomly generated per session.
+type baseObjects struct {
+	provider windows.GUID
+	filters  windows.GUID
+}
+
+// installFilters opens a dynamic WFP session and installs the netbird DNS
+// firewall filters. Returns a zero session on hard failure (session create,
+// base objects); a non-zero session with a non-nil error is a partial install
+// (some per-filter installs failed) and is safe to close.
+func installFilters(cfg installConfig) (session uintptr, err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			// Dynamic session: kernel will clean up on process exit even
+			// if we leave the handle dangling here.
+			err = fmt.Errorf("panic in installFilters: %v", r)
+		}
+	}()
+
+	if len(cfg.blockedPorts) == 0 {
+		return 0, errors.New("dns firewall: no blocked ports configured")
+	}
+	if cfg.strict && !cfg.virtualDNSIP.IsValid() {
+		return 0, errors.New("dns firewall: strict mode requires a valid virtual DNS IP")
+	}
+
+	session, err = createSession()
+	if err != nil {
+		return 0, err
+	}
+
+	base, err := registerBaseObjects(session)
+	if err != nil {
+		_ = fwpmEngineClose0(session)
+		return 0, fmt.Errorf("register base objects: %w", err)
+	}
+
+	var merr *multierror.Error
+	if cfg.strict {
+		if err := permitVirtualDNSIP(session, base, cfg.virtualDNSIP, cfg.blockedPorts, 15); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("permit virtual dns: %w", err))
+		}
+	} else {
+		if err := permitTunInterface(session, base, 15, cfg.tunLUID); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("permit tun interface: %w", err))
+		}
+	}
+	if err := permitDaemonByAppID(session, base, cfg.daemonExe, 14); err != nil {
+		merr = multierror.Append(merr, fmt.Errorf("permit netbird daemon: %w", err))
+	}
+	if err := blockDNSPorts(session, base, cfg.blockedPorts, 10); err != nil {
+		merr = multierror.Append(merr, fmt.Errorf("block dns ports: %w", err))
+	}
+
+	return session, nberrors.FormatErrorOrNil(merr)
+}
+
+// closeSession tears down a WFP session previously opened by installFilters.
+// All filters owned by the session are removed.
+func closeSession(session uintptr) (err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = fmt.Errorf("panic in closeSession: %v", r)
+		}
+	}()
+
+	if session == 0 {
+		return nil
+	}
+	if err := fwpmEngineClose0(session); err != nil {
+		return wrapErr(err)
+	}
+	return nil
+}
+
+func createSession() (uintptr, error) {
+	displayData, err := createWtFwpmDisplayData0("NetBird DNS firewall", "NetBird DNS firewall dynamic session")
+	if err != nil {
+		return 0, wrapErr(err)
+	}
+	session := wtFwpmSession0{
+		displayData:          *displayData,
+		flags:                cFWPM_SESSION_FLAG_DYNAMIC,
+		txnWaitTimeoutInMSec: windows.INFINITE,
+	}
+	var handle uintptr
+	if err := fwpmEngineOpen0(nil, cRPC_C_AUTHN_WINNT, nil, &session, unsafe.Pointer(&handle)); err != nil {
+		return 0, wrapErr(err)
+	}
+	return handle, nil
+}
+
+func registerBaseObjects(session uintptr) (*baseObjects, error) {
+	bo := &baseObjects{}
+	var err error
+	if bo.provider, err = windows.GenerateGUID(); err != nil {
+		return nil, wrapErr(err)
+	}
+	if bo.filters, err = windows.GenerateGUID(); err != nil {
+		return nil, wrapErr(err)
+	}
+
+	displayData, err := createWtFwpmDisplayData0("NetBird DNS firewall", "NetBird DNS firewall provider")
+	if err != nil {
+		return nil, wrapErr(err)
+	}
+	provider := wtFwpmProvider0{
+		providerKey: bo.provider,
+		displayData: *displayData,
+	}
+	if err := fwpmProviderAdd0(session, &provider, 0); err != nil {
+		return nil, wrapErr(err)
+	}
+
+	subDisplay, err := createWtFwpmDisplayData0("NetBird DNS firewall filters", "Permit and block filters")
+	if err != nil {
+		return nil, wrapErr(err)
+	}
+	sublayer := wtFwpmSublayer0{
+		subLayerKey: bo.filters,
+		displayData: *subDisplay,
+		providerKey: &bo.provider,
+		weight:      ^uint16(0),
+	}
+	if err := fwpmSubLayerAdd0(session, &sublayer, 0); err != nil {
+		return nil, wrapErr(err)
+	}
+	return bo, nil
+}
+
+// daemonAppID returns the WFP App-ID byte blob for the given executable path.
+func daemonAppID(path string) (*wtFwpByteBlob, error) {
+	pathPtr, err := windows.UTF16PtrFromString(path)
+	if err != nil {
+		return nil, wrapErr(err)
+	}
+	var appID *wtFwpByteBlob
+	if err := fwpmGetAppIdFromFileName0(pathPtr, unsafe.Pointer(&appID)); err != nil {
+		return nil, wrapErr(err)
+	}
+	return appID, nil
+}
--- a/client/internal/dns/dnsfw/syscall_windows.go
+++ b/client/internal/dns/dnsfw/syscall_windows.go
@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2019-2021 WireGuard LLC. All Rights Reserved.
+ *
+ * Adapted from wireguard-windows tunnel/firewall/syscall_windows.go.
+ */
+
+package dnsfw
+
+// https://docs.microsoft.com/en-us/windows/desktop/api/fwpmu/nf-fwpmu-fwpmengineopen0
+//sys	fwpmEngineOpen0(serverName *uint16, authnService wtRpcCAuthN, authIdentity *uintptr, session *wtFwpmSession0, engineHandle unsafe.Pointer) (err error) [failretval!=0] = fwpuclnt.FwpmEngineOpen0
+
+// https://docs.microsoft.com/en-us/windows/desktop/api/fwpmu/nf-fwpmu-fwpmengineclose0
+//sys	fwpmEngineClose0(engineHandle uintptr) (err error) [failretval!=0] = fwpuclnt.FwpmEngineClose0
+
+// https://docs.microsoft.com/en-us/windows/desktop/api/fwpmu/nf-fwpmu-fwpmsublayeradd0
+//sys	fwpmSubLayerAdd0(engineHandle uintptr, subLayer *wtFwpmSublayer0, sd uintptr) (err error) [failretval!=0] = fwpuclnt.FwpmSubLayerAdd0
+
+// https://docs.microsoft.com/en-us/windows/desktop/api/fwpmu/nf-fwpmu-fwpmgetappidfromfilename0
+//sys	fwpmGetAppIdFromFileName0(fileName *uint16, appID unsafe.Pointer) (err error) [failretval!=0] = fwpuclnt.FwpmGetAppIdFromFileName0
+
+// https://docs.microsoft.com/en-us/windows/desktop/api/fwpmu/nf-fwpmu-fwpmfreememory0
+//sys	fwpmFreeMemory0(p unsafe.Pointer) = fwpuclnt.FwpmFreeMemory0
+
+// https://docs.microsoft.com/en-us/windows/desktop/api/fwpmu/nf-fwpmu-fwpmfilteradd0
+//sys	fwpmFilterAdd0(engineHandle uintptr, filter *wtFwpmFilter0, sd uintptr, id *uint64) (err error) [failretval!=0] = fwpuclnt.FwpmFilterAdd0
+
+// https://docs.microsoft.com/en-us/windows/desktop/api/Fwpmu/nf-fwpmu-fwpmtransactionbegin0
+//sys	fwpmTransactionBegin0(engineHandle uintptr, flags uint32) (err error) [failretval!=0] = fwpuclnt.FwpmTransactionBegin0
+
+// https://docs.microsoft.com/en-us/windows/desktop/api/fwpmu/nf-fwpmu-fwpmtransactioncommit0
+//sys	fwpmTransactionCommit0(engineHandle uintptr) (err error) [failretval!=0] = fwpuclnt.FwpmTransactionCommit0
+
+// https://docs.microsoft.com/en-us/windows/desktop/api/fwpmu/nf-fwpmu-fwpmtransactionabort0
+//sys	fwpmTransactionAbort0(engineHandle uintptr) (err error) [failretval!=0] = fwpuclnt.FwpmTransactionAbort0
+
+// https://docs.microsoft.com/en-us/windows/desktop/api/fwpmu/nf-fwpmu-fwpmprovideradd0
+//sys	fwpmProviderAdd0(engineHandle uintptr, provider *wtFwpmProvider0, sd uintptr) (err error) [failretval!=0] = fwpuclnt.FwpmProviderAdd0
--- a/client/internal/dns/dnsfw/types_windows.go
+++ b/client/internal/dns/dnsfw/types_windows.go
@@ -0,0 +1,414 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2019-2021 WireGuard LLC. All Rights Reserved.
+ *
+ * Adapted from wireguard-windows tunnel/firewall/types_windows.go.
+ */
+
+package dnsfw
+
+import "golang.org/x/sys/windows"
+
+const (
+	anysizeArray = 1 // ANYSIZE_ARRAY defined in winnt.h
+
+	wtFwpBitmapArray64_Size = 8
+
+	wtFwpByteArray16_Size = 16
+
+	wtFwpByteArray6_Size = 6
+
+	wtFwpmAction0_Size              = 20
+	wtFwpmAction0_filterType_Offset = 4
+
+	wtFwpV4AddrAndMask_Size        = 8
+	wtFwpV4AddrAndMask_mask_Offset = 4
+
+	wtFwpV6AddrAndMask_Size                = 17
+	wtFwpV6AddrAndMask_prefixLength_Offset = 16
+)
+
+type wtFwpActionFlag uint32
+
+const (
+	cFWP_ACTION_FLAG_TERMINATING     wtFwpActionFlag = 0x00001000
+	cFWP_ACTION_FLAG_NON_TERMINATING wtFwpActionFlag = 0x00002000
+	cFWP_ACTION_FLAG_CALLOUT         wtFwpActionFlag = 0x00004000
+)
+
+// FWP_ACTION_TYPE defined in fwptypes.h
+type wtFwpActionType uint32
+
+const (
+	cFWP_ACTION_BLOCK               wtFwpActionType = wtFwpActionType(0x00000001 | cFWP_ACTION_FLAG_TERMINATING)
+	cFWP_ACTION_PERMIT              wtFwpActionType = wtFwpActionType(0x00000002 | cFWP_ACTION_FLAG_TERMINATING)
+	cFWP_ACTION_CALLOUT_TERMINATING wtFwpActionType = wtFwpActionType(0x00000003 | cFWP_ACTION_FLAG_CALLOUT | cFWP_ACTION_FLAG_TERMINATING)
+	cFWP_ACTION_CALLOUT_INSPECTION  wtFwpActionType = wtFwpActionType(0x00000004 | cFWP_ACTION_FLAG_CALLOUT | cFWP_ACTION_FLAG_NON_TERMINATING)
+	cFWP_ACTION_CALLOUT_UNKNOWN     wtFwpActionType = wtFwpActionType(0x00000005 | cFWP_ACTION_FLAG_CALLOUT)
+	cFWP_ACTION_CONTINUE            wtFwpActionType = wtFwpActionType(0x00000006 | cFWP_ACTION_FLAG_NON_TERMINATING)
+	cFWP_ACTION_NONE                wtFwpActionType = 0x00000007
+	cFWP_ACTION_NONE_NO_MATCH       wtFwpActionType = 0x00000008
+	cFWP_ACTION_BITMAP_INDEX_SET    wtFwpActionType = 0x00000009
+)
+
+// FWP_BYTE_BLOB defined in fwptypes.h
+// (https://docs.microsoft.com/en-us/windows/desktop/api/fwptypes/ns-fwptypes-fwp_byte_blob_)
+type wtFwpByteBlob struct {
+	size uint32
+	data *uint8
+}
+
+// FWP_MATCH_TYPE defined in fwptypes.h
+// (https://docs.microsoft.com/en-us/windows/desktop/api/fwptypes/ne-fwptypes-fwp_match_type_)
+type wtFwpMatchType uint32
+
+const (
+	cFWP_MATCH_EQUAL                  wtFwpMatchType = 0
+	cFWP_MATCH_GREATER                wtFwpMatchType = cFWP_MATCH_EQUAL + 1
+	cFWP_MATCH_LESS                   wtFwpMatchType = cFWP_MATCH_GREATER + 1
+	cFWP_MATCH_GREATER_OR_EQUAL       wtFwpMatchType = cFWP_MATCH_LESS + 1
+	cFWP_MATCH_LESS_OR_EQUAL          wtFwpMatchType = cFWP_MATCH_GREATER_OR_EQUAL + 1
+	cFWP_MATCH_RANGE                  wtFwpMatchType = cFWP_MATCH_LESS_OR_EQUAL + 1
+	cFWP_MATCH_FLAGS_ALL_SET          wtFwpMatchType = cFWP_MATCH_RANGE + 1
+	cFWP_MATCH_FLAGS_ANY_SET          wtFwpMatchType = cFWP_MATCH_FLAGS_ALL_SET + 1
+	cFWP_MATCH_FLAGS_NONE_SET         wtFwpMatchType = cFWP_MATCH_FLAGS_ANY_SET + 1
+	cFWP_MATCH_EQUAL_CASE_INSENSITIVE wtFwpMatchType = cFWP_MATCH_FLAGS_NONE_SET + 1
+	cFWP_MATCH_NOT_EQUAL              wtFwpMatchType = cFWP_MATCH_EQUAL_CASE_INSENSITIVE + 1
+	cFWP_MATCH_PREFIX                 wtFwpMatchType = cFWP_MATCH_NOT_EQUAL + 1
+	cFWP_MATCH_NOT_PREFIX             wtFwpMatchType = cFWP_MATCH_PREFIX + 1
+	cFWP_MATCH_TYPE_MAX               wtFwpMatchType = cFWP_MATCH_NOT_PREFIX + 1
+)
+
+// FWPM_ACTION0 defined in fwpmtypes.h
+// (https://docs.microsoft.com/en-us/windows/desktop/api/fwpmtypes/ns-fwpmtypes-fwpm_action0_)
+type wtFwpmAction0 struct {
+	_type      wtFwpActionType
+	filterType windows.GUID // Windows type: GUID
+}
+
+// Defined in fwpmu.h. 4cd62a49-59c3-4969-b7f3-bda5d32890a4
+var cFWPM_CONDITION_IP_LOCAL_INTERFACE = windows.GUID{
+	Data1: 0x4cd62a49,
+	Data2: 0x59c3,
+	Data3: 0x4969,
+	Data4: [8]byte{0xb7, 0xf3, 0xbd, 0xa5, 0xd3, 0x28, 0x90, 0xa4},
+}
+
+// Defined in fwpmu.h. b235ae9a-1d64-49b8-a44c-5ff3d9095045
+var cFWPM_CONDITION_IP_REMOTE_ADDRESS = windows.GUID{
+	Data1: 0xb235ae9a,
+	Data2: 0x1d64,
+	Data3: 0x49b8,
+	Data4: [8]byte{0xa4, 0x4c, 0x5f, 0xf3, 0xd9, 0x09, 0x50, 0x45},
+}
+
+// Defined in fwpmu.h. 3971ef2b-623e-4f9a-8cb1-6e79b806b9a7
+var cFWPM_CONDITION_IP_PROTOCOL = windows.GUID{
+	Data1: 0x3971ef2b,
+	Data2: 0x623e,
+	Data3: 0x4f9a,
+	Data4: [8]byte{0x8c, 0xb1, 0x6e, 0x79, 0xb8, 0x06, 0xb9, 0xa7},
+}
+
+// Defined in fwpmu.h. 0c1ba1af-5765-453f-af22-a8f791ac775b
+var cFWPM_CONDITION_IP_LOCAL_PORT = windows.GUID{
+	Data1: 0x0c1ba1af,
+	Data2: 0x5765,
+	Data3: 0x453f,
+	Data4: [8]byte{0xaf, 0x22, 0xa8, 0xf7, 0x91, 0xac, 0x77, 0x5b},
+}
+
+// Defined in fwpmu.h. c35a604d-d22b-4e1a-91b4-68f674ee674b
+var cFWPM_CONDITION_IP_REMOTE_PORT = windows.GUID{
+	Data1: 0xc35a604d,
+	Data2: 0xd22b,
+	Data3: 0x4e1a,
+	Data4: [8]byte{0x91, 0xb4, 0x68, 0xf6, 0x74, 0xee, 0x67, 0x4b},
+}
+
+// Defined in fwpmu.h. d78e1e87-8644-4ea5-9437-d809ecefc971
+var cFWPM_CONDITION_ALE_APP_ID = windows.GUID{
+	Data1: 0xd78e1e87,
+	Data2: 0x8644,
+	Data3: 0x4ea5,
+	Data4: [8]byte{0x94, 0x37, 0xd8, 0x09, 0xec, 0xef, 0xc9, 0x71},
+}
+
+// af043a0a-b34d-4f86-979c-c90371af6e66
+var cFWPM_CONDITION_ALE_USER_ID = windows.GUID{
+	Data1: 0xaf043a0a,
+	Data2: 0xb34d,
+	Data3: 0x4f86,
+	Data4: [8]byte{0x97, 0x9c, 0xc9, 0x03, 0x71, 0xaf, 0x6e, 0x66},
+}
+
+// d9ee00de-c1ef-4617-bfe3-ffd8f5a08957
+var cFWPM_CONDITION_IP_LOCAL_ADDRESS = windows.GUID{
+	Data1: 0xd9ee00de,
+	Data2: 0xc1ef,
+	Data3: 0x4617,
+	Data4: [8]byte{0xbf, 0xe3, 0xff, 0xd8, 0xf5, 0xa0, 0x89, 0x57},
+}
+
+var (
+	cFWPM_CONDITION_ICMP_TYPE = cFWPM_CONDITION_IP_LOCAL_PORT
+	cFWPM_CONDITION_ICMP_CODE = cFWPM_CONDITION_IP_REMOTE_PORT
+)
+
+// 7bc43cbf-37ba-45f1-b74a-82ff518eeb10
+var cFWPM_CONDITION_L2_FLAGS = windows.GUID{
+	Data1: 0x7bc43cbf,
+	Data2: 0x37ba,
+	Data3: 0x45f1,
+	Data4: [8]byte{0xb7, 0x4a, 0x82, 0xff, 0x51, 0x8e, 0xeb, 0x10},
+}
+
+type wtFwpmL2Flags uint32
+
+const cFWP_CONDITION_L2_IS_VM2VM wtFwpmL2Flags = 0x00000010
+
+var cFWPM_CONDITION_FLAGS = windows.GUID{
+	Data1: 0x632ce23b,
+	Data2: 0x5167,
+	Data3: 0x435c,
+	Data4: [8]byte{0x86, 0xd7, 0xe9, 0x03, 0x68, 0x4a, 0xa8, 0x0c},
+}
+
+type wtFwpmFlags uint32
+
+const cFWP_CONDITION_FLAG_IS_LOOPBACK wtFwpmFlags = 0x00000001
+
+// Defined in fwpmtypes.h
+type wtFwpmFilterFlags uint32
+
+const (
+	cFWPM_FILTER_FLAG_NONE                                wtFwpmFilterFlags = 0x00000000
+	cFWPM_FILTER_FLAG_PERSISTENT                          wtFwpmFilterFlags = 0x00000001
+	cFWPM_FILTER_FLAG_BOOTTIME                            wtFwpmFilterFlags = 0x00000002
+	cFWPM_FILTER_FLAG_HAS_PROVIDER_CONTEXT                wtFwpmFilterFlags = 0x00000004
+	cFWPM_FILTER_FLAG_CLEAR_ACTION_RIGHT                  wtFwpmFilterFlags = 0x00000008
+	cFWPM_FILTER_FLAG_PERMIT_IF_CALLOUT_UNREGISTERED      wtFwpmFilterFlags = 0x00000010
+	cFWPM_FILTER_FLAG_DISABLED                            wtFwpmFilterFlags = 0x00000020
+	cFWPM_FILTER_FLAG_INDEXED                             wtFwpmFilterFlags = 0x00000040
+	cFWPM_FILTER_FLAG_HAS_SECURITY_REALM_PROVIDER_CONTEXT wtFwpmFilterFlags = 0x00000080
+	cFWPM_FILTER_FLAG_SYSTEMOS_ONLY                       wtFwpmFilterFlags = 0x00000100
+	cFWPM_FILTER_FLAG_GAMEOS_ONLY                         wtFwpmFilterFlags = 0x00000200
+	cFWPM_FILTER_FLAG_SILENT_MODE                         wtFwpmFilterFlags = 0x00000400
+	cFWPM_FILTER_FLAG_IPSEC_NO_ACQUIRE_INITIATE           wtFwpmFilterFlags = 0x00000800
+)
+
+// FWPM_LAYER_ALE_AUTH_CONNECT_V4 (c38d57d1-05a7-4c33-904f-7fbceee60e82) defined in fwpmu.h
+var cFWPM_LAYER_ALE_AUTH_CONNECT_V4 = windows.GUID{
+	Data1: 0xc38d57d1,
+	Data2: 0x05a7,
+	Data3: 0x4c33,
+	Data4: [8]byte{0x90, 0x4f, 0x7f, 0xbc, 0xee, 0xe6, 0x0e, 0x82},
+}
+
+// e1cd9fe7-f4b5-4273-96c0-592e487b8650
+var cFWPM_LAYER_ALE_AUTH_RECV_ACCEPT_V4 = windows.GUID{
+	Data1: 0xe1cd9fe7,
+	Data2: 0xf4b5,
+	Data3: 0x4273,
+	Data4: [8]byte{0x96, 0xc0, 0x59, 0x2e, 0x48, 0x7b, 0x86, 0x50},
+}
+
+// FWPM_LAYER_ALE_AUTH_CONNECT_V6 (4a72393b-319f-44bc-84c3-ba54dcb3b6b4) defined in fwpmu.h
+var cFWPM_LAYER_ALE_AUTH_CONNECT_V6 = windows.GUID{
+	Data1: 0x4a72393b,
+	Data2: 0x319f,
+	Data3: 0x44bc,
+	Data4: [8]byte{0x84, 0xc3, 0xba, 0x54, 0xdc, 0xb3, 0xb6, 0xb4},
+}
+
+// a3b42c97-9f04-4672-b87e-cee9c483257f
+var cFWPM_LAYER_ALE_AUTH_RECV_ACCEPT_V6 = windows.GUID{
+	Data1: 0xa3b42c97,
+	Data2: 0x9f04,
+	Data3: 0x4672,
+	Data4: [8]byte{0xb8, 0x7e, 0xce, 0xe9, 0xc4, 0x83, 0x25, 0x7f},
+}
+
+// 94c44912-9d6f-4ebf-b995-05ab8a088d1b
+var cFWPM_LAYER_OUTBOUND_MAC_FRAME_NATIVE = windows.GUID{
+	Data1: 0x94c44912,
+	Data2: 0x9d6f,
+	Data3: 0x4ebf,
+	Data4: [8]byte{0xb9, 0x95, 0x05, 0xab, 0x8a, 0x08, 0x8d, 0x1b},
+}
+
+// d4220bd3-62ce-4f08-ae88-b56e8526df50
+var cFWPM_LAYER_INBOUND_MAC_FRAME_NATIVE = windows.GUID{
+	Data1: 0xd4220bd3,
+	Data2: 0x62ce,
+	Data3: 0x4f08,
+	Data4: [8]byte{0xae, 0x88, 0xb5, 0x6e, 0x85, 0x26, 0xdf, 0x50},
+}
+
+// FWP_BITMAP_ARRAY64 defined in fwtypes.h
+type wtFwpBitmapArray64 struct {
+	bitmapArray64 [8]uint8 // Windows type: [8]UINT8
+}
+
+// FWP_BYTE_ARRAY6 defined in fwtypes.h
+// (https://docs.microsoft.com/en-us/windows/desktop/api/fwptypes/ns-fwptypes-fwp_byte_array6_)
+type wtFwpByteArray6 struct {
+	byteArray6 [6]uint8 // Windows type: [6]UINT8
+}
+
+// FWP_BYTE_ARRAY16 defined in fwptypes.h
+// (https://docs.microsoft.com/en-us/windows/desktop/api/fwptypes/ns-fwptypes-fwp_byte_array16_)
+type wtFwpByteArray16 struct {
+	byteArray16 [16]uint8 // Windows type [16]UINT8
+}
+
+// FWP_CONDITION_VALUE0 defined in fwptypes.h
+// (https://docs.microsoft.com/en-us/windows/desktop/api/fwptypes/ns-fwptypes-fwp_condition_value0).
+type wtFwpConditionValue0 wtFwpValue0
+
+// FWP_DATA_TYPE defined in fwptypes.h
+// (https://docs.microsoft.com/en-us/windows/desktop/api/fwptypes/ne-fwptypes-fwp_data_type_)
+type wtFwpDataType uint
+
+const (
+	cFWP_EMPTY                         wtFwpDataType = 0
+	cFWP_UINT8                         wtFwpDataType = cFWP_EMPTY + 1
+	cFWP_UINT16                        wtFwpDataType = cFWP_UINT8 + 1
+	cFWP_UINT32                        wtFwpDataType = cFWP_UINT16 + 1
+	cFWP_UINT64                        wtFwpDataType = cFWP_UINT32 + 1
+	cFWP_INT8                          wtFwpDataType = cFWP_UINT64 + 1
+	cFWP_INT16                         wtFwpDataType = cFWP_INT8 + 1
+	cFWP_INT32                         wtFwpDataType = cFWP_INT16 + 1
+	cFWP_INT64                         wtFwpDataType = cFWP_INT32 + 1
+	cFWP_FLOAT                         wtFwpDataType = cFWP_INT64 + 1
+	cFWP_DOUBLE                        wtFwpDataType = cFWP_FLOAT + 1
+	cFWP_BYTE_ARRAY16_TYPE             wtFwpDataType = cFWP_DOUBLE + 1
+	cFWP_BYTE_BLOB_TYPE                wtFwpDataType = cFWP_BYTE_ARRAY16_TYPE + 1
+	cFWP_SID                           wtFwpDataType = cFWP_BYTE_BLOB_TYPE + 1
+	cFWP_SECURITY_DESCRIPTOR_TYPE      wtFwpDataType = cFWP_SID + 1
+	cFWP_TOKEN_INFORMATION_TYPE        wtFwpDataType = cFWP_SECURITY_DESCRIPTOR_TYPE + 1
+	cFWP_TOKEN_ACCESS_INFORMATION_TYPE wtFwpDataType = cFWP_TOKEN_INFORMATION_TYPE + 1
+	cFWP_UNICODE_STRING_TYPE           wtFwpDataType = cFWP_TOKEN_ACCESS_INFORMATION_TYPE + 1
+	cFWP_BYTE_ARRAY6_TYPE              wtFwpDataType = cFWP_UNICODE_STRING_TYPE + 1
+	cFWP_BITMAP_INDEX_TYPE             wtFwpDataType = cFWP_BYTE_ARRAY6_TYPE + 1
+	cFWP_BITMAP_ARRAY64_TYPE           wtFwpDataType = cFWP_BITMAP_INDEX_TYPE + 1
+	cFWP_SINGLE_DATA_TYPE_MAX          wtFwpDataType = 0xff
+	cFWP_V4_ADDR_MASK                  wtFwpDataType = cFWP_SINGLE_DATA_TYPE_MAX + 1
+	cFWP_V6_ADDR_MASK                  wtFwpDataType = cFWP_V4_ADDR_MASK + 1
+	cFWP_RANGE_TYPE                    wtFwpDataType = cFWP_V6_ADDR_MASK + 1
+	cFWP_DATA_TYPE_MAX                 wtFwpDataType = cFWP_RANGE_TYPE + 1
+)
+
+// FWP_V4_ADDR_AND_MASK defined in fwptypes.h
+// (https://docs.microsoft.com/en-us/windows/desktop/api/fwptypes/ns-fwptypes-fwp_v4_addr_and_mask).
+type wtFwpV4AddrAndMask struct {
+	addr uint32
+	mask uint32
+}
+
+// FWP_V6_ADDR_AND_MASK defined in fwptypes.h
+// (https://docs.microsoft.com/en-us/windows/desktop/api/fwptypes/ns-fwptypes-fwp_v6_addr_and_mask).
+type wtFwpV6AddrAndMask struct {
+	addr         [16]uint8
+	prefixLength uint8
+}
+
+// FWP_VALUE0 defined in fwptypes.h
+// (https://docs.microsoft.com/en-us/windows/desktop/api/fwptypes/ns-fwptypes-fwp_value0_)
+type wtFwpValue0 struct {
+	_type wtFwpDataType
+	value uintptr
+}
+
+// FWPM_DISPLAY_DATA0 defined in fwptypes.h
+// (https://docs.microsoft.com/en-us/windows/desktop/api/fwptypes/ns-fwptypes-fwpm_display_data0).
+type wtFwpmDisplayData0 struct {
+	name        *uint16 // Windows type: *wchar_t
+	description *uint16 // Windows type: *wchar_t
+}
+
+// FWPM_FILTER_CONDITION0 defined in fwpmtypes.h
+// (https://docs.microsoft.com/en-us/windows/desktop/api/fwpmtypes/ns-fwpmtypes-fwpm_filter_condition0).
+type wtFwpmFilterCondition0 struct {
+	fieldKey       windows.GUID // Windows type: GUID
+	matchType      wtFwpMatchType
+	conditionValue wtFwpConditionValue0
+}
+
+// FWPM_PROVIDER0 defined in fwpmtypes.h
+// (https://docs.microsoft.com/en-us/windows/desktop/api/fwpmtypes/ns-fwpmtypes-fwpm_provider0_)
+type wtFwpProvider0 struct {
+	providerKey  windows.GUID // Windows type: GUID
+	displayData  wtFwpmDisplayData0
+	flags        uint32
+	providerData wtFwpByteBlob
+	serviceName  *uint16 // Windows type: *wchar_t
+}
+
+type wtFwpmSessionFlagsValue uint32
+
+const (
+	cFWPM_SESSION_FLAG_DYNAMIC wtFwpmSessionFlagsValue = 0x00000001 // FWPM_SESSION_FLAG_DYNAMIC defined in fwpmtypes.h
+)
+
+// FWPM_SESSION0 defined in fwpmtypes.h
+// (https://docs.microsoft.com/en-us/windows/desktop/api/fwpmtypes/ns-fwpmtypes-fwpm_session0).
+type wtFwpmSession0 struct {
+	sessionKey           windows.GUID // Windows type: GUID
+	displayData          wtFwpmDisplayData0
+	flags                wtFwpmSessionFlagsValue // Windows type UINT32
+	txnWaitTimeoutInMSec uint32
+	processId            uint32 // Windows type: DWORD
+	sid                  *windows.SID
+	username             *uint16 // Windows type: *wchar_t
+	kernelMode           uint8   // Windows type: BOOL
+}
+
+type wtFwpmSublayerFlags uint32
+
+const (
+	cFWPM_SUBLAYER_FLAG_PERSISTENT wtFwpmSublayerFlags = 0x00000001 // FWPM_SUBLAYER_FLAG_PERSISTENT defined in fwpmtypes.h
+)
+
+// FWPM_SUBLAYER0 defined in fwpmtypes.h
+// (https://docs.microsoft.com/en-us/windows/desktop/api/fwpmtypes/ns-fwpmtypes-fwpm_sublayer0_)
+type wtFwpmSublayer0 struct {
+	subLayerKey  windows.GUID // Windows type: GUID
+	displayData  wtFwpmDisplayData0
+	flags        wtFwpmSublayerFlags
+	providerKey  *windows.GUID // Windows type: *GUID
+	providerData wtFwpByteBlob
+	weight       uint16
+}
+
+// Defined in rpcdce.h
+type wtRpcCAuthN uint32
+
+const (
+	cRPC_C_AUTHN_NONE    wtRpcCAuthN = 0
+	cRPC_C_AUTHN_WINNT   wtRpcCAuthN = 10
+	cRPC_C_AUTHN_DEFAULT wtRpcCAuthN = 0xFFFFFFFF
+)
+
+// FWPM_PROVIDER0 defined in fwpmtypes.h
+// (https://docs.microsoft.com/sv-se/windows/desktop/api/fwpmtypes/ns-fwpmtypes-fwpm_provider0).
+type wtFwpmProvider0 struct {
+	providerKey  windows.GUID
+	displayData  wtFwpmDisplayData0
+	flags        uint32
+	providerData wtFwpByteBlob
+	serviceName  *uint16
+}
+
+type wtIPProto uint32
+
+const (
+	cIPPROTO_ICMP   wtIPProto = 1
+	cIPPROTO_ICMPV6 wtIPProto = 58
+	cIPPROTO_TCP    wtIPProto = 6
+	cIPPROTO_UDP    wtIPProto = 17
+)
+
+const (
+	cFWP_ACTRL_MATCH_FILTER = 1
+)
--- a/client/internal/dns/dnsfw/types_windows_32.go
+++ b/client/internal/dns/dnsfw/types_windows_32.go
@@ -0,0 +1,92 @@
+//go:build windows && (386 || arm)
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2019-2021 WireGuard LLC. All Rights Reserved.
+ *
+ * Adapted from wireguard-windows tunnel/firewall/types_windows_32.go.
+ */
+
+package dnsfw
+
+import "golang.org/x/sys/windows"
+
+const (
+	wtFwpByteBlob_Size        = 8
+	wtFwpByteBlob_data_Offset = 4
+
+	wtFwpConditionValue0_Size         = 8
+	wtFwpConditionValue0_uint8_Offset = 4
+
+	wtFwpmDisplayData0_Size               = 8
+	wtFwpmDisplayData0_description_Offset = 4
+
+	wtFwpmFilter0_Size                       = 152
+	wtFwpmFilter0_displayData_Offset         = 16
+	wtFwpmFilter0_flags_Offset               = 24
+	wtFwpmFilter0_providerKey_Offset         = 28
+	wtFwpmFilter0_providerData_Offset        = 32
+	wtFwpmFilter0_layerKey_Offset            = 40
+	wtFwpmFilter0_subLayerKey_Offset         = 56
+	wtFwpmFilter0_weight_Offset              = 72
+	wtFwpmFilter0_numFilterConditions_Offset = 80
+	wtFwpmFilter0_filterCondition_Offset     = 84
+	wtFwpmFilter0_action_Offset              = 88
+	wtFwpmFilter0_providerContextKey_Offset  = 112
+	wtFwpmFilter0_reserved_Offset            = 128
+	wtFwpmFilter0_filterID_Offset            = 136
+	wtFwpmFilter0_effectiveWeight_Offset     = 144
+
+	wtFwpmFilterCondition0_Size                  = 28
+	wtFwpmFilterCondition0_matchType_Offset      = 16
+	wtFwpmFilterCondition0_conditionValue_Offset = 20
+
+	wtFwpmSession0_Size                        = 48
+	wtFwpmSession0_displayData_Offset          = 16
+	wtFwpmSession0_flags_Offset                = 24
+	wtFwpmSession0_txnWaitTimeoutInMSec_Offset = 28
+	wtFwpmSession0_processId_Offset            = 32
+	wtFwpmSession0_sid_Offset                  = 36
+	wtFwpmSession0_username_Offset             = 40
+	wtFwpmSession0_kernelMode_Offset           = 44
+
+	wtFwpmSublayer0_Size                = 44
+	wtFwpmSublayer0_displayData_Offset  = 16
+	wtFwpmSublayer0_flags_Offset        = 24
+	wtFwpmSublayer0_providerKey_Offset  = 28
+	wtFwpmSublayer0_providerData_Offset = 32
+	wtFwpmSublayer0_weight_Offset       = 40
+
+	wtFwpProvider0_Size                = 40
+	wtFwpProvider0_displayData_Offset  = 16
+	wtFwpProvider0_flags_Offset        = 24
+	wtFwpProvider0_providerData_Offset = 28
+	wtFwpProvider0_serviceName_Offset  = 36
+
+	wtFwpTokenInformation_Size = 16
+
+	wtFwpValue0_Size         = 8
+	wtFwpValue0_value_Offset = 4
+)
+
+// FWPM_FILTER0 defined in fwpmtypes.h
+// (https://docs.microsoft.com/en-us/windows/desktop/api/fwpmtypes/ns-fwpmtypes-fwpm_filter0).
+type wtFwpmFilter0 struct {
+	filterKey           windows.GUID // Windows type: GUID
+	displayData         wtFwpmDisplayData0
+	flags               wtFwpmFilterFlags
+	providerKey         *windows.GUID // Windows type: *GUID
+	providerData        wtFwpByteBlob
+	layerKey            windows.GUID // Windows type: GUID
+	subLayerKey         windows.GUID // Windows type: GUID
+	weight              wtFwpValue0
+	numFilterConditions uint32
+	filterCondition     *wtFwpmFilterCondition0
+	action              wtFwpmAction0
+	offset1             [4]byte       // Layout correction field
+	providerContextKey  windows.GUID  // Windows type: GUID
+	reserved            *windows.GUID // Windows type: *GUID
+	offset2             [4]byte       // Layout correction field
+	filterID            uint64
+	effectiveWeight     wtFwpValue0
+}
--- a/client/internal/dns/dnsfw/types_windows_64.go
+++ b/client/internal/dns/dnsfw/types_windows_64.go
@@ -0,0 +1,89 @@
+//go:build windows && (amd64 || arm64)
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2019-2021 WireGuard LLC. All Rights Reserved.
+ *
+ * Adapted from wireguard-windows tunnel/firewall/types_windows_64.go.
+ */
+
+package dnsfw
+
+import "golang.org/x/sys/windows"
+
+const (
+	wtFwpByteBlob_Size        = 16
+	wtFwpByteBlob_data_Offset = 8
+
+	wtFwpConditionValue0_Size         = 16
+	wtFwpConditionValue0_uint8_Offset = 8
+
+	wtFwpmDisplayData0_Size               = 16
+	wtFwpmDisplayData0_description_Offset = 8
+
+	wtFwpmFilter0_Size                       = 200
+	wtFwpmFilter0_displayData_Offset         = 16
+	wtFwpmFilter0_flags_Offset               = 32
+	wtFwpmFilter0_providerKey_Offset         = 40
+	wtFwpmFilter0_providerData_Offset        = 48
+	wtFwpmFilter0_layerKey_Offset            = 64
+	wtFwpmFilter0_subLayerKey_Offset         = 80
+	wtFwpmFilter0_weight_Offset              = 96
+	wtFwpmFilter0_numFilterConditions_Offset = 112
+	wtFwpmFilter0_filterCondition_Offset     = 120
+	wtFwpmFilter0_action_Offset              = 128
+	wtFwpmFilter0_providerContextKey_Offset  = 152
+	wtFwpmFilter0_reserved_Offset            = 168
+	wtFwpmFilter0_filterID_Offset            = 176
+	wtFwpmFilter0_effectiveWeight_Offset     = 184
+
+	wtFwpmFilterCondition0_Size                  = 40
+	wtFwpmFilterCondition0_matchType_Offset      = 16
+	wtFwpmFilterCondition0_conditionValue_Offset = 24
+
+	wtFwpmSession0_Size                        = 72
+	wtFwpmSession0_displayData_Offset          = 16
+	wtFwpmSession0_flags_Offset                = 32
+	wtFwpmSession0_txnWaitTimeoutInMSec_Offset = 36
+	wtFwpmSession0_processId_Offset            = 40
+	wtFwpmSession0_sid_Offset                  = 48
+	wtFwpmSession0_username_Offset             = 56
+	wtFwpmSession0_kernelMode_Offset           = 64
+
+	wtFwpmSublayer0_Size                = 72
+	wtFwpmSublayer0_displayData_Offset  = 16
+	wtFwpmSublayer0_flags_Offset        = 32
+	wtFwpmSublayer0_providerKey_Offset  = 40
+	wtFwpmSublayer0_providerData_Offset = 48
+	wtFwpmSublayer0_weight_Offset       = 64
+
+	wtFwpProvider0_Size                = 64
+	wtFwpProvider0_displayData_Offset  = 16
+	wtFwpProvider0_flags_Offset        = 32
+	wtFwpProvider0_providerData_Offset = 40
+	wtFwpProvider0_serviceName_Offset  = 56
+
+	wtFwpValue0_Size         = 16
+	wtFwpValue0_value_Offset = 8
+)
+
+// FWPM_FILTER0 defined in fwpmtypes.h
+// (https://docs.microsoft.com/en-us/windows/desktop/api/fwpmtypes/ns-fwpmtypes-fwpm_filter0).
+type wtFwpmFilter0 struct {
+	filterKey           windows.GUID // Windows type: GUID
+	displayData         wtFwpmDisplayData0
+	flags               wtFwpmFilterFlags // Windows type: UINT32
+	providerKey         *windows.GUID     // Windows type: *GUID
+	providerData        wtFwpByteBlob
+	layerKey            windows.GUID // Windows type: GUID
+	subLayerKey         windows.GUID // Windows type: GUID
+	weight              wtFwpValue0
+	numFilterConditions uint32
+	filterCondition     *wtFwpmFilterCondition0
+	action              wtFwpmAction0
+	offset1             [4]byte       // Layout correction field
+	providerContextKey  windows.GUID  // Windows type: GUID
+	reserved            *windows.GUID // Windows type: *GUID
+	filterID            uint64
+	effectiveWeight     wtFwpValue0
+}
--- a/client/internal/dns/dnsfw/zsyscall_windows.go
+++ b/client/internal/dns/dnsfw/zsyscall_windows.go
@@ -0,0 +1,130 @@
+// Code generated by 'go generate'; DO NOT EDIT.
+
+package dnsfw
+
+import (
+	"syscall"
+	"unsafe"
+
+	"golang.org/x/sys/windows"
+)
+
+var _ unsafe.Pointer
+
+// Do the interface allocations only once for common
+// Errno values.
+const (
+	errnoERROR_IO_PENDING = 997
+)
+
+var (
+	errERROR_IO_PENDING error = syscall.Errno(errnoERROR_IO_PENDING)
+	errERROR_EINVAL     error = syscall.EINVAL
+)
+
+// errnoErr returns common boxed Errno values, to prevent
+// allocations at runtime.
+func errnoErr(e syscall.Errno) error {
+	switch e {
+	case 0:
+		return errERROR_EINVAL
+	case errnoERROR_IO_PENDING:
+		return errERROR_IO_PENDING
+	}
+	// TODO: add more here, after collecting data on the common
+	// error values see on Windows. (perhaps when running
+	// all.bat?)
+	return e
+}
+
+var (
+	modfwpuclnt = windows.NewLazySystemDLL("fwpuclnt.dll")
+
+	procFwpmEngineClose0          = modfwpuclnt.NewProc("FwpmEngineClose0")
+	procFwpmEngineOpen0           = modfwpuclnt.NewProc("FwpmEngineOpen0")
+	procFwpmFilterAdd0            = modfwpuclnt.NewProc("FwpmFilterAdd0")
+	procFwpmFreeMemory0           = modfwpuclnt.NewProc("FwpmFreeMemory0")
+	procFwpmGetAppIdFromFileName0 = modfwpuclnt.NewProc("FwpmGetAppIdFromFileName0")
+	procFwpmProviderAdd0          = modfwpuclnt.NewProc("FwpmProviderAdd0")
+	procFwpmSubLayerAdd0          = modfwpuclnt.NewProc("FwpmSubLayerAdd0")
+	procFwpmTransactionAbort0     = modfwpuclnt.NewProc("FwpmTransactionAbort0")
+	procFwpmTransactionBegin0     = modfwpuclnt.NewProc("FwpmTransactionBegin0")
+	procFwpmTransactionCommit0    = modfwpuclnt.NewProc("FwpmTransactionCommit0")
+)
+
+func fwpmEngineClose0(engineHandle uintptr) (err error) {
+	r1, _, e1 := syscall.Syscall(procFwpmEngineClose0.Addr(), 1, uintptr(engineHandle), 0, 0)
+	if r1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func fwpmEngineOpen0(serverName *uint16, authnService wtRpcCAuthN, authIdentity *uintptr, session *wtFwpmSession0, engineHandle unsafe.Pointer) (err error) {
+	r1, _, e1 := syscall.Syscall6(procFwpmEngineOpen0.Addr(), 5, uintptr(unsafe.Pointer(serverName)), uintptr(authnService), uintptr(unsafe.Pointer(authIdentity)), uintptr(unsafe.Pointer(session)), uintptr(engineHandle), 0)
+	if r1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func fwpmFilterAdd0(engineHandle uintptr, filter *wtFwpmFilter0, sd uintptr, id *uint64) (err error) {
+	r1, _, e1 := syscall.Syscall6(procFwpmFilterAdd0.Addr(), 4, uintptr(engineHandle), uintptr(unsafe.Pointer(filter)), uintptr(sd), uintptr(unsafe.Pointer(id)), 0, 0)
+	if r1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func fwpmFreeMemory0(p unsafe.Pointer) {
+	syscall.Syscall(procFwpmFreeMemory0.Addr(), 1, uintptr(p), 0, 0)
+	return
+}
+
+func fwpmGetAppIdFromFileName0(fileName *uint16, appID unsafe.Pointer) (err error) {
+	r1, _, e1 := syscall.Syscall(procFwpmGetAppIdFromFileName0.Addr(), 2, uintptr(unsafe.Pointer(fileName)), uintptr(appID), 0)
+	if r1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func fwpmProviderAdd0(engineHandle uintptr, provider *wtFwpmProvider0, sd uintptr) (err error) {
+	r1, _, e1 := syscall.Syscall(procFwpmProviderAdd0.Addr(), 3, uintptr(engineHandle), uintptr(unsafe.Pointer(provider)), uintptr(sd))
+	if r1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func fwpmSubLayerAdd0(engineHandle uintptr, subLayer *wtFwpmSublayer0, sd uintptr) (err error) {
+	r1, _, e1 := syscall.Syscall(procFwpmSubLayerAdd0.Addr(), 3, uintptr(engineHandle), uintptr(unsafe.Pointer(subLayer)), uintptr(sd))
+	if r1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func fwpmTransactionAbort0(engineHandle uintptr) (err error) {
+	r1, _, e1 := syscall.Syscall(procFwpmTransactionAbort0.Addr(), 1, uintptr(engineHandle), 0, 0)
+	if r1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func fwpmTransactionBegin0(engineHandle uintptr, flags uint32) (err error) {
+	r1, _, e1 := syscall.Syscall(procFwpmTransactionBegin0.Addr(), 2, uintptr(engineHandle), uintptr(flags), 0)
+	if r1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func fwpmTransactionCommit0(engineHandle uintptr) (err error) {
+	r1, _, e1 := syscall.Syscall(procFwpmTransactionCommit0.Addr(), 1, uintptr(engineHandle), 0, 0)
+	if r1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
--- a/client/internal/dns/host_windows.go
+++ b/client/internal/dns/host_windows.go
@@ -16,6 +16,7 @@ import (
 	"golang.org/x/sys/windows/registry"

 	nberrors "github.com/netbirdio/netbird/client/errors"
+	"github.com/netbirdio/netbird/client/internal/dns/dnsfw"
 	"github.com/netbirdio/netbird/client/internal/statemanager"
 	"github.com/netbirdio/netbird/client/internal/winregistry"
 )
@@ -71,6 +72,7 @@ type registryConfigurator struct {
 	routingAll     bool
 	gpo            bool
 	nrptEntryCount int
+	dnsFirewall    dnsfw.Manager
 }

 func newHostManager(wgInterface WGIface) (*registryConfigurator, error) {
@@ -90,8 +92,9 @@ func newHostManager(wgInterface WGIface) (*registryConfigurator, error) {
 	}

 	configurator := &registryConfigurator{
-		guid: guid,
-		gpo:  useGPO,
+		guid:        guid,
+		gpo:         useGPO,
+		dnsFirewall: dnsfw.New(),
 	}

 	if err := configurator.configureInterface(); err != nil {
@@ -169,16 +172,8 @@ func (r *registryConfigurator) disableWINSForInterface() error {
 }

 func (r *registryConfigurator) applyDNSConfig(config HostDNSConfig, stateManager *statemanager.Manager) error {
-	if config.RouteAll {
-		if err := r.addDNSSetupForAll(config.ServerIP); err != nil {
-			return fmt.Errorf("add dns setup: %w", err)
-		}
-	} else if r.routingAll {
-		if err := r.deleteInterfaceRegistryKeyProperty(interfaceConfigNameServerKey); err != nil {
-			return fmt.Errorf("delete interface registry key property: %w", err)
-		}
-		r.routingAll = false
-		log.Infof("removed %s as main DNS forwarder for this peer", config.ServerIP)
+	if err := r.applyRouteAll(config); err != nil {
+		return err
 	}

 	r.updateState(stateManager)
@@ -220,6 +215,35 @@ func (r *registryConfigurator) applyDNSConfig(config HostDNSConfig, stateManager
 	return nil
 }

+func (r *registryConfigurator) applyRouteAll(config HostDNSConfig) error {
+	if config.RouteAll {
+		if err := r.dnsFirewall.Enable(r.guid, config.ServerIP); err != nil {
+			return fmt.Errorf("dns firewall: %w", err)
+		}
+		if err := r.addDNSSetupForAll(config.ServerIP); err != nil {
+			merr := multierror.Append(nil, fmt.Errorf("add dns setup: %w", err))
+			if dErr := r.dnsFirewall.Disable(); dErr != nil {
+				merr = multierror.Append(merr, fmt.Errorf("rollback dns firewall: %w", dErr))
+			}
+			return nberrors.FormatErrorOrNil(merr)
+		}
+		return nil
+	}
+
+	if err := r.dnsFirewall.Disable(); err != nil {
+		log.Errorf("disable dns firewall: %v", err)
+	}
+	if !r.routingAll {
+		return nil
+	}
+	if err := r.deleteInterfaceRegistryKeyProperty(interfaceConfigNameServerKey); err != nil {
+		return fmt.Errorf("delete interface registry key property: %w", err)
+	}
+	r.routingAll = false
+	log.Infof("removed %s as main DNS forwarder for this peer", config.ServerIP)
+	return nil
+}
+
 func (r *registryConfigurator) updateState(stateManager *statemanager.Manager) {
 	if err := stateManager.UpdateState(&ShutdownState{
 		Guid:           r.guid,
@@ -406,6 +430,10 @@ func (r *registryConfigurator) restoreHostDNS() error {
 		return fmt.Errorf("remove interface registry key: %w", err)
 	}

+	if err := r.dnsFirewall.Disable(); err != nil {
+		log.Errorf("disable dns firewall: %v", err)
+	}
+
 	go r.flushDNSCache()

 	return nil
--- a/client/internal/portforward/pcp/nat.go
+++ b/client/internal/portforward/pcp/nat.go
@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"net"
 	"net/netip"
+	"runtime"
 	"sync"
 	"time"

@@ -177,7 +178,12 @@ func getDefaultGateway() (gateway net.IP, localIP net.IP, err error) {
 		return nil, nil, err
 	}

-	_, gateway, localIP, err = router.Route(net.IPv4zero)
+	dst := net.IPv4zero
+	if runtime.GOOS == "linux" {
+		// go-netroute v0.4.0 rejects unspecified destinations client-side on Linux.
+		dst = net.IPv4(0, 0, 0, 1)
+	}
+	_, gateway, localIP, err = router.Route(dst)
 	if err != nil {
 		return nil, nil, err
 	}
@@ -196,7 +202,12 @@ func getDefaultGateway6() (gateway net.IP, localIP net.IP, err error) {
 		return nil, nil, err
 	}

-	_, gateway, localIP, err = router.Route(net.IPv6zero)
+	dst := net.IPv6zero
+	if runtime.GOOS == "linux" {
+		// ::2
+		dst = net.IP{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2}
+	}
+	_, gateway, localIP, err = router.Route(dst)
 	if err != nil {
 		return nil, nil, err
 	}
--- a/client/internal/routemanager/systemops/systemops_generic.go
+++ b/client/internal/routemanager/systemops/systemops_generic.go
@@ -342,6 +342,22 @@ func GetNextHop(ip netip.Addr) (Nexthop, error) {
 	if err != nil {
 		return Nexthop{}, fmt.Errorf("new netroute: %w", err)
 	}
+
+	// go-netroute v0.4.0 rejects unspecified destinations on Linux with a hard
+	// client-side check. Substitute the lowest non-loopback address so the
+	// lookup falls through to the default route (::1 / 127.0.0.1 would match
+	// loopback, ::/0.0.0.0 are unspec). BSD/Windows pass the query straight to
+	// the kernel and need no substitution.
+	if runtime.GOOS == "linux" && ip.IsUnspecified() {
+		if ip.Is6() {
+			// ::2
+			ip = netip.AddrFrom16([16]byte{15: 2})
+		} else {
+			// 0.0.0.1
+			ip = netip.AddrFrom4([4]byte{0, 0, 0, 1})
+		}
+	}
+
 	intf, gateway, preferredSrc, err := r.Route(ip.AsSlice())
 	if err != nil {
 		log.Debugf("Failed to get route for %s: %v", ip, err)
--- a/client/internal/routemanager/systemops/systemops_generic_test.go
+++ b/client/internal/routemanager/systemops/systemops_generic_test.go
@@ -354,9 +354,13 @@ func TestAddRouteToNonVPNIntf(t *testing.T) {
 			require.NoError(t, err, "Should be able to get IPv4 default route")
 			t.Logf("Initial IPv4 next hop: %s", initialNextHopV4)

+			if testCase.prefix.Addr().Is6() && !testCase.expectError {
+				ensureIPv6DefaultRoute(t)
+			}
+
 			initialNextHopV6, err := GetNextHop(netip.IPv6Unspecified())
 			if testCase.prefix.Addr().Is6() &&
-				(errors.Is(err, vars.ErrRouteNotFound) || initialNextHopV6.Intf != nil && strings.HasPrefix(initialNextHopV6.Intf.Name, "utun")) {
+				initialNextHopV6.Intf != nil && strings.HasPrefix(initialNextHopV6.Intf.Name, "utun") {
 				t.Skip("Skipping test as no ipv6 default route is available")
 			}
 			if err != nil && !errors.Is(err, vars.ErrRouteNotFound) {
--- a/client/internal/routemanager/systemops/v6route_bsd_test.go
+++ b/client/internal/routemanager/systemops/v6route_bsd_test.go
@@ -0,0 +1,30 @@
+//go:build darwin || dragonfly || freebsd || netbsd || openbsd
+
+package systemops
+
+import (
+	"bytes"
+	"os/exec"
+	"testing"
+)
+
+// ensureIPv6DefaultRoute installs an IPv6 default route via the loopback
+// interface so route lookups for global IPv6 prefixes resolve in environments
+// without v6 connectivity. If a default already exists it is left alone.
+func ensureIPv6DefaultRoute(t *testing.T) {
+	t.Helper()
+
+	out, err := exec.Command("route", "-6", "add", "default", "-iface", "lo0").CombinedOutput()
+	if err != nil {
+		// Existing default; nothing to install or clean up.
+		if bytes.Contains(out, []byte("route already in table")) {
+			return
+		}
+		t.Skipf("install IPv6 fallback default route: %v: %s", err, out)
+	}
+	t.Cleanup(func() {
+		if out, err := exec.Command("route", "-6", "delete", "default").CombinedOutput(); err != nil {
+			t.Logf("delete IPv6 fallback default route: %v: %s", err, out)
+		}
+	})
+}
--- a/client/internal/routemanager/systemops/v6route_linux_test.go
+++ b/client/internal/routemanager/systemops/v6route_linux_test.go
@@ -0,0 +1,41 @@
+//go:build linux && !android
+
+package systemops
+
+import (
+	"errors"
+	"net"
+	"syscall"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	"github.com/vishvananda/netlink"
+)
+
+// ensureIPv6DefaultRoute installs a low-preference IPv6 default route via the
+// loopback interface so route lookups for global IPv6 prefixes resolve in
+// environments without v6 connectivity. Any pre-existing default route wins
+// because of its lower metric.
+func ensureIPv6DefaultRoute(t *testing.T) {
+	t.Helper()
+
+	lo, err := netlink.LinkByName("lo")
+	require.NoError(t, err, "find loopback interface")
+
+	route := &netlink.Route{
+		Dst:       &net.IPNet{IP: net.IPv6zero, Mask: net.CIDRMask(0, 128)},
+		LinkIndex: lo.Attrs().Index,
+		Priority:  1 << 20,
+	}
+	if err := netlink.RouteAdd(route); err != nil {
+		if errors.Is(err, syscall.EEXIST) {
+			return
+		}
+		t.Skipf("install IPv6 fallback default route: %v", err)
+	}
+	t.Cleanup(func() {
+		if err := netlink.RouteDel(route); err != nil && !errors.Is(err, syscall.ESRCH) {
+			t.Logf("delete IPv6 fallback default route: %v", err)
+		}
+	})
+}
--- a/client/internal/routemanager/systemops/v6route_windows_test.go
+++ b/client/internal/routemanager/systemops/v6route_windows_test.go
@@ -0,0 +1,34 @@
+//go:build windows
+
+package systemops
+
+import (
+	"bytes"
+	"os/exec"
+	"testing"
+)
+
+const loopbackIfaceWindows = "Loopback Pseudo-Interface 1"
+
+// ensureIPv6DefaultRoute installs an IPv6 default route via the loopback
+// interface so route lookups for global IPv6 prefixes resolve in environments
+// without v6 connectivity. If a default already exists it is left alone.
+func ensureIPv6DefaultRoute(t *testing.T) {
+	t.Helper()
+
+	script := `New-NetRoute -DestinationPrefix "::/0" -InterfaceAlias "` + loopbackIfaceWindows + `" -RouteMetric 9999 -PolicyStore ActiveStore -ErrorAction Stop`
+	out, err := exec.Command("powershell", "-Command", script).CombinedOutput()
+	if err != nil {
+		// Existing default; nothing to install or clean up.
+		if bytes.Contains(out, []byte("already exists")) {
+			return
+		}
+		t.Skipf("install IPv6 fallback default route: %v: %s", err, out)
+	}
+	t.Cleanup(func() {
+		script := `Remove-NetRoute -DestinationPrefix "::/0" -InterfaceAlias "` + loopbackIfaceWindows + `" -Confirm:$false -ErrorAction Stop`
+		if out, err := exec.Command("powershell", "-Command", script).CombinedOutput(); err != nil {
+			t.Logf("delete IPv6 fallback default route: %v: %s", err, out)
+		}
+	})
+}
--- a/go.mod
+++ b/go.mod
@@ -17,8 +17,8 @@ require (
 	github.com/spf13/cobra v1.10.1
 	github.com/spf13/pflag v1.0.9
 	github.com/vishvananda/netlink v1.3.1
-	golang.org/x/crypto v0.49.0
-	golang.org/x/sys v0.42.0
+	golang.org/x/crypto v0.50.0
+	golang.org/x/sys v0.43.0
 	golang.zx2c4.com/wireguard v0.0.0-20230704135630-469159ecf7d1
 	golang.zx2c4.com/wireguard/wgctrl v0.0.0-20230429144221-925a1e7659e6
 	golang.zx2c4.com/wireguard/windows v0.5.3
@@ -68,7 +68,7 @@ require (
 	github.com/jackc/pgx/v5 v5.5.5
 	github.com/libdns/route53 v1.5.0
 	github.com/libp2p/go-nat v0.2.0
-	github.com/libp2p/go-netroute v0.2.1
+	github.com/libp2p/go-netroute v0.4.0
 	github.com/lrh3321/ipset-go v0.0.0-20250619021614-54a0a98ace81
 	github.com/mdlayher/socket v0.5.1
 	github.com/mdp/qrterminal/v3 v3.2.1
@@ -118,11 +118,11 @@ require (
 	goauthentik.io/api/v3 v3.2023051.3
 	golang.org/x/exp v0.0.0-20250620022241-b7579e27df2b
 	golang.org/x/mobile v0.0.0-20251113184115-a159579294ab
-	golang.org/x/mod v0.33.0
-	golang.org/x/net v0.52.0
+	golang.org/x/mod v0.34.0
+	golang.org/x/net v0.53.0
 	golang.org/x/oauth2 v0.36.0
 	golang.org/x/sync v0.20.0
-	golang.org/x/term v0.41.0
+	golang.org/x/term v0.42.0
 	golang.org/x/time v0.15.0
 	google.golang.org/api v0.276.0
 	gopkg.in/yaml.v3 v3.0.1
@@ -303,8 +303,8 @@ require (
 	go.uber.org/multierr v1.11.0 // indirect
 	go.yaml.in/yaml/v2 v2.4.3 // indirect
 	golang.org/x/image v0.33.0 // indirect
-	golang.org/x/text v0.35.0 // indirect
-	golang.org/x/tools v0.42.0 // indirect
+	golang.org/x/text v0.36.0 // indirect
+	golang.org/x/tools v0.43.0 // indirect
 	golang.zx2c4.com/wintun v0.0.0-20230126152724-0fa3db229ce2 // indirect
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20260401024825-9d38bb4040a9 // indirect
 	gopkg.in/square/go-jose.v2 v2.6.0 // indirect
@@ -323,8 +323,6 @@ replace github.com/cloudflare/circl => github.com/cunicu/circl v0.0.0-2023080111

 replace github.com/pion/ice/v4 => github.com/netbirdio/ice/v4 v4.0.0-20250908184934-6202be846b51

-replace github.com/libp2p/go-netroute => github.com/netbirdio/go-netroute v0.0.0-20240611143515-f59b0e1d3944
-
 replace github.com/dexidp/dex => github.com/netbirdio/dex v0.244.0

 replace github.com/mailru/easyjson => github.com/netbirdio/easyjson v0.9.0
--- a/go.sum
+++ b/go.sum
@@ -395,6 +395,8 @@ github.com/libdns/route53 v1.5.0 h1:2SKdpPFl/qgWsXQvsLNJJAoX7rSxlk7zgoL4jnWdXVA=
 github.com/libdns/route53 v1.5.0/go.mod h1:joT4hKmaTNKHEwb7GmZ65eoDz1whTu7KKYPS8ZqIh6Q=
 github.com/libp2p/go-nat v0.2.0 h1:Tyz+bUFAYqGyJ/ppPPymMGbIgNRH+WqC5QrT5fKrrGk=
 github.com/libp2p/go-nat v0.2.0/go.mod h1:3MJr+GRpRkyT65EpVPBstXLvOlAPzUVlG6Pwg9ohLJk=
+github.com/libp2p/go-netroute v0.4.0 h1:sZZx9hyANYUx9PZyqcgE/E1GUG3iEtTZHUEvdtXT7/Q=
+github.com/libp2p/go-netroute v0.4.0/go.mod h1:Nkd5ShYgSMS5MUKy/MU2T57xFoOKvvLR92Lic48LEyA=
 github.com/lrh3321/ipset-go v0.0.0-20250619021614-54a0a98ace81 h1:J56rFEfUTFT9j9CiRXhi1r8lUJ4W5idG3CiaBZGojNU=
 github.com/lrh3321/ipset-go v0.0.0-20250619021614-54a0a98ace81/go.mod h1:RD8ML/YdXctQ7qbcizZkw5mZ6l8Ogrl1dodBzVJduwI=
 github.com/lufia/plan9stats v0.0.0-20211012122336-39d0f177ccd0/go.mod h1:zJYVVT2jmtg6P3p1VtQj7WsuWi/y4VnjVBn7F8KPB3I=
@@ -453,8 +455,6 @@ github.com/netbirdio/dex v0.244.0 h1:1GOvi8wnXYassnKGildzNqRHq0RbcfEUw7LKYpKIN7U
 github.com/netbirdio/dex v0.244.0/go.mod h1:STGInJhPcAflrHmDO7vyit2kSq03PdL+8zQPoGALtcU=
 github.com/netbirdio/easyjson v0.9.0 h1:6Nw2lghSVuy8RSkAYDhDv1thBVEmfVbKZnV7T7Z6Aus=
 github.com/netbirdio/easyjson v0.9.0/go.mod h1:1+xMtQp2MRNVL/V1bOzuP3aP8VNwRW55fQUto+XFtTU=
-github.com/netbirdio/go-netroute v0.0.0-20240611143515-f59b0e1d3944 h1:TDtJKmM6Sf8uYFx/dMeqNOL90KUoRscdfpFZ3Im89uk=
-github.com/netbirdio/go-netroute v0.0.0-20240611143515-f59b0e1d3944/go.mod h1:sHA6TRxjQ6RLbnI+3R4DZo2Eseg/iKiPRfNmcuNySVQ=
 github.com/netbirdio/ice/v4 v4.0.0-20250908184934-6202be846b51 h1:Ov4qdafATOgGMB1wbSuh+0aAHcwz9hdvB6VZjh1mVMI=
 github.com/netbirdio/ice/v4 v4.0.0-20250908184934-6202be846b51/go.mod h1:ZSIbPdBn5hePO8CpF1PekH2SfpTxg1PDhEwtbqZS7R8=
 github.com/netbirdio/management-integrations/integrations v0.0.0-20260416123949-2355d972be42 h1:F3zS5fT9xzD1OFLfcdAE+3FfyiwjGukF1hvj0jErgs8=
@@ -711,8 +711,8 @@ golang.org/x/crypto v0.18.0/go.mod h1:R0j02AL6hcrfOiy9T4ZYp/rcWeMxM3L6QYxlOuEG1m
 golang.org/x/crypto v0.19.0/go.mod h1:Iy9bg/ha4yyC70EfRS8jz+B6ybOBKMaSxLj6P6oBDfU=
 golang.org/x/crypto v0.23.0/go.mod h1:CKFgDieR+mRhux2Lsu27y0fO304Db0wZe70UKqHu0v8=
 golang.org/x/crypto v0.31.0/go.mod h1:kDsLvtWBEx7MV9tJOj9bnXsPbxwJQ6csT/x4KIN4Ssk=
-golang.org/x/crypto v0.49.0 h1:+Ng2ULVvLHnJ/ZFEq4KdcDd/cfjrrjjNSXNzxg0Y4U4=
-golang.org/x/crypto v0.49.0/go.mod h1:ErX4dUh2UM+CFYiXZRTcMpEcN8b/1gxEuv3nODoYtCA=
+golang.org/x/crypto v0.50.0 h1:zO47/JPrL6vsNkINmLoo/PH1gcxpls50DNogFvB5ZGI=
+golang.org/x/crypto v0.50.0/go.mod h1:3muZ7vA7PBCE6xgPX7nkzzjiUq87kRItoJQM1Yo8S+Q=
 golang.org/x/exp v0.0.0-20250620022241-b7579e27df2b h1:M2rDM6z3Fhozi9O7NWsxAkg/yqS/lQJ6PmkyIV3YP+o=
 golang.org/x/exp v0.0.0-20250620022241-b7579e27df2b/go.mod h1:3//PLf8L/X+8b4vuAfHzxeRUl04Adcb341+IGKfnqS8=
 golang.org/x/image v0.33.0 h1:LXRZRnv1+zGd5XBUVRFmYEphyyKJjQjCRiOuAP3sZfQ=
@@ -729,8 +729,8 @@ golang.org/x/mod v0.8.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
 golang.org/x/mod v0.12.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
 golang.org/x/mod v0.15.0/go.mod h1:hTbmBsO62+eylJbnUtE2MGJUyE7QWk4xUqPFrRgJ+7c=
 golang.org/x/mod v0.17.0/go.mod h1:hTbmBsO62+eylJbnUtE2MGJUyE7QWk4xUqPFrRgJ+7c=
-golang.org/x/mod v0.33.0 h1:tHFzIWbBifEmbwtGz65eaWyGiGZatSrT9prnU8DbVL8=
-golang.org/x/mod v0.33.0/go.mod h1:swjeQEj+6r7fODbD2cqrnje9PnziFuw4bmLbBZFrQ5w=
+golang.org/x/mod v0.34.0 h1:xIHgNUUnW6sYkcM5Jleh05DvLOtwc6RitGHbDk4akRI=
+golang.org/x/mod v0.34.0/go.mod h1:ykgH52iCZe79kzLLMhyCUzhMci+nQj+0XkbXpNYtVjY=
 golang.org/x/net v0.0.0-20180906233101-161cd47e91fd/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20190603091049-60506f45cf65/go.mod h1:HSz+uSET+XFnRR8LxR5pz3Of3rY3CfYBVs4xY44aLks=
@@ -749,8 +749,8 @@ golang.org/x/net v0.15.0/go.mod h1:idbUs1IY1+zTqbi8yxTbhexhEEk5ur9LInksu6HrEpk=
 golang.org/x/net v0.20.0/go.mod h1:z8BVo6PvndSri0LbOE3hAn0apkU+1YvI6E70E9jsnvY=
 golang.org/x/net v0.21.0/go.mod h1:bIjVDfnllIU7BJ2DNgfnXvpSvtn8VRwhlsaeUTyUS44=
 golang.org/x/net v0.25.0/go.mod h1:JkAGAh7GEvH74S6FOH42FLoXpXbE/aqXSrIQjXgsiwM=
-golang.org/x/net v0.52.0 h1:He/TN1l0e4mmR3QqHMT2Xab3Aj3L9qjbhRm78/6jrW0=
-golang.org/x/net v0.52.0/go.mod h1:R1MAz7uMZxVMualyPXb+VaqGSa3LIaUqk0eEt3w36Sw=
+golang.org/x/net v0.53.0 h1:d+qAbo5L0orcWAr0a9JweQpjXF19LMXJE8Ey7hwOdUA=
+golang.org/x/net v0.53.0/go.mod h1:JvMuJH7rrdiCfbeHoo3fCQU24Lf5JJwT9W3sJFulfgs=
 golang.org/x/oauth2 v0.8.0/go.mod h1:yr7u4HXZRm1R1kBWqr/xKNqewf0plRYoB7sla+BCIXE=
 golang.org/x/oauth2 v0.36.0 h1:peZ/1z27fi9hUOFCAZaHyrpWG5lwe0RJEEEeH0ThlIs=
 golang.org/x/oauth2 v0.36.0/go.mod h1:YDBUJMTkDnJS+A4BP4eZBjCqtokkg1hODuPjwiGPO7Q=
@@ -801,8 +801,8 @@ golang.org/x/sys v0.17.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/sys v0.19.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/sys v0.20.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/sys v0.28.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
-golang.org/x/sys v0.42.0 h1:omrd2nAlyT5ESRdCLYdm3+fMfNFE/+Rf4bDIQImRJeo=
-golang.org/x/sys v0.42.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
+golang.org/x/sys v0.43.0 h1:Rlag2XtaFTxp19wS8MXlJwTvoh8ArU6ezoyFsMyCTNI=
+golang.org/x/sys v0.43.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
 golang.org/x/telemetry v0.0.0-20240228155512-f48c80bd79b2/go.mod h1:TeRTkGYfJXctD9OcfyVLyj2J3IxLnKwHJR8f4D8a3YE=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
@@ -815,8 +815,8 @@ golang.org/x/term v0.16.0/go.mod h1:yn7UURbUtPyrVJPGPq404EukNFxcm/foM+bV/bfcDsY=
 golang.org/x/term v0.17.0/go.mod h1:lLRBjIVuehSbZlaOtGMbcMncT+aqLLLmKrsjNrUguwk=
 golang.org/x/term v0.20.0/go.mod h1:8UkIAJTvZgivsXaD6/pH6U9ecQzZ45awqEOzuCvwpFY=
 golang.org/x/term v0.27.0/go.mod h1:iMsnZpn0cago0GOrHO2+Y7u7JPn5AylBrcoWkElMTSM=
-golang.org/x/term v0.41.0 h1:QCgPso/Q3RTJx2Th4bDLqML4W6iJiaXFq2/ftQF13YU=
-golang.org/x/term v0.41.0/go.mod h1:3pfBgksrReYfZ5lvYM0kSO0LIkAl4Yl2bXOkKP7Ec2A=
+golang.org/x/term v0.42.0 h1:UiKe+zDFmJobeJ5ggPwOshJIVt6/Ft0rcfrXZDLWAWY=
+golang.org/x/term v0.42.0/go.mod h1:Dq/D+snpsbazcBG5+F9Q1n2rXV8Ma+71xEjTRufARgY=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
@@ -828,8 +828,8 @@ golang.org/x/text v0.13.0/go.mod h1:TvPlkZtksWOMsz7fbANvkp4WM8x/WCo/om8BMLbz+aE=
 golang.org/x/text v0.14.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
 golang.org/x/text v0.15.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
 golang.org/x/text v0.21.0/go.mod h1:4IBbMaMmOPCJ8SecivzSH54+73PCFmPWxNTLm+vZkEQ=
-golang.org/x/text v0.35.0 h1:JOVx6vVDFokkpaq1AEptVzLTpDe9KGpj5tR4/X+ybL8=
-golang.org/x/text v0.35.0/go.mod h1:khi/HExzZJ2pGnjenulevKNX1W67CUy0AsXcNubPGCA=
+golang.org/x/text v0.36.0 h1:JfKh3XmcRPqZPKevfXVpI1wXPTqbkE5f7JA92a55Yxg=
+golang.org/x/text v0.36.0/go.mod h1:NIdBknypM8iqVmPiuco0Dh6P5Jcdk8lJL0CUebqK164=
 golang.org/x/time v0.15.0 h1:bbrp8t3bGUeFOx08pvsMYRTCVSMk89u4tKbNOZbp88U=
 golang.org/x/time v0.15.0/go.mod h1:Y4YMaQmXwGQZoFaVFk4YpCt4FLQMYKZe9oeV/f4MSno=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
@@ -843,8 +843,8 @@ golang.org/x/tools v0.1.12/go.mod h1:hNGJHUnrk76NpqgfD5Aqm5Crs+Hm0VOH/i9J2+nxYbc
 golang.org/x/tools v0.6.0/go.mod h1:Xwgl3UAJ/d3gWutnCtw505GrjyAbvKui8lOU390QaIU=
 golang.org/x/tools v0.13.0/go.mod h1:HvlwmtVNQAhOuCjW7xxvovg8wbNq7LwfXh/k7wXUl58=
 golang.org/x/tools v0.21.1-0.20240508182429-e35e4ccd0d2d/go.mod h1:aiJjzUbINMkxbQROHiO6hDPo2LHcIPhhQsa9DLh0yGk=
-golang.org/x/tools v0.42.0 h1:uNgphsn75Tdz5Ji2q36v/nsFSfR/9BRFvqhGBaJGd5k=
-golang.org/x/tools v0.42.0/go.mod h1:Ma6lCIwGZvHK6XtgbswSoWroEkhugApmsXyrUmBhfr0=
+golang.org/x/tools v0.43.0 h1:12BdW9CeB3Z+J/I/wj34VMl8X+fEXBxVR90JeMX5E7s=
+golang.org/x/tools v0.43.0/go.mod h1:uHkMso649BX2cZK6+RpuIPXS3ho2hZo4FVwfoy1vIk0=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
--- a/sharedsock/sock_linux.go
+++ b/sharedsock/sock_linux.go
@@ -10,15 +10,13 @@ import (
 	"context"
 	"fmt"
 	"net"
-	"sync"
 	"time"

 	"github.com/google/gopacket"
 	"github.com/google/gopacket/layers"
-	"github.com/google/gopacket/routing"
-	"github.com/libp2p/go-netroute"
 	"github.com/mdlayher/socket"
 	log "github.com/sirupsen/logrus"
+	"github.com/vishvananda/netlink"
 	"golang.org/x/sync/errgroup"
 	"golang.org/x/sys/unix"

@@ -37,8 +35,6 @@ type SharedSocket struct {
 	conn6       *socket.Conn
 	port        int
 	mtu         uint16
-	routerMux   sync.RWMutex
-	router      routing.Router
 	packetDemux chan rcvdPacket
 	cancel      context.CancelFunc
 }
@@ -82,11 +78,6 @@ func Listen(port int, filter BPFFilter, mtu uint16) (_ net.PacketConn, err error
 		}
 	}()

-	rawSock.router, err = netroute.New()
-	if err != nil {
-		return nil, fmt.Errorf("failed to create raw socket router: %w", err)
-	}
-
 	rawSock.conn4, err = socket.Socket(unix.AF_INET, unix.SOCK_RAW, unix.IPPROTO_UDP, "raw_udp4", nil)
 	if err != nil {
 		return nil, fmt.Errorf("failed to create ipv4 raw socket: %w", err)
@@ -127,31 +118,26 @@ func Listen(port int, filter BPFFilter, mtu uint16) (_ net.PacketConn, err error
 		go rawSock.read(rawSock.conn6.Recvfrom)
 	}

-	go rawSock.updateRouter()
-
 	return rawSock, nil
 }

-// updateRouter updates the listener routing table client
-// this is needed to avoid outdated information across different client networks
-func (s *SharedSocket) updateRouter() {
-	ticker := time.NewTicker(15 * time.Second)
-	defer ticker.Stop()
-	for {
-		select {
-		case <-s.ctx.Done():
-			return
-		case <-ticker.C:
-			router, err := netroute.New()
-			if err != nil {
-				log.Errorf("Failed to create and update packet router for stunListener: %s", err)
-				continue
-			}
-			s.routerMux.Lock()
-			s.router = router
-			s.routerMux.Unlock()
+// resolveSrc returns the source IP the kernel will pick for a packet sent to
+// dst by these raw sockets, mirroring the fwmark the kernel will see on send.
+func (s *SharedSocket) resolveSrc(dst net.IP) (net.IP, error) {
+	opts := &netlink.RouteGetOptions{}
+	if nbnet.AdvancedRouting() {
+		opts.Mark = nbnet.ControlPlaneMark
+	}
+	routes, err := netlink.RouteGetWithOptions(dst, opts)
+	if err != nil {
+		return nil, fmt.Errorf("route get %s: %w", dst, err)
+	}
+	for _, r := range routes {
+		if r.Src != nil {
+			return r.Src, nil
 		}
 	}
+	return nil, fmt.Errorf("no source IP for %s", dst)
 }

 // LocalAddr returns the local address, preferring IPv4 for backward compatibility.
@@ -310,15 +296,15 @@ func (s *SharedSocket) WriteTo(buf []byte, rAddr net.Addr) (n int, err error) {
 		DstPort: layers.UDPPort(rUDPAddr.Port),
 	}

-	s.routerMux.RLock()
-	defer s.routerMux.RUnlock()
-
-	_, _, src, err := s.router.Route(rUDPAddr.IP)
+	src, err := s.resolveSrc(rUDPAddr.IP)
 	if err != nil {
-		return 0, fmt.Errorf("got an error while checking route, err: %w", err)
+		return 0, fmt.Errorf("resolve source for %s: %w", rUDPAddr.IP, err)
 	}

 	rSockAddr, conn, nwLayer := s.getWriterObjects(src, rUDPAddr.IP)
+	if conn == nil {
+		return 0, fmt.Errorf("no raw socket for %s", rUDPAddr.IP)
+	}

 	if err := udp.SetNetworkLayerForChecksum(nwLayer); err != nil {
 		return -1, fmt.Errorf("failed to set network layer for checksum: %w", err)
Author	SHA1	Message	Date
Viktor Liu	f42b8aed90	Reject port 0 in NB_DNS_FIREWALL_PORTS and roll back firewall on DNS setup failure	2026-05-05 18:38:45 +02:00
Viktor Liu	0415137acd	Address CodeRabbit nits: errors.As, defensive disable, port-aware filter name, log wording, provenance	2026-05-05 18:29:23 +02:00
Viktor Liu	7fd16666e3	Fix Windows lint: handle close error and exclude vendored WFP types from unused	2026-05-05 18:25:53 +02:00
Viktor Liu	0571eeaba0	Move strictMode to Windows-only and add manager unit tests	2026-05-05 18:24:09 +02:00
Viktor Liu	6a201d12b5	Extract applyRouteAll helper and reorder package declarations	2026-05-05 18:16:28 +02:00
Viktor Liu	4810e79a00	Add Windows DNS firewall to block DNS leaks from non-netbird processes	2026-05-05 18:11:06 +02:00
Nicolas Frati	1795bc801d	chores: updated discussions and issues templates (#6073 )	2026-05-05 07:53:01 -07:00
Viktor Liu	31395f8bd2	[client] Use fwmark-aware route lookup for raw socket UDP checksum source (#6070 ) * Use fwmark-aware route lookup for raw socket UDP checksum source * Guard nil raw socket in sharedsock WriteTo	2026-05-05 16:18:22 +02:00
Viktor Liu	cd8e71002f	[client] Bump go-netroute to v0.4.0 and drop fork (#6062 )	2026-05-05 15:26:27 +02:00