Include MTU and SSH auth/JWT cache config in debug bundle

Detecting shutdown by inspecting the gRPC status code conflates a local
context cancellation with a server- or proxy-sent codes.Canceled. When
the latter occurs (e.g. an intermediary proxy resets the stream), the
retry loop silently terminates and the client never reconnects.

Switch to ctx.Err() in the signal Receive loop and management Sync/Job
handlers, and stop matching gRPC Canceled/DeadlineExceeded in the flow
client's isContextDone helper. With this change, a server-sent Canceled
is treated as a transient error and the backoff retry loop continues.

.github/workflows/release.yml

@@ -9,7 +9,7 @@ on:
   pull_request:
 
 env:
-  SIGN_PIPE_VER: "v0.1.2"
+  SIGN_PIPE_VER: "v0.1.4"
   GORELEASER_VER: "v2.14.3"
   PRODUCT_NAME: "NetBird"
   COPYRIGHT: "NetBird GmbH"
@@ -114,7 +114,13 @@ jobs:
           retention-days: 30
 
   release:
-    runs-on: ubuntu-latest-m
+    runs-on: ubuntu-24.04-8-core
+    outputs:
+      release_artifact_url: ${{ steps.upload_release.outputs.artifact-url }}
+      linux_packages_artifact_url: ${{ steps.upload_linux_packages.outputs.artifact-url }}
+      windows_packages_artifact_url: ${{ steps.upload_windows_packages.outputs.artifact-url }}
+      macos_packages_artifact_url: ${{ steps.upload_macos_packages.outputs.artifact-url }}
+      ghcr_images: ${{ steps.tag_and_push_images.outputs.images_markdown }}
     env:
       flags: ""
     steps:
@@ -213,10 +219,13 @@ jobs:
         if: always()
         run: rm -f /tmp/gpg-rpm-signing-key.asc
       - name: Tag and push images (amd64 only)
+        id: tag_and_push_images
         if: |
           (github.event_name == 'pull_request' && github.event.pull_request.head.repo.full_name == github.repository) ||
           (github.event_name == 'push' && github.ref == 'refs/heads/main')
         run: |
+          set -euo pipefail
+
           resolve_tags() {
             if [[ "${{ github.event_name }}" == "pull_request" ]]; then
               echo "pr-${{ github.event.pull_request.number }}"
@@ -225,6 +234,17 @@ jobs:
             fi
           }
 
+          ghcr_package_url() {
+            local image="$1" package encoded_package
+            package="${image#ghcr.io/}"
+            package="${package#*/}"
+            package="${package%%:*}"
+            encoded_package="${package//\//%2F}"
+            echo "https://github.com/orgs/netbirdio/packages/container/package/${encoded_package}"
+          }
+
+          image_refs=()
+
           tag_and_push() {
             local src="$1" img_name tag dst
             img_name="${src%%:*}"
@@ -233,35 +253,56 @@ jobs:
               echo "Tagging ${src} -> ${dst}"
               docker tag "$src" "$dst"
               docker push "$dst"
+              image_refs+=("$dst")
             done
           }
 
-          export -f tag_and_push resolve_tags
+          cat > /tmp/goreleaser-artifacts.json <<'JSON'
+          ${{ steps.goreleaser.outputs.artifacts }}
+          JSON
 
-          echo '${{ steps.goreleaser.outputs.artifacts }}' | \
+          mapfile -t src_images < <(
-            jq -r '.[] | select(.type == "Docker Image") | select(.goarch == "amd64") | .name' | \
+            jq -r '.[] | select(.type == "Docker Image") | select(.goarch == "amd64") | .name | select(startswith("ghcr.io/"))' /tmp/goreleaser-artifacts.json
-            grep '^ghcr.io/' | while read -r SRC; do
+          )
-              tag_and_push "$SRC"
+
-            done
+          for src in "${src_images[@]}"; do
+            tag_and_push "$src"
+          done
+
+          {
+            echo "images_markdown<<EOF"
+            if [[ ${#image_refs[@]} -eq 0 ]]; then
+              echo "_No GHCR images were pushed._"
+            else
+              printf '%s\n' "${image_refs[@]}" | sort -u | while read -r image; do
+                printf -- '- [`%s`](%s)\n' "$image" "$(ghcr_package_url "$image")"
+              done
+            fi
+            echo "EOF"
+          } >> "$GITHUB_OUTPUT"
       - name: upload non tags for debug purposes
+        id: upload_release
         uses: actions/upload-artifact@v4
         with:
           name: release
           path: dist/
           retention-days: 7
       - name: upload linux packages
+        id: upload_linux_packages
         uses: actions/upload-artifact@v4
         with:
           name: linux-packages
           path: dist/netbird_linux**
           retention-days: 7
       - name: upload windows packages
+        id: upload_windows_packages
         uses: actions/upload-artifact@v4
         with:
           name: windows-packages
           path: dist/netbird_windows**
           retention-days: 7
       - name: upload macos packages
+        id: upload_macos_packages
         uses: actions/upload-artifact@v4
         with:
           name: macos-packages
@@ -270,6 +311,8 @@ jobs:
 
   release_ui:
     runs-on: ubuntu-latest
+    outputs:
+      release_ui_artifact_url: ${{ steps.upload_release_ui.outputs.artifact-url }}
     steps:
       - name: Parse semver string
         id: semver_parser
@@ -360,6 +403,7 @@ jobs:
         if: always()
         run: rm -f /tmp/gpg-rpm-signing-key.asc
       - name: upload non tags for debug purposes
+        id: upload_release_ui
         uses: actions/upload-artifact@v4
         with:
           name: release-ui
@@ -368,6 +412,8 @@ jobs:
 
   release_ui_darwin:
     runs-on: macos-latest
+    outputs:
+      release_ui_darwin_artifact_url: ${{ steps.upload_release_ui_darwin.outputs.artifact-url }}
     steps:
       - if: ${{ !startsWith(github.ref, 'refs/tags/v') }}
         run: echo "flags=--snapshot" >> $GITHUB_ENV
@@ -402,15 +448,258 @@ jobs:
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
       - name: upload non tags for debug purposes
+        id: upload_release_ui_darwin
         uses: actions/upload-artifact@v4
         with:
           name: release-ui-darwin
           path: dist/
           retention-days: 3
 
-  trigger_signer:
+  test_windows_installer:
+    name: "Windows Installer / Build Test"
+    runs-on: windows-2022
+    needs: [release, release_ui]
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - arch: amd64
+            wintun_arch: amd64
+          - arch: arm64
+            wintun_arch: arm64
+    defaults:
+      run:
+        shell: powershell
+    env:
+      PackageWorkdir: netbird_windows_${{ matrix.arch }}
+      downloadPath: '${{ github.workspace }}\temp'
+    steps:
+      - name: Parse semver string
+        id: semver_parser
+        uses: booxmedialtd/ws-action-parse-semver@v1
+        with:
+          input_string: ${{ (startsWith(github.ref, 'refs/tags/v') && github.ref) || 'refs/tags/v0.0.0' }}
+          version_extractor_regex: '\/v(.*)$'
+
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Add 7-Zip to PATH
+        run: echo "C:\Program Files\7-Zip" | Out-File -FilePath $env:GITHUB_PATH -Encoding utf8 -Append
+
+      - name: Download release artifacts
+        uses: actions/download-artifact@v4
+        with:
+          name: release
+          path: release
+
+      - name: Download UI release artifacts
+        uses: actions/download-artifact@v4
+        with:
+          name: release-ui
+          path: release-ui
+
+      - name: Stage binaries into dist
+        run: |
+          $workdir = "dist\${{ env.PackageWorkdir }}"
+          New-Item -ItemType Directory -Force -Path $workdir | Out-Null
+          $client = Get-ChildItem -Recurse -Path release -Filter "netbird_*_windows_${{ matrix.arch }}.tar.gz" | Select-Object -First 1
+          $ui = Get-ChildItem -Recurse -Path release-ui -Filter "netbird-ui-windows_*_windows_${{ matrix.arch }}.tar.gz" | Select-Object -First 1
+          if (-not $client) { Write-Host "::error::client tarball not found for ${{ matrix.arch }}"; exit 1 }
+          if (-not $ui) { Write-Host "::error::ui tarball not found for ${{ matrix.arch }}"; exit 1 }
+          Write-Host "Client: $($client.FullName)"
+          Write-Host "UI:     $($ui.FullName)"
+          tar -zvxf $client.FullName -C $workdir
+          tar -zvxf $ui.FullName -C $workdir
+          Get-ChildItem $workdir
+
+      - name: Download wintun
+        uses: carlosperate/download-file-action@v2
+        id: download-wintun
+        with:
+          file-url: https://pkgs.netbird.io/wintun/wintun-0.14.1.zip
+          file-name: wintun.zip
+          location: ${{ env.downloadPath }}
+          sha256: '07c256185d6ee3652e09fa55c0b673e2624b565e02c4b9091c79ca7d2f24ef51'
+
+      - name: Decompress wintun files
+        run: tar -zvxf "${{ steps.download-wintun.outputs.file-path }}" -C ${{ env.downloadPath }}
+
+      - name: Move wintun.dll into dist
+        run: mv ${{ env.downloadPath }}\wintun\bin\${{ matrix.wintun_arch }}\wintun.dll ${{ github.workspace }}\dist\${{ env.PackageWorkdir }}\
+
+      - name: Download Mesa3D (amd64 only)
+        uses: carlosperate/download-file-action@v2
+        id: download-mesa3d
+        if: matrix.arch == 'amd64'
+        with:
+          file-url: https://downloads.fdossena.com/Projects/Mesa3D/Builds/MesaForWindows-x64-20.1.8.7z
+          file-name: mesa3d.7z
+          location: ${{ env.downloadPath }}
+          sha256: '71c7cb64ec229a1d6b8d62fa08e1889ed2bd17c0eeede8689daf0f25cb31d6b9'
+
+      - name: Extract Mesa3D driver (amd64 only)
+        if: matrix.arch == 'amd64'
+        run: 7z x -o"${{ env.downloadPath }}" "${{ env.downloadPath }}/mesa3d.7z"
+
+      - name: Move opengl32.dll into dist (amd64 only)
+        if: matrix.arch == 'amd64'
+        run: mv ${{ env.downloadPath }}\opengl32.dll ${{ github.workspace }}\dist\${{ env.PackageWorkdir }}\
+
+      - name: Download EnVar plugin for NSIS
+        uses: carlosperate/download-file-action@v2
+        with:
+          file-url: https://nsis.sourceforge.io/mediawiki/images/7/7f/EnVar_plugin.zip
+          file-name: envar_plugin.zip
+          location: ${{ github.workspace }}
+
+      - name: Extract EnVar plugin
+        run: 7z x -o"${{ github.workspace }}/NSIS_Plugins" "${{ github.workspace }}/envar_plugin.zip"
+
+      - name: Download ShellExecAsUser plugin for NSIS (amd64 only)
+        uses: carlosperate/download-file-action@v2
+        if: matrix.arch == 'amd64'
+        with:
+          file-url: https://nsis.sourceforge.io/mediawiki/images/6/68/ShellExecAsUser_amd64-Unicode.7z
+          file-name: ShellExecAsUser_amd64-Unicode.7z
+          location: ${{ github.workspace }}
+
+      - name: Extract ShellExecAsUser plugin (amd64 only)
+        if: matrix.arch == 'amd64'
+        run: 7z x -o"${{ github.workspace }}/NSIS_Plugins" "${{ github.workspace }}/ShellExecAsUser_amd64-Unicode.7z"
+
+      - name: Build NSIS installer
+        uses: joncloud/makensis-action@v3.3
+        with:
+          additional-plugin-paths: ${{ github.workspace }}/NSIS_Plugins/Plugins
+          script-file: client/installer.nsis
+          arguments: "/V4 /DARCH=${{ matrix.arch }}"
+        env:
+          APPVER: ${{ steps.semver_parser.outputs.major }}.${{ steps.semver_parser.outputs.minor }}.${{ steps.semver_parser.outputs.patch }}.${{ github.run_id }}
+
+      - name: Rename NSIS installer
+        run: mv netbird-installer.exe netbird_installer_test_windows_${{ matrix.arch }}.exe
+
+      - name: Install WiX
+        run: |
+          dotnet tool install --global wix --version 6.0.2
+          wix extension add WixToolset.Util.wixext/6.0.2
+
+      - name: Build MSI installer
+        env:
+          NETBIRD_VERSION: "${{ steps.semver_parser.outputs.fullversion }}"
+        run: wix build -arch ${{ matrix.arch == 'amd64' && 'x64' || 'arm64' }} -ext WixToolset.Util.wixext -o netbird_installer_test_windows_${{ matrix.arch }}.msi .\client\netbird.wxs -d ProcessorArchitecture=${{ matrix.arch == 'amd64' && 'x64' || 'arm64' }} -d ArchSuffix=${{ matrix.arch }}
+
+      - name: Upload installer artifacts
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: windows-installer-test-${{ matrix.arch }}
+          path: |
+            netbird_installer_test_windows_${{ matrix.arch }}.exe
+            netbird_installer_test_windows_${{ matrix.arch }}.msi
+          retention-days: 3
+
+  comment_release_artifacts:
+    name: Comment release artifacts
     runs-on: ubuntu-latest
     needs: [release, release_ui, release_ui_darwin]
+    if: ${{ always() && github.event_name == 'pull_request' && github.event.pull_request.head.repo.full_name == github.repository }}
+    permissions:
+      contents: read
+      issues: write
+      pull-requests: write
+    steps:
+      - name: Create or update PR comment
+        uses: actions/github-script@v7
+        env:
+          RELEASE_RESULT: ${{ needs.release.result }}
+          RELEASE_UI_RESULT: ${{ needs.release_ui.result }}
+          RELEASE_UI_DARWIN_RESULT: ${{ needs.release_ui_darwin.result }}
+          RELEASE_ARTIFACT_URL: ${{ needs.release.outputs.release_artifact_url }}
+          LINUX_PACKAGES_ARTIFACT_URL: ${{ needs.release.outputs.linux_packages_artifact_url }}
+          WINDOWS_PACKAGES_ARTIFACT_URL: ${{ needs.release.outputs.windows_packages_artifact_url }}
+          MACOS_PACKAGES_ARTIFACT_URL: ${{ needs.release.outputs.macos_packages_artifact_url }}
+          RELEASE_UI_ARTIFACT_URL: ${{ needs.release_ui.outputs.release_ui_artifact_url }}
+          RELEASE_UI_DARWIN_ARTIFACT_URL: ${{ needs.release_ui_darwin.outputs.release_ui_darwin_artifact_url }}
+          GHCR_IMAGES_MARKDOWN: ${{ needs.release.outputs.ghcr_images }}
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          script: |
+            const marker = '<!-- netbird-release-artifacts -->';
+            const { owner, repo } = context.repo;
+            const issue_number = context.payload.pull_request.number;
+            const runUrl = `${context.serverUrl}/${owner}/${repo}/actions/runs/${context.runId}`;
+            const shortSha = context.payload.pull_request.head.sha.slice(0, 7);
+
+            const artifactCell = (url, result) => {
+              if (url) return `[Download](${url})`;
+              return result && result !== 'success' ? `_Not available (${result})_` : '_Not available_';
+            };
+
+            const artifacts = [
+              ['All release artifacts', process.env.RELEASE_ARTIFACT_URL, process.env.RELEASE_RESULT],
+              ['Linux packages', process.env.LINUX_PACKAGES_ARTIFACT_URL, process.env.RELEASE_RESULT],
+              ['Windows packages', process.env.WINDOWS_PACKAGES_ARTIFACT_URL, process.env.RELEASE_RESULT],
+              ['macOS packages', process.env.MACOS_PACKAGES_ARTIFACT_URL, process.env.RELEASE_RESULT],
+              ['UI artifacts', process.env.RELEASE_UI_ARTIFACT_URL, process.env.RELEASE_UI_RESULT],
+              ['UI macOS artifacts', process.env.RELEASE_UI_DARWIN_ARTIFACT_URL, process.env.RELEASE_UI_DARWIN_RESULT],
+            ];
+
+            const artifactRows = artifacts
+              .map(([name, url, result]) => `| ${name} | ${artifactCell(url, result)} |`)
+              .join('\n');
+
+            const ghcrImages = (process.env.GHCR_IMAGES_MARKDOWN || '').trim() || '_No GHCR images were pushed._';
+
+            const body = [
+              marker,
+              '## Release artifacts',
+              '',
+              `Built for PR head \`${shortSha}\` in [workflow run #${process.env.GITHUB_RUN_NUMBER}](${runUrl}).`,
+              '',
+              '| Artifact | Link |',
+              '| --- | --- |',
+              artifactRows,
+              '',
+              '### GHCR images (amd64)',
+              ghcrImages,
+              '',
+              '_This comment is updated by the Release workflow. Artifact links expire according to the workflow retention policy._',
+            ].join('\n');
+
+            const comments = await github.paginate(github.rest.issues.listComments, {
+              owner,
+              repo,
+              issue_number,
+              per_page: 100,
+            });
+
+            const previous = comments.find(comment =>
+              comment.user?.type === 'Bot' && comment.body?.includes(marker)
+            );
+
+            if (previous) {
+              await github.rest.issues.updateComment({
+                owner,
+                repo,
+                comment_id: previous.id,
+                body,
+              });
+              core.info(`Updated release artifacts comment ${previous.id}`);
+            } else {
+              const { data } = await github.rest.issues.createComment({
+                owner,
+                repo,
+                issue_number,
+                body,
+              });
+              core.info(`Created release artifacts comment ${data.id}`);
+            }
+
+  trigger_signer:
+    runs-on: ubuntu-latest
+    needs: [release, release_ui, release_ui_darwin, test_windows_installer]
     if: startsWith(github.ref, 'refs/tags/')
     steps:
       - name: Trigger binaries sign pipelines

.github/workflows/sync-tag.yml

@@ -9,6 +9,8 @@ concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}-${{ github.head_ref || github.actor_id }}
   cancel-in-progress: true
 
+# Receiving workflows (cloud sync-tag, mobile bump-netbird) expect the short
+# tag form (e.g. v0.30.0), not refs/tags/v0.30.0 — github.ref_name, not github.ref.
 jobs:
   trigger_sync_tag:
     runs-on: ubuntu-latest
@@ -20,4 +22,30 @@ jobs:
           ref: main
           repo: ${{ secrets.UPSTREAM_REPO }}
           token: ${{ secrets.NC_GITHUB_TOKEN }}
+          inputs: '{ "tag": "${{ github.ref_name }}" }'
+
+  trigger_android_bump:
+    runs-on: ubuntu-latest
+    if: github.event.created && !github.event.deleted && startsWith(github.ref, 'refs/tags/v') && !contains(github.ref_name, '-')
+    steps:
+      - name: Trigger android-client submodule bump
+        uses: benc-uk/workflow-dispatch@7a027648b88c2413826b6ddd6c76114894dc5ec4 # v1.3.1
+        with:
+          workflow: bump-netbird.yml
+          ref: main
+          repo: netbirdio/android-client
+          token: ${{ secrets.NC_GITHUB_TOKEN }}
+          inputs: '{ "tag": "${{ github.ref_name }}" }'
+
+  trigger_ios_bump:
+    runs-on: ubuntu-latest
+    if: github.event.created && !github.event.deleted && startsWith(github.ref, 'refs/tags/v') && !contains(github.ref_name, '-')
+    steps:
+      - name: Trigger ios-client submodule bump
+        uses: benc-uk/workflow-dispatch@7a027648b88c2413826b6ddd6c76114894dc5ec4 # v1.3.1
+        with:
+          workflow: bump-netbird.yml
+          ref: main
+          repo: netbirdio/ios-client
+          token: ${{ secrets.NC_GITHUB_TOKEN }}
           inputs: '{ "tag": "${{ github.ref_name }}" }'

.golangci.yaml

@@ -58,6 +58,11 @@ linters:
     govet:
       enable:
         - nilness
+      disable:
+        # The inline analyzer flags x/exp/maps Clone/Clear with //go:fix inline
+        # directives but cannot perform the rewrite due to generic type
+        # parameter inference limitations in the Go inliner.
+        - inline
       enable-all: false
     revive:
       rules:

Makefile

@@ -5,7 +5,7 @@ GOLANGCI_LINT := $(shell pwd)/bin/golangci-lint
 $(GOLANGCI_LINT):
 	@echo "Installing golangci-lint..."
 	@mkdir -p ./bin
-	@GOBIN=$(shell pwd)/bin go install github.com/golangci/golangci-lint/cmd/golangci-lint@latest
+	@GOBIN=$(shell pwd)/bin go install github.com/golangci/golangci-lint/v2/cmd/golangci-lint@latest
 
 # Lint only changed files (fast, for pre-push)
 lint: $(GOLANGCI_LINT)

client/Dockerfile

@@ -17,6 +17,7 @@ ENV \
     NETBIRD_BIN="/usr/local/bin/netbird" \
     NB_LOG_FILE="console,/var/log/netbird/client.log" \
     NB_DAEMON_ADDR="unix:///var/run/netbird.sock" \
+    NB_ENABLE_CAPTURE="false" \
     NB_ENTRYPOINT_SERVICE_TIMEOUT="30"
 
 ENTRYPOINT [ "/usr/local/bin/netbird-entrypoint.sh" ]

client/Dockerfile-rootless

@@ -23,6 +23,7 @@ ENV \
     NB_DAEMON_ADDR="unix:///var/lib/netbird/netbird.sock" \
     NB_LOG_FILE="console,/var/lib/netbird/client.log" \
     NB_DISABLE_DNS="true" \
+    NB_ENABLE_CAPTURE="false" \
     NB_ENTRYPOINT_SERVICE_TIMEOUT="30"
 
 ENTRYPOINT [ "/usr/local/bin/netbird-entrypoint.sh" ]

client/android/client.go

@@ -8,6 +8,7 @@ import (
 	"os"
 	"slices"
 	"sync"
+	"time"
 
 	"golang.org/x/exp/maps"
 
@@ -15,6 +16,7 @@ import (
 
 	"github.com/netbirdio/netbird/client/iface/device"
 	"github.com/netbirdio/netbird/client/internal"
+	"github.com/netbirdio/netbird/client/internal/debug"
 	"github.com/netbirdio/netbird/client/internal/dns"
 	"github.com/netbirdio/netbird/client/internal/listener"
 	"github.com/netbirdio/netbird/client/internal/peer"
@@ -26,6 +28,7 @@ import (
 	"github.com/netbirdio/netbird/formatter"
 	"github.com/netbirdio/netbird/route"
 	"github.com/netbirdio/netbird/shared/management/domain"
+	types "github.com/netbirdio/netbird/upload-server/types"
 )
 
 // ConnectionListener export internal Listener for mobile
@@ -68,7 +71,30 @@ type Client struct {
 	uiVersion             string
 	networkChangeListener listener.NetworkChangeListener
 
+	stateMu       sync.RWMutex
 	connectClient *internal.ConnectClient
+	config        *profilemanager.Config
+	cacheDir      string
+}
+
+func (c *Client) setState(cfg *profilemanager.Config, cacheDir string, cc *internal.ConnectClient) {
+	c.stateMu.Lock()
+	defer c.stateMu.Unlock()
+	c.config = cfg
+	c.cacheDir = cacheDir
+	c.connectClient = cc
+}
+
+func (c *Client) stateSnapshot() (*profilemanager.Config, string, *internal.ConnectClient) {
+	c.stateMu.RLock()
+	defer c.stateMu.RUnlock()
+	return c.config, c.cacheDir, c.connectClient
+}
+
+func (c *Client) getConnectClient() *internal.ConnectClient {
+	c.stateMu.RLock()
+	defer c.stateMu.RUnlock()
+	return c.connectClient
 }
 
 // NewClient instantiate a new Client
@@ -93,6 +119,7 @@ func (c *Client) Run(platformFiles PlatformFiles, urlOpener URLOpener, isAndroid
 
 	cfgFile := platformFiles.ConfigurationFilePath()
 	stateFile := platformFiles.StateFilePath()
+	cacheDir := platformFiles.CacheDir()
 
 	log.Infof("Starting client with config: %s, state: %s", cfgFile, stateFile)
 
@@ -124,8 +151,9 @@ func (c *Client) Run(platformFiles PlatformFiles, urlOpener URLOpener, isAndroid
 
 	// todo do not throw error in case of cancelled context
 	ctx = internal.CtxInitState(ctx)
-	c.connectClient = internal.NewConnectClient(ctx, cfg, c.recorder)
+	connectClient := internal.NewConnectClient(ctx, cfg, c.recorder)
-	return c.connectClient.RunOnAndroid(c.tunAdapter, c.iFaceDiscover, c.networkChangeListener, slices.Clone(dns.items), dnsReadyListener, stateFile)
+	c.setState(cfg, cacheDir, connectClient)
+	return connectClient.RunOnAndroid(c.tunAdapter, c.iFaceDiscover, c.networkChangeListener, slices.Clone(dns.items), dnsReadyListener, stateFile, cacheDir)
 }
 
 // RunWithoutLogin we apply this type of run function when the backed has been started without UI (i.e. after reboot).
@@ -135,6 +163,7 @@ func (c *Client) RunWithoutLogin(platformFiles PlatformFiles, dns *DNSList, dnsR
 
 	cfgFile := platformFiles.ConfigurationFilePath()
 	stateFile := platformFiles.StateFilePath()
+	cacheDir := platformFiles.CacheDir()
 
 	log.Infof("Starting client without login with config: %s, state: %s", cfgFile, stateFile)
 
@@ -157,8 +186,9 @@ func (c *Client) RunWithoutLogin(platformFiles PlatformFiles, dns *DNSList, dnsR
 
 	// todo do not throw error in case of cancelled context
 	ctx = internal.CtxInitState(ctx)
-	c.connectClient = internal.NewConnectClient(ctx, cfg, c.recorder)
+	connectClient := internal.NewConnectClient(ctx, cfg, c.recorder)
-	return c.connectClient.RunOnAndroid(c.tunAdapter, c.iFaceDiscover, c.networkChangeListener, slices.Clone(dns.items), dnsReadyListener, stateFile)
+	c.setState(cfg, cacheDir, connectClient)
+	return connectClient.RunOnAndroid(c.tunAdapter, c.iFaceDiscover, c.networkChangeListener, slices.Clone(dns.items), dnsReadyListener, stateFile, cacheDir)
 }
 
 // Stop the internal client and free the resources
@@ -173,11 +203,12 @@ func (c *Client) Stop() {
 }
 
 func (c *Client) RenewTun(fd int) error {
-	if c.connectClient == nil {
+	cc := c.getConnectClient()
+	if cc == nil {
 		return fmt.Errorf("engine not running")
 	}
 
-	e := c.connectClient.Engine()
+	e := cc.Engine()
 	if e == nil {
 		return fmt.Errorf("engine not initialized")
 	}
@@ -185,6 +216,73 @@ func (c *Client) RenewTun(fd int) error {
 	return e.RenewTun(fd)
 }
 
+// DebugBundle generates a debug bundle, uploads it, and returns the upload key.
+// It works both with and without a running engine.
+func (c *Client) DebugBundle(platformFiles PlatformFiles, anonymize bool) (string, error) {
+	cfg, cacheDir, cc := c.stateSnapshot()
+
+	// If the engine hasn't been started, load config from disk
+	if cfg == nil {
+		var err error
+		cfg, err = profilemanager.UpdateOrCreateConfig(profilemanager.ConfigInput{
+			ConfigPath: platformFiles.ConfigurationFilePath(),
+		})
+		if err != nil {
+			return "", fmt.Errorf("load config: %w", err)
+		}
+		cacheDir = platformFiles.CacheDir()
+	}
+
+	deps := debug.GeneratorDependencies{
+		InternalConfig: cfg,
+		StatusRecorder: c.recorder,
+		TempDir:        cacheDir,
+	}
+
+	if cc != nil {
+		resp, err := cc.GetLatestSyncResponse()
+		if err != nil {
+			log.Warnf("get latest sync response: %v", err)
+		}
+		deps.SyncResponse = resp
+
+		if e := cc.Engine(); e != nil {
+			if cm := e.GetClientMetrics(); cm != nil {
+				deps.ClientMetrics = cm
+			}
+		}
+	}
+
+	bundleGenerator := debug.NewBundleGenerator(
+		deps,
+		debug.BundleConfig{
+			Anonymize:         anonymize,
+			IncludeSystemInfo: true,
+		},
+	)
+
+	path, err := bundleGenerator.Generate()
+	if err != nil {
+		return "", fmt.Errorf("generate debug bundle: %w", err)
+	}
+	defer func() {
+		if err := os.Remove(path); err != nil {
+			log.Errorf("failed to remove debug bundle file: %v", err)
+		}
+	}()
+
+	uploadCtx, cancel := context.WithTimeout(context.Background(), 2*time.Minute)
+	defer cancel()
+
+	key, err := debug.UploadDebugBundle(uploadCtx, types.DefaultBundleURL, cfg.ManagementURL.String(), path)
+	if err != nil {
+		return "", fmt.Errorf("upload debug bundle: %w", err)
+	}
+
+	log.Infof("debug bundle uploaded with key %s", key)
+	return key, nil
+}
+
 // SetTraceLogLevel configure the logger to trace level
 func (c *Client) SetTraceLogLevel() {
 	log.SetLevel(log.TraceLevel)
@@ -214,12 +312,13 @@ func (c *Client) PeersList() *PeerInfoArray {
 }
 
 func (c *Client) Networks() *NetworkArray {
-	if c.connectClient == nil {
+	cc := c.getConnectClient()
+	if cc == nil {
 		log.Error("not connected")
 		return nil
 	}
 
-	engine := c.connectClient.Engine()
+	engine := cc.Engine()
 	if engine == nil {
 		log.Error("could not get engine")
 		return nil
@@ -300,7 +399,7 @@ func (c *Client) toggleRoute(command routeCommand) error {
 }
 
 func (c *Client) getRouteManager() (routemanager.Manager, error) {
-	client := c.connectClient
+	client := c.getConnectClient()
 	if client == nil {
 		return nil, fmt.Errorf("not connected")
 	}

client/android/platform_files.go

@@ -7,4 +7,5 @@ package android
 type PlatformFiles interface {
 	ConfigurationFilePath() string
 	StateFilePath() string
+	CacheDir() string
 }

client/cmd/capture.go

@@ -0,0 +1,196 @@
+package cmd
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"os"
+	"os/signal"
+	"path/filepath"
+	"strings"
+	"syscall"
+
+	"github.com/hashicorp/go-multierror"
+	"github.com/spf13/cobra"
+	"google.golang.org/grpc/status"
+	"google.golang.org/protobuf/types/known/durationpb"
+
+	nberrors "github.com/netbirdio/netbird/client/errors"
+	"github.com/netbirdio/netbird/client/proto"
+	"github.com/netbirdio/netbird/util/capture"
+)
+
+var captureCmd = &cobra.Command{
+	Use:   "capture",
+	Short: "Capture packets on the WireGuard interface",
+	Long: `Captures decrypted packets flowing through the WireGuard interface.
+
+Default output is human-readable text. Use --pcap or --output for pcap binary.
+Requires --enable-capture to be set at service install or reconfigure time.
+
+Examples:
+  netbird debug capture
+  netbird debug capture host 100.64.0.1 and port 443
+  netbird debug capture tcp
+  netbird debug capture icmp
+  netbird debug capture src host 10.0.0.1 and dst port 80
+  netbird debug capture -o capture.pcap
+  netbird debug capture --pcap | tshark -r -
+  netbird debug capture --pcap | tcpdump -r - -n`,
+	Args: cobra.ArbitraryArgs,
+	RunE: runCapture,
+}
+
+func init() {
+	debugCmd.AddCommand(captureCmd)
+
+	captureCmd.Flags().Bool("pcap", false, "Force pcap binary output (default when --output is set)")
+	captureCmd.Flags().BoolP("verbose", "v", false, "Show seq/ack, TTL, window, total length")
+	captureCmd.Flags().Bool("ascii", false, "Print payload as ASCII after each packet (useful for HTTP)")
+	captureCmd.Flags().Uint32("snap-len", 0, "Max bytes per packet (0 = full)")
+	captureCmd.Flags().DurationP("duration", "d", 0, "Capture duration (0 = until interrupted)")
+	captureCmd.Flags().StringP("output", "o", "", "Write pcap to file instead of stdout")
+}
+
+func runCapture(cmd *cobra.Command, args []string) error {
+	conn, err := getClient(cmd)
+	if err != nil {
+		return err
+	}
+	defer func() {
+		if err := conn.Close(); err != nil {
+			cmd.PrintErrf(errCloseConnection, err)
+		}
+	}()
+
+	client := proto.NewDaemonServiceClient(conn)
+
+	req, err := buildCaptureRequest(cmd, args)
+	if err != nil {
+		return err
+	}
+
+	ctx, cancel := signal.NotifyContext(cmd.Context(), syscall.SIGINT, syscall.SIGTERM)
+	defer cancel()
+
+	stream, err := client.StartCapture(ctx, req)
+	if err != nil {
+		return handleCaptureError(err)
+	}
+
+	// First Recv is the empty acceptance message from the server. If the
+	// device is unavailable (kernel WG, not connected, capture disabled),
+	// the server returns an error instead.
+	if _, err := stream.Recv(); err != nil {
+		return handleCaptureError(err)
+	}
+
+	out, cleanup, err := captureOutput(cmd)
+	if err != nil {
+		return err
+	}
+
+	if req.TextOutput {
+		cmd.PrintErrf("Capturing packets... Press Ctrl+C to stop.\n")
+	} else {
+		cmd.PrintErrf("Capturing packets (pcap)... Press Ctrl+C to stop.\n")
+	}
+
+	streamErr := streamCapture(ctx, cmd, stream, out)
+	cleanupErr := cleanup()
+	if streamErr != nil {
+		return streamErr
+	}
+	return cleanupErr
+}
+
+func buildCaptureRequest(cmd *cobra.Command, args []string) (*proto.StartCaptureRequest, error) {
+	req := &proto.StartCaptureRequest{}
+
+	if len(args) > 0 {
+		expr := strings.Join(args, " ")
+		if _, err := capture.ParseFilter(expr); err != nil {
+			return nil, fmt.Errorf("invalid filter: %w", err)
+		}
+		req.FilterExpr = expr
+	}
+
+	if snap, _ := cmd.Flags().GetUint32("snap-len"); snap > 0 {
+		req.SnapLen = snap
+	}
+	if d, _ := cmd.Flags().GetDuration("duration"); d != 0 {
+		if d < 0 {
+			return nil, fmt.Errorf("duration must not be negative")
+		}
+		req.Duration = durationpb.New(d)
+	}
+	req.Verbose, _ = cmd.Flags().GetBool("verbose")
+	req.Ascii, _ = cmd.Flags().GetBool("ascii")
+
+	outPath, _ := cmd.Flags().GetString("output")
+	forcePcap, _ := cmd.Flags().GetBool("pcap")
+	req.TextOutput = !forcePcap && outPath == ""
+
+	return req, nil
+}
+
+func streamCapture(ctx context.Context, cmd *cobra.Command, stream proto.DaemonService_StartCaptureClient, out io.Writer) error {
+	for {
+		pkt, err := stream.Recv()
+		if err != nil {
+			if ctx.Err() != nil {
+				cmd.PrintErrf("\nCapture stopped.\n")
+				return nil //nolint:nilerr // user interrupted
+			}
+			if err == io.EOF {
+				cmd.PrintErrf("\nCapture finished.\n")
+				return nil
+			}
+			return handleCaptureError(err)
+		}
+		if _, err := out.Write(pkt.GetData()); err != nil {
+			return fmt.Errorf("write output: %w", err)
+		}
+	}
+}
+
+// captureOutput returns the writer for capture data and a cleanup function
+// that finalizes the file. Errors from the cleanup must be propagated.
+func captureOutput(cmd *cobra.Command) (io.Writer, func() error, error) {
+	outPath, _ := cmd.Flags().GetString("output")
+	if outPath == "" {
+		return os.Stdout, func() error { return nil }, nil
+	}
+
+	f, err := os.CreateTemp(filepath.Dir(outPath), filepath.Base(outPath)+".*.tmp")
+	if err != nil {
+		return nil, nil, fmt.Errorf("create output file: %w", err)
+	}
+	tmpPath := f.Name()
+	return f, func() error {
+		var merr *multierror.Error
+		if err := f.Close(); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("close output file: %w", err))
+		}
+		fi, statErr := os.Stat(tmpPath)
+		if statErr != nil || fi.Size() == 0 {
+			if rmErr := os.Remove(tmpPath); rmErr != nil && !os.IsNotExist(rmErr) {
+				merr = multierror.Append(merr, fmt.Errorf("remove empty output file: %w", rmErr))
+			}
+			return nberrors.FormatErrorOrNil(merr)
+		}
+		if err := os.Rename(tmpPath, outPath); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("rename output file: %w", err))
+			return nberrors.FormatErrorOrNil(merr)
+		}
+		cmd.PrintErrf("Wrote %s\n", outPath)
+		return nberrors.FormatErrorOrNil(merr)
+	}, nil
+}
+
+func handleCaptureError(err error) error {
+	if s, ok := status.FromError(err); ok {
+		return fmt.Errorf("%s", s.Message())
+	}
+	return err
+}

client/cmd/debug.go

@@ -9,6 +9,7 @@ import (
 	log "github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
 	"google.golang.org/grpc/status"
+	"google.golang.org/protobuf/types/known/durationpb"
 
 	"github.com/netbirdio/netbird/client/internal"
 	"github.com/netbirdio/netbird/client/internal/debug"
@@ -239,11 +240,50 @@ func runForDuration(cmd *cobra.Command, args []string) error {
 		}()
 	}
 
+	captureStarted := false
+	if wantCapture, _ := cmd.Flags().GetBool("capture"); wantCapture {
+		captureTimeout := duration + 30*time.Second
+		const maxBundleCapture = 10 * time.Minute
+		if captureTimeout > maxBundleCapture {
+			captureTimeout = maxBundleCapture
+		}
+		_, err := client.StartBundleCapture(cmd.Context(), &proto.StartBundleCaptureRequest{
+			Timeout: durationpb.New(captureTimeout),
+		})
+		if err != nil {
+			cmd.PrintErrf("Failed to start packet capture: %v\n", status.Convert(err).Message())
+		} else {
+			captureStarted = true
+			cmd.Println("Packet capture started.")
+			// Safety: always stop on exit, even if the normal stop below runs too.
+			defer func() {
+				if captureStarted {
+					stopCtx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+					defer cancel()
+					if _, err := client.StopBundleCapture(stopCtx, &proto.StopBundleCaptureRequest{}); err != nil {
+						cmd.PrintErrf("Failed to stop packet capture: %v\n", err)
+					}
+				}
+			}()
+		}
+	}
+
 	if waitErr := waitForDurationOrCancel(cmd.Context(), duration, cmd); waitErr != nil {
 		return waitErr
 	}
 	cmd.Println("\nDuration completed")
 
+	if captureStarted {
+		stopCtx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+		defer cancel()
+		if _, err := client.StopBundleCapture(stopCtx, &proto.StopBundleCaptureRequest{}); err != nil {
+			cmd.PrintErrf("Failed to stop packet capture: %v\n", err)
+		} else {
+			captureStarted = false
+			cmd.Println("Packet capture stopped.")
+		}
+	}
+
 	if cpuProfilingStarted {
 		if _, err := client.StopCPUProfile(cmd.Context(), &proto.StopCPUProfileRequest{}); err != nil {
 			cmd.PrintErrf("Failed to stop CPU profiling: %v\n", err)
@@ -416,4 +456,5 @@ func init() {
 	forCmd.Flags().BoolVarP(&systemInfoFlag, "system-info", "S", true, "Adds system information to the debug bundle")
 	forCmd.Flags().BoolVarP(&uploadBundleFlag, "upload-bundle", "U", false, "Uploads the debug bundle to a server")
 	forCmd.Flags().StringVar(&uploadBundleURLFlag, "upload-bundle-url", types.DefaultBundleURL, "Service URL to get an URL to upload the debug bundle")
+	forCmd.Flags().Bool("capture", false, "Capture packets during the debug duration and include in bundle")
 }

client/cmd/login.go

@@ -10,6 +10,7 @@ import (
 
 	log "github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
+	"golang.org/x/term"
 	"google.golang.org/grpc/codes"
 	gstatus "google.golang.org/grpc/status"
 
@@ -23,6 +24,7 @@ import (
 
 func init() {
 	loginCmd.PersistentFlags().BoolVar(&noBrowser, noBrowserFlag, false, noBrowserDesc)
+	loginCmd.PersistentFlags().BoolVar(&showQR, showQRFlag, false, showQRDesc)
 	loginCmd.PersistentFlags().StringVar(&profileName, profileNameFlag, "", profileNameDesc)
 	loginCmd.PersistentFlags().StringVarP(&configPath, "config", "c", "", "(DEPRECATED) Netbird config file location")
 }
@@ -256,7 +258,7 @@ func doForegroundLogin(ctx context.Context, cmd *cobra.Command, setupKey string,
 }
 
 func handleSSOLogin(ctx context.Context, cmd *cobra.Command, loginResp *proto.LoginResponse, client proto.DaemonServiceClient, pm *profilemanager.ProfileManager) error {
-	openURL(cmd, loginResp.VerificationURIComplete, loginResp.UserCode, noBrowser)
+	openURL(cmd, loginResp.VerificationURIComplete, loginResp.UserCode, noBrowser, showQR)
 
 	resp, err := client.WaitSSOLogin(ctx, &proto.WaitSSOLoginRequest{UserCode: loginResp.UserCode, Hostname: hostName})
 	if err != nil {
@@ -324,7 +326,7 @@ func foregroundGetTokenInfo(ctx context.Context, cmd *cobra.Command, config *pro
 		return nil, fmt.Errorf("getting a request OAuth flow info failed: %v", err)
 	}
 
-	openURL(cmd, flowInfo.VerificationURIComplete, flowInfo.UserCode, noBrowser)
+	openURL(cmd, flowInfo.VerificationURIComplete, flowInfo.UserCode, noBrowser, showQR)
 
 	tokenInfo, err := oAuthFlow.WaitToken(context.TODO(), flowInfo)
 	if err != nil {
@@ -334,7 +336,7 @@ func foregroundGetTokenInfo(ctx context.Context, cmd *cobra.Command, config *pro
 	return &tokenInfo, nil
 }
 
-func openURL(cmd *cobra.Command, verificationURIComplete, userCode string, noBrowser bool) {
+func openURL(cmd *cobra.Command, verificationURIComplete, userCode string, noBrowser, showQR bool) {
 	var codeMsg string
 	if userCode != "" && !strings.Contains(verificationURIComplete, userCode) {
 		codeMsg = fmt.Sprintf("and enter the code %s to authenticate.", userCode)
@@ -348,6 +350,12 @@ func openURL(cmd *cobra.Command, verificationURIComplete, userCode string, noBro
 			verificationURIComplete + " " + codeMsg)
 	}
 
+	if showQR {
+		if f, ok := cmd.OutOrStdout().(*os.File); ok && term.IsTerminal(int(f.Fd())) {
+			printQRCode(f, verificationURIComplete)
+		}
+	}
+
 	cmd.Println("")
 
 	if !noBrowser {

client/cmd/qr.go

@@ -0,0 +1,25 @@
+package cmd
+
+import (
+	"io"
+
+	"github.com/mdp/qrterminal/v3"
+)
+
+// printQRCode prints a QR code for the given URL to the writer.
+// Called only when the user explicitly requests QR output via --qr.
+func printQRCode(w io.Writer, url string) {
+	if url == "" {
+		return
+	}
+	qrterminal.GenerateWithConfig(url, qrterminal.Config{
+		Level:          qrterminal.M,
+		Writer:         w,
+		HalfBlocks:     true,
+		BlackChar:      qrterminal.BLACK_BLACK,
+		WhiteChar:      qrterminal.WHITE_WHITE,
+		BlackWhiteChar: qrterminal.BLACK_WHITE,
+		WhiteBlackChar: qrterminal.WHITE_BLACK,
+		QuietZone:      qrterminal.QUIET_ZONE,
+	})
+}

client/cmd/qr_test.go

@@ -0,0 +1,26 @@
+package cmd
+
+import (
+	"bytes"
+	"testing"
+)
+
+func TestPrintQRCode_EmptyURL(t *testing.T) {
+	var buf bytes.Buffer
+
+	printQRCode(&buf, "")
+
+	if buf.Len() != 0 {
+		t.Error("expected no output for empty URL")
+	}
+}
+
+func TestPrintQRCode_WritesOutput(t *testing.T) {
+	var buf bytes.Buffer
+
+	printQRCode(&buf, "https://example.com/auth")
+
+	if buf.Len() == 0 {
+		t.Error("expected QR code output for non-empty URL")
+	}
+}

client/cmd/root.go

@@ -75,6 +75,7 @@ var (
 	mtu                     uint16
 	profilesDisabled        bool
 	updateSettingsDisabled  bool
+	captureEnabled          bool
 	networksDisabled        bool
 
 	rootCmd = &cobra.Command{

client/cmd/service.go

@@ -44,6 +44,7 @@ func init() {
 	serviceCmd.AddCommand(runCmd, startCmd, stopCmd, restartCmd, svcStatusCmd, installCmd, uninstallCmd, reconfigureCmd, resetParamsCmd)
 	serviceCmd.PersistentFlags().BoolVar(&profilesDisabled, "disable-profiles", false, "Disables profiles feature. If enabled, the client will not be able to change or edit any profile. To persist this setting, use: netbird service install --disable-profiles")
 	serviceCmd.PersistentFlags().BoolVar(&updateSettingsDisabled, "disable-update-settings", false, "Disables update settings feature. If enabled, the client will not be able to change or edit any settings. To persist this setting, use: netbird service install --disable-update-settings")
+	serviceCmd.PersistentFlags().BoolVar(&captureEnabled, "enable-capture", false, "Enables packet capture via 'netbird debug capture'. To persist, use: netbird service install --enable-capture")
 	serviceCmd.PersistentFlags().BoolVar(&networksDisabled, "disable-networks", false, "Disables network selection. If enabled, the client will not allow listing, selecting, or deselecting networks. To persist, use: netbird service install --disable-networks")
 
 	rootCmd.PersistentFlags().StringVarP(&serviceName, "service", "s", defaultServiceName, "Netbird system service name")

client/cmd/service_controller.go

@@ -61,7 +61,7 @@ func (p *program) Start(svc service.Service) error {
 			}
 		}
 
-		serverInstance := server.New(p.ctx, util.FindFirstLogPath(logFiles), configPath, profilesDisabled, updateSettingsDisabled, networksDisabled)
+		serverInstance := server.New(p.ctx, util.FindFirstLogPath(logFiles), configPath, profilesDisabled, updateSettingsDisabled, captureEnabled, networksDisabled)
 		if err := serverInstance.Start(); err != nil {
 			log.Fatalf("failed to start daemon: %v", err)
 		}

client/cmd/service_installer.go

@@ -59,6 +59,10 @@ func buildServiceArguments() []string {
 		args = append(args, "--disable-update-settings")
 	}
 
+	if captureEnabled {
+		args = append(args, "--enable-capture")
+	}
+
 	if networksDisabled {
 		args = append(args, "--disable-networks")
 	}

client/cmd/service_params.go

@@ -28,6 +28,7 @@ type serviceParams struct {
 	LogFiles              []string          `json:"log_files,omitempty"`
 	DisableProfiles       bool              `json:"disable_profiles,omitempty"`
 	DisableUpdateSettings bool              `json:"disable_update_settings,omitempty"`
+	EnableCapture         bool              `json:"enable_capture,omitempty"`
 	DisableNetworks       bool              `json:"disable_networks,omitempty"`
 	ServiceEnvVars        map[string]string `json:"service_env_vars,omitempty"`
 }
@@ -79,6 +80,7 @@ func currentServiceParams() *serviceParams {
 		LogFiles:              logFiles,
 		DisableProfiles:       profilesDisabled,
 		DisableUpdateSettings: updateSettingsDisabled,
+		EnableCapture:         captureEnabled,
 		DisableNetworks:       networksDisabled,
 	}
 
@@ -144,6 +146,10 @@ func applyServiceParams(cmd *cobra.Command, params *serviceParams) {
 		updateSettingsDisabled = params.DisableUpdateSettings
 	}
 
+	if !serviceCmd.PersistentFlags().Changed("enable-capture") {
+		captureEnabled = params.EnableCapture
+	}
+
 	if !serviceCmd.PersistentFlags().Changed("disable-networks") {
 		networksDisabled = params.DisableNetworks
 	}

client/cmd/service_params_test.go

@@ -535,6 +535,7 @@ func fieldToGlobalVar(field string) string {
 		"LogFiles":              "logFiles",
 		"DisableProfiles":       "profilesDisabled",
 		"DisableUpdateSettings": "updateSettingsDisabled",
+		"EnableCapture":         "captureEnabled",
 		"DisableNetworks":       "networksDisabled",
 		"ServiceEnvVars":        "serviceEnvVars",
 	}

client/cmd/testutil_test.go

@@ -135,7 +135,7 @@ func startManagement(t *testing.T, config *config.Config, testFile string) (*grp
 	if err != nil {
 		t.Fatal(err)
 	}
-	mgmtServer, err := nbgrpc.NewServer(config, accountManager, settingsMockManager, jobManager, secretsManager, nil, nil, &mgmt.MockIntegratedValidator{}, networkMapController, nil)
+	mgmtServer, err := nbgrpc.NewServer(config, accountManager, settingsMockManager, jobManager, secretsManager, nil, nil, &mgmt.MockIntegratedValidator{}, networkMapController, nil, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -160,7 +160,7 @@ func startClientDaemon(
 	s := grpc.NewServer()
 
 	server := client.New(ctx,
-		"", "", false, false, false)
+		"", "", false, false, false, false)
 	if err := server.Start(); err != nil {
 		t.Fatal(err)
 	}

client/cmd/up.go

@@ -39,6 +39,9 @@ const (
 	noBrowserFlag = "no-browser"
 	noBrowserDesc = "do not open the browser for SSO login"
 
+	showQRFlag = "qr"
+	showQRDesc = "show QR code for the SSO login URL (useful for headless machines without browser access)"
+
 	profileNameFlag = "profile"
 	profileNameDesc = "profile name to use for the login. If not specified, the last used profile will be used."
 )
@@ -48,6 +51,7 @@ var (
 	dnsLabels          []string
 	dnsLabelsValidated domain.List
 	noBrowser          bool
+	showQR             bool
 	profileName        string
 	configPath         string
 
@@ -80,6 +84,7 @@ func init() {
 	)
 
 	upCmd.PersistentFlags().BoolVar(&noBrowser, noBrowserFlag, false, noBrowserDesc)
+	upCmd.PersistentFlags().BoolVar(&showQR, showQRFlag, false, showQRDesc)
 	upCmd.PersistentFlags().StringVar(&profileName, profileNameFlag, "", profileNameDesc)
 	upCmd.PersistentFlags().StringVarP(&configPath, "config", "c", "", "(DEPRECATED) NetBird config file location. ")
 

client/embed/capture.go

@@ -0,0 +1,65 @@
+package embed
+
+import (
+	"io"
+
+	"github.com/netbirdio/netbird/client/internal"
+	"github.com/netbirdio/netbird/util/capture"
+)
+
+// CaptureOptions configures a packet capture session.
+type CaptureOptions struct {
+	// Output receives pcap-formatted data. Nil disables pcap output.
+	Output io.Writer
+	// TextOutput receives human-readable packet summaries. Nil disables text output.
+	TextOutput io.Writer
+	// Filter is a BPF-like filter expression (e.g. "host 10.0.0.1 and tcp port 443").
+	// Empty captures all packets.
+	Filter string
+	// Verbose adds seq/ack, TTL, window, and total length to text output.
+	Verbose bool
+	// ASCII dumps transport payload as printable ASCII after each packet line.
+	ASCII bool
+}
+
+// CaptureStats reports capture session counters.
+type CaptureStats struct {
+	Packets int64
+	Bytes   int64
+	Dropped int64
+}
+
+// CaptureSession represents an active packet capture. Call Stop to end the
+// capture and flush buffered packets.
+type CaptureSession struct {
+	sess   *capture.Session
+	engine *internal.Engine
+}
+
+// Stop ends the capture, flushes remaining packets, and detaches from the device.
+// Safe to call multiple times.
+func (cs *CaptureSession) Stop() {
+	if cs.engine != nil {
+		_ = cs.engine.SetCapture(nil)
+		cs.engine = nil
+	}
+	if cs.sess != nil {
+		cs.sess.Stop()
+	}
+}
+
+// Stats returns current capture counters.
+func (cs *CaptureSession) Stats() CaptureStats {
+	s := cs.sess.Stats()
+	return CaptureStats{
+		Packets: s.Packets,
+		Bytes:   s.Bytes,
+		Dropped: s.Dropped,
+	}
+}
+
+// Done returns a channel that is closed when the capture's writer goroutine
+// has fully exited and all buffered packets have been flushed.
+func (cs *CaptureSession) Done() <-chan struct{} {
+	return cs.sess.Done()
+}

client/embed/embed.go

@@ -24,6 +24,7 @@ import (
 	"github.com/netbirdio/netbird/client/system"
 	"github.com/netbirdio/netbird/shared/management/domain"
 	mgmProto "github.com/netbirdio/netbird/shared/management/proto"
+	"github.com/netbirdio/netbird/util/capture"
 )
 
 var (
@@ -65,7 +66,7 @@ type Options struct {
 	PrivateKey string
 	// ManagementURL overrides the default management server URL
 	ManagementURL string
-	// PreSharedKey is the pre-shared key for the WireGuard interface
+	// PreSharedKey is the pre-shared key for the tunnel interface
 	PreSharedKey string
 	// LogOutput is the output destination for logs (defaults to os.Stderr if nil)
 	LogOutput io.Writer
@@ -81,9 +82,9 @@ type Options struct {
 	DisableClientRoutes bool
 	// BlockInbound blocks all inbound connections from peers
 	BlockInbound bool
-	// WireguardPort is the port for the WireGuard interface. Use 0 for a random port.
+	// WireguardPort is the port for the tunnel interface. Use 0 for a random port.
 	WireguardPort *int
-	// MTU is the MTU for the WireGuard interface.
+	// MTU is the MTU for the tunnel interface.
 	// Valid values are in the range 576..8192 bytes.
 	// If non-nil, this value overrides any value stored in the config file.
 	// If nil, the existing config MTU (if non-zero) is preserved; otherwise it defaults to 1280.
@@ -469,6 +470,52 @@ func (c *Client) VerifySSHHostKey(peerAddress string, key []byte) error {
 	return sshcommon.VerifyHostKey(storedKey, key, peerAddress)
 }
 
+// StartCapture begins capturing packets on this client's tunnel device.
+// Only one capture can be active at a time; starting a new one stops the previous.
+// Call StopCapture (or CaptureSession.Stop) to end it.
+func (c *Client) StartCapture(opts CaptureOptions) (*CaptureSession, error) {
+	engine, err := c.getEngine()
+	if err != nil {
+		return nil, err
+	}
+
+	var matcher capture.Matcher
+	if opts.Filter != "" {
+		m, err := capture.ParseFilter(opts.Filter)
+		if err != nil {
+			return nil, fmt.Errorf("parse filter: %w", err)
+		}
+		matcher = m
+	}
+
+	sess, err := capture.NewSession(capture.Options{
+		Output:     opts.Output,
+		TextOutput: opts.TextOutput,
+		Matcher:    matcher,
+		Verbose:    opts.Verbose,
+		ASCII:      opts.ASCII,
+	})
+	if err != nil {
+		return nil, fmt.Errorf("create capture session: %w", err)
+	}
+
+	if err := engine.SetCapture(sess); err != nil {
+		sess.Stop()
+		return nil, fmt.Errorf("set capture: %w", err)
+	}
+
+	return &CaptureSession{sess: sess, engine: engine}, nil
+}
+
+// StopCapture stops the active capture session if one is running.
+func (c *Client) StopCapture() error {
+	engine, err := c.getEngine()
+	if err != nil {
+		return err
+	}
+	return engine.SetCapture(nil)
+}
+
 // getEngine safely retrieves the engine from the client with proper locking.
 // Returns ErrClientNotStarted if the client is not started.
 // Returns ErrEngineNotStarted if the engine is not available.

client/firewall/firewalld/firewalld.go

@@ -0,0 +1,11 @@
+// Package firewalld integrates with the firewalld daemon so NetBird can place
+// its wg interface into firewalld's "trusted" zone. This is required because
+// firewalld's nftables chains are created with NFT_CHAIN_OWNER on recent
+// versions, which returns EPERM to any other process that tries to insert
+// rules into them. The workaround mirrors what Tailscale does: let firewalld
+// itself add the accept rules to its own chains by trusting the interface.
+package firewalld
+
+// TrustedZone is the firewalld zone name used for interfaces whose traffic
+// should bypass firewalld filtering.
+const TrustedZone = "trusted"

client/firewall/firewalld/firewalld_linux.go

@@ -0,0 +1,260 @@
+//go:build linux
+
+package firewalld
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"os/exec"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/godbus/dbus/v5"
+	log "github.com/sirupsen/logrus"
+)
+
+const (
+	dbusDest      = "org.fedoraproject.FirewallD1"
+	dbusPath      = "/org/fedoraproject/FirewallD1"
+	dbusRootIface = "org.fedoraproject.FirewallD1"
+	dbusZoneIface = "org.fedoraproject.FirewallD1.zone"
+
+	errZoneAlreadySet = "ZONE_ALREADY_SET"
+	errAlreadyEnabled = "ALREADY_ENABLED"
+	errUnknownIface   = "UNKNOWN_INTERFACE"
+	errNotEnabled     = "NOT_ENABLED"
+
+	// callTimeout bounds each individual DBus or firewall-cmd invocation.
+	// A fresh context is created for each call so a slow DBus probe can't
+	// exhaust the deadline before the firewall-cmd fallback gets to run.
+	callTimeout = 3 * time.Second
+)
+
+var (
+	errDBusUnavailable = errors.New("firewalld dbus unavailable")
+
+	// trustLogOnce ensures the "added to trusted zone" message is logged at
+	// Info level only for the first successful add per process; repeat adds
+	// from other init paths are quieter.
+	trustLogOnce sync.Once
+
+	parentCtxMu sync.RWMutex
+	parentCtx   context.Context = context.Background()
+)
+
+// SetParentContext installs a parent context whose cancellation aborts any
+// in-flight TrustInterface call. It does not affect UntrustInterface, which
+// always uses a fresh Background-rooted timeout so cleanup can still run
+// during engine shutdown when the engine context is already cancelled.
+func SetParentContext(ctx context.Context) {
+	parentCtxMu.Lock()
+	parentCtx = ctx
+	parentCtxMu.Unlock()
+}
+
+func getParentContext() context.Context {
+	parentCtxMu.RLock()
+	defer parentCtxMu.RUnlock()
+	return parentCtx
+}
+
+// TrustInterface places iface into firewalld's trusted zone if firewalld is
+// running. It is idempotent and best-effort: errors are returned so callers
+// can log, but a non-running firewalld is not an error. Only the first
+// successful call per process logs at Info. Respects the parent context set
+// via SetParentContext so startup-time cancellation unblocks it.
+func TrustInterface(iface string) error {
+	parent := getParentContext()
+	if !isRunning(parent) {
+		return nil
+	}
+	if err := addTrusted(parent, iface); err != nil {
+		return fmt.Errorf("add %s to firewalld trusted zone: %w", iface, err)
+	}
+	trustLogOnce.Do(func() {
+		log.Infof("added %s to firewalld trusted zone", iface)
+	})
+	log.Debugf("firewalld: ensured %s is in trusted zone", iface)
+	return nil
+}
+
+// UntrustInterface removes iface from firewalld's trusted zone if firewalld
+// is running. Idempotent. Uses a Background-rooted timeout so it still runs
+// during shutdown after the engine context has been cancelled.
+func UntrustInterface(iface string) error {
+	if !isRunning(context.Background()) {
+		return nil
+	}
+	if err := removeTrusted(context.Background(), iface); err != nil {
+		return fmt.Errorf("remove %s from firewalld trusted zone: %w", iface, err)
+	}
+	return nil
+}
+
+func newCallContext(parent context.Context) (context.Context, context.CancelFunc) {
+	return context.WithTimeout(parent, callTimeout)
+}
+
+func isRunning(parent context.Context) bool {
+	ctx, cancel := newCallContext(parent)
+	ok, err := isRunningDBus(ctx)
+	cancel()
+	if err == nil {
+		return ok
+	}
+	if errors.Is(err, errDBusUnavailable) || errors.Is(err, context.DeadlineExceeded) {
+		ctx, cancel = newCallContext(parent)
+		defer cancel()
+		return isRunningCLI(ctx)
+	}
+	return false
+}
+
+func addTrusted(parent context.Context, iface string) error {
+	ctx, cancel := newCallContext(parent)
+	err := addDBus(ctx, iface)
+	cancel()
+	if err == nil {
+		return nil
+	}
+	if !errors.Is(err, errDBusUnavailable) {
+		log.Debugf("firewalld: dbus add failed, falling back to firewall-cmd: %v", err)
+	}
+	ctx, cancel = newCallContext(parent)
+	defer cancel()
+	return addCLI(ctx, iface)
+}
+
+func removeTrusted(parent context.Context, iface string) error {
+	ctx, cancel := newCallContext(parent)
+	err := removeDBus(ctx, iface)
+	cancel()
+	if err == nil {
+		return nil
+	}
+	if !errors.Is(err, errDBusUnavailable) {
+		log.Debugf("firewalld: dbus remove failed, falling back to firewall-cmd: %v", err)
+	}
+	ctx, cancel = newCallContext(parent)
+	defer cancel()
+	return removeCLI(ctx, iface)
+}
+
+func isRunningDBus(ctx context.Context) (bool, error) {
+	conn, err := dbus.SystemBus()
+	if err != nil {
+		return false, fmt.Errorf("%w: %v", errDBusUnavailable, err)
+	}
+	obj := conn.Object(dbusDest, dbusPath)
+
+	var zone string
+	if err := obj.CallWithContext(ctx, dbusRootIface+".getDefaultZone", 0).Store(&zone); err != nil {
+		return false, fmt.Errorf("firewalld getDefaultZone: %w", err)
+	}
+	return true, nil
+}
+
+func isRunningCLI(ctx context.Context) bool {
+	if _, err := exec.LookPath("firewall-cmd"); err != nil {
+		return false
+	}
+	return exec.CommandContext(ctx, "firewall-cmd", "--state").Run() == nil
+}
+
+func addDBus(ctx context.Context, iface string) error {
+	conn, err := dbus.SystemBus()
+	if err != nil {
+		return fmt.Errorf("%w: %v", errDBusUnavailable, err)
+	}
+	obj := conn.Object(dbusDest, dbusPath)
+
+	call := obj.CallWithContext(ctx, dbusZoneIface+".addInterface", 0, TrustedZone, iface)
+	if call.Err == nil {
+		return nil
+	}
+
+	if dbusErrContains(call.Err, errAlreadyEnabled) {
+		return nil
+	}
+
+	if dbusErrContains(call.Err, errZoneAlreadySet) {
+		move := obj.CallWithContext(ctx, dbusZoneIface+".changeZoneOfInterface", 0, TrustedZone, iface)
+		if move.Err != nil {
+			return fmt.Errorf("firewalld changeZoneOfInterface: %w", move.Err)
+		}
+		return nil
+	}
+
+	return fmt.Errorf("firewalld addInterface: %w", call.Err)
+}
+
+func removeDBus(ctx context.Context, iface string) error {
+	conn, err := dbus.SystemBus()
+	if err != nil {
+		return fmt.Errorf("%w: %v", errDBusUnavailable, err)
+	}
+	obj := conn.Object(dbusDest, dbusPath)
+
+	call := obj.CallWithContext(ctx, dbusZoneIface+".removeInterface", 0, TrustedZone, iface)
+	if call.Err == nil {
+		return nil
+	}
+
+	if dbusErrContains(call.Err, errUnknownIface) || dbusErrContains(call.Err, errNotEnabled) {
+		return nil
+	}
+
+	return fmt.Errorf("firewalld removeInterface: %w", call.Err)
+}
+
+func addCLI(ctx context.Context, iface string) error {
+	if _, err := exec.LookPath("firewall-cmd"); err != nil {
+		return fmt.Errorf("firewall-cmd not available: %w", err)
+	}
+
+	// --change-interface (no --permanent) binds the interface for the
+	// current runtime only; we do not want membership to persist across
+	// reboots because netbird re-asserts it on every startup.
+	out, err := exec.CommandContext(ctx,
+		"firewall-cmd", "--zone="+TrustedZone, "--change-interface="+iface,
+	).CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("firewall-cmd change-interface: %w: %s", err, strings.TrimSpace(string(out)))
+	}
+	return nil
+}
+
+func removeCLI(ctx context.Context, iface string) error {
+	if _, err := exec.LookPath("firewall-cmd"); err != nil {
+		return fmt.Errorf("firewall-cmd not available: %w", err)
+	}
+
+	out, err := exec.CommandContext(ctx,
+		"firewall-cmd", "--zone="+TrustedZone, "--remove-interface="+iface,
+	).CombinedOutput()
+	if err != nil {
+		msg := strings.TrimSpace(string(out))
+		if strings.Contains(msg, errUnknownIface) || strings.Contains(msg, errNotEnabled) {
+			return nil
+		}
+		return fmt.Errorf("firewall-cmd remove-interface: %w: %s", err, msg)
+	}
+	return nil
+}
+
+func dbusErrContains(err error, code string) bool {
+	if err == nil {
+		return false
+	}
+	var de dbus.Error
+	if errors.As(err, &de) {
+		for _, b := range de.Body {
+			if s, ok := b.(string); ok && strings.Contains(s, code) {
+				return true
+			}
+		}
+	}
+	return strings.Contains(err.Error(), code)
+}

client/firewall/firewalld/firewalld_linux_test.go

@@ -0,0 +1,49 @@
+//go:build linux
+
+package firewalld
+
+import (
+	"errors"
+	"testing"
+
+	"github.com/godbus/dbus/v5"
+)
+
+func TestDBusErrContains(t *testing.T) {
+	tests := []struct {
+		name string
+		err  error
+		code string
+		want bool
+	}{
+		{"nil error", nil, errZoneAlreadySet, false},
+		{"plain error match", errors.New("ZONE_ALREADY_SET: wt0"), errZoneAlreadySet, true},
+		{"plain error miss", errors.New("something else"), errZoneAlreadySet, false},
+		{
+			"dbus.Error body match",
+			dbus.Error{Name: "org.fedoraproject.FirewallD1.Exception", Body: []any{"ZONE_ALREADY_SET: wt0"}},
+			errZoneAlreadySet,
+			true,
+		},
+		{
+			"dbus.Error body miss",
+			dbus.Error{Name: "org.fedoraproject.FirewallD1.Exception", Body: []any{"INVALID_INTERFACE"}},
+			errAlreadyEnabled,
+			false,
+		},
+		{
+			"dbus.Error non-string body falls back to Error()",
+			dbus.Error{Name: "x", Body: []any{123}},
+			"x",
+			true,
+		},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			got := dbusErrContains(tc.err, tc.code)
+			if got != tc.want {
+				t.Fatalf("dbusErrContains(%v, %q) = %v; want %v", tc.err, tc.code, got, tc.want)
+			}
+		})
+	}
+}

client/firewall/firewalld/firewalld_other.go

@@ -0,0 +1,25 @@
+//go:build !linux
+
+package firewalld
+
+import "context"
+
+// SetParentContext is a no-op on non-Linux platforms because firewalld only
+// runs on Linux.
+func SetParentContext(context.Context) {
+	// intentionally empty: firewalld is a Linux-only daemon
+}
+
+// TrustInterface is a no-op on non-Linux platforms because firewalld only
+// runs on Linux.
+func TrustInterface(string) error {
+	// intentionally empty: firewalld is a Linux-only daemon
+	return nil
+}
+
+// UntrustInterface is a no-op on non-Linux platforms because firewalld only
+// runs on Linux.
+func UntrustInterface(string) error {
+	// intentionally empty: firewalld is a Linux-only daemon
+	return nil
+}

client/firewall/iptables/manager_linux.go

@@ -12,6 +12,7 @@ import (
 	log "github.com/sirupsen/logrus"
 
 	nberrors "github.com/netbirdio/netbird/client/errors"
+	"github.com/netbirdio/netbird/client/firewall/firewalld"
 	firewall "github.com/netbirdio/netbird/client/firewall/manager"
 	"github.com/netbirdio/netbird/client/iface/wgaddr"
 	"github.com/netbirdio/netbird/client/internal/statemanager"
@@ -86,6 +87,12 @@ func (m *Manager) Init(stateManager *statemanager.Manager) error {
 		log.Warnf("raw table not available, notrack rules will be disabled: %v", err)
 	}
 
+	// Trust after all fatal init steps so a later failure doesn't leave the
+	// interface in firewalld's trusted zone without a corresponding Close.
+	if err := firewalld.TrustInterface(m.wgIface.Name()); err != nil {
+		log.Warnf("failed to trust interface in firewalld: %v", err)
+	}
+
 	// persist early to ensure cleanup of chains
 	go func() {
 		if err := stateManager.PersistState(context.Background()); err != nil {
@@ -191,6 +198,12 @@ func (m *Manager) Close(stateManager *statemanager.Manager) error {
 		merr = multierror.Append(merr, fmt.Errorf("reset router: %w", err))
 	}
 
+	// Appending to merr intentionally blocks DeleteState below so ShutdownState
+	// stays persisted and the crash-recovery path retries firewalld cleanup.
+	if err := firewalld.UntrustInterface(m.wgIface.Name()); err != nil {
+		merr = multierror.Append(merr, err)
+	}
+
 	// attempt to delete state only if all other operations succeeded
 	if merr == nil {
 		if err := stateManager.DeleteState(&ShutdownState{}); err != nil {
@@ -217,6 +230,11 @@ func (m *Manager) AllowNetbird() error {
 	if err != nil {
 		return fmt.Errorf("allow netbird interface traffic: %w", err)
 	}
+
+	if err := firewalld.TrustInterface(m.wgIface.Name()); err != nil {
+		log.Warnf("failed to trust interface in firewalld: %v", err)
+	}
+
 	return nil
 }
 

client/firewall/nftables/manager_linux.go

@@ -14,6 +14,7 @@ import (
 	log "github.com/sirupsen/logrus"
 	"golang.org/x/sys/unix"
 
+	"github.com/netbirdio/netbird/client/firewall/firewalld"
 	firewall "github.com/netbirdio/netbird/client/firewall/manager"
 	"github.com/netbirdio/netbird/client/iface/wgaddr"
 	"github.com/netbirdio/netbird/client/internal/statemanager"
@@ -217,6 +218,10 @@ func (m *Manager) AllowNetbird() error {
 		return fmt.Errorf("flush allow input netbird rules: %w", err)
 	}
 
+	if err := firewalld.TrustInterface(m.wgIface.Name()); err != nil {
+		log.Warnf("failed to trust interface in firewalld: %v", err)
+	}
+
 	return nil
 }
 

client/firewall/nftables/router_linux.go

@@ -19,6 +19,7 @@ import (
 	"golang.org/x/sys/unix"
 
 	nberrors "github.com/netbirdio/netbird/client/errors"
+	"github.com/netbirdio/netbird/client/firewall/firewalld"
 	firewall "github.com/netbirdio/netbird/client/firewall/manager"
 	nbid "github.com/netbirdio/netbird/client/internal/acl/id"
 	"github.com/netbirdio/netbird/client/internal/routemanager/ipfwdstate"
@@ -40,6 +41,8 @@ const (
 	chainNameForward       = "FORWARD"
 	chainNameMangleForward = "netbird-mangle-forward"
 
+	firewalldTableName = "firewalld"
+
 	userDataAcceptForwardRuleIif = "frwacceptiif"
 	userDataAcceptForwardRuleOif = "frwacceptoif"
 	userDataAcceptInputRule      = "inputaccept"
@@ -133,6 +136,10 @@ func (r *router) Reset() error {
 		merr = multierror.Append(merr, fmt.Errorf("remove accept filter rules: %w", err))
 	}
 
+	if err := firewalld.UntrustInterface(r.wgIface.Name()); err != nil {
+		merr = multierror.Append(merr, err)
+	}
+
 	if err := r.removeNatPreroutingRules(); err != nil {
 		merr = multierror.Append(merr, fmt.Errorf("remove filter prerouting rules: %w", err))
 	}
@@ -280,6 +287,10 @@ func (r *router) createContainers() error {
 		log.Errorf("failed to add accept rules for the forward chain: %s", err)
 	}
 
+	if err := firewalld.TrustInterface(r.wgIface.Name()); err != nil {
+		log.Warnf("failed to trust interface in firewalld: %v", err)
+	}
+
 	if err := r.refreshRulesMap(); err != nil {
 		log.Errorf("failed to refresh rules: %s", err)
 	}
@@ -1319,6 +1330,13 @@ func (r *router) isExternalChain(chain *nftables.Chain) bool {
 		return false
 	}
 
+	// Skip firewalld-owned chains. Firewalld creates its chains with the
+	// NFT_CHAIN_OWNER flag, so inserting rules into them returns EPERM.
+	// We delegate acceptance to firewalld by trusting the interface instead.
+	if chain.Table.Name == firewalldTableName {
+		return false
+	}
+
 	// Skip all iptables-managed tables in the ip family
 	if chain.Table.Family == nftables.TableFamilyIPv4 && isIptablesTable(chain.Table.Name) {
 		return false

client/firewall/uspfilter/allow_netbird.go

@@ -3,6 +3,9 @@
 package uspfilter
 
 import (
+	log "github.com/sirupsen/logrus"
+
+	"github.com/netbirdio/netbird/client/firewall/firewalld"
 	"github.com/netbirdio/netbird/client/internal/statemanager"
 )
 
@@ -16,6 +19,9 @@ func (m *Manager) Close(stateManager *statemanager.Manager) error {
 	if m.nativeFirewall != nil {
 		return m.nativeFirewall.Close(stateManager)
 	}
+	if err := firewalld.UntrustInterface(m.wgIface.Name()); err != nil {
+		log.Warnf("failed to untrust interface in firewalld: %v", err)
+	}
 	return nil
 }
 
@@ -24,5 +30,8 @@ func (m *Manager) AllowNetbird() error {
 	if m.nativeFirewall != nil {
 		return m.nativeFirewall.AllowNetbird()
 	}
+	if err := firewalld.TrustInterface(m.wgIface.Name()); err != nil {
+		log.Warnf("failed to trust interface in firewalld: %v", err)
+	}
 	return nil
 }

client/firewall/uspfilter/common/iface.go

@@ -9,6 +9,7 @@ import (
 
 // IFaceMapper defines subset methods of interface required for manager
 type IFaceMapper interface {
+	Name() string
 	SetFilter(device.PacketFilter) error
 	Address() wgaddr.Address
 	GetWGDevice() *wgdevice.Device

client/firewall/uspfilter/filter.go

@@ -115,12 +115,13 @@ type Manager struct {
 
 	localipmanager *localIPManager
 
-	udpTracker  *conntrack.UDPTracker
+	udpTracker     *conntrack.UDPTracker
-	icmpTracker *conntrack.ICMPTracker
+	icmpTracker    *conntrack.ICMPTracker
-	tcpTracker  *conntrack.TCPTracker
+	tcpTracker     *conntrack.TCPTracker
-	forwarder   atomic.Pointer[forwarder.Forwarder]
+	forwarder      atomic.Pointer[forwarder.Forwarder]
-	logger      *nblog.Logger
+	pendingCapture atomic.Pointer[forwarder.PacketCapture]
-	flowLogger  nftypes.FlowLogger
+	logger         *nblog.Logger
+	flowLogger     nftypes.FlowLogger
 
 	blockRule firewall.Rule
 
@@ -351,6 +352,19 @@ func (m *Manager) determineRouting() error {
 	return nil
 }
 
+// SetPacketCapture sets or clears packet capture on the forwarder endpoint.
+// This captures outbound response packets that bypass the FilteredDevice in netstack mode.
+func (m *Manager) SetPacketCapture(pc forwarder.PacketCapture) {
+	if pc == nil {
+		m.pendingCapture.Store(nil)
+	} else {
+		m.pendingCapture.Store(&pc)
+	}
+	if fwder := m.forwarder.Load(); fwder != nil {
+		fwder.SetCapture(pc)
+	}
+}
+
 // initForwarder initializes the forwarder, it disables routing on errors
 func (m *Manager) initForwarder() error {
 	if m.forwarder.Load() != nil {
@@ -372,6 +386,11 @@ func (m *Manager) initForwarder() error {
 
 	m.forwarder.Store(forwarder)
 
+	// Re-load after store: a concurrent SetPacketCapture may have seen forwarder as nil and only updated pendingCapture.
+	if pc := m.pendingCapture.Load(); pc != nil {
+		forwarder.SetCapture(*pc)
+	}
+
 	log.Debug("forwarder initialized")
 
 	return nil
@@ -614,6 +633,7 @@ func (m *Manager) resetState() {
 	}
 
 	if fwder := m.forwarder.Load(); fwder != nil {
+		fwder.SetCapture(nil)
 		fwder.Stop()
 	}
 

client/firewall/uspfilter/filter_test.go

@@ -31,12 +31,20 @@ var logger = log.NewFromLogrus(logrus.StandardLogger())
 var flowLogger = netflow.NewManager(nil, []byte{}, nil).GetLogger()
 
 type IFaceMock struct {
+	NameFunc        func() string
 	SetFilterFunc   func(device.PacketFilter) error
 	AddressFunc     func() wgaddr.Address
 	GetWGDeviceFunc func() *wgdevice.Device
 	GetDeviceFunc   func() *device.FilteredDevice
 }
 
+func (i *IFaceMock) Name() string {
+	if i.NameFunc == nil {
+		return "wgtest"
+	}
+	return i.NameFunc()
+}
+
 func (i *IFaceMock) GetWGDevice() *wgdevice.Device {
 	if i.GetWGDeviceFunc == nil {
 		return nil

client/firewall/uspfilter/forwarder/endpoint.go

@@ -12,12 +12,19 @@ import (
 	nblog "github.com/netbirdio/netbird/client/firewall/uspfilter/log"
 )
 
+// PacketCapture captures raw packets for debugging. Implementations must be
+// safe for concurrent use and must not block.
+type PacketCapture interface {
+	Offer(data []byte, outbound bool)
+}
+
 // endpoint implements stack.LinkEndpoint and handles integration with the wireguard device
 type endpoint struct {
 	logger     *nblog.Logger
 	dispatcher stack.NetworkDispatcher
 	device     *wgdevice.Device
 	mtu        atomic.Uint32
+	capture    atomic.Pointer[PacketCapture]
 }
 
 func (e *endpoint) Attach(dispatcher stack.NetworkDispatcher) {
@@ -54,13 +61,17 @@ func (e *endpoint) WritePackets(pkts stack.PacketBufferList) (int, tcpip.Error)
 			continue
 		}
 
-		// Send the packet through WireGuard
+		pktBytes := data.AsSlice()
+
 		address := netHeader.DestinationAddress()
-		err := e.device.CreateOutboundPacket(data.AsSlice(), address.AsSlice())
+		if err := e.device.CreateOutboundPacket(pktBytes, address.AsSlice()); err != nil {
-		if err != nil {
 			e.logger.Error1("CreateOutboundPacket: %v", err)
 			continue
 		}
+
+		if pc := e.capture.Load(); pc != nil {
+			(*pc).Offer(pktBytes, true)
+		}
 		written++
 	}
 

client/firewall/uspfilter/forwarder/forwarder.go

@@ -139,6 +139,16 @@ func New(iface common.IFaceMapper, logger *nblog.Logger, flowLogger nftypes.Flow
 	return f, nil
 }
 
+// SetCapture sets or clears the packet capture on the forwarder endpoint.
+// This captures outbound packets that bypass the FilteredDevice (netstack forwarding).
+func (f *Forwarder) SetCapture(pc PacketCapture) {
+	if pc == nil {
+		f.endpoint.capture.Store(nil)
+		return
+	}
+	f.endpoint.capture.Store(&pc)
+}
+
 func (f *Forwarder) InjectIncomingPacket(payload []byte) error {
 	if len(payload) < header.IPv4MinimumSize {
 		return fmt.Errorf("packet too small: %d bytes", len(payload))

client/firewall/uspfilter/forwarder/icmp.go

@@ -270,5 +270,9 @@ func (f *Forwarder) injectICMPReply(id stack.TransportEndpointID, icmpPayload []
 		return 0
 	}
 
+	if pc := f.endpoint.capture.Load(); pc != nil {
+		(*pc).Offer(fullPacket, true)
+	}
+
 	return len(fullPacket)
 }

client/iface/bind/ice_bind_test.go

@@ -239,8 +239,12 @@ func TestICEBind_HandlesConcurrentMixedTraffic(t *testing.T) {
 		ipv6Count++
 	}
 
-	assert.Equal(t, packetsPerFamily, ipv4Count)
+	// Allow some UDP packet loss under load (e.g. FreeBSD/QEMU runners). The
-	assert.Equal(t, packetsPerFamily, ipv6Count)
+	// routing-correctness checks above are the real assertions; the counts
+	// are a sanity bound to catch a totally silent path.
+	minDelivered := packetsPerFamily * 80 / 100
+	assert.GreaterOrEqual(t, ipv4Count, minDelivered, "IPv4 delivery below threshold")
+	assert.GreaterOrEqual(t, ipv6Count, minDelivered, "IPv6 delivery below threshold")
 }
 
 func TestICEBind_DetectsAddressFamilyFromConnection(t *testing.T) {

client/iface/device/device_filter.go

@@ -3,6 +3,7 @@ package device
 import (
 	"net/netip"
 	"sync"
+	"sync/atomic"
 
 	"golang.zx2c4.com/wireguard/tun"
 )
@@ -28,11 +29,20 @@ type PacketFilter interface {
 	SetTCPPacketHook(ip netip.Addr, dPort uint16, hook func(packet []byte) bool)
 }
 
+// PacketCapture captures raw packets for debugging. Implementations must be
+// safe for concurrent use and must not block.
+type PacketCapture interface {
+	// Offer submits a packet for capture. outbound is true for packets
+	// leaving the host (Read path), false for packets arriving (Write path).
+	Offer(data []byte, outbound bool)
+}
+
 // FilteredDevice to override Read or Write of packets
 type FilteredDevice struct {
 	tun.Device
 
 	filter    PacketFilter
+	capture   atomic.Pointer[PacketCapture]
 	mutex     sync.RWMutex
 	closeOnce sync.Once
 }
@@ -63,20 +73,25 @@ func (d *FilteredDevice) Read(bufs [][]byte, sizes []int, offset int) (n int, er
 	if n, err = d.Device.Read(bufs, sizes, offset); err != nil {
 		return 0, err
 	}
+
 	d.mutex.RLock()
 	filter := d.filter
 	d.mutex.RUnlock()
 
-	if filter == nil {
+	if filter != nil {
-		return
+		for i := 0; i < n; i++ {
+			if filter.FilterOutbound(bufs[i][offset:offset+sizes[i]], sizes[i]) {
+				bufs = append(bufs[:i], bufs[i+1:]...)
+				sizes = append(sizes[:i], sizes[i+1:]...)
+				n--
+				i--
+			}
+		}
 	}
 
-	for i := 0; i < n; i++ {
+	if pc := d.capture.Load(); pc != nil {
-		if filter.FilterOutbound(bufs[i][offset:offset+sizes[i]], sizes[i]) {
+		for i := 0; i < n; i++ {
-			bufs = append(bufs[:i], bufs[i+1:]...)
+			(*pc).Offer(bufs[i][offset:offset+sizes[i]], true)
-			sizes = append(sizes[:i], sizes[i+1:]...)
-			n--
-			i--
 		}
 	}
 
@@ -85,6 +100,13 @@ func (d *FilteredDevice) Read(bufs [][]byte, sizes []int, offset int) (n int, er
 
 // Write wraps write method with filtering feature
 func (d *FilteredDevice) Write(bufs [][]byte, offset int) (int, error) {
+	// Capture before filtering so dropped packets are still visible in captures.
+	if pc := d.capture.Load(); pc != nil {
+		for _, buf := range bufs {
+			(*pc).Offer(buf[offset:], false)
+		}
+	}
+
 	d.mutex.RLock()
 	filter := d.filter
 	d.mutex.RUnlock()
@@ -96,9 +118,10 @@ func (d *FilteredDevice) Write(bufs [][]byte, offset int) (int, error) {
 	filteredBufs := make([][]byte, 0, len(bufs))
 	dropped := 0
 	for _, buf := range bufs {
-		if !filter.FilterInbound(buf[offset:], len(buf)) {
+		if filter.FilterInbound(buf[offset:], len(buf)) {
-			filteredBufs = append(filteredBufs, buf)
 			dropped++
+		} else {
+			filteredBufs = append(filteredBufs, buf)
 		}
 	}
 
@@ -113,3 +136,14 @@ func (d *FilteredDevice) SetFilter(filter PacketFilter) {
 	d.filter = filter
 	d.mutex.Unlock()
 }
+
+// SetCapture sets or clears the packet capture sink. Pass nil to disable.
+// Uses atomic store so the hot path (Read/Write) is a single pointer load
+// with no locking overhead when capture is off.
+func (d *FilteredDevice) SetCapture(pc PacketCapture) {
+	if pc == nil {
+		d.capture.Store(nil)
+		return
+	}
+	d.capture.Store(&pc)
+}

client/iface/device/device_filter_test.go

@@ -158,7 +158,7 @@ func TestDeviceWrapperRead(t *testing.T) {
 			t.Errorf("unexpected error: %v", err)
 			return
 		}
-		if n != 0 {
+		if n != 1 {
 			t.Errorf("expected n=1, got %d", n)
 			return
 		}

client/iface/iface.go

@@ -217,7 +217,6 @@ func (w *WGIface) RemoveAllowedIP(peerKey string, allowedIP netip.Prefix) error
 // Close closes the tunnel interface
 func (w *WGIface) Close() error {
 	w.mu.Lock()
-	defer w.mu.Unlock()
 
 	var result *multierror.Error
 
@@ -225,7 +224,15 @@ func (w *WGIface) Close() error {
 		result = multierror.Append(result, fmt.Errorf("failed to free WireGuard proxy: %w", err))
 	}
 
-	if err := w.tun.Close(); err != nil {
+	// Release w.mu before calling w.tun.Close(): the underlying
+	// wireguard-go device.Close() waits for its send/receive goroutines
+	// to drain. Some of those goroutines re-enter WGIface methods that
+	// take w.mu (e.g. the packet filter DNS hook calls GetDevice()), so
+	// holding the mutex here would deadlock the shutdown path.
+	tun := w.tun
+	w.mu.Unlock()
+
+	if err := tun.Close(); err != nil {
 		result = multierror.Append(result, fmt.Errorf("failed to close wireguard interface %s: %w", w.Name(), err))
 	}
 

client/iface/iface_close_test.go

@@ -0,0 +1,113 @@
+//go:build !android
+
+package iface
+
+import (
+	"errors"
+	"sync"
+	"testing"
+	"time"
+
+	wgdevice "golang.zx2c4.com/wireguard/device"
+	"golang.zx2c4.com/wireguard/tun/netstack"
+
+	"github.com/netbirdio/netbird/client/iface/device"
+	"github.com/netbirdio/netbird/client/iface/udpmux"
+	"github.com/netbirdio/netbird/client/iface/wgaddr"
+	"github.com/netbirdio/netbird/client/iface/wgproxy"
+)
+
+// fakeTunDevice implements WGTunDevice and lets the test control when
+// Close() returns. It mimics the wireguard-go shutdown path, which blocks
+// until its goroutines drain. Some of those goroutines (e.g. the packet
+// filter DNS hook in client/internal/dns) call back into WGIface, so if
+// WGIface.Close() held w.mu across tun.Close() the shutdown would
+// deadlock.
+type fakeTunDevice struct {
+	closeStarted chan struct{}
+	unblockClose chan struct{}
+}
+
+func (f *fakeTunDevice) Create() (device.WGConfigurer, error) {
+	return nil, errors.New("not implemented")
+}
+func (f *fakeTunDevice) Up() (*udpmux.UniversalUDPMuxDefault, error) {
+	return nil, errors.New("not implemented")
+}
+func (f *fakeTunDevice) UpdateAddr(wgaddr.Address) error      { return nil }
+func (f *fakeTunDevice) WgAddress() wgaddr.Address            { return wgaddr.Address{} }
+func (f *fakeTunDevice) MTU() uint16                          { return DefaultMTU }
+func (f *fakeTunDevice) DeviceName() string                   { return "nb-close-test" }
+func (f *fakeTunDevice) FilteredDevice() *device.FilteredDevice { return nil }
+func (f *fakeTunDevice) Device() *wgdevice.Device             { return nil }
+func (f *fakeTunDevice) GetNet() *netstack.Net                { return nil }
+func (f *fakeTunDevice) GetICEBind() device.EndpointManager   { return nil }
+
+func (f *fakeTunDevice) Close() error {
+	close(f.closeStarted)
+	<-f.unblockClose
+	return nil
+}
+
+type fakeProxyFactory struct{}
+
+func (fakeProxyFactory) GetProxy() wgproxy.Proxy { return nil }
+func (fakeProxyFactory) GetProxyPort() uint16    { return 0 }
+func (fakeProxyFactory) Free() error             { return nil }
+
+// TestWGIface_CloseReleasesMutexBeforeTunClose guards against a deadlock
+// that surfaces as a macOS test-timeout in
+// TestDNSPermanent_updateUpstream: WGIface.Close() used to hold w.mu
+// while waiting for the wireguard-go device goroutines to finish, and
+// one of those goroutines (the DNS filter hook) calls back into
+// WGIface.GetDevice() which needs the same mutex. The fix is to drop
+// the lock before tun.Close() returns control.
+func TestWGIface_CloseReleasesMutexBeforeTunClose(t *testing.T) {
+	tun := &fakeTunDevice{
+		closeStarted: make(chan struct{}),
+		unblockClose: make(chan struct{}),
+	}
+	w := &WGIface{
+		tun:            tun,
+		wgProxyFactory: fakeProxyFactory{},
+	}
+
+	closeDone := make(chan error, 1)
+	go func() {
+		closeDone <- w.Close()
+	}()
+
+	select {
+	case <-tun.closeStarted:
+	case <-time.After(2 * time.Second):
+		close(tun.unblockClose)
+		t.Fatal("tun.Close() was never invoked")
+	}
+
+	// Simulate the WireGuard read goroutine calling back into WGIface
+	// via the packet filter's DNS hook. If Close() still held w.mu
+	// during tun.Close(), this would block until the test timeout.
+	getDeviceDone := make(chan struct{})
+	var wg sync.WaitGroup
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		_ = w.GetDevice()
+		close(getDeviceDone)
+	}()
+
+	select {
+	case <-getDeviceDone:
+	case <-time.After(2 * time.Second):
+		close(tun.unblockClose)
+		wg.Wait()
+		t.Fatal("GetDevice() deadlocked while WGIface.Close was closing the tun")
+	}
+
+	close(tun.unblockClose)
+	select {
+	case <-closeDone:
+	case <-time.After(2 * time.Second):
+		t.Fatal("WGIface.Close() never returned after the tun was unblocked")
+	}
+}

client/iface/udpmux/universal.go

@@ -171,7 +171,7 @@ func (u *UDPConn) performFilterCheck(addr net.Addr) error {
 	}
 
 	if u.address.Network.Contains(a) {
-		log.Warnf("Address %s is part of the NetBird network %s, refusing to write", addr, u.address)
+		log.Warnf("address %s is part of the NetBird network %s, refusing to write", addr, u.address)
 		return fmt.Errorf("address %s is part of the NetBird network %s, refusing to write", addr, u.address)
 	}
 
@@ -181,7 +181,7 @@ func (u *UDPConn) performFilterCheck(addr net.Addr) error {
 		u.addrCache.Store(addr.String(), isRouted)
 		if isRouted {
 			// Extra log, as the error only shows up with ICE logging enabled
-			log.Infof("Address %s is part of routed network %s, refusing to write", addr, prefix)
+			log.Infof("address %s is part of routed network %s, refusing to write", addr, prefix)
 			return fmt.Errorf("address %s is part of routed network %s, refusing to write", addr, prefix)
 		}
 	}

client/installer.nsis

@@ -201,7 +201,18 @@ Pop $0
 
 Function .onInit
 StrCpy $INSTDIR "${INSTALL_DIR}"
+; Default autostart to enabled so silent installs (/S) match the interactive default
+StrCpy $AutostartEnabled "1"
+
+; Pre-0.70.1 installers ran without SetRegView, so their uninstall keys live
+; in the 32-bit view. Fall back to it so upgrades still find them.
+SetRegView 64
 ReadRegStr $R0 HKLM "Software\Microsoft\Windows\CurrentVersion\Uninstall\$(^NAME)" "UninstallString"
+${If} $R0 == ""
+    SetRegView 32
+    ReadRegStr $R0 HKLM "Software\Microsoft\Windows\CurrentVersion\Uninstall\$(^NAME)" "UninstallString"
+    SetRegView 64
+${EndIf}
 ${If} $R0 != ""
     # if silent install jump to uninstall step
     IfSilent uninstall
@@ -214,6 +225,10 @@ ${If} $R0 != ""
 
 ${EndIf}
 FunctionEnd
+
+Function un.onInit
+SetRegView 64
+FunctionEnd
 ######################################################################
 Section -MainProgram
     ${INSTALL_TYPE}
@@ -228,6 +243,7 @@ Section -MainProgram
     !else
         File /r "..\\dist\\netbird_windows_amd64\\"
     !endif
+    File "..\\client\\ui\\assets\\netbird.png"
 SectionEnd
 ######################################################################
 
@@ -247,9 +263,11 @@ WriteRegStr ${REG_ROOT} "${UI_REG_APP_PATH}" "" "$INSTDIR\${UI_APP_EXE}"
 ; Create autostart registry entry based on checkbox
 DetailPrint "Autostart enabled: $AutostartEnabled"
 ${If} $AutostartEnabled == "1"
-    WriteRegStr HKCU "${AUTOSTART_REG_KEY}" "${APP_NAME}" "$INSTDIR\${UI_APP_EXE}.exe"
+    WriteRegStr HKLM "${AUTOSTART_REG_KEY}" "${APP_NAME}" '"$INSTDIR\${UI_APP_EXE}.exe"'
     DetailPrint "Added autostart registry entry: $INSTDIR\${UI_APP_EXE}.exe"
 ${Else}
+    DeleteRegValue HKLM "${AUTOSTART_REG_KEY}" "${APP_NAME}"
+    ; Legacy: pre-HKLM installs wrote to HKCU; clean that up too.
     DeleteRegValue HKCU "${AUTOSTART_REG_KEY}" "${APP_NAME}"
     DetailPrint "Autostart not enabled by user"
 ${EndIf}
@@ -283,6 +301,8 @@ ExecWait `taskkill /im ${UI_APP_EXE}.exe /f`
 
 ; Remove autostart registry entry
 DetailPrint "Removing autostart registry entry if exists..."
+DeleteRegValue HKLM "${AUTOSTART_REG_KEY}" "${APP_NAME}"
+; Legacy: pre-HKLM installs wrote to HKCU; clean that up too.
 DeleteRegValue HKCU "${AUTOSTART_REG_KEY}" "${APP_NAME}"
 
 ; Handle data deletion based on checkbox
@@ -321,6 +341,7 @@ DetailPrint "Removing registry keys..."
 DeleteRegKey ${REG_ROOT} "${REG_APP_PATH}"
 DeleteRegKey ${REG_ROOT} "${UNINSTALL_PATH}"
 DeleteRegKey ${REG_ROOT} "${UI_REG_APP_PATH}"
+DeleteRegKey HKCU "Software\Classes\AppUserModelId\${APP_NAME}"
 
 DetailPrint "Removing application directory from PATH..."
 EnVar::SetHKLM

client/internal/connect.go

@@ -94,6 +94,7 @@ func (c *ConnectClient) RunOnAndroid(
 	dnsAddresses []netip.AddrPort,
 	dnsReadyListener dns.ReadyListener,
 	stateFilePath string,
+	cacheDir string,
 ) error {
 	// in case of non Android os these variables will be nil
 	mobileDependency := MobileDependency{
@@ -103,6 +104,7 @@ func (c *ConnectClient) RunOnAndroid(
 		HostDNSAddresses:      dnsAddresses,
 		DnsReadyListener:      dnsReadyListener,
 		StateFilePath:         stateFilePath,
+		TempDir:               cacheDir,
 	}
 	return c.run(mobileDependency, nil, "")
 }
@@ -331,6 +333,10 @@ func (c *ConnectClient) run(mobileDependency MobileDependency, runningChan chan
 		c.statusRecorder.MarkSignalConnected()
 
 		relayURLs, token := parseRelayInfo(loginResp)
+		if override, ok := peer.OverrideRelayURLs(); ok {
+			log.Infof("overriding relay URLs from %s: %v", peer.EnvKeyNBHomeRelayServers, override)
+			relayURLs = override
+		}
 		peerConfig := loginResp.GetPeerConfig()
 
 		engineConfig, err := createEngineConfig(myPrivateKey, c.config, peerConfig, logPath)
@@ -338,6 +344,7 @@ func (c *ConnectClient) run(mobileDependency MobileDependency, runningChan chan
 			log.Error(err)
 			return wrapErr(err)
 		}
+		engineConfig.TempDir = mobileDependency.TempDir
 
 		relayManager := relayClient.NewManager(engineCtx, relayURLs, myPrivateKey.PublicKey().String(), engineConfig.MTU)
 		c.statusRecorder.SetRelayMgr(relayManager)

client/internal/debug/debug.go

@@ -16,7 +16,6 @@ import (
 	"path/filepath"
 	"runtime"
 	"runtime/pprof"
-	"slices"
 	"sort"
 	"strings"
 	"time"
@@ -31,7 +30,6 @@ import (
 	"github.com/netbirdio/netbird/client/internal/updater/installer"
 	nbstatus "github.com/netbirdio/netbird/client/status"
 	mgmProto "github.com/netbirdio/netbird/shared/management/proto"
-	"github.com/netbirdio/netbird/util"
 )
 
 const readmeContent = `Netbird debug bundle
@@ -63,6 +61,7 @@ allocs.prof: Allocations profiling information.
 threadcreate.prof: Thread creation profiling information.
 cpu.prof: CPU profiling information.
 stack_trace.txt: Complete stack traces of all goroutines at the time of bundle creation.
+capture.pcap: Packet capture in pcap format. Only present when capture was running during bundle collection. Omitted from anonymized bundles because it contains raw decrypted packet data.
 
 
 Anonymization Process
@@ -234,7 +233,9 @@ type BundleGenerator struct {
 	statusRecorder *peer.Status
 	syncResponse   *mgmProto.SyncResponse
 	logPath        string
+	tempDir        string
 	cpuProfile     []byte
+	capturePath    string
 	refreshStatus  func() // Optional callback to refresh status before bundle generation
 	clientMetrics  MetricsExporter
 
@@ -256,8 +257,10 @@ type GeneratorDependencies struct {
 	StatusRecorder *peer.Status
 	SyncResponse   *mgmProto.SyncResponse
 	LogPath        string
+	TempDir        string // Directory for temporary bundle zip files. If empty, os.TempDir() is used.
 	CPUProfile     []byte
-	RefreshStatus  func() // Optional callback to refresh status before bundle generation
+	CapturePath    string
+	RefreshStatus  func()
 	ClientMetrics  MetricsExporter
 }
 
@@ -275,7 +278,9 @@ func NewBundleGenerator(deps GeneratorDependencies, cfg BundleConfig) *BundleGen
 		statusRecorder: deps.StatusRecorder,
 		syncResponse:   deps.SyncResponse,
 		logPath:        deps.LogPath,
+		tempDir:        deps.TempDir,
 		cpuProfile:     deps.CPUProfile,
+		capturePath:    deps.CapturePath,
 		refreshStatus:  deps.RefreshStatus,
 		clientMetrics:  deps.ClientMetrics,
 
@@ -287,7 +292,7 @@ func NewBundleGenerator(deps GeneratorDependencies, cfg BundleConfig) *BundleGen
 
 // Generate creates a debug bundle and returns the location.
 func (g *BundleGenerator) Generate() (resp string, err error) {
-	bundlePath, err := os.CreateTemp("", "netbird.debug.*.zip")
+	bundlePath, err := os.CreateTemp(g.tempDir, "netbird.debug.*.zip")
 	if err != nil {
 		return "", fmt.Errorf("create zip file: %w", err)
 	}
@@ -345,6 +350,10 @@ func (g *BundleGenerator) createArchive() error {
 		log.Errorf("failed to add CPU profile to debug bundle: %v", err)
 	}
 
+	if err := g.addCaptureFile(); err != nil {
+		log.Errorf("failed to add capture file to debug bundle: %v", err)
+	}
+
 	if err := g.addStackTrace(); err != nil {
 		log.Errorf("failed to add stack trace to debug bundle: %v", err)
 	}
@@ -373,15 +382,8 @@ func (g *BundleGenerator) createArchive() error {
 		log.Errorf("failed to add wg show output: %v", err)
 	}
 
-	if g.logPath != "" && !slices.Contains(util.SpecialLogs, g.logPath) {
+	if err := g.addPlatformLog(); err != nil {
-		if err := g.addLogfile(); err != nil {
+		log.Errorf("failed to add logs to debug bundle: %v", err)
-			log.Errorf("failed to add log file to debug bundle: %v", err)
-			if err := g.trySystemdLogFallback(); err != nil {
-				log.Errorf("failed to add systemd logs as fallback: %v", err)
-			}
-		}
-	} else if err := g.trySystemdLogFallback(); err != nil {
-		log.Errorf("failed to add systemd logs: %v", err)
 	}
 
 	if err := g.addUpdateLogs(); err != nil {
@@ -605,6 +607,12 @@ func (g *BundleGenerator) addCommonConfigFields(configContent *strings.Builder)
 	if g.internalConfig.EnableSSHRemotePortForwarding != nil {
 		configContent.WriteString(fmt.Sprintf("EnableSSHRemotePortForwarding: %v\n", *g.internalConfig.EnableSSHRemotePortForwarding))
 	}
+	if g.internalConfig.DisableSSHAuth != nil {
+		configContent.WriteString(fmt.Sprintf("DisableSSHAuth: %v\n", *g.internalConfig.DisableSSHAuth))
+	}
+	if g.internalConfig.SSHJWTCacheTTL != nil {
+		configContent.WriteString(fmt.Sprintf("SSHJWTCacheTTL: %d\n", *g.internalConfig.SSHJWTCacheTTL))
+	}
 
 	configContent.WriteString(fmt.Sprintf("DisableClientRoutes: %v\n", g.internalConfig.DisableClientRoutes))
 	configContent.WriteString(fmt.Sprintf("DisableServerRoutes: %v\n", g.internalConfig.DisableServerRoutes))
@@ -631,6 +639,7 @@ func (g *BundleGenerator) addCommonConfigFields(configContent *strings.Builder)
 	}
 
 	configContent.WriteString(fmt.Sprintf("LazyConnectionEnabled: %v\n", g.internalConfig.LazyConnectionEnabled))
+	configContent.WriteString(fmt.Sprintf("MTU: %d\n", g.internalConfig.MTU))
 }
 
 func (g *BundleGenerator) addProf() (err error) {
@@ -675,6 +684,29 @@ func (g *BundleGenerator) addCPUProfile() error {
 	return nil
 }
 
+func (g *BundleGenerator) addCaptureFile() error {
+	if g.capturePath == "" {
+		return nil
+	}
+
+	if g.anonymize {
+		log.Info("skipping capture file in anonymized bundle (contains raw packet data)")
+		return nil
+	}
+
+	f, err := os.Open(g.capturePath)
+	if err != nil {
+		return fmt.Errorf("open capture file: %w", err)
+	}
+	defer f.Close()
+
+	if err := g.addFileToZip(f, "capture.pcap"); err != nil {
+		return fmt.Errorf("add capture file to zip: %w", err)
+	}
+
+	return nil
+}
+
 func (g *BundleGenerator) addStackTrace() error {
 	buf := make([]byte, 5242880) // 5 MB buffer
 	n := runtime.Stack(buf, true)

client/internal/debug/debug_android.go

@@ -0,0 +1,41 @@
+//go:build android
+
+package debug
+
+import (
+	"fmt"
+	"io"
+	"os/exec"
+
+	log "github.com/sirupsen/logrus"
+)
+
+func (g *BundleGenerator) addPlatformLog() error {
+	cmd := exec.Command("/system/bin/logcat", "-d")
+	stdout, err := cmd.StdoutPipe()
+	if err != nil {
+		return fmt.Errorf("logcat stdout pipe: %w", err)
+	}
+
+	if err := cmd.Start(); err != nil {
+		return fmt.Errorf("start logcat: %w", err)
+	}
+
+	var logReader io.Reader = stdout
+	if g.anonymize {
+		var pw *io.PipeWriter
+		logReader, pw = io.Pipe()
+		go anonymizeLog(stdout, pw, g.anonymizer)
+	}
+
+	if err := g.addFileToZip(logReader, "logcat.txt"); err != nil {
+		return fmt.Errorf("add logcat to zip: %w", err)
+	}
+
+	if err := cmd.Wait(); err != nil {
+		return fmt.Errorf("wait logcat: %w", err)
+	}
+
+	log.Debug("added logcat output to debug bundle")
+	return nil
+}

client/internal/debug/debug_nonandroid.go

@@ -0,0 +1,25 @@
+//go:build !android
+
+package debug
+
+import (
+	"slices"
+
+	log "github.com/sirupsen/logrus"
+
+	"github.com/netbirdio/netbird/util"
+)
+
+func (g *BundleGenerator) addPlatformLog() error {
+	if g.logPath != "" && !slices.Contains(util.SpecialLogs, g.logPath) {
+		if err := g.addLogfile(); err != nil {
+			log.Errorf("failed to add log file to debug bundle: %v", err)
+			if err := g.trySystemdLogFallback(); err != nil {
+				return err
+			}
+		}
+	} else if err := g.trySystemdLogFallback(); err != nil {
+		return err
+	}
+	return nil
+}

client/internal/debug/debug_test.go

@@ -5,16 +5,21 @@ import (
 	"bytes"
 	"encoding/json"
 	"net"
+	"net/url"
 	"os"
 	"path/filepath"
+	"reflect"
 	"strings"
 	"testing"
+	"time"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
 	"github.com/netbirdio/netbird/client/anonymize"
 	"github.com/netbirdio/netbird/client/configs"
+	"github.com/netbirdio/netbird/client/internal/profilemanager"
+	"github.com/netbirdio/netbird/shared/management/domain"
 	mgmProto "github.com/netbirdio/netbird/shared/management/proto"
 )
 
@@ -471,8 +476,8 @@ func TestSanitizeServiceEnvVars(t *testing.T) {
 			anonymize: false,
 			input: map[string]any{
 				jsonKeyServiceEnv: map[string]any{
-					"HOME":       "/root",
+					"HOME":         "/root",
-					"PATH":       "/usr/bin",
+					"PATH":         "/usr/bin",
 					"NB_LOG_LEVEL": "debug",
 				},
 			},
@@ -489,9 +494,9 @@ func TestSanitizeServiceEnvVars(t *testing.T) {
 			anonymize: false,
 			input: map[string]any{
 				jsonKeyServiceEnv: map[string]any{
-					"NB_SETUP_KEY":  "abc123",
+					"NB_SETUP_KEY": "abc123",
-					"NB_API_TOKEN":  "tok_xyz",
+					"NB_API_TOKEN": "tok_xyz",
-					"NB_LOG_LEVEL":  "info",
+					"NB_LOG_LEVEL": "info",
 				},
 			},
 			check: func(t *testing.T, params map[string]any) {
@@ -766,3 +771,127 @@ Chain OUTPUT (policy ACCEPT 0 packets, 0 bytes)
 	assert.Contains(t, anonNftables, "chain input {")
 	assert.Contains(t, anonNftables, "type filter hook input priority filter; policy accept;")
 }
+
+// TestAddConfig_AllFieldsCovered uses reflection to ensure every field in
+// profilemanager.Config is either rendered in the debug bundle or explicitly
+// excluded. When a new field is added to Config, this test fails until the
+// developer either dumps it in addConfig/addCommonConfigFields or adds it to
+// the excluded set with a justification.
+func TestAddConfig_AllFieldsCovered(t *testing.T) {
+	excluded := map[string]string{
+		"PrivateKey":        "sensitive: WireGuard private key",
+		"PreSharedKey":      "sensitive: WireGuard pre-shared key",
+		"SSHKey":            "sensitive: SSH private key",
+		"ClientCertKeyPair": "non-config: parsed cert pair, not serialized",
+	}
+
+	mURL, _ := url.Parse("https://api.example.com:443")
+	aURL, _ := url.Parse("https://admin.example.com:443")
+	bTrue := true
+	iVal := 42
+	cfg := &profilemanager.Config{
+		PrivateKey:                    "priv",
+		PreSharedKey:                  "psk",
+		ManagementURL:                 mURL,
+		AdminURL:                      aURL,
+		WgIface:                       "wt0",
+		WgPort:                        51820,
+		NetworkMonitor:                &bTrue,
+		IFaceBlackList:                []string{"eth0"},
+		DisableIPv6Discovery:          true,
+		RosenpassEnabled:              true,
+		RosenpassPermissive:           true,
+		ServerSSHAllowed:              &bTrue,
+		EnableSSHRoot:                 &bTrue,
+		EnableSSHSFTP:                 &bTrue,
+		EnableSSHLocalPortForwarding:  &bTrue,
+		EnableSSHRemotePortForwarding: &bTrue,
+		DisableSSHAuth:                &bTrue,
+		SSHJWTCacheTTL:                &iVal,
+		DisableClientRoutes:           true,
+		DisableServerRoutes:           true,
+		DisableDNS:                    true,
+		DisableFirewall:               true,
+		BlockLANAccess:                true,
+		BlockInbound:                  true,
+		DisableNotifications:          &bTrue,
+		DNSLabels:                     domain.List{},
+		SSHKey:                        "sshkey",
+		NATExternalIPs:                []string{"1.2.3.4"},
+		CustomDNSAddress:              "1.1.1.1:53",
+		DisableAutoConnect:            true,
+		DNSRouteInterval:              5 * time.Second,
+		ClientCertPath:                "/tmp/cert",
+		ClientCertKeyPath:             "/tmp/key",
+		LazyConnectionEnabled:         true,
+		MTU:                           1280,
+	}
+
+	for _, anonymize := range []bool{false, true} {
+		t.Run("anonymize="+map[bool]string{true: "true", false: "false"}[anonymize], func(t *testing.T) {
+			g := &BundleGenerator{
+				anonymizer:     newAnonymizerForTest(),
+				internalConfig: cfg,
+				anonymize:      anonymize,
+			}
+
+			var sb strings.Builder
+			g.addCommonConfigFields(&sb)
+			rendered := sb.String() + renderAddConfigSpecific(g)
+
+			val := reflect.ValueOf(cfg).Elem()
+			typ := val.Type()
+			var missing []string
+			for i := 0; i < typ.NumField(); i++ {
+				name := typ.Field(i).Name
+				if _, ok := excluded[name]; ok {
+					continue
+				}
+				if !strings.Contains(rendered, name+":") {
+					missing = append(missing, name)
+				}
+			}
+			if len(missing) > 0 {
+				t.Fatalf("Config field(s) not present in debug bundle output: %v\n"+
+					"Either render the field in addCommonConfigFields/addConfig, "+
+					"or add it to the excluded map with a justification.", missing)
+			}
+		})
+	}
+}
+
+// renderAddConfigSpecific renders the fields handled by the anonymize/non-anonymize
+// branches in addConfig (ManagementURL, AdminURL, NATExternalIPs, CustomDNSAddress).
+// addCommonConfigFields covers the rest. Keeping this in the test mirrors the
+// production shape without needing to write an actual zip.
+func renderAddConfigSpecific(g *BundleGenerator) string {
+	var sb strings.Builder
+	if g.anonymize {
+		if g.internalConfig.ManagementURL != nil {
+			sb.WriteString("ManagementURL: " + g.anonymizer.AnonymizeURI(g.internalConfig.ManagementURL.String()) + "\n")
+		}
+		if g.internalConfig.AdminURL != nil {
+			sb.WriteString("AdminURL: " + g.anonymizer.AnonymizeURI(g.internalConfig.AdminURL.String()) + "\n")
+		}
+		sb.WriteString("NATExternalIPs: x\n")
+		if g.internalConfig.CustomDNSAddress != "" {
+			sb.WriteString("CustomDNSAddress: " + g.anonymizer.AnonymizeString(g.internalConfig.CustomDNSAddress) + "\n")
+		}
+	} else {
+		if g.internalConfig.ManagementURL != nil {
+			sb.WriteString("ManagementURL: " + g.internalConfig.ManagementURL.String() + "\n")
+		}
+		if g.internalConfig.AdminURL != nil {
+			sb.WriteString("AdminURL: " + g.internalConfig.AdminURL.String() + "\n")
+		}
+		sb.WriteString("NATExternalIPs: x\n")
+		if g.internalConfig.CustomDNSAddress != "" {
+			sb.WriteString("CustomDNSAddress: " + g.internalConfig.CustomDNSAddress + "\n")
+		}
+	}
+	return sb.String()
+}
+
+func newAnonymizerForTest() *anonymize.Anonymizer {
+	return anonymize.NewAnonymizer(anonymize.DefaultAddresses())
+}

client/internal/debug/upload_test.go

@@ -3,10 +3,12 @@ package debug
 import (
 	"context"
 	"errors"
+	"net"
 	"net/http"
 	"os"
 	"path/filepath"
 	"testing"
+	"time"
 
 	"github.com/stretchr/testify/require"
 
@@ -19,8 +21,10 @@ func TestUpload(t *testing.T) {
 		t.Skip("Skipping upload test on docker ci")
 	}
 	testDir := t.TempDir()
-	testURL := "http://localhost:8080"
+	addr := reserveLoopbackPort(t)
+	testURL := "http://" + addr
 	t.Setenv("SERVER_URL", testURL)
+	t.Setenv("SERVER_ADDRESS", addr)
 	t.Setenv("STORE_DIR", testDir)
 	srv := server.NewServer()
 	go func() {
@@ -33,6 +37,7 @@ func TestUpload(t *testing.T) {
 			t.Errorf("Failed to stop server: %v", err)
 		}
 	})
+	waitForServer(t, addr)
 
 	file := filepath.Join(t.TempDir(), "tmpfile")
 	fileContent := []byte("test file content")
@@ -47,3 +52,30 @@ func TestUpload(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, fileContent, createdFileContent)
 }
+
+// reserveLoopbackPort binds an ephemeral port on loopback to learn a free
+// address, then releases it so the server under test can rebind. The close/
+// rebind window is racy in theory; on loopback with a kernel-assigned port
+// it's essentially never contended in practice.
+func reserveLoopbackPort(t *testing.T) string {
+	t.Helper()
+	l, err := net.Listen("tcp", "127.0.0.1:0")
+	require.NoError(t, err)
+	addr := l.Addr().String()
+	require.NoError(t, l.Close())
+	return addr
+}
+
+func waitForServer(t *testing.T, addr string) {
+	t.Helper()
+	deadline := time.Now().Add(5 * time.Second)
+	for time.Now().Before(deadline) {
+		c, err := net.DialTimeout("tcp", addr, 100*time.Millisecond)
+		if err == nil {
+			_ = c.Close()
+			return
+		}
+		time.Sleep(20 * time.Millisecond)
+	}
+	t.Fatalf("server did not start listening on %s in time", addr)
+}

client/internal/dns/file_parser_unix.go

@@ -13,6 +13,7 @@ import (
 
 const (
 	defaultResolvConfPath = "/etc/resolv.conf"
+	nsswitchConfPath      = "/etc/nsswitch.conf"
 )
 
 type resolvConf struct {

client/internal/dns/handler_chain.go

@@ -1,7 +1,10 @@
 package dns
 
 import (
+	"context"
 	"fmt"
+	"math"
+	"net"
 	"slices"
 	"strconv"
 	"strings"
@@ -192,6 +195,12 @@ func (c *HandlerChain) logHandlers() {
 }
 
 func (c *HandlerChain) ServeDNS(w dns.ResponseWriter, r *dns.Msg) {
+	c.dispatch(w, r, math.MaxInt)
+}
+
+// dispatch routes a DNS request through the chain, skipping handlers with
+// priority > maxPriority. Shared by ServeDNS and ResolveInternal.
+func (c *HandlerChain) dispatch(w dns.ResponseWriter, r *dns.Msg, maxPriority int) {
 	if len(r.Question) == 0 {
 		return
 	}
@@ -216,6 +225,9 @@ func (c *HandlerChain) ServeDNS(w dns.ResponseWriter, r *dns.Msg) {
 
 	// Try handlers in priority order
 	for _, entry := range handlers {
+		if entry.Priority > maxPriority {
+			continue
+		}
 		if !c.isHandlerMatch(qname, entry) {
 			continue
 		}
@@ -273,6 +285,55 @@ func (c *HandlerChain) logResponse(logger *log.Entry, cw *ResponseWriterChain, q
 		cw.response.Len(), meta, time.Since(startTime))
 }
 
+// ResolveInternal runs an in-process DNS query against the chain, skipping any
+// handler with priority > maxPriority. Used by internal callers (e.g. the mgmt
+// cache refresher) that must bypass themselves to avoid loops. Honors ctx
+// cancellation; on ctx.Done the dispatch goroutine is left to drain on its own
+// (bounded by the invoked handler's internal timeout).
+func (c *HandlerChain) ResolveInternal(ctx context.Context, r *dns.Msg, maxPriority int) (*dns.Msg, error) {
+	if len(r.Question) == 0 {
+		return nil, fmt.Errorf("empty question")
+	}
+
+	base := &internalResponseWriter{}
+	done := make(chan struct{})
+	go func() {
+		c.dispatch(base, r, maxPriority)
+		close(done)
+	}()
+
+	select {
+	case <-done:
+	case <-ctx.Done():
+		// Prefer a completed response if dispatch finished concurrently with cancellation.
+		select {
+		case <-done:
+		default:
+			return nil, fmt.Errorf("resolve %s: %w", strings.ToLower(r.Question[0].Name), ctx.Err())
+		}
+	}
+
+	if base.response == nil || base.response.Rcode == dns.RcodeRefused {
+		return nil, fmt.Errorf("no handler resolved %s at priority ≤ %d",
+			strings.ToLower(r.Question[0].Name), maxPriority)
+	}
+	return base.response, nil
+}
+
+// HasRootHandlerAtOrBelow reports whether any "." handler is registered at
+// priority ≤ maxPriority.
+func (c *HandlerChain) HasRootHandlerAtOrBelow(maxPriority int) bool {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+
+	for _, h := range c.handlers {
+		if h.Pattern == "." && h.Priority <= maxPriority {
+			return true
+		}
+	}
+	return false
+}
+
 func (c *HandlerChain) isHandlerMatch(qname string, entry HandlerEntry) bool {
 	switch {
 	case entry.Pattern == ".":
@@ -291,3 +352,36 @@ func (c *HandlerChain) isHandlerMatch(qname string, entry HandlerEntry) bool {
 		}
 	}
 }
+
+// internalResponseWriter captures a dns.Msg for in-process chain queries.
+type internalResponseWriter struct {
+	response *dns.Msg
+}
+
+func (w *internalResponseWriter) WriteMsg(m *dns.Msg) error { w.response = m; return nil }
+func (w *internalResponseWriter) LocalAddr() net.Addr       { return nil }
+func (w *internalResponseWriter) RemoteAddr() net.Addr      { return nil }
+
+// Write unpacks raw DNS bytes so handlers that call Write instead of WriteMsg
+// still surface their answer to ResolveInternal.
+func (w *internalResponseWriter) Write(p []byte) (int, error) {
+	msg := new(dns.Msg)
+	if err := msg.Unpack(p); err != nil {
+		return 0, err
+	}
+	w.response = msg
+	return len(p), nil
+}
+
+func (w *internalResponseWriter) Close() error      { return nil }
+func (w *internalResponseWriter) TsigStatus() error { return nil }
+
+// TsigTimersOnly is part of dns.ResponseWriter.
+func (w *internalResponseWriter) TsigTimersOnly(bool) {
+	// no-op: in-process queries carry no TSIG state.
+}
+
+// Hijack is part of dns.ResponseWriter.
+func (w *internalResponseWriter) Hijack() {
+	// no-op: in-process queries have no underlying connection to hand off.
+}

client/internal/dns/handler_chain_test.go

@@ -1,11 +1,15 @@
 package dns_test
 
 import (
+	"context"
+	"net"
 	"testing"
+	"time"
 
 	"github.com/miekg/dns"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/mock"
+	"github.com/stretchr/testify/require"
 
 	nbdns "github.com/netbirdio/netbird/client/internal/dns"
 	"github.com/netbirdio/netbird/client/internal/dns/test"
@@ -1042,3 +1046,163 @@ func TestHandlerChain_AddRemoveRoundtrip(t *testing.T) {
 		})
 	}
 }
+
+// answeringHandler writes a fixed A record to ack the query. Used to verify
+// which handler ResolveInternal dispatches to.
+type answeringHandler struct {
+	name string
+	ip   string
+}
+
+func (h *answeringHandler) ServeDNS(w dns.ResponseWriter, r *dns.Msg) {
+	resp := &dns.Msg{}
+	resp.SetReply(r)
+	resp.Answer = []dns.RR{&dns.A{
+		Hdr: dns.RR_Header{Name: r.Question[0].Name, Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: 60},
+		A:   net.ParseIP(h.ip).To4(),
+	}}
+	_ = w.WriteMsg(resp)
+}
+
+func (h *answeringHandler) String() string { return h.name }
+
+func TestHandlerChain_ResolveInternal_SkipsAboveMaxPriority(t *testing.T) {
+	chain := nbdns.NewHandlerChain()
+
+	high := &answeringHandler{name: "high", ip: "10.0.0.1"}
+	low := &answeringHandler{name: "low", ip: "10.0.0.2"}
+
+	chain.AddHandler("example.com.", high, nbdns.PriorityMgmtCache)
+	chain.AddHandler("example.com.", low, nbdns.PriorityUpstream)
+
+	r := new(dns.Msg)
+	r.SetQuestion("example.com.", dns.TypeA)
+
+	resp, err := chain.ResolveInternal(context.Background(), r, nbdns.PriorityUpstream)
+	assert.NoError(t, err)
+	assert.NotNil(t, resp)
+	assert.Equal(t, 1, len(resp.Answer))
+	a, ok := resp.Answer[0].(*dns.A)
+	assert.True(t, ok)
+	assert.Equal(t, "10.0.0.2", a.A.String(), "should skip mgmtCache handler and resolve via upstream")
+}
+
+func TestHandlerChain_ResolveInternal_ErrorWhenNoMatch(t *testing.T) {
+	chain := nbdns.NewHandlerChain()
+	high := &answeringHandler{name: "high", ip: "10.0.0.1"}
+	chain.AddHandler("example.com.", high, nbdns.PriorityMgmtCache)
+
+	r := new(dns.Msg)
+	r.SetQuestion("example.com.", dns.TypeA)
+
+	_, err := chain.ResolveInternal(context.Background(), r, nbdns.PriorityUpstream)
+	assert.Error(t, err, "no handler at or below maxPriority should error")
+}
+
+// rawWriteHandler packs a response and calls ResponseWriter.Write directly
+// (instead of WriteMsg), exercising the internalResponseWriter.Write path.
+type rawWriteHandler struct {
+	ip string
+}
+
+func (h *rawWriteHandler) ServeDNS(w dns.ResponseWriter, r *dns.Msg) {
+	resp := &dns.Msg{}
+	resp.SetReply(r)
+	resp.Answer = []dns.RR{&dns.A{
+		Hdr: dns.RR_Header{Name: r.Question[0].Name, Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: 60},
+		A:   net.ParseIP(h.ip).To4(),
+	}}
+	packed, err := resp.Pack()
+	if err != nil {
+		return
+	}
+	_, _ = w.Write(packed)
+}
+
+func TestHandlerChain_ResolveInternal_CapturesRawWrite(t *testing.T) {
+	chain := nbdns.NewHandlerChain()
+	chain.AddHandler("example.com.", &rawWriteHandler{ip: "10.0.0.3"}, nbdns.PriorityUpstream)
+
+	r := new(dns.Msg)
+	r.SetQuestion("example.com.", dns.TypeA)
+
+	resp, err := chain.ResolveInternal(context.Background(), r, nbdns.PriorityUpstream)
+	assert.NoError(t, err)
+	require.NotNil(t, resp)
+	require.Len(t, resp.Answer, 1)
+	a, ok := resp.Answer[0].(*dns.A)
+	require.True(t, ok)
+	assert.Equal(t, "10.0.0.3", a.A.String(), "handlers calling Write(packed) must still surface their answer")
+}
+
+func TestHandlerChain_ResolveInternal_EmptyQuestion(t *testing.T) {
+	chain := nbdns.NewHandlerChain()
+	_, err := chain.ResolveInternal(context.Background(), new(dns.Msg), nbdns.PriorityUpstream)
+	assert.Error(t, err)
+}
+
+// hangingHandler blocks indefinitely until closed, simulating a wedged upstream.
+type hangingHandler struct {
+	block chan struct{}
+}
+
+func (h *hangingHandler) ServeDNS(w dns.ResponseWriter, r *dns.Msg) {
+	<-h.block
+	resp := &dns.Msg{}
+	resp.SetReply(r)
+	_ = w.WriteMsg(resp)
+}
+
+func (h *hangingHandler) String() string { return "hangingHandler" }
+
+func TestHandlerChain_ResolveInternal_HonorsContextTimeout(t *testing.T) {
+	chain := nbdns.NewHandlerChain()
+	h := &hangingHandler{block: make(chan struct{})}
+	defer close(h.block)
+
+	chain.AddHandler("example.com.", h, nbdns.PriorityUpstream)
+
+	r := new(dns.Msg)
+	r.SetQuestion("example.com.", dns.TypeA)
+
+	ctx, cancel := context.WithTimeout(context.Background(), 100*time.Millisecond)
+	defer cancel()
+
+	start := time.Now()
+	_, err := chain.ResolveInternal(ctx, r, nbdns.PriorityUpstream)
+	elapsed := time.Since(start)
+
+	assert.Error(t, err)
+	assert.ErrorIs(t, err, context.DeadlineExceeded)
+	assert.Less(t, elapsed, 500*time.Millisecond, "ResolveInternal must return shortly after ctx deadline")
+}
+
+func TestHandlerChain_HasRootHandlerAtOrBelow(t *testing.T) {
+	chain := nbdns.NewHandlerChain()
+	h := &answeringHandler{name: "h", ip: "10.0.0.1"}
+
+	assert.False(t, chain.HasRootHandlerAtOrBelow(nbdns.PriorityUpstream), "empty chain")
+
+	chain.AddHandler("example.com.", h, nbdns.PriorityUpstream)
+	assert.False(t, chain.HasRootHandlerAtOrBelow(nbdns.PriorityUpstream), "non-root handler does not count")
+
+	chain.AddHandler(".", h, nbdns.PriorityMgmtCache)
+	assert.False(t, chain.HasRootHandlerAtOrBelow(nbdns.PriorityUpstream), "root handler above threshold excluded")
+
+	chain.AddHandler(".", h, nbdns.PriorityDefault)
+	assert.True(t, chain.HasRootHandlerAtOrBelow(nbdns.PriorityUpstream), "root handler at PriorityDefault included")
+
+	chain.RemoveHandler(".", nbdns.PriorityDefault)
+	assert.False(t, chain.HasRootHandlerAtOrBelow(nbdns.PriorityUpstream))
+
+	// Primary nsgroup case: root handler lands at PriorityUpstream.
+	chain.AddHandler(".", h, nbdns.PriorityUpstream)
+	assert.True(t, chain.HasRootHandlerAtOrBelow(nbdns.PriorityUpstream), "root at PriorityUpstream included")
+	chain.RemoveHandler(".", nbdns.PriorityUpstream)
+
+	// Fallback case: original /etc/resolv.conf entries land at PriorityFallback.
+	chain.AddHandler(".", h, nbdns.PriorityFallback)
+	assert.True(t, chain.HasRootHandlerAtOrBelow(nbdns.PriorityUpstream), "root at PriorityFallback included")
+	chain.RemoveHandler(".", nbdns.PriorityFallback)
+	assert.False(t, chain.HasRootHandlerAtOrBelow(nbdns.PriorityUpstream))
+}

client/internal/dns/host_unix.go

@@ -46,12 +46,12 @@ type restoreHostManager interface {
 }
 
 func newHostManager(wgInterface string) (hostManager, error) {
-	osManager, err := getOSDNSManagerType()
+	osManager, reason, err := getOSDNSManagerType()
 	if err != nil {
 		return nil, fmt.Errorf("get os dns manager type: %w", err)
 	}
 
-	log.Infof("System DNS manager discovered: %s", osManager)
+	log.Infof("System DNS manager discovered: %s (%s)", osManager, reason)
 	mgr, err := newHostManagerFromType(wgInterface, osManager)
 	// need to explicitly return nil mgr on error to avoid returning a non-nil interface containing a nil value
 	if err != nil {
@@ -74,17 +74,49 @@ func newHostManagerFromType(wgInterface string, osManager osManagerType) (restor
 	}
 }
 
-func getOSDNSManagerType() (osManagerType, error) {
+func getOSDNSManagerType() (osManagerType, string, error) {
+	resolved := isSystemdResolvedRunning()
+	nss := isLibnssResolveUsed()
+	stub := checkStub()
+
+	// Prefer systemd-resolved whenever it owns libc resolution, regardless of
+	// who wrote /etc/resolv.conf. File-mode rewrites do not affect lookups
+	// that go through nss-resolve, and in foreign mode they can loop back
+	// through resolved as an upstream.
+	if resolved && (nss || stub) {
+		return systemdManager, fmt.Sprintf("systemd-resolved active (nss-resolve=%t, stub=%t)", nss, stub), nil
+	}
+
+	mgr, reason, rejected, err := scanResolvConfHeader()
+	if err != nil {
+		return 0, "", err
+	}
+	if reason != "" {
+		return mgr, reason, nil
+	}
+
+	fallback := fmt.Sprintf("no manager matched (resolved=%t, nss-resolve=%t, stub=%t)", resolved, nss, stub)
+	if len(rejected) > 0 {
+		fallback += "; rejected: " + strings.Join(rejected, ", ")
+	}
+	return fileManager, fallback, nil
+}
+
+// scanResolvConfHeader walks /etc/resolv.conf header comments and returns the
+// matching manager. If reason is empty the caller should pick file mode and
+// use rejected for diagnostics.
+func scanResolvConfHeader() (osManagerType, string, []string, error) {
 	file, err := os.Open(defaultResolvConfPath)
 	if err != nil {
-		return 0, fmt.Errorf("unable to open %s for checking owner, got error: %w", defaultResolvConfPath, err)
+		return 0, "", nil, fmt.Errorf("unable to open %s for checking owner, got error: %w", defaultResolvConfPath, err)
 	}
 	defer func() {
-		if err := file.Close(); err != nil {
+		if cerr := file.Close(); cerr != nil {
-			log.Errorf("close file %s: %s", defaultResolvConfPath, err)
+			log.Errorf("close file %s: %s", defaultResolvConfPath, cerr)
 		}
 	}()
 
+	var rejected []string
 	scanner := bufio.NewScanner(file)
 	for scanner.Scan() {
 		text := scanner.Text()
@@ -92,41 +124,48 @@ func getOSDNSManagerType() (osManagerType, error) {
 			continue
 		}
 		if text[0] != '#' {
-			return fileManager, nil
+			break
 		}
-		if strings.Contains(text, fileGeneratedResolvConfContentHeader) {
+		if mgr, reason, rej := matchResolvConfHeader(text); reason != "" {
-			return netbirdManager, nil
+			return mgr, reason, nil, nil
-		}
+		} else if rej != "" {
-		if strings.Contains(text, "NetworkManager") && isDbusListenerRunning(networkManagerDest, networkManagerDbusObjectNode) && isNetworkManagerSupported() {
+			rejected = append(rejected, rej)
-			return networkManager, nil
-		}
-		if strings.Contains(text, "systemd-resolved") && isSystemdResolvedRunning() {
-			if checkStub() {
-				return systemdManager, nil
-			} else {
-				return fileManager, nil
-			}
-		}
-		if strings.Contains(text, "resolvconf") {
-			if isSystemdResolveConfMode() {
-				return systemdManager, nil
-			}
-
-			return resolvConfManager, nil
 		}
 	}
 	if err := scanner.Err(); err != nil && err != io.EOF {
-		return 0, fmt.Errorf("scan: %w", err)
+		return 0, "", nil, fmt.Errorf("scan: %w", err)
 	}
-
+	return 0, "", rejected, nil
-	return fileManager, nil
 }
 
-// checkStub checks if the stub resolver is disabled in systemd-resolved. If it is disabled, we fall back to file manager.
+// matchResolvConfHeader inspects a single comment line. Returns either a
+// definitive (manager, reason) or a non-empty rejected diagnostic.
+func matchResolvConfHeader(text string) (osManagerType, string, string) {
+	if strings.Contains(text, fileGeneratedResolvConfContentHeader) {
+		return netbirdManager, "netbird-managed resolv.conf header detected", ""
+	}
+	if strings.Contains(text, "NetworkManager") {
+		if isDbusListenerRunning(networkManagerDest, networkManagerDbusObjectNode) && isNetworkManagerSupported() {
+			return networkManager, "NetworkManager header + supported version on dbus", ""
+		}
+		return 0, "", "NetworkManager header (no dbus or unsupported version)"
+	}
+	if strings.Contains(text, "resolvconf") {
+		if isSystemdResolveConfMode() {
+			return systemdManager, "resolvconf header in systemd-resolved compatibility mode", ""
+		}
+		return resolvConfManager, "resolvconf header detected", ""
+	}
+	return 0, "", ""
+}
+
+// checkStub reports whether systemd-resolved's stub (127.0.0.53) is listed
+// in /etc/resolv.conf. On parse failure we assume it is, to avoid dropping
+// into file mode while resolved is active.
 func checkStub() bool {
 	rConf, err := parseDefaultResolvConf()
 	if err != nil {
-		log.Warnf("failed to parse resolv conf: %s", err)
+		log.Warnf("failed to parse resolv conf, assuming stub is active: %s", err)
 		return true
 	}
 
@@ -139,3 +178,36 @@ func checkStub() bool {
 
 	return false
 }
+
+// isLibnssResolveUsed reports whether nss-resolve is listed before dns on
+// the hosts: line of /etc/nsswitch.conf. When it is, libc lookups are
+// delegated to systemd-resolved regardless of /etc/resolv.conf.
+func isLibnssResolveUsed() bool {
+	bs, err := os.ReadFile(nsswitchConfPath)
+	if err != nil {
+		log.Debugf("read %s: %v", nsswitchConfPath, err)
+		return false
+	}
+	return parseNsswitchResolveAhead(bs)
+}
+
+func parseNsswitchResolveAhead(data []byte) bool {
+	for _, line := range strings.Split(string(data), "\n") {
+		if i := strings.IndexByte(line, '#'); i >= 0 {
+			line = line[:i]
+		}
+		fields := strings.Fields(line)
+		if len(fields) < 2 || fields[0] != "hosts:" {
+			continue
+		}
+		for _, module := range fields[1:] {
+			switch module {
+			case "dns":
+				return false
+			case "resolve":
+				return true
+			}
+		}
+	}
+	return false
+}

client/internal/dns/host_unix_test.go

@@ -0,0 +1,76 @@
+//go:build (linux && !android) || freebsd
+
+package dns
+
+import "testing"
+
+func TestParseNsswitchResolveAhead(t *testing.T) {
+	tests := []struct {
+		name string
+		in   string
+		want bool
+	}{
+		{
+			name: "resolve before dns with action token",
+			in:   "hosts: mymachines resolve [!UNAVAIL=return] files myhostname dns\n",
+			want: true,
+		},
+		{
+			name: "dns before resolve",
+			in:   "hosts: files mdns4_minimal [NOTFOUND=return] dns resolve\n",
+			want: false,
+		},
+		{
+			name: "debian default with only dns",
+			in:   "hosts: files mdns4_minimal [NOTFOUND=return] dns mymachines\n",
+			want: false,
+		},
+		{
+			name: "neither resolve nor dns",
+			in:   "hosts: files myhostname\n",
+			want: false,
+		},
+		{
+			name: "no hosts line",
+			in:   "passwd: files systemd\ngroup: files systemd\n",
+			want: false,
+		},
+		{
+			name: "empty",
+			in:   "",
+			want: false,
+		},
+		{
+			name: "comments and blank lines ignored",
+			in:   "# comment\n\n# another\nhosts: resolve dns\n",
+			want: true,
+		},
+		{
+			name: "trailing inline comment",
+			in:   "hosts: resolve [!UNAVAIL=return] dns # fallback\n",
+			want: true,
+		},
+		{
+			name: "hosts token must be the first field",
+			in:   "  hosts: resolve dns\n",
+			want: true,
+		},
+		{
+			name: "other db line mentioning resolve is ignored",
+			in:   "networks: resolve\nhosts: dns\n",
+			want: false,
+		},
+		{
+			name: "only resolve, no dns",
+			in:   "hosts: files resolve\n",
+			want: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := parseNsswitchResolveAhead([]byte(tt.in)); got != tt.want {
+				t.Errorf("parseNsswitchResolveAhead() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}

client/internal/dns/mgmt/mgmt.go

@@ -2,40 +2,83 @@ package mgmt
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"net"
-	"net/netip"
 	"net/url"
+	"os"
+	"slices"
 	"strings"
 	"sync"
+	"sync/atomic"
 	"time"
 
 	"github.com/miekg/dns"
 	log "github.com/sirupsen/logrus"
+	"golang.org/x/sync/singleflight"
 
 	dnsconfig "github.com/netbirdio/netbird/client/internal/dns/config"
+	"github.com/netbirdio/netbird/client/internal/dns/resutil"
 	"github.com/netbirdio/netbird/shared/management/domain"
 )
 
-const dnsTimeout = 5 * time.Second
+const (
+	dnsTimeout     = 5 * time.Second
+	defaultTTL     = 300 * time.Second
+	refreshBackoff = 30 * time.Second
 
-// Resolver caches critical NetBird infrastructure domains
+	// envMgmtCacheTTL overrides defaultTTL for integration/dev testing.
+	envMgmtCacheTTL = "NB_MGMT_CACHE_TTL"
+)
+
+// ChainResolver lets the cache refresh stale entries through the DNS handler
+// chain instead of net.DefaultResolver, avoiding loopback when NetBird is the
+// system resolver.
+type ChainResolver interface {
+	ResolveInternal(ctx context.Context, msg *dns.Msg, maxPriority int) (*dns.Msg, error)
+	HasRootHandlerAtOrBelow(maxPriority int) bool
+}
+
+// cachedRecord holds DNS records plus timestamps used for TTL refresh.
+// records and cachedAt are set at construction and treated as immutable;
+// lastFailedRefresh and consecFailures are mutable and must be accessed under
+// Resolver.mutex.
+type cachedRecord struct {
+	records           []dns.RR
+	cachedAt          time.Time
+	lastFailedRefresh time.Time
+	consecFailures    int
+}
+
+// Resolver caches critical NetBird infrastructure domains.
+// records, refreshing, mgmtDomain and serverDomains are all guarded by mutex.
 type Resolver struct {
-	records       map[dns.Question][]dns.RR
+	records       map[dns.Question]*cachedRecord
 	mgmtDomain    *domain.Domain
 	serverDomains *dnsconfig.ServerDomains
 	mutex         sync.RWMutex
-}
 
-type ipsResponse struct {
+	chain            ChainResolver
-	ips []netip.Addr
+	chainMaxPriority int
-	err error
+	refreshGroup     singleflight.Group
+
+	// refreshing tracks questions whose refresh is running via the OS
+	// fallback path. A ServeDNS hit for a question in this map indicates
+	// the OS resolver routed the recursive query back to us (loop). Only
+	// the OS path arms this so chain-path refreshes don't produce false
+	// positives. The atomic bool is CAS-flipped once per refresh to
+	// throttle the warning log.
+	refreshing map[dns.Question]*atomic.Bool
+
+	cacheTTL time.Duration
 }
 
 // NewResolver creates a new management domains cache resolver.
 func NewResolver() *Resolver {
 	return &Resolver{
-		records: make(map[dns.Question][]dns.RR),
+		records:    make(map[dns.Question]*cachedRecord),
+		refreshing: make(map[dns.Question]*atomic.Bool),
+		cacheTTL:   resolveCacheTTL(),
 	}
 }
 
@@ -44,7 +87,19 @@ func (m *Resolver) String() string {
 	return "MgmtCacheResolver"
 }
 
-// ServeDNS implements dns.Handler interface.
+// SetChainResolver wires the handler chain used to refresh stale cache entries.
+// maxPriority caps which handlers may answer refresh queries (typically
+// PriorityUpstream, so upstream/default/fallback handlers are consulted and
+// mgmt/route/local handlers are skipped).
+func (m *Resolver) SetChainResolver(chain ChainResolver, maxPriority int) {
+	m.mutex.Lock()
+	m.chain = chain
+	m.chainMaxPriority = maxPriority
+	m.mutex.Unlock()
+}
+
+// ServeDNS serves cached A/AAAA records. Stale entries are returned
+// immediately and refreshed asynchronously (stale-while-revalidate).
 func (m *Resolver) ServeDNS(w dns.ResponseWriter, r *dns.Msg) {
 	if len(r.Question) == 0 {
 		m.continueToNext(w, r)
@@ -60,7 +115,14 @@ func (m *Resolver) ServeDNS(w dns.ResponseWriter, r *dns.Msg) {
 	}
 
 	m.mutex.RLock()
-	records, found := m.records[question]
+	cached, found := m.records[question]
+	inflight := m.refreshing[question]
+	var shouldRefresh bool
+	if found {
+		stale := time.Since(cached.cachedAt) > m.cacheTTL
+		inBackoff := !cached.lastFailedRefresh.IsZero() && time.Since(cached.lastFailedRefresh) < refreshBackoff
+		shouldRefresh = stale && !inBackoff
+	}
 	m.mutex.RUnlock()
 
 	if !found {
@@ -68,12 +130,23 @@ func (m *Resolver) ServeDNS(w dns.ResponseWriter, r *dns.Msg) {
 		return
 	}
 
+	if inflight != nil && inflight.CompareAndSwap(false, true) {
+		log.Warnf("mgmt cache: possible resolver loop for domain=%s: served stale while an OS-fallback refresh was inflight (if NetBird is the system resolver, the OS-path predicate is wrong)",
+			question.Name)
+	}
+
+	// Skip scheduling a refresh goroutine if one is already inflight for
+	// this question; singleflight would dedup anyway but skipping avoids
+	// a parked goroutine per stale hit under bursty load.
+	if shouldRefresh && inflight == nil {
+		m.scheduleRefresh(question, cached)
+	}
+
 	resp := &dns.Msg{}
 	resp.SetReply(r)
 	resp.Authoritative = false
 	resp.RecursionAvailable = true
-
+	resp.Answer = cloneRecordsWithTTL(cached.records, m.responseTTL(cached.cachedAt))
-	resp.Answer = append(resp.Answer, records...)
 
 	log.Debugf("serving %d cached records for domain=%s", len(resp.Answer), question.Name)
 
@@ -98,101 +171,260 @@ func (m *Resolver) continueToNext(w dns.ResponseWriter, r *dns.Msg) {
 	}
 }
 
-// AddDomain manually adds a domain to cache by resolving it.
+// AddDomain resolves a domain and stores its A/AAAA records in the cache.
+// A family that resolves NODATA (nil err, zero records) evicts any stale
+// entry for that qtype.
 func (m *Resolver) AddDomain(ctx context.Context, d domain.Domain) error {
 	dnsName := strings.ToLower(dns.Fqdn(d.PunycodeString()))
 
 	ctx, cancel := context.WithTimeout(ctx, dnsTimeout)
 	defer cancel()
 
-	ips, err := lookupIPWithExtraTimeout(ctx, d)
+	aRecords, aaaaRecords, errA, errAAAA := m.lookupBoth(ctx, d, dnsName)
-	if err != nil {
+
-		return err
+	if errA != nil && errAAAA != nil {
+		return fmt.Errorf("resolve %s: %w", d.SafeString(), errors.Join(errA, errAAAA))
 	}
 
-	var aRecords, aaaaRecords []dns.RR
+	if len(aRecords) == 0 && len(aaaaRecords) == 0 {
-	for _, ip := range ips {
+		if err := errors.Join(errA, errAAAA); err != nil {
-		if ip.Is4() {
+			return fmt.Errorf("resolve %s: no A/AAAA records: %w", d.SafeString(), err)
-			rr := &dns.A{
-				Hdr: dns.RR_Header{
-					Name:   dnsName,
-					Rrtype: dns.TypeA,
-					Class:  dns.ClassINET,
-					Ttl:    300,
-				},
-				A: ip.AsSlice(),
-			}
-			aRecords = append(aRecords, rr)
-		} else if ip.Is6() {
-			rr := &dns.AAAA{
-				Hdr: dns.RR_Header{
-					Name:   dnsName,
-					Rrtype: dns.TypeAAAA,
-					Class:  dns.ClassINET,
-					Ttl:    300,
-				},
-				AAAA: ip.AsSlice(),
-			}
-			aaaaRecords = append(aaaaRecords, rr)
 		}
+		return fmt.Errorf("resolve %s: no A/AAAA records", d.SafeString())
 	}
 
+	now := time.Now()
 	m.mutex.Lock()
+	defer m.mutex.Unlock()
 
-	if len(aRecords) > 0 {
+	m.applyFamilyRecords(dnsName, dns.TypeA, aRecords, errA, now)
-		aQuestion := dns.Question{
+	m.applyFamilyRecords(dnsName, dns.TypeAAAA, aaaaRecords, errAAAA, now)
-			Name:   dnsName,
-			Qtype:  dns.TypeA,
-			Qclass: dns.ClassINET,
-		}
-		m.records[aQuestion] = aRecords
-	}
 
-	if len(aaaaRecords) > 0 {
+	log.Debugf("added/updated domain=%s with %d A records and %d AAAA records",
-		aaaaQuestion := dns.Question{
-			Name:   dnsName,
-			Qtype:  dns.TypeAAAA,
-			Qclass: dns.ClassINET,
-		}
-		m.records[aaaaQuestion] = aaaaRecords
-	}
-
-	m.mutex.Unlock()
-
-	log.Debugf("added domain=%s with %d A records and %d AAAA records",
 		d.SafeString(), len(aRecords), len(aaaaRecords))
 
 	return nil
 }
 
-func lookupIPWithExtraTimeout(ctx context.Context, d domain.Domain) ([]netip.Addr, error) {
+// applyFamilyRecords writes records, evicts on NODATA, leaves the cache
-	log.Infof("looking up IP for mgmt domain=%s", d.SafeString())
+// untouched on error. Caller holds m.mutex.
-	defer log.Infof("done looking up IP for mgmt domain=%s", d.SafeString())
+func (m *Resolver) applyFamilyRecords(dnsName string, qtype uint16, records []dns.RR, err error, now time.Time) {
-	resultChan := make(chan *ipsResponse, 1)
+	q := dns.Question{Name: dnsName, Qtype: qtype, Qclass: dns.ClassINET}
+	switch {
+	case len(records) > 0:
+		m.records[q] = &cachedRecord{records: records, cachedAt: now}
+	case err == nil:
+		delete(m.records, q)
+	}
+}
 
-	go func() {
+// scheduleRefresh kicks off an async refresh. DoChan spawns one goroutine per
-		ips, err := net.DefaultResolver.LookupNetIP(ctx, "ip", d.PunycodeString())
+// unique in-flight key; bursty stale hits share its channel. expected is the
-		resultChan <- &ipsResponse{
+// cachedRecord pointer observed by the caller; the refresh only mutates the
-			err: err,
+// cache if that pointer is still the one stored, so a stale in-flight refresh
-			ips: ips,
+// can't clobber a newer entry written by AddDomain or a competing refresh.
+func (m *Resolver) scheduleRefresh(question dns.Question, expected *cachedRecord) {
+	key := question.Name + "|" + dns.TypeToString[question.Qtype]
+	_ = m.refreshGroup.DoChan(key, func() (any, error) {
+		return nil, m.refreshQuestion(question, expected)
+	})
+}
+
+// refreshQuestion replaces the cached records on success, or marks the entry
+// failed (arming the backoff) on failure. While this runs, ServeDNS can detect
+// a resolver loop by spotting a query for this same question arriving on us.
+// expected pins the cache entry observed at schedule time; mutations only apply
+// if m.records[question] still points at it.
+func (m *Resolver) refreshQuestion(question dns.Question, expected *cachedRecord) error {
+	ctx, cancel := context.WithTimeout(context.Background(), dnsTimeout)
+	defer cancel()
+
+	d, err := domain.FromString(strings.TrimSuffix(question.Name, "."))
+	if err != nil {
+		m.markRefreshFailed(question, expected)
+		return fmt.Errorf("parse domain: %w", err)
+	}
+
+	records, err := m.lookupRecords(ctx, d, question)
+	if err != nil {
+		fails := m.markRefreshFailed(question, expected)
+		logf := log.Warnf
+		if fails == 0 || fails > 1 {
+			logf = log.Debugf
 		}
-	}()
+		logf("refresh mgmt cache domain=%s type=%s: %v (consecutive failures=%d)",
-
+			d.SafeString(), dns.TypeToString[question.Qtype], err, fails)
-	var resp *ipsResponse
+		return err
-
-	select {
-	case <-time.After(dnsTimeout + time.Millisecond*500):
-		log.Warnf("timed out waiting for IP for mgmt domain=%s", d.SafeString())
-		return nil, fmt.Errorf("timed out waiting for ips to be available for domain %s", d.SafeString())
-	case <-ctx.Done():
-		return nil, ctx.Err()
-	case resp = <-resultChan:
 	}
 
-	if resp.err != nil {
+	// NOERROR/NODATA: family gone upstream, evict so we stop serving stale.
-		return nil, fmt.Errorf("resolve domain %s: %w", d.SafeString(), resp.err)
+	if len(records) == 0 {
+		m.mutex.Lock()
+		if m.records[question] == expected {
+			delete(m.records, question)
+			m.mutex.Unlock()
+			log.Infof("removed mgmt cache domain=%s type=%s: no records returned",
+				d.SafeString(), dns.TypeToString[question.Qtype])
+			return nil
+		}
+		m.mutex.Unlock()
+		log.Debugf("skipping refresh evict for domain=%s type=%s: entry changed during refresh",
+			d.SafeString(), dns.TypeToString[question.Qtype])
+		return nil
 	}
-	return resp.ips, nil
+
+	now := time.Now()
+	m.mutex.Lock()
+	if m.records[question] != expected {
+		m.mutex.Unlock()
+		log.Debugf("skipping refresh write for domain=%s type=%s: entry changed during refresh",
+			d.SafeString(), dns.TypeToString[question.Qtype])
+		return nil
+	}
+	m.records[question] = &cachedRecord{records: records, cachedAt: now}
+	m.mutex.Unlock()
+
+	log.Infof("refreshed mgmt cache domain=%s type=%s",
+		d.SafeString(), dns.TypeToString[question.Qtype])
+	return nil
+}
+
+func (m *Resolver) markRefreshing(question dns.Question) {
+	m.mutex.Lock()
+	m.refreshing[question] = &atomic.Bool{}
+	m.mutex.Unlock()
+}
+
+func (m *Resolver) clearRefreshing(question dns.Question) {
+	m.mutex.Lock()
+	delete(m.refreshing, question)
+	m.mutex.Unlock()
+}
+
+// markRefreshFailed arms the backoff and returns the new consecutive-failure
+// count so callers can downgrade subsequent failure logs to debug.
+func (m *Resolver) markRefreshFailed(question dns.Question, expected *cachedRecord) int {
+	m.mutex.Lock()
+	defer m.mutex.Unlock()
+	c, ok := m.records[question]
+	if !ok || c != expected {
+		return 0
+	}
+	c.lastFailedRefresh = time.Now()
+	c.consecFailures++
+	return c.consecFailures
+}
+
+// lookupBoth resolves A and AAAA via chain or OS. Per-family errors let
+// callers tell records, NODATA (nil err, no records), and failure apart.
+func (m *Resolver) lookupBoth(ctx context.Context, d domain.Domain, dnsName string) (aRecords, aaaaRecords []dns.RR, errA, errAAAA error) {
+	m.mutex.RLock()
+	chain := m.chain
+	maxPriority := m.chainMaxPriority
+	m.mutex.RUnlock()
+
+	if chain != nil && chain.HasRootHandlerAtOrBelow(maxPriority) {
+		aRecords, errA = m.lookupViaChain(ctx, chain, maxPriority, dnsName, dns.TypeA)
+		aaaaRecords, errAAAA = m.lookupViaChain(ctx, chain, maxPriority, dnsName, dns.TypeAAAA)
+		return
+	}
+
+	// TODO: drop once every supported OS registers a fallback resolver. Safe
+	// today: no root handler at priority ≤ PriorityUpstream means NetBird is
+	// not the system resolver, so net.DefaultResolver will not loop back.
+	aRecords, errA = m.osLookup(ctx, d, dnsName, dns.TypeA)
+	aaaaRecords, errAAAA = m.osLookup(ctx, d, dnsName, dns.TypeAAAA)
+	return
+}
+
+// lookupRecords resolves a single record type via chain or OS. The OS branch
+// arms the loop detector for the duration of its call so that ServeDNS can
+// spot the OS resolver routing the recursive query back to us.
+func (m *Resolver) lookupRecords(ctx context.Context, d domain.Domain, q dns.Question) ([]dns.RR, error) {
+	m.mutex.RLock()
+	chain := m.chain
+	maxPriority := m.chainMaxPriority
+	m.mutex.RUnlock()
+
+	if chain != nil && chain.HasRootHandlerAtOrBelow(maxPriority) {
+		return m.lookupViaChain(ctx, chain, maxPriority, q.Name, q.Qtype)
+	}
+
+	// TODO: drop once every supported OS registers a fallback resolver.
+	m.markRefreshing(q)
+	defer m.clearRefreshing(q)
+
+	return m.osLookup(ctx, d, q.Name, q.Qtype)
+}
+
+// lookupViaChain resolves via the handler chain and rewrites each RR to use
+// dnsName as owner and m.cacheTTL as TTL, so CNAME-backed domains don't cache
+// target-owned records or upstream TTLs. NODATA returns (nil, nil).
+func (m *Resolver) lookupViaChain(ctx context.Context, chain ChainResolver, maxPriority int, dnsName string, qtype uint16) ([]dns.RR, error) {
+	msg := &dns.Msg{}
+	msg.SetQuestion(dnsName, qtype)
+	msg.RecursionDesired = true
+
+	resp, err := chain.ResolveInternal(ctx, msg, maxPriority)
+	if err != nil {
+		return nil, fmt.Errorf("chain resolve: %w", err)
+	}
+	if resp == nil {
+		return nil, fmt.Errorf("chain resolve returned nil response")
+	}
+	if resp.Rcode != dns.RcodeSuccess {
+		return nil, fmt.Errorf("chain resolve rcode=%s", dns.RcodeToString[resp.Rcode])
+	}
+
+	ttl := uint32(m.cacheTTL.Seconds())
+	owners := cnameOwners(dnsName, resp.Answer)
+	var filtered []dns.RR
+	for _, rr := range resp.Answer {
+		h := rr.Header()
+		if h.Class != dns.ClassINET || h.Rrtype != qtype {
+			continue
+		}
+		if !owners[strings.ToLower(dns.Fqdn(h.Name))] {
+			continue
+		}
+		if cp := cloneIPRecord(rr, dnsName, ttl); cp != nil {
+			filtered = append(filtered, cp)
+		}
+	}
+	return filtered, nil
+}
+
+// osLookup resolves a single family via net.DefaultResolver using resutil,
+// which disambiguates NODATA from NXDOMAIN and Unmaps v4-mapped-v6. NODATA
+// returns (nil, nil).
+func (m *Resolver) osLookup(ctx context.Context, d domain.Domain, dnsName string, qtype uint16) ([]dns.RR, error) {
+	network := resutil.NetworkForQtype(qtype)
+	if network == "" {
+		return nil, fmt.Errorf("unsupported qtype %s", dns.TypeToString[qtype])
+	}
+
+	log.Infof("looking up IP for mgmt domain=%s type=%s", d.SafeString(), dns.TypeToString[qtype])
+	defer log.Infof("done looking up IP for mgmt domain=%s type=%s", d.SafeString(), dns.TypeToString[qtype])
+
+	result := resutil.LookupIP(ctx, net.DefaultResolver, network, d.PunycodeString(), qtype)
+	if result.Rcode == dns.RcodeSuccess {
+		return resutil.IPsToRRs(dnsName, result.IPs, uint32(m.cacheTTL.Seconds())), nil
+	}
+
+	if result.Err != nil {
+		return nil, fmt.Errorf("resolve %s type=%s: %w", d.SafeString(), dns.TypeToString[qtype], result.Err)
+	}
+	return nil, fmt.Errorf("resolve %s type=%s: rcode=%s", d.SafeString(), dns.TypeToString[qtype], dns.RcodeToString[result.Rcode])
+}
+
+// responseTTL returns the remaining cache lifetime in seconds (rounded up),
+// so downstream resolvers don't cache an answer for longer than we will.
+func (m *Resolver) responseTTL(cachedAt time.Time) uint32 {
+	remaining := m.cacheTTL - time.Since(cachedAt)
+	if remaining <= 0 {
+		return 0
+	}
+	return uint32((remaining + time.Second - 1) / time.Second)
 }
 
 // PopulateFromConfig extracts and caches domains from the client configuration.
@@ -224,19 +456,12 @@ func (m *Resolver) RemoveDomain(d domain.Domain) error {
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
 
-	aQuestion := dns.Question{
+	qA := dns.Question{Name: dnsName, Qtype: dns.TypeA, Qclass: dns.ClassINET}
-		Name:   dnsName,
+	qAAAA := dns.Question{Name: dnsName, Qtype: dns.TypeAAAA, Qclass: dns.ClassINET}
-		Qtype:  dns.TypeA,
+	delete(m.records, qA)
-		Qclass: dns.ClassINET,
+	delete(m.records, qAAAA)
-	}
+	delete(m.refreshing, qA)
-	delete(m.records, aQuestion)
+	delete(m.refreshing, qAAAA)
-
-	aaaaQuestion := dns.Question{
-		Name:   dnsName,
-		Qtype:  dns.TypeAAAA,
-		Qclass: dns.ClassINET,
-	}
-	delete(m.records, aaaaQuestion)
 
 	log.Debugf("removed domain=%s from cache", d.SafeString())
 	return nil
@@ -394,3 +619,73 @@ func (m *Resolver) extractDomainsFromServerDomains(serverDomains dnsconfig.Serve
 
 	return domains
 }
+
+// cloneIPRecord returns a deep copy of rr retargeted to owner with ttl. Non
+// A/AAAA records return nil.
+func cloneIPRecord(rr dns.RR, owner string, ttl uint32) dns.RR {
+	switch r := rr.(type) {
+	case *dns.A:
+		cp := *r
+		cp.Hdr.Name = owner
+		cp.Hdr.Ttl = ttl
+		cp.A = slices.Clone(r.A)
+		return &cp
+	case *dns.AAAA:
+		cp := *r
+		cp.Hdr.Name = owner
+		cp.Hdr.Ttl = ttl
+		cp.AAAA = slices.Clone(r.AAAA)
+		return &cp
+	}
+	return nil
+}
+
+// cloneRecordsWithTTL clones A/AAAA records preserving their owner and
+// stamping ttl so the response shares no memory with the cached slice.
+func cloneRecordsWithTTL(records []dns.RR, ttl uint32) []dns.RR {
+	out := make([]dns.RR, 0, len(records))
+	for _, rr := range records {
+		if cp := cloneIPRecord(rr, rr.Header().Name, ttl); cp != nil {
+			out = append(out, cp)
+		}
+	}
+	return out
+}
+
+// cnameOwners returns dnsName plus every target reachable by following CNAMEs
+// in answer, iterating until fixed point so out-of-order chains resolve.
+func cnameOwners(dnsName string, answer []dns.RR) map[string]bool {
+	owners := map[string]bool{dnsName: true}
+	for {
+		added := false
+		for _, rr := range answer {
+			cname, ok := rr.(*dns.CNAME)
+			if !ok {
+				continue
+			}
+			name := strings.ToLower(dns.Fqdn(cname.Hdr.Name))
+			if !owners[name] {
+				continue
+			}
+			target := strings.ToLower(dns.Fqdn(cname.Target))
+			if !owners[target] {
+				owners[target] = true
+				added = true
+			}
+		}
+		if !added {
+			return owners
+		}
+	}
+}
+
+// resolveCacheTTL reads the cache TTL override env var; invalid or empty
+// values fall back to defaultTTL. Called once per Resolver from NewResolver.
+func resolveCacheTTL() time.Duration {
+	if v := os.Getenv(envMgmtCacheTTL); v != "" {
+		if d, err := time.ParseDuration(v); err == nil && d > 0 {
+			return d
+		}
+	}
+	return defaultTTL
+}

client/internal/dns/mgmt/mgmt_refresh_test.go

@@ -0,0 +1,408 @@
+package mgmt
+
+import (
+	"context"
+	"errors"
+	"net"
+	"sync"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	"github.com/miekg/dns"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/netbirdio/netbird/client/internal/dns/test"
+	"github.com/netbirdio/netbird/shared/management/domain"
+)
+
+type fakeChain struct {
+	mu       sync.Mutex
+	calls    map[string]int
+	answers  map[string][]dns.RR
+	err      error
+	hasRoot  bool
+	onLookup func()
+}
+
+func newFakeChain() *fakeChain {
+	return &fakeChain{
+		calls:   map[string]int{},
+		answers: map[string][]dns.RR{},
+		hasRoot: true,
+	}
+}
+
+func (f *fakeChain) HasRootHandlerAtOrBelow(maxPriority int) bool {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	return f.hasRoot
+}
+
+func (f *fakeChain) ResolveInternal(ctx context.Context, msg *dns.Msg, maxPriority int) (*dns.Msg, error) {
+	f.mu.Lock()
+	q := msg.Question[0]
+	key := q.Name + "|" + dns.TypeToString[q.Qtype]
+	f.calls[key]++
+	answers := f.answers[key]
+	err := f.err
+	onLookup := f.onLookup
+	f.mu.Unlock()
+
+	if onLookup != nil {
+		onLookup()
+	}
+	if err != nil {
+		return nil, err
+	}
+	resp := &dns.Msg{}
+	resp.SetReply(msg)
+	resp.Answer = answers
+	return resp, nil
+}
+
+func (f *fakeChain) setAnswer(name string, qtype uint16, ip string) {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	key := name + "|" + dns.TypeToString[qtype]
+	hdr := dns.RR_Header{Name: name, Rrtype: qtype, Class: dns.ClassINET, Ttl: 60}
+	switch qtype {
+	case dns.TypeA:
+		f.answers[key] = []dns.RR{&dns.A{Hdr: hdr, A: net.ParseIP(ip).To4()}}
+	case dns.TypeAAAA:
+		f.answers[key] = []dns.RR{&dns.AAAA{Hdr: hdr, AAAA: net.ParseIP(ip).To16()}}
+	}
+}
+
+func (f *fakeChain) callCount(name string, qtype uint16) int {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	return f.calls[name+"|"+dns.TypeToString[qtype]]
+}
+
+// waitFor polls the predicate until it returns true or the deadline passes.
+func waitFor(t *testing.T, d time.Duration, fn func() bool) {
+	t.Helper()
+	deadline := time.Now().Add(d)
+	for time.Now().Before(deadline) {
+		if fn() {
+			return
+		}
+		time.Sleep(5 * time.Millisecond)
+	}
+	t.Fatalf("condition not met within %s", d)
+}
+
+func queryA(t *testing.T, r *Resolver, name string) *dns.Msg {
+	t.Helper()
+	msg := new(dns.Msg)
+	msg.SetQuestion(name, dns.TypeA)
+	w := &test.MockResponseWriter{}
+	r.ServeDNS(w, msg)
+	return w.GetLastResponse()
+}
+
+func firstA(t *testing.T, resp *dns.Msg) string {
+	t.Helper()
+	require.NotNil(t, resp)
+	require.Greater(t, len(resp.Answer), 0, "expected at least one answer")
+	a, ok := resp.Answer[0].(*dns.A)
+	require.True(t, ok, "expected A record")
+	return a.A.String()
+}
+
+func TestResolver_CacheTTLGatesRefresh(t *testing.T) {
+	// Same cached entry age, different cacheTTL values: the shorter TTL must
+	// trigger a background refresh, the longer one must not. Proves that the
+	// per-Resolver cacheTTL field actually drives the stale decision.
+	cachedAt := time.Now().Add(-100 * time.Millisecond)
+
+	newRec := func() *cachedRecord {
+		return &cachedRecord{
+			records: []dns.RR{&dns.A{
+				Hdr: dns.RR_Header{Name: "mgmt.example.com.", Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: 60},
+				A:   net.ParseIP("10.0.0.1").To4(),
+			}},
+			cachedAt: cachedAt,
+		}
+	}
+	q := dns.Question{Name: "mgmt.example.com.", Qtype: dns.TypeA, Qclass: dns.ClassINET}
+
+	t.Run("short TTL treats entry as stale and refreshes", func(t *testing.T) {
+		r := NewResolver()
+		r.cacheTTL = 10 * time.Millisecond
+		chain := newFakeChain()
+		chain.setAnswer(q.Name, dns.TypeA, "10.0.0.2")
+		r.SetChainResolver(chain, 50)
+		r.records[q] = newRec()
+
+		resp := queryA(t, r, q.Name)
+		assert.Equal(t, "10.0.0.1", firstA(t, resp), "stale entry must be served while refresh runs")
+
+		waitFor(t, time.Second, func() bool {
+			return chain.callCount(q.Name, dns.TypeA) >= 1
+		})
+	})
+
+	t.Run("long TTL keeps entry fresh and skips refresh", func(t *testing.T) {
+		r := NewResolver()
+		r.cacheTTL = time.Hour
+		chain := newFakeChain()
+		chain.setAnswer(q.Name, dns.TypeA, "10.0.0.2")
+		r.SetChainResolver(chain, 50)
+		r.records[q] = newRec()
+
+		resp := queryA(t, r, q.Name)
+		assert.Equal(t, "10.0.0.1", firstA(t, resp))
+
+		time.Sleep(50 * time.Millisecond)
+		assert.Equal(t, 0, chain.callCount(q.Name, dns.TypeA), "fresh entry must not trigger refresh")
+	})
+}
+
+func TestResolver_ServeFresh_NoRefresh(t *testing.T) {
+	r := NewResolver()
+	chain := newFakeChain()
+	chain.setAnswer("mgmt.example.com.", dns.TypeA, "10.0.0.2")
+	r.SetChainResolver(chain, 50)
+
+	r.records[dns.Question{Name: "mgmt.example.com.", Qtype: dns.TypeA, Qclass: dns.ClassINET}] = &cachedRecord{
+		records: []dns.RR{&dns.A{
+			Hdr: dns.RR_Header{Name: "mgmt.example.com.", Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: 60},
+			A:   net.ParseIP("10.0.0.1").To4(),
+		}},
+		cachedAt: time.Now(), // fresh
+	}
+
+	resp := queryA(t, r, "mgmt.example.com.")
+	assert.Equal(t, "10.0.0.1", firstA(t, resp))
+
+	time.Sleep(20 * time.Millisecond)
+	assert.Equal(t, 0, chain.callCount("mgmt.example.com.", dns.TypeA), "fresh entry must not trigger refresh")
+}
+
+func TestResolver_StaleTriggersAsyncRefresh(t *testing.T) {
+	r := NewResolver()
+	chain := newFakeChain()
+	chain.setAnswer("mgmt.example.com.", dns.TypeA, "10.0.0.2")
+	r.SetChainResolver(chain, 50)
+
+	q := dns.Question{Name: "mgmt.example.com.", Qtype: dns.TypeA, Qclass: dns.ClassINET}
+	r.records[q] = &cachedRecord{
+		records: []dns.RR{&dns.A{
+			Hdr: dns.RR_Header{Name: q.Name, Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: 60},
+			A:   net.ParseIP("10.0.0.1").To4(),
+		}},
+		cachedAt: time.Now().Add(-2 * defaultTTL), // stale
+	}
+
+	// First query: serves stale immediately.
+	resp := queryA(t, r, "mgmt.example.com.")
+	assert.Equal(t, "10.0.0.1", firstA(t, resp), "stale entry must be served while refresh runs")
+
+	waitFor(t, time.Second, func() bool {
+		return chain.callCount("mgmt.example.com.", dns.TypeA) >= 1
+	})
+
+	// Next query should now return the refreshed IP.
+	waitFor(t, time.Second, func() bool {
+		resp := queryA(t, r, "mgmt.example.com.")
+		return resp != nil && len(resp.Answer) > 0 && firstA(t, resp) == "10.0.0.2"
+	})
+}
+
+func TestResolver_ConcurrentStaleHitsCollapseRefresh(t *testing.T) {
+	r := NewResolver()
+	chain := newFakeChain()
+	chain.setAnswer("mgmt.example.com.", dns.TypeA, "10.0.0.2")
+
+	var inflight atomic.Int32
+	var maxInflight atomic.Int32
+	chain.onLookup = func() {
+		cur := inflight.Add(1)
+		defer inflight.Add(-1)
+		for {
+			prev := maxInflight.Load()
+			if cur <= prev || maxInflight.CompareAndSwap(prev, cur) {
+				break
+			}
+		}
+		time.Sleep(50 * time.Millisecond) // hold inflight long enough to collide
+	}
+
+	r.SetChainResolver(chain, 50)
+
+	q := dns.Question{Name: "mgmt.example.com.", Qtype: dns.TypeA, Qclass: dns.ClassINET}
+	r.records[q] = &cachedRecord{
+		records: []dns.RR{&dns.A{
+			Hdr: dns.RR_Header{Name: q.Name, Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: 60},
+			A:   net.ParseIP("10.0.0.1").To4(),
+		}},
+		cachedAt: time.Now().Add(-2 * defaultTTL),
+	}
+
+	var wg sync.WaitGroup
+	for i := 0; i < 50; i++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			queryA(t, r, "mgmt.example.com.")
+		}()
+	}
+	wg.Wait()
+
+	waitFor(t, 2*time.Second, func() bool {
+		return inflight.Load() == 0
+	})
+
+	calls := chain.callCount("mgmt.example.com.", dns.TypeA)
+	assert.LessOrEqual(t, calls, 2, "singleflight must collapse concurrent refreshes (got %d)", calls)
+	assert.Equal(t, int32(1), maxInflight.Load(), "only one refresh should run concurrently")
+}
+
+func TestResolver_RefreshFailureArmsBackoff(t *testing.T) {
+	r := NewResolver()
+	chain := newFakeChain()
+	chain.err = errors.New("boom")
+	r.SetChainResolver(chain, 50)
+
+	q := dns.Question{Name: "mgmt.example.com.", Qtype: dns.TypeA, Qclass: dns.ClassINET}
+	r.records[q] = &cachedRecord{
+		records: []dns.RR{&dns.A{
+			Hdr: dns.RR_Header{Name: q.Name, Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: 60},
+			A:   net.ParseIP("10.0.0.1").To4(),
+		}},
+		cachedAt: time.Now().Add(-2 * defaultTTL),
+	}
+
+	// First stale hit triggers a refresh attempt that fails.
+	resp := queryA(t, r, "mgmt.example.com.")
+	assert.Equal(t, "10.0.0.1", firstA(t, resp), "stale entry served while refresh fails")
+
+	waitFor(t, time.Second, func() bool {
+		return chain.callCount("mgmt.example.com.", dns.TypeA) == 1
+	})
+	waitFor(t, time.Second, func() bool {
+		r.mutex.RLock()
+		defer r.mutex.RUnlock()
+		c, ok := r.records[q]
+		return ok && !c.lastFailedRefresh.IsZero()
+	})
+
+	// Subsequent stale hits within backoff window should not schedule more refreshes.
+	for i := 0; i < 10; i++ {
+		queryA(t, r, "mgmt.example.com.")
+	}
+	time.Sleep(50 * time.Millisecond)
+	assert.Equal(t, 1, chain.callCount("mgmt.example.com.", dns.TypeA), "backoff must suppress further refreshes")
+}
+
+func TestResolver_NoRootHandler_SkipsChain(t *testing.T) {
+	r := NewResolver()
+	chain := newFakeChain()
+	chain.hasRoot = false
+	chain.setAnswer("mgmt.example.com.", dns.TypeA, "10.0.0.2")
+	r.SetChainResolver(chain, 50)
+
+	// With hasRoot=false the chain must not be consulted. Use a short
+	// deadline so the OS fallback returns quickly without waiting on a
+	// real network call in CI.
+	ctx, cancel := context.WithTimeout(context.Background(), 50*time.Millisecond)
+	defer cancel()
+	_, _, _, _ = r.lookupBoth(ctx, domain.Domain("mgmt.example.com"), "mgmt.example.com.")
+
+	assert.Equal(t, 0, chain.callCount("mgmt.example.com.", dns.TypeA),
+		"chain must not be used when no root handler is registered at the bound priority")
+}
+
+func TestResolver_ServeDuringRefreshSetsLoopFlag(t *testing.T) {
+	// ServeDNS being invoked for a question while a refresh for that question
+	// is inflight indicates a resolver loop (OS resolver sent the recursive
+	// query back to us). The inflightRefresh.loopLoggedOnce flag must be set.
+	r := NewResolver()
+
+	q := dns.Question{Name: "mgmt.example.com.", Qtype: dns.TypeA, Qclass: dns.ClassINET}
+	r.records[q] = &cachedRecord{
+		records: []dns.RR{&dns.A{
+			Hdr: dns.RR_Header{Name: q.Name, Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: 60},
+			A:   net.ParseIP("10.0.0.1").To4(),
+		}},
+		cachedAt: time.Now(),
+	}
+
+	// Simulate an inflight refresh.
+	r.markRefreshing(q)
+	defer r.clearRefreshing(q)
+
+	resp := queryA(t, r, "mgmt.example.com.")
+	assert.Equal(t, "10.0.0.1", firstA(t, resp), "stale entry must still be served to avoid breaking external queries")
+
+	r.mutex.RLock()
+	inflight := r.refreshing[q]
+	r.mutex.RUnlock()
+	require.NotNil(t, inflight)
+	assert.True(t, inflight.Load(), "loop flag must be set once a ServeDNS during refresh was observed")
+}
+
+func TestResolver_LoopFlagOnlyTrippedOncePerRefresh(t *testing.T) {
+	r := NewResolver()
+
+	q := dns.Question{Name: "mgmt.example.com.", Qtype: dns.TypeA, Qclass: dns.ClassINET}
+	r.records[q] = &cachedRecord{
+		records: []dns.RR{&dns.A{
+			Hdr: dns.RR_Header{Name: q.Name, Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: 60},
+			A:   net.ParseIP("10.0.0.1").To4(),
+		}},
+		cachedAt: time.Now(),
+	}
+
+	r.markRefreshing(q)
+	defer r.clearRefreshing(q)
+
+	// Multiple ServeDNS calls during the same refresh must not re-set the flag
+	// (CompareAndSwap from false -> true returns true only on the first call).
+	for range 5 {
+		queryA(t, r, "mgmt.example.com.")
+	}
+
+	r.mutex.RLock()
+	inflight := r.refreshing[q]
+	r.mutex.RUnlock()
+	assert.True(t, inflight.Load())
+}
+
+func TestResolver_NoLoopFlagWhenNotRefreshing(t *testing.T) {
+	r := NewResolver()
+
+	q := dns.Question{Name: "mgmt.example.com.", Qtype: dns.TypeA, Qclass: dns.ClassINET}
+	r.records[q] = &cachedRecord{
+		records: []dns.RR{&dns.A{
+			Hdr: dns.RR_Header{Name: q.Name, Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: 60},
+			A:   net.ParseIP("10.0.0.1").To4(),
+		}},
+		cachedAt: time.Now(),
+	}
+
+	queryA(t, r, "mgmt.example.com.")
+
+	r.mutex.RLock()
+	_, ok := r.refreshing[q]
+	r.mutex.RUnlock()
+	assert.False(t, ok, "no refresh inflight means no loop tracking")
+}
+
+func TestResolver_AddDomain_UsesChainWhenRootRegistered(t *testing.T) {
+	r := NewResolver()
+	chain := newFakeChain()
+	chain.setAnswer("mgmt.example.com.", dns.TypeA, "10.0.0.2")
+	chain.setAnswer("mgmt.example.com.", dns.TypeAAAA, "fd00::2")
+	r.SetChainResolver(chain, 50)
+
+	require.NoError(t, r.AddDomain(context.Background(), domain.Domain("mgmt.example.com")))
+
+	resp := queryA(t, r, "mgmt.example.com.")
+	assert.Equal(t, "10.0.0.2", firstA(t, resp))
+	assert.Equal(t, 1, chain.callCount("mgmt.example.com.", dns.TypeA))
+	assert.Equal(t, 1, chain.callCount("mgmt.example.com.", dns.TypeAAAA))
+}

client/internal/dns/mgmt/mgmt_test.go

@@ -6,6 +6,7 @@ import (
 	"net/url"
 	"strings"
 	"testing"
+	"time"
 
 	"github.com/miekg/dns"
 	"github.com/stretchr/testify/assert"
@@ -23,6 +24,60 @@ func TestResolver_NewResolver(t *testing.T) {
 	assert.False(t, resolver.MatchSubdomains())
 }
 
+func TestResolveCacheTTL(t *testing.T) {
+	tests := []struct {
+		name  string
+		value string
+		want  time.Duration
+	}{
+		{"unset falls back to default", "", defaultTTL},
+		{"valid duration", "45s", 45 * time.Second},
+		{"valid minutes", "2m", 2 * time.Minute},
+		{"malformed falls back to default", "not-a-duration", defaultTTL},
+		{"zero falls back to default", "0s", defaultTTL},
+		{"negative falls back to default", "-5s", defaultTTL},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Setenv(envMgmtCacheTTL, tc.value)
+			got := resolveCacheTTL()
+			assert.Equal(t, tc.want, got, "parsed TTL should match")
+		})
+	}
+}
+
+func TestNewResolver_CacheTTLFromEnv(t *testing.T) {
+	t.Setenv(envMgmtCacheTTL, "7s")
+	r := NewResolver()
+	assert.Equal(t, 7*time.Second, r.cacheTTL, "NewResolver should evaluate cacheTTL once from env")
+}
+
+func TestResolver_ResponseTTL(t *testing.T) {
+	now := time.Now()
+	tests := []struct {
+		name     string
+		cacheTTL time.Duration
+		cachedAt time.Time
+		wantMin  uint32
+		wantMax  uint32
+	}{
+		{"fresh entry returns full TTL", 60 * time.Second, now, 59, 60},
+		{"half-aged entry returns half TTL", 60 * time.Second, now.Add(-30 * time.Second), 29, 31},
+		{"expired entry returns zero", 60 * time.Second, now.Add(-61 * time.Second), 0, 0},
+		{"exactly expired returns zero", 10 * time.Second, now.Add(-10 * time.Second), 0, 0},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			r := &Resolver{cacheTTL: tc.cacheTTL}
+			got := r.responseTTL(tc.cachedAt)
+			assert.GreaterOrEqual(t, got, tc.wantMin, "remaining TTL should be >= wantMin")
+			assert.LessOrEqual(t, got, tc.wantMax, "remaining TTL should be <= wantMax")
+		})
+	}
+}
+
 func TestResolver_ExtractDomainFromURL(t *testing.T) {
 	tests := []struct {
 		name        string

client/internal/dns/server.go

@@ -212,6 +212,7 @@ func newDefaultServer(
 	ctx, stop := context.WithCancel(ctx)
 
 	mgmtCacheResolver := mgmt.NewResolver()
+	mgmtCacheResolver.SetChainResolver(handlerChain, PriorityUpstream)
 
 	defaultServer := &DefaultServer{
 		ctx:               ctx,

client/internal/engine.go

@@ -26,7 +26,9 @@ import (
 
 	nberrors "github.com/netbirdio/netbird/client/errors"
 	"github.com/netbirdio/netbird/client/firewall"
+	"github.com/netbirdio/netbird/client/firewall/firewalld"
 	firewallManager "github.com/netbirdio/netbird/client/firewall/manager"
+	"github.com/netbirdio/netbird/client/firewall/uspfilter/forwarder"
 	"github.com/netbirdio/netbird/client/iface"
 	"github.com/netbirdio/netbird/client/iface/device"
 	nbnetstack "github.com/netbirdio/netbird/client/iface/netstack"
@@ -67,6 +69,7 @@ import (
 	signal "github.com/netbirdio/netbird/shared/signal/client"
 	sProto "github.com/netbirdio/netbird/shared/signal/proto"
 	"github.com/netbirdio/netbird/util"
+	"github.com/netbirdio/netbird/util/capture"
 )
 
 // PeerConnectionTimeoutMax is a timeout of an initial connection attempt to a remote peer.
@@ -140,6 +143,7 @@ type EngineConfig struct {
 	ProfileConfig *profilemanager.Config
 
 	LogPath string
+	TempDir string
 }
 
 // EngineServices holds the external service dependencies required by the Engine.
@@ -216,6 +220,8 @@ type Engine struct {
 	portForwardManager *portforward.Manager
 	srWatcher          *guard.SRWatcher
 
+	afpacketCapture *capture.AFPacketCapture
+
 	// Sync response persistence (protected by syncRespMux)
 	syncRespMux         sync.RWMutex
 	persistSyncResponse bool
@@ -569,7 +575,7 @@ func (e *Engine) Start(netbirdConfig *mgmProto.NetbirdConfig, mgmtURL *url.URL)
 	e.connMgr.Start(e.ctx)
 
 	e.srWatcher = guard.NewSRWatcher(e.signal, e.relayManager, e.mobileDep.IFaceDiscover, iceCfg)
-	e.srWatcher.Start()
+	e.srWatcher.Start(peer.IsForceRelayed())
 
 	e.receiveSignalEvents()
 	e.receiveManagementEvents()
@@ -603,6 +609,8 @@ func (e *Engine) createFirewall() error {
 		return nil
 	}
 
+	firewalld.SetParentContext(e.ctx)
+
 	var err error
 	e.firewall, err = firewall.NewFirewall(e.wgInterface, e.stateManager, e.flowManager.GetLogger(), e.config.DisableServerRoutes, e.config.MTU)
 	if err != nil {
@@ -940,7 +948,12 @@ func (e *Engine) handleRelayUpdate(update *mgmProto.RelayConfig) error {
 			return fmt.Errorf("update relay token: %w", err)
 		}
 
-		e.relayManager.UpdateServerURLs(update.Urls)
+		urls := update.Urls
+		if override, ok := peer.OverrideRelayURLs(); ok {
+			log.Infof("overriding relay URLs from %s: %v", peer.EnvKeyNBHomeRelayServers, override)
+			urls = override
+		}
+		e.relayManager.UpdateServerURLs(urls)
 
 		// Just in case the agent started with an MGM server where the relay was disabled but was later enabled.
 		// We can ignore all errors because the guard will manage the reconnection retries.
@@ -1095,6 +1108,7 @@ func (e *Engine) handleBundle(params *mgmProto.BundleParameters) (*mgmProto.JobR
 		StatusRecorder: e.statusRecorder,
 		SyncResponse:   syncResponse,
 		LogPath:        e.config.LogPath,
+		TempDir:        e.config.TempDir,
 		ClientMetrics:  e.clientMetrics,
 		RefreshStatus: func() {
 			e.RunHealthProbes(true)
@@ -1693,6 +1707,11 @@ func (e *Engine) parseNATExternalIPMappings() []string {
 }
 
 func (e *Engine) close() {
+	if e.afpacketCapture != nil {
+		e.afpacketCapture.Stop()
+		e.afpacketCapture = nil
+	}
+
 	log.Debugf("removing Netbird interface %s", e.config.WgIfaceName)
 
 	if e.wgInterface != nil {
@@ -2158,6 +2177,62 @@ func (e *Engine) Address() (netip.Addr, error) {
 	return e.wgInterface.Address().IP, nil
 }
 
+// SetCapture sets or clears packet capture on the WireGuard device.
+// On userspace WireGuard, it taps the FilteredDevice directly.
+// On kernel WireGuard (Linux), it falls back to AF_PACKET raw socket capture.
+// Pass nil to disable capture.
+func (e *Engine) SetCapture(pc device.PacketCapture) error {
+	e.syncMsgMux.Lock()
+	defer e.syncMsgMux.Unlock()
+
+	intf := e.wgInterface
+	if intf == nil {
+		return errors.New("wireguard interface not initialized")
+	}
+
+	if e.afpacketCapture != nil {
+		e.afpacketCapture.Stop()
+		e.afpacketCapture = nil
+	}
+
+	dev := intf.GetDevice()
+	if dev != nil {
+		dev.SetCapture(pc)
+		e.setForwarderCapture(pc)
+		return nil
+	}
+
+	// Kernel mode: no FilteredDevice. Use AF_PACKET on Linux.
+	if pc == nil {
+		return nil
+	}
+	sess, ok := pc.(*capture.Session)
+	if !ok {
+		return errors.New("filtered device not available and AF_PACKET requires *capture.Session")
+	}
+
+	afc := capture.NewAFPacketCapture(intf.Name(), sess)
+	if err := afc.Start(); err != nil {
+		return fmt.Errorf("start AF_PACKET capture on %s: %w", intf.Name(), err)
+	}
+	e.afpacketCapture = afc
+	return nil
+}
+
+// setForwarderCapture propagates capture to the USP filter's forwarder endpoint.
+// This captures outbound response packets that bypass the FilteredDevice in netstack mode.
+func (e *Engine) setForwarderCapture(pc device.PacketCapture) {
+	if e.firewall == nil {
+		return
+	}
+	type forwarderCapturer interface {
+		SetPacketCapture(pc forwarder.PacketCapture)
+	}
+	if fc, ok := e.firewall.(forwarderCapturer); ok {
+		fc.SetPacketCapture(pc)
+	}
+}
+
 func (e *Engine) updateForwardRules(rules []*mgmProto.ForwardingRule) ([]firewallManager.ForwardRule, error) {
 	if e.firewall == nil {
 		log.Warn("firewall is disabled, not updating forwarding rules")
@@ -2379,6 +2454,8 @@ func convertToOfferAnswer(msg *sProto.Message) (*peer.OfferAnswer, error) {
 		}
 	}
 
+	relayIP := decodeRelayIP(msg.GetBody().GetRelayServerIP())
+
 	offerAnswer := peer.OfferAnswer{
 		IceCredentials: peer.IceCredentials{
 			UFrag: remoteCred.UFrag,
@@ -2389,7 +2466,23 @@ func convertToOfferAnswer(msg *sProto.Message) (*peer.OfferAnswer, error) {
 		RosenpassPubKey: rosenpassPubKey,
 		RosenpassAddr:   rosenpassAddr,
 		RelaySrvAddress: msg.GetBody().GetRelayServerAddress(),
+		RelaySrvIP:      relayIP,
 		SessionID:       sessionID,
 	}
 	return &offerAnswer, nil
 }
+
+// decodeRelayIP decodes the proto relayServerIP bytes (4 or 16) into a
+// netip.Addr. Returns the zero value for empty input and logs a warning
+// for malformed payloads.
+func decodeRelayIP(b []byte) netip.Addr {
+	if len(b) == 0 {
+		return netip.Addr{}
+	}
+	ip, ok := netip.AddrFromSlice(b)
+	if !ok {
+		log.Warnf("invalid relayServerIP in signal message (%d bytes), ignoring", len(b))
+		return netip.Addr{}
+	}
+	return ip.Unmap()
+}

client/internal/engine_test.go

@@ -1671,7 +1671,7 @@ func startManagement(t *testing.T, dataDir, testFile string) (*grpc.Server, stri
 	if err != nil {
 		return nil, "", err
 	}
-	mgmtServer, err := nbgrpc.NewServer(config, accountManager, settingsMockManager, jobManager, secretsManager, nil, nil, &server.MockIntegratedValidator{}, networkMapController, nil)
+	mgmtServer, err := nbgrpc.NewServer(config, accountManager, settingsMockManager, jobManager, secretsManager, nil, nil, &server.MockIntegratedValidator{}, networkMapController, nil, nil)
 	if err != nil {
 		return nil, "", err
 	}

client/internal/lazyconn/activity/listener_bind_test.go

@@ -3,7 +3,6 @@ package activity
 import (
 	"net"
 	"net/netip"
-	"runtime"
 	"testing"
 	"time"
 
@@ -18,10 +17,6 @@ import (
 	peerid "github.com/netbirdio/netbird/client/internal/peer/id"
 )
 
-func isBindListenerPlatform() bool {
-	return runtime.GOOS == "windows" || runtime.GOOS == "js"
-}
-
 // mockEndpointManager implements device.EndpointManager for testing
 type mockEndpointManager struct {
 	endpoints map[netip.Addr]net.Conn
@@ -181,10 +176,6 @@ func TestBindListener_Close(t *testing.T) {
 }
 
 func TestManager_BindMode(t *testing.T) {
-	if !isBindListenerPlatform() {
-		t.Skip("BindListener only used on Windows/JS platforms")
-	}
-
 	mockEndpointMgr := newMockEndpointManager()
 	mockIface := &MockWGIfaceBind{endpointMgr: mockEndpointMgr}
 
@@ -226,10 +217,6 @@ func TestManager_BindMode(t *testing.T) {
 }
 
 func TestManager_BindMode_MultiplePeers(t *testing.T) {
-	if !isBindListenerPlatform() {
-		t.Skip("BindListener only used on Windows/JS platforms")
-	}
-
 	mockEndpointMgr := newMockEndpointManager()
 	mockIface := &MockWGIfaceBind{endpointMgr: mockEndpointMgr}
 

client/internal/lazyconn/activity/manager.go

@@ -4,14 +4,12 @@ import (
 	"errors"
 	"net"
 	"net/netip"
-	"runtime"
 	"sync"
 	"time"
 
 	log "github.com/sirupsen/logrus"
 	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
 
-	"github.com/netbirdio/netbird/client/iface/netstack"
 	"github.com/netbirdio/netbird/client/iface/wgaddr"
 	"github.com/netbirdio/netbird/client/internal/lazyconn"
 	peerid "github.com/netbirdio/netbird/client/internal/peer/id"
@@ -75,16 +73,6 @@ func (m *Manager) createListener(peerCfg lazyconn.PeerConfig) (listener, error)
 		return NewUDPListener(m.wgIface, peerCfg)
 	}
 
-	// BindListener is used on Windows, JS, and netstack platforms:
-	// - JS: Cannot listen to UDP sockets
-	// - Windows: IP_UNICAST_IF socket option forces packets out the interface the default
-	//   gateway points to, preventing them from reaching the loopback interface.
-	// - Netstack: Allows multiple instances on the same host without port conflicts.
-	// BindListener bypasses these issues by passing data directly through the bind.
-	if runtime.GOOS != "windows" && runtime.GOOS != "js" && !netstack.IsEnabled() {
-		return NewUDPListener(m.wgIface, peerCfg)
-	}
-
 	provider, ok := m.wgIface.(bindProvider)
 	if !ok {
 		return nil, errors.New("interface claims userspace bind but doesn't implement bindProvider")

client/internal/lazyconn/manager/manager.go

@@ -6,7 +6,6 @@ import (
 	"time"
 
 	log "github.com/sirupsen/logrus"
-	"golang.org/x/exp/maps"
 
 	"github.com/netbirdio/netbird/client/internal/lazyconn"
 	"github.com/netbirdio/netbird/client/internal/lazyconn/activity"
@@ -91,8 +90,8 @@ func (m *Manager) UpdateRouteHAMap(haMap route.HAMap) {
 	m.routesMu.Lock()
 	defer m.routesMu.Unlock()
 
-	maps.Clear(m.peerToHAGroups)
+	clear(m.peerToHAGroups)
-	maps.Clear(m.haGroupToPeers)
+	clear(m.haGroupToPeers)
 
 	for haUniqueID, routes := range haMap {
 		var peers []string

client/internal/mobile_dependency.go

@@ -22,4 +22,8 @@ type MobileDependency struct {
 	DnsManager     dns.IosDnsManager
 	FileDescriptor int32
 	StateFilePath  string
+
+	// TempDir is a writable directory for temporary files (e.g., debug bundle zip).
+	// On Android, this should be set to the app's cache directory.
+	TempDir string
 }

client/internal/netflow/store/memory.go

@@ -3,8 +3,6 @@ package store
 import (
 	"sync"
 
-	"golang.org/x/exp/maps"
-
 	"github.com/google/uuid"
 
 	"github.com/netbirdio/netbird/client/internal/netflow/types"
@@ -30,7 +28,7 @@ func (m *Memory) StoreEvent(event *types.Event) {
 func (m *Memory) Close() {
 	m.mux.Lock()
 	defer m.mux.Unlock()
-	maps.Clear(m.events)
+	clear(m.events)
 }
 
 func (m *Memory) GetEvents() []*types.Event {

client/internal/peer/conn.go

@@ -185,17 +185,20 @@ func (conn *Conn) Open(engineCtx context.Context) error {
 
 	conn.workerRelay = NewWorkerRelay(conn.ctx, conn.Log, isController(conn.config), conn.config, conn, conn.relayManager)
 
-	relayIsSupportedLocally := conn.workerRelay.RelayIsSupportedLocally()
+	forceRelay := IsForceRelayed()
-	workerICE, err := NewWorkerICE(conn.ctx, conn.Log, conn.config, conn, conn.signaler, conn.iFaceDiscover, conn.statusRecorder, relayIsSupportedLocally)
+	if !forceRelay {
-	if err != nil {
+		relayIsSupportedLocally := conn.workerRelay.RelayIsSupportedLocally()
-		return err
+		workerICE, err := NewWorkerICE(conn.ctx, conn.Log, conn.config, conn, conn.signaler, conn.iFaceDiscover, conn.statusRecorder, relayIsSupportedLocally)
+		if err != nil {
+			return err
+		}
+		conn.workerICE = workerICE
 	}
-	conn.workerICE = workerICE
 
 	conn.handshaker = NewHandshaker(conn.Log, conn.config, conn.signaler, conn.workerICE, conn.workerRelay, conn.metricsStages)
 
 	conn.handshaker.AddRelayListener(conn.workerRelay.OnNewOffer)
-	if !isForceRelayed() {
+	if !forceRelay {
 		conn.handshaker.AddICEListener(conn.workerICE.OnNewOffer)
 	}
 
@@ -251,7 +254,9 @@ func (conn *Conn) Close(signalToRemote bool) {
 		conn.wgWatcherCancel()
 	}
 	conn.workerRelay.CloseConn()
-	conn.workerICE.Close()
+	if conn.workerICE != nil {
+		conn.workerICE.Close()
+	}
 
 	if conn.wgProxyRelay != nil {
 		err := conn.wgProxyRelay.CloseConn()
@@ -294,7 +299,9 @@ func (conn *Conn) OnRemoteAnswer(answer OfferAnswer) {
 // OnRemoteCandidate Handles ICE connection Candidate provided by the remote peer.
 func (conn *Conn) OnRemoteCandidate(candidate ice.Candidate, haRoutes route.HAMap) {
 	conn.dumpState.RemoteCandidate()
-	conn.workerICE.OnRemoteCandidate(candidate, haRoutes)
+	if conn.workerICE != nil {
+		conn.workerICE.OnRemoteCandidate(candidate, haRoutes)
+	}
 }
 
 // SetOnConnected sets a handler function to be triggered by Conn when a new connection to a remote peer established
@@ -712,33 +719,35 @@ func (conn *Conn) evalStatus() ConnStatus {
 	return StatusConnecting
 }
 
-func (conn *Conn) isConnectedOnAllWay() (connected bool) {
+// isConnectedOnAllWay evaluates the overall connection status based on ICE and Relay transports.
-	// would be better to protect this with a mutex, but it could cause deadlock with Close function
+//
-
+// The result is a tri-state:
+//   - ConnStatusConnected:          all available transports are up
+//   - ConnStatusPartiallyConnected: relay is up but ICE is still pending/reconnecting
+//   - ConnStatusDisconnected:       no working transport
+func (conn *Conn) isConnectedOnAllWay() (status guard.ConnStatus) {
 	defer func() {
-		if !connected {
+		if status == guard.ConnStatusDisconnected {
 			conn.logTraceConnState()
 		}
 	}()
 
-	// For JS platform: only relay connection is supported
+	iceWorkerCreated := conn.workerICE != nil
-	if runtime.GOOS == "js" {
+
-		return conn.statusRelay.Get() == worker.StatusConnected
+	var iceInProgress bool
+	if iceWorkerCreated {
+		iceInProgress = conn.workerICE.InProgress()
 	}
 
-	// For non-JS platforms: check ICE connection status
+	return evalConnStatus(connStatusInputs{
-	if conn.statusICE.Get() == worker.StatusDisconnected && !conn.workerICE.InProgress() {
+		forceRelay:          IsForceRelayed(),
-		return false
+		peerUsesRelay:       conn.workerRelay.IsRelayConnectionSupportedWithPeer(),
-	}
+		relayConnected:      conn.statusRelay.Get() == worker.StatusConnected,
-
+		remoteSupportsICE:   conn.handshaker.RemoteICESupported(),
-	// If relay is supported with peer, it must also be connected
+		iceWorkerCreated:    iceWorkerCreated,
-	if conn.workerRelay.IsRelayConnectionSupportedWithPeer() {
+		iceStatusConnecting: conn.statusICE.Get() != worker.StatusDisconnected,
-		if conn.statusRelay.Get() == worker.StatusDisconnected {
+		iceInProgress:       iceInProgress,
-			return false
+	})
-		}
-	}
-
-	return true
 }
 
 func (conn *Conn) enableWgWatcherIfNeeded(enabledTime time.Time) {
@@ -926,3 +935,43 @@ func isController(config ConnConfig) bool {
 func isRosenpassEnabled(remoteRosenpassPubKey []byte) bool {
 	return remoteRosenpassPubKey != nil
 }
+
+func evalConnStatus(in connStatusInputs) guard.ConnStatus {
+	// "Relay up and needed" — the peer uses relay and the transport is connected.
+	relayUsedAndUp := in.peerUsesRelay && in.relayConnected
+
+	// Force-relay mode: ICE never runs. Relay is the only transport and must be up.
+	if in.forceRelay {
+		return boolToConnStatus(relayUsedAndUp)
+	}
+
+	// Remote peer doesn't support ICE, or we haven't created the worker yet:
+	// relay is the only possible transport.
+	if !in.remoteSupportsICE || !in.iceWorkerCreated {
+		return boolToConnStatus(relayUsedAndUp)
+	}
+
+	// ICE counts as "up" when the status is anything other than Disconnected, OR
+	// when a negotiation is currently in progress (so we don't spam offers while one is in flight).
+	iceUp := in.iceStatusConnecting || in.iceInProgress
+
+	// Relay side is acceptable if the peer doesn't rely on relay, or relay is connected.
+	relayOK := !in.peerUsesRelay || in.relayConnected
+
+	switch {
+	case iceUp && relayOK:
+		return guard.ConnStatusConnected
+	case relayUsedAndUp:
+		// Relay is up but ICE is down — partially connected.
+		return guard.ConnStatusPartiallyConnected
+	default:
+		return guard.ConnStatusDisconnected
+	}
+}
+
+func boolToConnStatus(connected bool) guard.ConnStatus {
+	if connected {
+		return guard.ConnStatusConnected
+	}
+	return guard.ConnStatusDisconnected
+}

client/internal/peer/conn_status.go

@@ -13,6 +13,20 @@ const (
 	StatusConnected
 )
 
+// connStatusInputs is the primitive-valued snapshot of the state that drives the
+// tri-state connection classification. Extracted so the decision logic can be unit-tested
+// without constructing full Worker/Handshaker objects.
+type connStatusInputs struct {
+	forceRelay          bool // NB_FORCE_RELAY or JS/WASM
+	peerUsesRelay       bool // remote peer advertises relay support AND local has relay
+	relayConnected      bool // statusRelay reports Connected (independent of whether peer uses relay)
+	remoteSupportsICE   bool // remote peer sent ICE credentials
+	iceWorkerCreated    bool // local WorkerICE exists (false in force-relay mode)
+	iceStatusConnecting bool // statusICE is anything other than Disconnected
+	iceInProgress       bool // a negotiation is currently in flight
+}
+
+
 // ConnStatus describe the status of a peer's connection
 type ConnStatus int32
 

client/internal/peer/conn_status_eval_test.go

@@ -0,0 +1,201 @@
+package peer
+
+import (
+	"testing"
+
+	"github.com/netbirdio/netbird/client/internal/peer/guard"
+)
+
+func TestEvalConnStatus_ForceRelay(t *testing.T) {
+	tests := []struct {
+		name string
+		in   connStatusInputs
+		want guard.ConnStatus
+	}{
+		{
+			name: "force relay, peer uses relay, relay up",
+			in: connStatusInputs{
+				forceRelay:     true,
+				peerUsesRelay:  true,
+				relayConnected: true,
+			},
+			want: guard.ConnStatusConnected,
+		},
+		{
+			name: "force relay, peer uses relay, relay down",
+			in: connStatusInputs{
+				forceRelay:     true,
+				peerUsesRelay:  true,
+				relayConnected: false,
+			},
+			want: guard.ConnStatusDisconnected,
+		},
+		{
+			name: "force relay, peer does NOT use relay - disconnected forever",
+			in: connStatusInputs{
+				forceRelay:     true,
+				peerUsesRelay:  false,
+				relayConnected: true,
+			},
+			want: guard.ConnStatusDisconnected,
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			if got := evalConnStatus(tc.in); got != tc.want {
+				t.Fatalf("evalConnStatus = %v, want %v", got, tc.want)
+			}
+		})
+	}
+}
+
+func TestEvalConnStatus_ICEUnavailable(t *testing.T) {
+	tests := []struct {
+		name string
+		in   connStatusInputs
+		want guard.ConnStatus
+	}{
+		{
+			name: "remote does not support ICE, peer uses relay, relay up",
+			in: connStatusInputs{
+				peerUsesRelay:     true,
+				relayConnected:    true,
+				remoteSupportsICE: false,
+				iceWorkerCreated:  true,
+			},
+			want: guard.ConnStatusConnected,
+		},
+		{
+			name: "remote does not support ICE, peer uses relay, relay down",
+			in: connStatusInputs{
+				peerUsesRelay:     true,
+				relayConnected:    false,
+				remoteSupportsICE: false,
+				iceWorkerCreated:  true,
+			},
+			want: guard.ConnStatusDisconnected,
+		},
+		{
+			name: "ICE worker not yet created, relay up",
+			in: connStatusInputs{
+				peerUsesRelay:     true,
+				relayConnected:    true,
+				remoteSupportsICE: true,
+				iceWorkerCreated:  false,
+			},
+			want: guard.ConnStatusConnected,
+		},
+		{
+			name: "remote does not support ICE, peer does not use relay",
+			in: connStatusInputs{
+				peerUsesRelay:     false,
+				relayConnected:    false,
+				remoteSupportsICE: false,
+				iceWorkerCreated:  true,
+			},
+			want: guard.ConnStatusDisconnected,
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			if got := evalConnStatus(tc.in); got != tc.want {
+				t.Fatalf("evalConnStatus = %v, want %v", got, tc.want)
+			}
+		})
+	}
+}
+
+func TestEvalConnStatus_FullyAvailable(t *testing.T) {
+	base := connStatusInputs{
+		remoteSupportsICE: true,
+		iceWorkerCreated:  true,
+	}
+
+	tests := []struct {
+		name    string
+		mutator func(*connStatusInputs)
+		want    guard.ConnStatus
+	}{
+		{
+			name: "ICE connected, relay connected, peer uses relay",
+			mutator: func(in *connStatusInputs) {
+				in.peerUsesRelay = true
+				in.relayConnected = true
+				in.iceStatusConnecting = true
+			},
+			want: guard.ConnStatusConnected,
+		},
+		{
+			name: "ICE connected, peer does NOT use relay",
+			mutator: func(in *connStatusInputs) {
+				in.peerUsesRelay = false
+				in.relayConnected = false
+				in.iceStatusConnecting = true
+			},
+			want: guard.ConnStatusConnected,
+		},
+		{
+			name: "ICE InProgress only, peer does NOT use relay",
+			mutator: func(in *connStatusInputs) {
+				in.peerUsesRelay = false
+				in.iceStatusConnecting = false
+				in.iceInProgress = true
+			},
+			want: guard.ConnStatusConnected,
+		},
+		{
+			name: "ICE down, relay up, peer uses relay -> partial",
+			mutator: func(in *connStatusInputs) {
+				in.peerUsesRelay = true
+				in.relayConnected = true
+				in.iceStatusConnecting = false
+				in.iceInProgress = false
+			},
+			want: guard.ConnStatusPartiallyConnected,
+		},
+		{
+			name: "ICE down, peer does NOT use relay -> disconnected",
+			mutator: func(in *connStatusInputs) {
+				in.peerUsesRelay = false
+				in.relayConnected = false
+				in.iceStatusConnecting = false
+				in.iceInProgress = false
+			},
+			want: guard.ConnStatusDisconnected,
+		},
+		{
+			name: "ICE up, peer uses relay but relay down -> partial (relay required, ICE ignored)",
+			mutator: func(in *connStatusInputs) {
+				in.peerUsesRelay = true
+				in.relayConnected = false
+				in.iceStatusConnecting = true
+			},
+			// relayOK = false (peer uses relay but it's down), iceUp = true
+			// first switch arm fails (relayOK false), relayUsedAndUp = false (relay down),
+			// falls into default: Disconnected.
+			want: guard.ConnStatusDisconnected,
+		},
+		{
+			name: "ICE down, relay up but peer does not use relay -> disconnected",
+			mutator: func(in *connStatusInputs) {
+				in.peerUsesRelay = false
+				in.relayConnected = true // not actually used since peer doesn't rely on it
+				in.iceStatusConnecting = false
+				in.iceInProgress = false
+			},
+			want: guard.ConnStatusDisconnected,
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			in := base
+			tc.mutator(&in)
+			if got := evalConnStatus(in); got != tc.want {
+				t.Fatalf("evalConnStatus = %v, want %v (inputs: %+v)", got, tc.want, in)
+			}
+		})
+	}
+}

client/internal/peer/env.go

@@ -7,12 +7,38 @@ import (
 )
 
 const (
-	EnvKeyNBForceRelay = "NB_FORCE_RELAY"
+	EnvKeyNBForceRelay       = "NB_FORCE_RELAY"
+	EnvKeyNBHomeRelayServers = "NB_HOME_RELAY_SERVERS"
 )
 
-func isForceRelayed() bool {
+func IsForceRelayed() bool {
 	if runtime.GOOS == "js" {
 		return true
 	}
 	return strings.EqualFold(os.Getenv(EnvKeyNBForceRelay), "true")
 }
+
+// OverrideRelayURLs returns the relay server URL list set in
+// NB_HOME_RELAY_SERVERS (comma-separated) and a boolean indicating whether
+// the override is active. When the env var is unset, the boolean is false
+// and the caller should keep the list received from the management server.
+// Intended for lab/debug scenarios where a peer must pin to a specific home
+// relay regardless of what management offers.
+func OverrideRelayURLs() ([]string, bool) {
+	raw := os.Getenv(EnvKeyNBHomeRelayServers)
+	if raw == "" {
+		return nil, false
+	}
+	parts := strings.Split(raw, ",")
+	urls := make([]string, 0, len(parts))
+	for _, p := range parts {
+		p = strings.TrimSpace(p)
+		if p != "" {
+			urls = append(urls, p)
+		}
+	}
+	if len(urls) == 0 {
+		return nil, false
+	}
+	return urls, true
+}

client/internal/peer/guard/guard.go

@@ -8,7 +8,19 @@ import (
 	log "github.com/sirupsen/logrus"
 )
 
-type isConnectedFunc func() bool
+// ConnStatus represents the connection state as seen by the guard.
+type ConnStatus int
+
+const (
+	// ConnStatusDisconnected means neither ICE nor Relay is connected.
+	ConnStatusDisconnected ConnStatus = iota
+	// ConnStatusPartiallyConnected means Relay is connected but ICE is not.
+	ConnStatusPartiallyConnected
+	// ConnStatusConnected means all required connections are established.
+	ConnStatusConnected
+)
+
+type connStatusFunc func() ConnStatus
 
 // Guard is responsible for the reconnection logic.
 // It will trigger to send an offer to the peer then has connection issues.
@@ -20,14 +32,14 @@ type isConnectedFunc func() bool
 // - ICE candidate changes
 type Guard struct {
 	log                     *log.Entry
-	isConnectedOnAllWay     isConnectedFunc
+	isConnectedOnAllWay     connStatusFunc
 	timeout                 time.Duration
 	srWatcher               *SRWatcher
 	relayedConnDisconnected chan struct{}
 	iCEConnDisconnected     chan struct{}
 }
 
-func NewGuard(log *log.Entry, isConnectedFn isConnectedFunc, timeout time.Duration, srWatcher *SRWatcher) *Guard {
+func NewGuard(log *log.Entry, isConnectedFn connStatusFunc, timeout time.Duration, srWatcher *SRWatcher) *Guard {
 	return &Guard{
 		log:                     log,
 		isConnectedOnAllWay:     isConnectedFn,
@@ -57,8 +69,17 @@ func (g *Guard) SetICEConnDisconnected() {
 	}
 }
 
-// reconnectLoopWithRetry periodically check the connection status.
+// reconnectLoopWithRetry periodically checks the connection status and sends offers to re-establish connectivity.
-// Try to send offer while the P2P is not established or while the Relay is not connected if is it supported
+//
+// Behavior depends on the connection state reported by isConnectedOnAllWay:
+//   - Connected: no action, the peer is fully reachable.
+//   - Disconnected (neither ICE nor Relay): retries aggressively with exponential backoff (800ms doubling
+//     up to timeout), never gives up. This ensures rapid recovery when the peer has no connectivity at all.
+//   - PartiallyConnected (Relay up, ICE not): retries up to 3 times with exponential backoff, then switches
+//     to one attempt per hour. This limits signaling traffic when relay already provides connectivity.
+//
+// External events (relay/ICE disconnect, signal/relay reconnect, candidate changes) reset the retry
+// counter and backoff ticker, giving ICE a fresh chance after network conditions change.
 func (g *Guard) reconnectLoopWithRetry(ctx context.Context, callback func()) {
 	srReconnectedChan := g.srWatcher.NewListener()
 	defer g.srWatcher.RemoveListener(srReconnectedChan)
@@ -68,36 +89,47 @@ func (g *Guard) reconnectLoopWithRetry(ctx context.Context, callback func()) {
 
 	tickerChannel := ticker.C
 
+	iceState := &iceRetryState{log: g.log}
+	defer iceState.reset()
+
 	for {
 		select {
-		case t := <-tickerChannel:
+		case <-tickerChannel:
-			if t.IsZero() {
+			switch g.isConnectedOnAllWay() {
-				g.log.Infof("retry timed out, stop periodic offer sending")
+			case ConnStatusConnected:
-				// after backoff timeout the ticker.C will be closed. We need to a dummy channel to avoid loop
+				// all good, nothing to do
-				tickerChannel = make(<-chan time.Time)
+			case ConnStatusDisconnected:
-				continue
+				callback()
+			case ConnStatusPartiallyConnected:
+				if iceState.shouldRetry() {
+					callback()
+				} else {
+					iceState.enterHourlyMode()
+					ticker.Stop()
+					tickerChannel = iceState.hourlyC()
+				}
 			}
 
-			if !g.isConnectedOnAllWay() {
-				callback()
-			}
 		case <-g.relayedConnDisconnected:
 			g.log.Debugf("Relay connection changed, reset reconnection ticker")
 			ticker.Stop()
-			ticker = g.prepareExponentTicker(ctx)
+			ticker = g.newReconnectTicker(ctx)
 			tickerChannel = ticker.C
+			iceState.reset()
 
 		case <-g.iCEConnDisconnected:
 			g.log.Debugf("ICE connection changed, reset reconnection ticker")
 			ticker.Stop()
-			ticker = g.prepareExponentTicker(ctx)
+			ticker = g.newReconnectTicker(ctx)
 			tickerChannel = ticker.C
+			iceState.reset()
 
 		case <-srReconnectedChan:
 			g.log.Debugf("has network changes, reset reconnection ticker")
 			ticker.Stop()
-			ticker = g.prepareExponentTicker(ctx)
+			ticker = g.newReconnectTicker(ctx)
 			tickerChannel = ticker.C
+			iceState.reset()
 
 		case <-ctx.Done():
 			g.log.Debugf("context is done, stop reconnect loop")
@@ -120,7 +152,7 @@ func (g *Guard) initialTicker(ctx context.Context) *backoff.Ticker {
 	return backoff.NewTicker(bo)
 }
 
-func (g *Guard) prepareExponentTicker(ctx context.Context) *backoff.Ticker {
+func (g *Guard) newReconnectTicker(ctx context.Context) *backoff.Ticker {
 	bo := backoff.WithContext(&backoff.ExponentialBackOff{
 		InitialInterval:     800 * time.Millisecond,
 		RandomizationFactor: 0.1,

client/internal/peer/guard/ice_retry_state.go

@@ -0,0 +1,61 @@
+package guard
+
+import (
+	"time"
+
+	log "github.com/sirupsen/logrus"
+)
+
+const (
+	// maxICERetries is the maximum number of ICE offer attempts when relay is connected
+	maxICERetries = 3
+	// iceRetryInterval is the periodic retry interval after ICE retries are exhausted
+	iceRetryInterval = 1 * time.Hour
+)
+
+// iceRetryState tracks the limited ICE retry attempts when relay is already connected.
+// After maxICERetries attempts it switches to a periodic hourly retry.
+type iceRetryState struct {
+	log     *log.Entry
+	retries int
+	hourly  *time.Ticker
+}
+
+func (s *iceRetryState) reset() {
+	s.retries = 0
+	if s.hourly != nil {
+		s.hourly.Stop()
+		s.hourly = nil
+	}
+}
+
+// shouldRetry reports whether the caller should send another ICE offer on this tick.
+// Returns false when the per-cycle retry budget is exhausted and the caller must switch
+// to the hourly ticker via enterHourlyMode + hourlyC.
+func (s *iceRetryState) shouldRetry() bool {
+	if s.hourly != nil {
+		s.log.Debugf("hourly ICE retry attempt")
+		return true
+	}
+
+	s.retries++
+	if s.retries <= maxICERetries {
+		s.log.Debugf("ICE retry attempt %d/%d", s.retries, maxICERetries)
+		return true
+	}
+
+	return false
+}
+
+// enterHourlyMode starts the hourly retry ticker. Must be called after shouldRetry returns false.
+func (s *iceRetryState) enterHourlyMode() {
+	s.log.Infof("ICE retries exhausted (%d/%d), switching to hourly retry", maxICERetries, maxICERetries)
+	s.hourly = time.NewTicker(iceRetryInterval)
+}
+
+func (s *iceRetryState) hourlyC() <-chan time.Time {
+	if s.hourly == nil {
+		return nil
+	}
+	return s.hourly.C
+}

client/internal/peer/guard/ice_retry_state_test.go

@@ -0,0 +1,103 @@
+package guard
+
+import (
+	"testing"
+
+	log "github.com/sirupsen/logrus"
+)
+
+func newTestRetryState() *iceRetryState {
+	return &iceRetryState{log: log.NewEntry(log.StandardLogger())}
+}
+
+func TestICERetryState_AllowsInitialBudget(t *testing.T) {
+	s := newTestRetryState()
+
+	for i := 1; i <= maxICERetries; i++ {
+		if !s.shouldRetry() {
+			t.Fatalf("shouldRetry returned false on attempt %d, want true (budget = %d)", i, maxICERetries)
+		}
+	}
+}
+
+func TestICERetryState_ExhaustsAfterBudget(t *testing.T) {
+	s := newTestRetryState()
+
+	for i := 0; i < maxICERetries; i++ {
+		_ = s.shouldRetry()
+	}
+
+	if s.shouldRetry() {
+		t.Fatalf("shouldRetry returned true after budget exhausted, want false")
+	}
+}
+
+func TestICERetryState_HourlyCNilBeforeEnterHourlyMode(t *testing.T) {
+	s := newTestRetryState()
+
+	if s.hourlyC() != nil {
+		t.Fatalf("hourlyC returned non-nil channel before enterHourlyMode")
+	}
+}
+
+func TestICERetryState_EnterHourlyModeArmsTicker(t *testing.T) {
+	s := newTestRetryState()
+	for i := 0; i < maxICERetries+1; i++ {
+		_ = s.shouldRetry()
+	}
+
+	s.enterHourlyMode()
+	defer s.reset()
+
+	if s.hourlyC() == nil {
+		t.Fatalf("hourlyC returned nil after enterHourlyMode")
+	}
+}
+
+func TestICERetryState_ShouldRetryTrueInHourlyMode(t *testing.T) {
+	s := newTestRetryState()
+	s.enterHourlyMode()
+	defer s.reset()
+
+	if !s.shouldRetry() {
+		t.Fatalf("shouldRetry returned false in hourly mode, want true")
+	}
+
+	// Subsequent calls also return true — we keep retrying on each hourly tick.
+	if !s.shouldRetry() {
+		t.Fatalf("second shouldRetry returned false in hourly mode, want true")
+	}
+}
+
+func TestICERetryState_ResetRestoresBudget(t *testing.T) {
+	s := newTestRetryState()
+	for i := 0; i < maxICERetries+1; i++ {
+		_ = s.shouldRetry()
+	}
+	s.enterHourlyMode()
+
+	s.reset()
+
+	if s.hourlyC() != nil {
+		t.Fatalf("hourlyC returned non-nil channel after reset")
+	}
+	if s.retries != 0 {
+		t.Fatalf("retries = %d after reset, want 0", s.retries)
+	}
+
+	for i := 1; i <= maxICERetries; i++ {
+		if !s.shouldRetry() {
+			t.Fatalf("shouldRetry returned false on attempt %d after reset, want true", i)
+		}
+	}
+}
+
+func TestICERetryState_ResetIsIdempotent(t *testing.T) {
+	s := newTestRetryState()
+	s.reset()
+	s.reset() // second call must not panic or re-stop a nil ticker
+
+	if s.hourlyC() != nil {
+		t.Fatalf("hourlyC non-nil after double reset")
+	}
+}

client/internal/peer/guard/sr_watcher.go

@@ -39,7 +39,7 @@ func NewSRWatcher(signalClient chNotifier, relayManager chNotifier, iFaceDiscove
 	return srw
 }
 
-func (w *SRWatcher) Start() {
+func (w *SRWatcher) Start(disableICEMonitor bool) {
 	w.mu.Lock()
 	defer w.mu.Unlock()
 
@@ -50,8 +50,10 @@ func (w *SRWatcher) Start() {
 	ctx, cancel := context.WithCancel(context.Background())
 	w.cancelIceMonitor = cancel
 
-	iceMonitor := NewICEMonitor(w.iFaceDiscover, w.iceConfig, GetICEMonitorPeriod())
+	if !disableICEMonitor {
-	go iceMonitor.Start(ctx, w.onICEChanged)
+		iceMonitor := NewICEMonitor(w.iFaceDiscover, w.iceConfig, GetICEMonitorPeriod())
+		go iceMonitor.Start(ctx, w.onICEChanged)
+	}
 	w.signalClient.SetOnReconnectedListener(w.onReconnected)
 	w.relayManager.SetOnReconnectedListener(w.onReconnected)
 

client/internal/peer/handshaker.go

@@ -3,7 +3,9 @@ package peer
 import (
 	"context"
 	"errors"
+	"net/netip"
 	"sync"
+	"sync/atomic"
 
 	log "github.com/sirupsen/logrus"
 
@@ -39,10 +41,18 @@ type OfferAnswer struct {
 
 	// relay server address
 	RelaySrvAddress string
+	// RelaySrvIP is the IP the remote peer is connected to on its
+	// relay server. Used as a dial target if DNS for RelaySrvAddress
+	// fails. Zero value if the peer did not advertise an IP.
+	RelaySrvIP netip.Addr
 	// SessionID is the unique identifier of the session, used to discard old messages
 	SessionID *ICESessionID
 }
 
+func (o *OfferAnswer) hasICECredentials() bool {
+	return o.IceCredentials.UFrag != "" && o.IceCredentials.Pwd != ""
+}
+
 type Handshaker struct {
 	mu            sync.Mutex
 	log           *log.Entry
@@ -59,6 +69,10 @@ type Handshaker struct {
 	relayListener *AsyncOfferListener
 	iceListener   func(remoteOfferAnswer *OfferAnswer)
 
+	// remoteICESupported tracks whether the remote peer includes ICE credentials in its offers/answers.
+	// When false, the local side skips ICE listener dispatch and suppresses ICE credentials in responses.
+	remoteICESupported atomic.Bool
+
 	// remoteOffersCh is a channel used to wait for remote credentials to proceed with the connection
 	remoteOffersCh chan OfferAnswer
 	// remoteAnswerCh is a channel used to wait for remote credentials answer (confirmation of our offer) to proceed with the connection
@@ -66,7 +80,7 @@ type Handshaker struct {
 }
 
 func NewHandshaker(log *log.Entry, config ConnConfig, signaler *Signaler, ice *WorkerICE, relay *WorkerRelay, metricsStages *MetricsStages) *Handshaker {
-	return &Handshaker{
+	h := &Handshaker{
 		log:            log,
 		config:         config,
 		signaler:       signaler,
@@ -76,6 +90,13 @@ func NewHandshaker(log *log.Entry, config ConnConfig, signaler *Signaler, ice *W
 		remoteOffersCh: make(chan OfferAnswer),
 		remoteAnswerCh: make(chan OfferAnswer),
 	}
+	// assume remote supports ICE until we learn otherwise from received offers
+	h.remoteICESupported.Store(ice != nil)
+	return h
+}
+
+func (h *Handshaker) RemoteICESupported() bool {
+	return h.remoteICESupported.Load()
 }
 
 func (h *Handshaker) AddRelayListener(offer func(remoteOfferAnswer *OfferAnswer)) {
@@ -90,18 +111,20 @@ func (h *Handshaker) Listen(ctx context.Context) {
 	for {
 		select {
 		case remoteOfferAnswer := <-h.remoteOffersCh:
-			h.log.Infof("received offer, running version %s, remote WireGuard listen port %d, session id: %s", remoteOfferAnswer.Version, remoteOfferAnswer.WgListenPort, remoteOfferAnswer.SessionIDString())
+			h.log.Infof("received offer, running version %s, remote WireGuard listen port %d, session id: %s, remote ICE supported: %t", remoteOfferAnswer.Version, remoteOfferAnswer.WgListenPort, remoteOfferAnswer.SessionIDString(), remoteOfferAnswer.hasICECredentials())
 
 			// Record signaling received for reconnection attempts
 			if h.metricsStages != nil {
 				h.metricsStages.RecordSignalingReceived()
 			}
 
+			h.updateRemoteICEState(&remoteOfferAnswer)
+
 			if h.relayListener != nil {
 				h.relayListener.Notify(&remoteOfferAnswer)
 			}
 
-			if h.iceListener != nil {
+			if h.iceListener != nil && h.RemoteICESupported() {
 				h.iceListener(&remoteOfferAnswer)
 			}
 
@@ -110,18 +133,20 @@ func (h *Handshaker) Listen(ctx context.Context) {
 				continue
 			}
 		case remoteOfferAnswer := <-h.remoteAnswerCh:
-			h.log.Infof("received answer, running version %s, remote WireGuard listen port %d, session id: %s", remoteOfferAnswer.Version, remoteOfferAnswer.WgListenPort, remoteOfferAnswer.SessionIDString())
+			h.log.Infof("received answer, running version %s, remote WireGuard listen port %d, session id: %s, remote ICE supported: %t", remoteOfferAnswer.Version, remoteOfferAnswer.WgListenPort, remoteOfferAnswer.SessionIDString(), remoteOfferAnswer.hasICECredentials())
 
 			// Record signaling received for reconnection attempts
 			if h.metricsStages != nil {
 				h.metricsStages.RecordSignalingReceived()
 			}
 
+			h.updateRemoteICEState(&remoteOfferAnswer)
+
 			if h.relayListener != nil {
 				h.relayListener.Notify(&remoteOfferAnswer)
 			}
 
-			if h.iceListener != nil {
+			if h.iceListener != nil && h.RemoteICESupported() {
 				h.iceListener(&remoteOfferAnswer)
 			}
 		case <-ctx.Done():
@@ -183,20 +208,39 @@ func (h *Handshaker) sendAnswer() error {
 }
 
 func (h *Handshaker) buildOfferAnswer() OfferAnswer {
-	uFrag, pwd := h.ice.GetLocalUserCredentials()
-	sid := h.ice.SessionID()
 	answer := OfferAnswer{
-		IceCredentials:  IceCredentials{uFrag, pwd},
 		WgListenPort:    h.config.LocalWgPort,
 		Version:         version.NetbirdVersion(),
 		RosenpassPubKey: h.config.RosenpassConfig.PubKey,
 		RosenpassAddr:   h.config.RosenpassConfig.Addr,
-		SessionID:       &sid,
 	}
 
-	if addr, err := h.relay.RelayInstanceAddress(); err == nil {
+	if h.ice != nil && h.RemoteICESupported() {
+		uFrag, pwd := h.ice.GetLocalUserCredentials()
+		sid := h.ice.SessionID()
+		answer.IceCredentials = IceCredentials{uFrag, pwd}
+		answer.SessionID = &sid
+	}
+
+	if addr, ip, err := h.relay.RelayInstanceAddress(); err == nil {
 		answer.RelaySrvAddress = addr
+		answer.RelaySrvIP = ip
 	}
 
 	return answer
 }
+
+func (h *Handshaker) updateRemoteICEState(offer *OfferAnswer) {
+	hasICE := offer.hasICECredentials()
+	prev := h.remoteICESupported.Swap(hasICE)
+	if prev != hasICE {
+		if hasICE {
+			h.log.Infof("remote peer started sending ICE credentials")
+		} else {
+			h.log.Infof("remote peer stopped sending ICE credentials")
+			if h.ice != nil {
+				h.ice.Close()
+			}
+		}
+	}
+}

client/internal/peer/notifier_test.go

@@ -8,6 +8,7 @@ import (
 type mocListener struct {
 	lastState int
 	wg        sync.WaitGroup
+	peersWg   sync.WaitGroup
 	peers     int
 }
 
@@ -33,6 +34,7 @@ func (l *mocListener) OnAddressChanged(host, addr string) {
 }
 func (l *mocListener) OnPeersListChanged(size int) {
 	l.peers = size
+	l.peersWg.Done()
 }
 
 func (l *mocListener) setWaiter() {
@@ -43,6 +45,14 @@ func (l *mocListener) wait() {
 	l.wg.Wait()
 }
 
+func (l *mocListener) setPeersWaiter() {
+	l.peersWg.Add(1)
+}
+
+func (l *mocListener) waitPeers() {
+	l.peersWg.Wait()
+}
+
 func Test_notifier_serverState(t *testing.T) {
 
 	type scenario struct {
@@ -72,11 +82,13 @@ func Test_notifier_serverState(t *testing.T) {
 func Test_notifier_SetListener(t *testing.T) {
 	listener := &mocListener{}
 	listener.setWaiter()
+	listener.setPeersWaiter()
 
 	n := newNotifier()
 	n.lastNotification = stateConnecting
 	n.setListener(listener)
 	listener.wait()
+	listener.waitPeers()
 	if listener.lastState != n.lastNotification {
 		t.Errorf("invalid state: %d, expected: %d", listener.lastState, n.lastNotification)
 	}
@@ -85,9 +97,14 @@ func Test_notifier_SetListener(t *testing.T) {
 func Test_notifier_RemoveListener(t *testing.T) {
 	listener := &mocListener{}
 	listener.setWaiter()
+	listener.setPeersWaiter()
 	n := newNotifier()
 	n.lastNotification = stateConnecting
 	n.setListener(listener)
+	// setListener replays cached state on a goroutine; wait for both the state
+	// and peers callbacks to finish so we don't race on listener.peers.
+	listener.wait()
+	listener.waitPeers()
 	n.removeListener()
 	n.peerListChanged(1)
 

client/internal/peer/signaler.go

@@ -46,23 +46,27 @@ func (s *Signaler) Ready() bool {
 
 // SignalOfferAnswer signals either an offer or an answer to remote peer
 func (s *Signaler) signalOfferAnswer(offerAnswer OfferAnswer, remoteKey string, bodyType sProto.Body_Type) error {
-	sessionIDBytes, err := offerAnswer.SessionID.Bytes()
+	var sessionIDBytes []byte
-	if err != nil {
+	if offerAnswer.SessionID != nil {
-		log.Warnf("failed to get session ID bytes: %v", err)
+		var err error
+		sessionIDBytes, err = offerAnswer.SessionID.Bytes()
+		if err != nil {
+			log.Warnf("failed to get session ID bytes: %v", err)
+		}
 	}
-	msg, err := signal.MarshalCredential(
+	msg, err := signal.MarshalCredential(s.wgPrivateKey, remoteKey, signal.CredentialPayload{
-		s.wgPrivateKey,
+		Type:         bodyType,
-		offerAnswer.WgListenPort,
+		WgListenPort: offerAnswer.WgListenPort,
-		remoteKey,
+		Credential: &signal.Credential{
-		&signal.Credential{
 			UFrag: offerAnswer.IceCredentials.UFrag,
 			Pwd:   offerAnswer.IceCredentials.Pwd,
 		},
-		bodyType,
+		RosenpassPubKey: offerAnswer.RosenpassPubKey,
-		offerAnswer.RosenpassPubKey,
+		RosenpassAddr:   offerAnswer.RosenpassAddr,
-		offerAnswer.RosenpassAddr,
+		RelaySrvAddress: offerAnswer.RelaySrvAddress,
-		offerAnswer.RelaySrvAddress,
+		RelaySrvIP:      offerAnswer.RelaySrvIP,
-		sessionIDBytes)
+		SessionID:       sessionIDBytes,
+	})
 	if err != nil {
 		return err
 	}

client/internal/peer/status.go

@@ -320,10 +320,10 @@ func (d *Status) RemovePeer(peerPubKey string) error {
 // UpdatePeerState updates peer status
 func (d *Status) UpdatePeerState(receivedState State) error {
 	d.mux.Lock()
-	defer d.mux.Unlock()
 
 	peerState, ok := d.peers[receivedState.PubKey]
 	if !ok {
+		d.mux.Unlock()
 		return errors.New("peer doesn't exist")
 	}
 
@@ -343,23 +343,29 @@ func (d *Status) UpdatePeerState(receivedState State) error {
 
 	d.peers[receivedState.PubKey] = peerState
 
-	if hasConnStatusChanged(oldState, receivedState.ConnStatus) {
+	notifyList := hasConnStatusChanged(oldState, receivedState.ConnStatus)
-		d.notifyPeerListChanged()
-	}
-
 	// when we close the connection we will not notify the router manager
-	if receivedState.ConnStatus == StatusIdle {
+	notifyRouter := receivedState.ConnStatus == StatusIdle
-		d.notifyPeerStateChangeListeners(receivedState.PubKey)
+	routerSnapshot := d.snapshotRouterPeersLocked(receivedState.PubKey, notifyRouter)
+	numPeers := d.numOfPeers()
+
+	d.mux.Unlock()
+
+	if notifyList {
+		d.notifier.peerListChanged(numPeers)
+	}
+	if notifyRouter {
+		d.dispatchRouterPeers(receivedState.PubKey, routerSnapshot)
 	}
 	return nil
 }
 
 func (d *Status) AddPeerStateRoute(peer string, route string, resourceId route.ResID) error {
 	d.mux.Lock()
-	defer d.mux.Unlock()
 
 	peerState, ok := d.peers[peer]
 	if !ok {
+		d.mux.Unlock()
 		return errors.New("peer doesn't exist")
 	}
 
@@ -371,17 +377,20 @@ func (d *Status) AddPeerStateRoute(peer string, route string, resourceId route.R
 		d.routeIDLookup.AddRemoteRouteID(resourceId, pref)
 	}
 
+	numPeers := d.numOfPeers()
+	d.mux.Unlock()
+
 	// todo: consider to make sense of this notification or not
-	d.notifyPeerListChanged()
+	d.notifier.peerListChanged(numPeers)
 	return nil
 }
 
 func (d *Status) RemovePeerStateRoute(peer string, route string) error {
 	d.mux.Lock()
-	defer d.mux.Unlock()
 
 	peerState, ok := d.peers[peer]
 	if !ok {
+		d.mux.Unlock()
 		return errors.New("peer doesn't exist")
 	}
 
@@ -393,8 +402,11 @@ func (d *Status) RemovePeerStateRoute(peer string, route string) error {
 		d.routeIDLookup.RemoveRemoteRouteID(pref)
 	}
 
+	numPeers := d.numOfPeers()
+	d.mux.Unlock()
+
 	// todo: consider to make sense of this notification or not
-	d.notifyPeerListChanged()
+	d.notifier.peerListChanged(numPeers)
 	return nil
 }
 
@@ -410,10 +422,10 @@ func (d *Status) CheckRoutes(ip netip.Addr) ([]byte, bool) {
 
 func (d *Status) UpdatePeerICEState(receivedState State) error {
 	d.mux.Lock()
-	defer d.mux.Unlock()
 
 	peerState, ok := d.peers[receivedState.PubKey]
 	if !ok {
+		d.mux.Unlock()
 		return errors.New("peer doesn't exist")
 	}
 
@@ -431,22 +443,28 @@ func (d *Status) UpdatePeerICEState(receivedState State) error {
 
 	d.peers[receivedState.PubKey] = peerState
 
-	if hasConnStatusChanged(oldState, receivedState.ConnStatus) {
+	notifyList := hasConnStatusChanged(oldState, receivedState.ConnStatus)
-		d.notifyPeerListChanged()
+	notifyRouter := hasStatusOrRelayedChange(oldState, receivedState.ConnStatus, oldIsRelayed, receivedState.Relayed)
-	}
+	routerSnapshot := d.snapshotRouterPeersLocked(receivedState.PubKey, notifyRouter)
+	numPeers := d.numOfPeers()
 
-	if hasStatusOrRelayedChange(oldState, receivedState.ConnStatus, oldIsRelayed, receivedState.Relayed) {
+	d.mux.Unlock()
-		d.notifyPeerStateChangeListeners(receivedState.PubKey)
+
+	if notifyList {
+		d.notifier.peerListChanged(numPeers)
+	}
+	if notifyRouter {
+		d.dispatchRouterPeers(receivedState.PubKey, routerSnapshot)
 	}
 	return nil
 }
 
 func (d *Status) UpdatePeerRelayedState(receivedState State) error {
 	d.mux.Lock()
-	defer d.mux.Unlock()
 
 	peerState, ok := d.peers[receivedState.PubKey]
 	if !ok {
+		d.mux.Unlock()
 		return errors.New("peer doesn't exist")
 	}
 
@@ -461,22 +479,28 @@ func (d *Status) UpdatePeerRelayedState(receivedState State) error {
 
 	d.peers[receivedState.PubKey] = peerState
 
-	if hasConnStatusChanged(oldState, receivedState.ConnStatus) {
+	notifyList := hasConnStatusChanged(oldState, receivedState.ConnStatus)
-		d.notifyPeerListChanged()
+	notifyRouter := hasStatusOrRelayedChange(oldState, receivedState.ConnStatus, oldIsRelayed, receivedState.Relayed)
-	}
+	routerSnapshot := d.snapshotRouterPeersLocked(receivedState.PubKey, notifyRouter)
+	numPeers := d.numOfPeers()
 
-	if hasStatusOrRelayedChange(oldState, receivedState.ConnStatus, oldIsRelayed, receivedState.Relayed) {
+	d.mux.Unlock()
-		d.notifyPeerStateChangeListeners(receivedState.PubKey)
+
+	if notifyList {
+		d.notifier.peerListChanged(numPeers)
+	}
+	if notifyRouter {
+		d.dispatchRouterPeers(receivedState.PubKey, routerSnapshot)
 	}
 	return nil
 }
 
 func (d *Status) UpdatePeerRelayedStateToDisconnected(receivedState State) error {
 	d.mux.Lock()
-	defer d.mux.Unlock()
 
 	peerState, ok := d.peers[receivedState.PubKey]
 	if !ok {
+		d.mux.Unlock()
 		return errors.New("peer doesn't exist")
 	}
 
@@ -490,22 +514,28 @@ func (d *Status) UpdatePeerRelayedStateToDisconnected(receivedState State) error
 
 	d.peers[receivedState.PubKey] = peerState
 
-	if hasConnStatusChanged(oldState, receivedState.ConnStatus) {
+	notifyList := hasConnStatusChanged(oldState, receivedState.ConnStatus)
-		d.notifyPeerListChanged()
+	notifyRouter := hasStatusOrRelayedChange(oldState, receivedState.ConnStatus, oldIsRelayed, receivedState.Relayed)
-	}
+	routerSnapshot := d.snapshotRouterPeersLocked(receivedState.PubKey, notifyRouter)
+	numPeers := d.numOfPeers()
 
-	if hasStatusOrRelayedChange(oldState, receivedState.ConnStatus, oldIsRelayed, receivedState.Relayed) {
+	d.mux.Unlock()
-		d.notifyPeerStateChangeListeners(receivedState.PubKey)
+
+	if notifyList {
+		d.notifier.peerListChanged(numPeers)
+	}
+	if notifyRouter {
+		d.dispatchRouterPeers(receivedState.PubKey, routerSnapshot)
 	}
 	return nil
 }
 
 func (d *Status) UpdatePeerICEStateToDisconnected(receivedState State) error {
 	d.mux.Lock()
-	defer d.mux.Unlock()
 
 	peerState, ok := d.peers[receivedState.PubKey]
 	if !ok {
+		d.mux.Unlock()
 		return errors.New("peer doesn't exist")
 	}
 
@@ -522,12 +552,18 @@ func (d *Status) UpdatePeerICEStateToDisconnected(receivedState State) error {
 
 	d.peers[receivedState.PubKey] = peerState
 
-	if hasConnStatusChanged(oldState, receivedState.ConnStatus) {
+	notifyList := hasConnStatusChanged(oldState, receivedState.ConnStatus)
-		d.notifyPeerListChanged()
+	notifyRouter := hasStatusOrRelayedChange(oldState, receivedState.ConnStatus, oldIsRelayed, receivedState.Relayed)
-	}
+	routerSnapshot := d.snapshotRouterPeersLocked(receivedState.PubKey, notifyRouter)
+	numPeers := d.numOfPeers()
 
-	if hasStatusOrRelayedChange(oldState, receivedState.ConnStatus, oldIsRelayed, receivedState.Relayed) {
+	d.mux.Unlock()
-		d.notifyPeerStateChangeListeners(receivedState.PubKey)
+
+	if notifyList {
+		d.notifier.peerListChanged(numPeers)
+	}
+	if notifyRouter {
+		d.dispatchRouterPeers(receivedState.PubKey, routerSnapshot)
 	}
 	return nil
 }
@@ -594,17 +630,33 @@ func (d *Status) UpdatePeerSSHHostKey(peerPubKey string, sshHostKey []byte) erro
 // FinishPeerListModifications this event invoke the notification
 func (d *Status) FinishPeerListModifications() {
 	d.mux.Lock()
-	defer d.mux.Unlock()
 
 	if !d.peerListChangedForNotification {
+		d.mux.Unlock()
 		return
 	}
 	d.peerListChangedForNotification = false
 
-	d.notifyPeerListChanged()
+	numPeers := d.numOfPeers()
 
+	// snapshot per-peer router state to deliver after the lock is released
+	type routerDispatch struct {
+		peerID   string
+		snapshot map[string]RouterState
+	}
+	dispatches := make([]routerDispatch, 0, len(d.peers))
 	for key := range d.peers {
-		d.notifyPeerStateChangeListeners(key)
+		snapshot := d.snapshotRouterPeersLocked(key, true)
+		if snapshot != nil {
+			dispatches = append(dispatches, routerDispatch{peerID: key, snapshot: snapshot})
+		}
+	}
+
+	d.mux.Unlock()
+
+	d.notifier.peerListChanged(numPeers)
+	for _, rd := range dispatches {
+		d.dispatchRouterPeers(rd.peerID, rd.snapshot)
 	}
 }
 
@@ -655,10 +707,12 @@ func (d *Status) GetLocalPeerState() LocalPeerState {
 // UpdateLocalPeerState updates local peer status
 func (d *Status) UpdateLocalPeerState(localPeerState LocalPeerState) {
 	d.mux.Lock()
-	defer d.mux.Unlock()
-
 	d.localPeer = localPeerState
-	d.notifyAddressChanged()
+	fqdn := d.localPeer.FQDN
+	ip := d.localPeer.IP
+	d.mux.Unlock()
+
+	d.notifier.localAddressChanged(fqdn, ip)
 }
 
 // AddLocalPeerStateRoute adds a route to the local peer state
@@ -721,30 +775,36 @@ func (d *Status) CleanLocalPeerStateRoutes() {
 // CleanLocalPeerState cleans local peer status
 func (d *Status) CleanLocalPeerState() {
 	d.mux.Lock()
-	defer d.mux.Unlock()
-
 	d.localPeer = LocalPeerState{}
-	d.notifyAddressChanged()
+	fqdn := d.localPeer.FQDN
+	ip := d.localPeer.IP
+	d.mux.Unlock()
+
+	d.notifier.localAddressChanged(fqdn, ip)
 }
 
 // MarkManagementDisconnected sets ManagementState to disconnected
 func (d *Status) MarkManagementDisconnected(err error) {
 	d.mux.Lock()
-	defer d.mux.Unlock()
-	defer d.onConnectionChanged()
-
 	d.managementState = false
 	d.managementError = err
+	mgm := d.managementState
+	sig := d.signalState
+	d.mux.Unlock()
+
+	d.notifier.updateServerStates(mgm, sig)
 }
 
 // MarkManagementConnected sets ManagementState to connected
 func (d *Status) MarkManagementConnected() {
 	d.mux.Lock()
-	defer d.mux.Unlock()
-	defer d.onConnectionChanged()
-
 	d.managementState = true
 	d.managementError = nil
+	mgm := d.managementState
+	sig := d.signalState
+	d.mux.Unlock()
+
+	d.notifier.updateServerStates(mgm, sig)
 }
 
 // UpdateSignalAddress update the address of the signal server
@@ -778,21 +838,25 @@ func (d *Status) UpdateLazyConnection(enabled bool) {
 // MarkSignalDisconnected sets SignalState to disconnected
 func (d *Status) MarkSignalDisconnected(err error) {
 	d.mux.Lock()
-	defer d.mux.Unlock()
-	defer d.onConnectionChanged()
-
 	d.signalState = false
 	d.signalError = err
+	mgm := d.managementState
+	sig := d.signalState
+	d.mux.Unlock()
+
+	d.notifier.updateServerStates(mgm, sig)
 }
 
 // MarkSignalConnected sets SignalState to connected
 func (d *Status) MarkSignalConnected() {
 	d.mux.Lock()
-	defer d.mux.Unlock()
-	defer d.onConnectionChanged()
-
 	d.signalState = true
 	d.signalError = nil
+	mgm := d.managementState
+	sig := d.signalState
+	d.mux.Unlock()
+
+	d.notifier.updateServerStates(mgm, sig)
 }
 
 func (d *Status) UpdateRelayStates(relayResults []relay.ProbeResult) {
@@ -919,7 +983,7 @@ func (d *Status) GetRelayStates() []relay.ProbeResult {
 
 	// if the server connection is not established then we will use the general address
 	// in case of connection we will use the instance specific address
-	instanceAddr, err := d.relayMgr.RelayInstanceAddress()
+	instanceAddr, _, err := d.relayMgr.RelayInstanceAddress()
 	if err != nil {
 		// TODO add their status
 		for _, r := range d.relayMgr.ServerURLs() {
@@ -1012,18 +1076,17 @@ func (d *Status) RemoveConnectionListener() {
 	d.notifier.removeListener()
 }
 
-func (d *Status) onConnectionChanged() {
+// snapshotRouterPeersLocked builds the RouterState map for a peer's subscribers.
-	d.notifier.updateServerStates(d.managementState, d.signalState)
+// Caller MUST hold d.mux. Returns nil when there are no subscribers for peerID
-}
+// or when notify is false. The snapshot is consumed later by dispatchRouterPeers
-
+// outside the lock so the channel send cannot stall any d.mux holder.
-// notifyPeerStateChangeListeners notifies route manager about the change in peer state
+func (d *Status) snapshotRouterPeersLocked(peerID string, notify bool) map[string]RouterState {
-func (d *Status) notifyPeerStateChangeListeners(peerID string) {
+	if !notify {
-	subs, ok := d.changeNotify[peerID]
+		return nil
-	if !ok {
+	}
-		return
+	if _, ok := d.changeNotify[peerID]; !ok {
+		return nil
 	}
-
-	// collect the relevant data for router peers
 	routerPeers := make(map[string]RouterState, len(d.changeNotify))
 	for pid := range d.changeNotify {
 		s, ok := d.peers[pid]
@@ -1031,13 +1094,35 @@ func (d *Status) notifyPeerStateChangeListeners(peerID string) {
 			log.Warnf("router peer not found in peers list: %s", pid)
 			continue
 		}
-
 		routerPeers[pid] = RouterState{
 			Status:  s.ConnStatus,
 			Relayed: s.Relayed,
 			Latency: s.Latency,
 		}
 	}
+	return routerPeers
+}
+
+// dispatchRouterPeers delivers a previously snapshotted router-state map to
+// the peer's subscribers. Caller MUST NOT hold d.mux. The method takes a
+// fresh, short read of d.changeNotify under the lock to grab subscriber
+// channels, then sends outside the lock so a slow consumer cannot block other
+// d.mux holders. The send itself stays blocking (only short-circuited by the
+// subscriber's context) so peer state transitions are not silently dropped.
+func (d *Status) dispatchRouterPeers(peerID string, routerPeers map[string]RouterState) {
+	if routerPeers == nil {
+		return
+	}
+
+	d.mux.Lock()
+	subsMap, ok := d.changeNotify[peerID]
+	subs := make([]*StatusChangeSubscription, 0, len(subsMap))
+	if ok {
+		for _, sub := range subsMap {
+			subs = append(subs, sub)
+		}
+	}
+	d.mux.Unlock()
 
 	for _, sub := range subs {
 		select {
@@ -1047,14 +1132,6 @@ func (d *Status) notifyPeerStateChangeListeners(peerID string) {
 	}
 }
 
-func (d *Status) notifyPeerListChanged() {
-	d.notifier.peerListChanged(d.numOfPeers())
-}
-
-func (d *Status) notifyAddressChanged() {
-	d.notifier.localAddressChanged(d.localPeer.FQDN, d.localPeer.IP)
-}
-
 func (d *Status) numOfPeers() int {
 	return len(d.peers) + len(d.offlinePeers)
 }

client/internal/peer/worker_relay.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"net"
+	"net/netip"
 	"sync"
 	"sync/atomic"
 
@@ -53,15 +54,19 @@ func (w *WorkerRelay) OnNewOffer(remoteOfferAnswer *OfferAnswer) {
 	w.relaySupportedOnRemotePeer.Store(true)
 
 	// the relayManager will return with error in case if the connection has lost with relay server
-	currentRelayAddress, err := w.relayManager.RelayInstanceAddress()
+	currentRelayAddress, _, err := w.relayManager.RelayInstanceAddress()
 	if err != nil {
 		w.log.Errorf("failed to handle new offer: %s", err)
 		return
 	}
 
 	srv := w.preferredRelayServer(currentRelayAddress, remoteOfferAnswer.RelaySrvAddress)
+	var serverIP netip.Addr
+	if srv == remoteOfferAnswer.RelaySrvAddress {
+		serverIP = remoteOfferAnswer.RelaySrvIP
+	}
 
-	relayedConn, err := w.relayManager.OpenConn(w.peerCtx, srv, w.config.Key)
+	relayedConn, err := w.relayManager.OpenConn(w.peerCtx, srv, w.config.Key, serverIP)
 	if err != nil {
 		if errors.Is(err, relayClient.ErrConnAlreadyExists) {
 			w.log.Debugf("handled offer by reusing existing relay connection")
@@ -90,7 +95,7 @@ func (w *WorkerRelay) OnNewOffer(remoteOfferAnswer *OfferAnswer) {
 	})
 }
 
-func (w *WorkerRelay) RelayInstanceAddress() (string, error) {
+func (w *WorkerRelay) RelayInstanceAddress() (string, netip.Addr, error) {
 	return w.relayManager.RelayInstanceAddress()
 }
 

client/internal/routemanager/systemops/systemops_bsd_other.go

@@ -0,0 +1,10 @@
+//go:build (dragonfly || freebsd || netbsd || openbsd) && !darwin
+
+package systemops
+
+// Non-darwin BSDs don't support the IP_BOUND_IF + scoped default model. They
+// always fall through to the ref-counter exclusion-route path; these stubs
+// exist only so systemops_unix.go compiles.
+func (r *SysOps) setupAdvancedRouting() error   { return nil }
+func (r *SysOps) cleanupAdvancedRouting() error { return nil }
+func (r *SysOps) flushPlatformExtras() error    { return nil }

client/internal/routemanager/systemops/systemops_darwin.go

@@ -0,0 +1,253 @@
+//go:build darwin && !ios
+
+package systemops
+
+import (
+	"errors"
+	"fmt"
+	"net/netip"
+	"os"
+	"time"
+
+	"github.com/hashicorp/go-multierror"
+	log "github.com/sirupsen/logrus"
+	"golang.org/x/net/route"
+	"golang.org/x/sys/unix"
+
+	nberrors "github.com/netbirdio/netbird/client/errors"
+	"github.com/netbirdio/netbird/client/internal/routemanager/vars"
+	nbnet "github.com/netbirdio/netbird/client/net"
+)
+
+// scopedRouteBudget bounds retries for the scoped default route. Installing or
+// deleting it matters enough that we're willing to spend longer waiting for the
+// kernel reply than for per-prefix exclusion routes.
+const scopedRouteBudget = 5 * time.Second
+
+// setupAdvancedRouting installs an RTF_IFSCOPE default route per address family
+// pinned to the current physical egress, so IP_BOUND_IF scoped lookups can
+// resolve gateway'd destinations while the VPN's split default owns the
+// unscoped table.
+//
+// Timing note: this runs during routeManager.Init, which happens before the
+// VPN interface is created and before any peer routes propagate. The initial
+// mgmt / signal / relay TCP dials always fire before this runs, so those
+// sockets miss the IP_BOUND_IF binding and rely on the kernel's normal route
+// lookup, which at that point correctly picks the physical default. Those
+// already-established TCP flows keep their originally-selected interface for
+// their lifetime on Darwin because the kernel caches the egress route
+// per-socket at connect time; adding the VPN's 0/1 + 128/1 split default
+// afterwards does not migrate them since the original en0 default stays in
+// the table. Any subsequent reconnect via nbnet.NewDialer picks up the
+// populated bound-iface cache and gets IP_BOUND_IF set cleanly.
+func (r *SysOps) setupAdvancedRouting() error {
+	// Drop any previously-cached egress interface before reinstalling. On a
+	// refresh, a family that no longer resolves would otherwise keep the stale
+	// binding, causing new sockets to scope to an interface without a matching
+	// scoped default.
+	nbnet.ClearBoundInterfaces()
+
+	if err := r.flushScopedDefaults(); err != nil {
+		log.Warnf("flush residual scoped defaults: %v", err)
+	}
+
+	var merr *multierror.Error
+	installed := 0
+
+	for _, unspec := range []netip.Addr{netip.IPv4Unspecified(), netip.IPv6Unspecified()} {
+		ok, err := r.installScopedDefaultFor(unspec)
+		if err != nil {
+			merr = multierror.Append(merr, err)
+			continue
+		}
+		if ok {
+			installed++
+		}
+	}
+
+	if installed == 0 && merr != nil {
+		return nberrors.FormatErrorOrNil(merr)
+	}
+	if merr != nil {
+		log.Warnf("advanced routing setup partially succeeded: %v", nberrors.FormatErrorOrNil(merr))
+	}
+	return nil
+}
+
+// installScopedDefaultFor resolves the physical default nexthop for the given
+// address family, installs a scoped default via it, and caches the iface for
+// subsequent IP_BOUND_IF / IPV6_BOUND_IF socket binds.
+func (r *SysOps) installScopedDefaultFor(unspec netip.Addr) (bool, error) {
+	nexthop, err := GetNextHop(unspec)
+	if err != nil {
+		if errors.Is(err, vars.ErrRouteNotFound) {
+			return false, nil
+		}
+		return false, fmt.Errorf("get default nexthop for %s: %w", unspec, err)
+	}
+	if nexthop.Intf == nil {
+		return false, fmt.Errorf("unusable default nexthop for %s (no interface)", unspec)
+	}
+
+	reused := false
+	if err := r.addScopedDefault(unspec, nexthop); err != nil {
+		if !errors.Is(err, unix.EEXIST) {
+			return false, fmt.Errorf("add scoped default on %s: %w", nexthop.Intf.Name, err)
+		}
+		// macOS installs its own RTF_IFSCOPE defaults for primary service
+		// selection on multi-NIC setups, so a route on this ifindex can
+		// already exist before we try. Binding to it via IP[V6]_BOUND_IF
+		// still produces the scoped lookup we need.
+		reused = true
+	}
+
+	af := unix.AF_INET
+	if unspec.Is6() {
+		af = unix.AF_INET6
+	}
+	nbnet.SetBoundInterface(af, nexthop.Intf)
+	via := "point-to-point"
+	if nexthop.IP.IsValid() {
+		via = nexthop.IP.String()
+	}
+	verb := "installed"
+	if reused {
+		verb = "reused existing"
+	}
+	log.Infof("%s scoped default route via %s on %s for %s", verb, via, nexthop.Intf.Name, afOf(unspec))
+	return true, nil
+}
+
+func (r *SysOps) cleanupAdvancedRouting() error {
+	nbnet.ClearBoundInterfaces()
+	return r.flushScopedDefaults()
+}
+
+// flushPlatformExtras runs darwin-specific residual cleanup hooked into the
+// generic FlushMarkedRoutes path, so a crashed daemon's scoped defaults get
+// removed on the next boot regardless of whether a profile is brought up.
+func (r *SysOps) flushPlatformExtras() error {
+	return r.flushScopedDefaults()
+}
+
+// flushScopedDefaults removes any scoped default routes tagged with routeProtoFlag.
+// Safe to call at startup to clear residual entries from a prior session.
+func (r *SysOps) flushScopedDefaults() error {
+	rib, err := retryFetchRIB()
+	if err != nil {
+		return fmt.Errorf("fetch routing table: %w", err)
+	}
+
+	msgs, err := route.ParseRIB(route.RIBTypeRoute, rib)
+	if err != nil {
+		return fmt.Errorf("parse routing table: %w", err)
+	}
+
+	var merr *multierror.Error
+	removed := 0
+
+	for _, msg := range msgs {
+		rtMsg, ok := msg.(*route.RouteMessage)
+		if !ok {
+			continue
+		}
+		if rtMsg.Flags&routeProtoFlag == 0 {
+			continue
+		}
+		if rtMsg.Flags&unix.RTF_IFSCOPE == 0 {
+			continue
+		}
+
+		info, err := MsgToRoute(rtMsg)
+		if err != nil {
+			log.Debugf("skip scoped flush: %v", err)
+			continue
+		}
+		if !info.Dst.IsValid() || info.Dst.Bits() != 0 {
+			continue
+		}
+
+		if err := r.deleteScopedRoute(rtMsg); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("delete scoped default %s on index %d: %w",
+				info.Dst, rtMsg.Index, err))
+			continue
+		}
+		removed++
+		log.Debugf("flushed residual scoped default %s on index %d", info.Dst, rtMsg.Index)
+	}
+
+	if removed > 0 {
+		log.Infof("flushed %d residual scoped default route(s)", removed)
+	}
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+func (r *SysOps) addScopedDefault(unspec netip.Addr, nexthop Nexthop) error {
+	return r.scopedRouteSocket(unix.RTM_ADD, unspec, nexthop)
+}
+
+func (r *SysOps) deleteScopedRoute(rtMsg *route.RouteMessage) error {
+	// Preserve identifying flags from the stored route (including RTF_GATEWAY
+	// only if present); kernel-set bits like RTF_DONE don't belong on RTM_DELETE.
+	keep := unix.RTF_UP | unix.RTF_STATIC | unix.RTF_GATEWAY | unix.RTF_IFSCOPE | routeProtoFlag
+	del := &route.RouteMessage{
+		Type:    unix.RTM_DELETE,
+		Flags:   rtMsg.Flags & keep,
+		Version: unix.RTM_VERSION,
+		Seq:     r.getSeq(),
+		Index:   rtMsg.Index,
+		Addrs:   rtMsg.Addrs,
+	}
+	return r.writeRouteMessage(del, scopedRouteBudget)
+}
+
+func (r *SysOps) scopedRouteSocket(action int, unspec netip.Addr, nexthop Nexthop) error {
+	flags := unix.RTF_UP | unix.RTF_STATIC | unix.RTF_IFSCOPE | routeProtoFlag
+
+	msg := &route.RouteMessage{
+		Type:    action,
+		Flags:   flags,
+		Version: unix.RTM_VERSION,
+		ID:      uintptr(os.Getpid()),
+		Seq:     r.getSeq(),
+		Index:   nexthop.Intf.Index,
+	}
+
+	const numAddrs = unix.RTAX_NETMASK + 1
+	addrs := make([]route.Addr, numAddrs)
+
+	dst, err := addrToRouteAddr(unspec)
+	if err != nil {
+		return fmt.Errorf("build destination: %w", err)
+	}
+	mask, err := prefixToRouteNetmask(netip.PrefixFrom(unspec, 0))
+	if err != nil {
+		return fmt.Errorf("build netmask: %w", err)
+	}
+	addrs[unix.RTAX_DST] = dst
+	addrs[unix.RTAX_NETMASK] = mask
+
+	if nexthop.IP.IsValid() {
+		msg.Flags |= unix.RTF_GATEWAY
+		gw, err := addrToRouteAddr(nexthop.IP.Unmap())
+		if err != nil {
+			return fmt.Errorf("build gateway: %w", err)
+		}
+		addrs[unix.RTAX_GATEWAY] = gw
+	} else {
+		addrs[unix.RTAX_GATEWAY] = &route.LinkAddr{
+			Index: nexthop.Intf.Index,
+			Name:  nexthop.Intf.Name,
+		}
+	}
+	msg.Addrs = addrs
+
+	return r.writeRouteMessage(msg, scopedRouteBudget)
+}
+
+func afOf(a netip.Addr) string {
+	if a.Is4() {
+		return "IPv4"
+	}
+	return "IPv6"
+}

client/internal/routemanager/systemops/systemops_generic.go

@@ -21,6 +21,7 @@ import (
 	"github.com/netbirdio/netbird/client/internal/routemanager/util"
 	"github.com/netbirdio/netbird/client/internal/routemanager/vars"
 	"github.com/netbirdio/netbird/client/internal/statemanager"
+	nbnet "github.com/netbirdio/netbird/client/net"
 	"github.com/netbirdio/netbird/client/net/hooks"
 )
 
@@ -31,8 +32,6 @@ var splitDefaultv4_2 = netip.PrefixFrom(netip.AddrFrom4([4]byte{128}), 1)
 var splitDefaultv6_1 = netip.PrefixFrom(netip.IPv6Unspecified(), 1)
 var splitDefaultv6_2 = netip.PrefixFrom(netip.AddrFrom16([16]byte{0x80}), 1)
 
-var ErrRoutingIsSeparate = errors.New("routing is separate")
-
 func (r *SysOps) setupRefCounter(initAddresses []net.IP, stateManager *statemanager.Manager) error {
 	stateManager.RegisterState(&ShutdownState{})
 
@@ -397,12 +396,16 @@ func ipToAddr(ip net.IP, intf *net.Interface) (netip.Addr, error) {
 }
 
 // IsAddrRouted checks if the candidate address would route to the vpn, in which case it returns true and the matched prefix.
+// When advanced routing is active the WG socket is bound to the physical interface (fwmark on linux,
+// IP_UNICAST_IF on windows, IP_BOUND_IF on darwin) and bypasses the main routing table, so the check is skipped.
 func IsAddrRouted(addr netip.Addr, vpnRoutes []netip.Prefix) (bool, netip.Prefix) {
-	localRoutes, err := hasSeparateRouting()
+	if nbnet.AdvancedRouting() {
+		return false, netip.Prefix{}
+	}
+
+	localRoutes, err := GetRoutesFromTable()
 	if err != nil {
-		if !errors.Is(err, ErrRoutingIsSeparate) {
+		log.Errorf("Failed to get routes: %v", err)
-			log.Errorf("Failed to get routes: %v", err)
-		}
 		return false, netip.Prefix{}
 	}
 

client/internal/routemanager/systemops/systemops_js.go

@@ -22,10 +22,6 @@ func GetRoutesFromTable() ([]netip.Prefix, error) {
 	return []netip.Prefix{}, nil
 }
 
-func hasSeparateRouting() ([]netip.Prefix, error) {
-	return []netip.Prefix{}, nil
-}
-
 // GetDetailedRoutesFromTable returns empty routes for WASM.
 func GetDetailedRoutesFromTable() ([]DetailedRoute, error) {
 	return []DetailedRoute{}, nil

client/internal/routemanager/systemops/systemops_linux.go

@@ -894,13 +894,6 @@ func getAddressFamily(prefix netip.Prefix) int {
 	return netlink.FAMILY_V6
 }
 
-func hasSeparateRouting() ([]netip.Prefix, error) {
-	if !nbnet.AdvancedRouting() {
-		return GetRoutesFromTable()
-	}
-	return nil, ErrRoutingIsSeparate
-}
-
 func isOpErr(err error) bool {
 	// EAFTNOSUPPORT when ipv6 is disabled via sysctl, EOPNOTSUPP when disabled in boot options or otherwise not supported
 	if errors.Is(err, syscall.EAFNOSUPPORT) || errors.Is(err, syscall.EOPNOTSUPP) {

client/internal/routemanager/systemops/systemops_nonlinux.go

@@ -48,10 +48,6 @@ func EnableIPForwarding() error {
 	return nil
 }
 
-func hasSeparateRouting() ([]netip.Prefix, error) {
-	return GetRoutesFromTable()
-}
-
 // GetIPRules returns IP rules for debugging (not supported on non-Linux platforms)
 func GetIPRules() ([]IPRule, error) {
 	log.Infof("IP rules collection is not supported on %s", runtime.GOOS)

client/internal/routemanager/systemops/systemops_unix.go

@@ -25,6 +25,9 @@ import (
 
 const (
 	envRouteProtoFlag = "NB_ROUTE_PROTO_FLAG"
+
+	// routeBudget bounds retries for per-prefix exclusion route programming.
+	routeBudget = 1 * time.Second
 )
 
 var routeProtoFlag int
@@ -41,26 +44,42 @@ func init() {
 }
 
 func (r *SysOps) SetupRouting(initAddresses []net.IP, stateManager *statemanager.Manager, advancedRouting bool) error {
+	if advancedRouting {
+		return r.setupAdvancedRouting()
+	}
+
+	log.Infof("Using legacy routing setup with ref counters")
 	return r.setupRefCounter(initAddresses, stateManager)
 }
 
 func (r *SysOps) CleanupRouting(stateManager *statemanager.Manager, advancedRouting bool) error {
+	if advancedRouting {
+		return r.cleanupAdvancedRouting()
+	}
+
 	return r.cleanupRefCounter(stateManager)
 }
 
 // FlushMarkedRoutes removes single IP exclusion routes marked with the configured RTF_PROTO flag.
+// On darwin it also flushes residual RTF_IFSCOPE scoped default routes so a
+// crashed prior session can't leave crud in the table.
 func (r *SysOps) FlushMarkedRoutes() error {
+	var merr *multierror.Error
+
+	if err := r.flushPlatformExtras(); err != nil {
+		merr = multierror.Append(merr, fmt.Errorf("flush platform extras: %w", err))
+	}
+
 	rib, err := retryFetchRIB()
 	if err != nil {
-		return fmt.Errorf("fetch routing table: %w", err)
+		return nberrors.FormatErrorOrNil(multierror.Append(merr, fmt.Errorf("fetch routing table: %w", err)))
 	}
 
 	msgs, err := route.ParseRIB(route.RIBTypeRoute, rib)
 	if err != nil {
-		return fmt.Errorf("parse routing table: %w", err)
+		return nberrors.FormatErrorOrNil(multierror.Append(merr, fmt.Errorf("parse routing table: %w", err)))
 	}
 
-	var merr *multierror.Error
 	flushedCount := 0
 
 	for _, msg := range msgs {
@@ -117,12 +136,12 @@ func (r *SysOps) routeSocket(action int, prefix netip.Prefix, nexthop Nexthop) e
 		return fmt.Errorf("invalid prefix: %s", prefix)
 	}
 
-	expBackOff := backoff.NewExponentialBackOff()
+	msg, err := r.buildRouteMessage(action, prefix, nexthop)
-	expBackOff.InitialInterval = 50 * time.Millisecond
+	if err != nil {
-	expBackOff.MaxInterval = 500 * time.Millisecond
+		return fmt.Errorf("build route message: %w", err)
-	expBackOff.MaxElapsedTime = 1 * time.Second
+	}
 
-	if err := backoff.Retry(r.routeOp(action, prefix, nexthop), expBackOff); err != nil {
+	if err := r.writeRouteMessage(msg, routeBudget); err != nil {
 		a := "add"
 		if action == unix.RTM_DELETE {
 			a = "remove"
@@ -132,50 +151,91 @@ func (r *SysOps) routeSocket(action int, prefix netip.Prefix, nexthop Nexthop) e
 	return nil
 }
 
-func (r *SysOps) routeOp(action int, prefix netip.Prefix, nexthop Nexthop) func() error {
+// writeRouteMessage sends a route message over AF_ROUTE and waits for the
-	operation := func() error {
+// kernel's matching reply, retrying transient failures until budget elapses.
-		fd, err := unix.Socket(syscall.AF_ROUTE, syscall.SOCK_RAW, syscall.AF_UNSPEC)
+// Callers do not need to manage sockets or seq numbers themselves.
-		if err != nil {
+func (r *SysOps) writeRouteMessage(msg *route.RouteMessage, budget time.Duration) error {
-			return fmt.Errorf("open routing socket: %w", err)
+	expBackOff := backoff.NewExponentialBackOff()
+	expBackOff.InitialInterval = 50 * time.Millisecond
+	expBackOff.MaxInterval = 500 * time.Millisecond
+	expBackOff.MaxElapsedTime = budget
+
+	return backoff.Retry(func() error { return routeMessageRoundtrip(msg) }, expBackOff)
+}
+
+func routeMessageRoundtrip(msg *route.RouteMessage) error {
+	fd, err := unix.Socket(syscall.AF_ROUTE, syscall.SOCK_RAW, syscall.AF_UNSPEC)
+	if err != nil {
+		return fmt.Errorf("open routing socket: %w", err)
+	}
+	defer func() {
+		if err := unix.Close(fd); err != nil && !errors.Is(err, unix.EBADF) {
+			log.Warnf("close routing socket: %v", err)
 		}
-		defer func() {
+	}()
-			if err := unix.Close(fd); err != nil && !errors.Is(err, unix.EBADF) {
+
-				log.Warnf("failed to close routing socket: %v", err)
+	tv := unix.Timeval{Sec: 1}
+	if err := unix.SetsockoptTimeval(fd, unix.SOL_SOCKET, unix.SO_RCVTIMEO, &tv); err != nil {
+		return backoff.Permanent(fmt.Errorf("set recv timeout: %w", err))
+	}
+
+	// AF_ROUTE is a broadcast channel: every route socket on the host sees
+	// every RTM_* event. With concurrent route programming the default
+	// per-socket queue overflows and our own reply gets dropped.
+	if err := unix.SetsockoptInt(fd, unix.SOL_SOCKET, unix.SO_RCVBUF, 1<<20); err != nil {
+		log.Debugf("set SO_RCVBUF on route socket: %v", err)
+	}
+
+	bytes, err := msg.Marshal()
+	if err != nil {
+		return backoff.Permanent(fmt.Errorf("marshal: %w", err))
+	}
+
+	if _, err = unix.Write(fd, bytes); err != nil {
+		if errors.Is(err, unix.ENOBUFS) || errors.Is(err, unix.EAGAIN) {
+			return fmt.Errorf("write: %w", err)
+		}
+		return backoff.Permanent(fmt.Errorf("write: %w", err))
+	}
+	return readRouteResponse(fd, msg.Type, msg.Seq)
+}
+
+// readRouteResponse reads from the AF_ROUTE socket until it sees a reply
+// matching our write (same type, seq, and pid). AF_ROUTE SOCK_RAW is a
+// broadcast channel: interface up/down, third-party route changes and neighbor
+// discovery events can all land between our write and read, so we must filter.
+func readRouteResponse(fd, wantType, wantSeq int) error {
+	pid := int32(os.Getpid())
+	resp := make([]byte, 2048)
+	deadline := time.Now().Add(time.Second)
+	for {
+		if time.Now().After(deadline) {
+			// Transient: under concurrent pressure the kernel can drop our reply
+			// from the socket buffer. Let backoff.Retry re-send with a fresh seq.
+			return fmt.Errorf("read: timeout waiting for route reply type=%d seq=%d", wantType, wantSeq)
+		}
+		n, err := unix.Read(fd, resp)
+		if err != nil {
+			if errors.Is(err, unix.EAGAIN) || errors.Is(err, unix.EWOULDBLOCK) {
+				// SO_RCVTIMEO fired while waiting; loop to re-check the absolute deadline.
+				continue
 			}
-		}()
+			return backoff.Permanent(fmt.Errorf("read: %w", err))
-
-		msg, err := r.buildRouteMessage(action, prefix, nexthop)
-		if err != nil {
-			return backoff.Permanent(fmt.Errorf("build route message: %w", err))
 		}
-
+		if n < int(unsafe.Sizeof(unix.RtMsghdr{})) {
-		msgBytes, err := msg.Marshal()
+			continue
-		if err != nil {
-			return backoff.Permanent(fmt.Errorf("marshal route message: %w", err))
 		}
-
+		hdr := (*unix.RtMsghdr)(unsafe.Pointer(&resp[0]))
-		if _, err = unix.Write(fd, msgBytes); err != nil {
+		// Darwin reflects the sender's pid on replies; matching (Type, Seq, Pid)
-			if errors.Is(err, unix.ENOBUFS) || errors.Is(err, unix.EAGAIN) {
+		// uniquely identifies our own reply among broadcast traffic.
-				return fmt.Errorf("write: %w", err)
+		if int(hdr.Type) != wantType || int(hdr.Seq) != wantSeq || hdr.Pid != pid {
-			}
+			continue
-			return backoff.Permanent(fmt.Errorf("write: %w", err))
 		}
-
+		if hdr.Errno != 0 {
-		respBuf := make([]byte, 2048)
+			return backoff.Permanent(fmt.Errorf("kernel: %w", syscall.Errno(hdr.Errno)))
-		n, err := unix.Read(fd, respBuf)
-		if err != nil {
-			return backoff.Permanent(fmt.Errorf("read route response: %w", err))
 		}
-
-		if n > 0 {
-			if err := r.parseRouteResponse(respBuf[:n]); err != nil {
-				return backoff.Permanent(err)
-			}
-		}
-
 		return nil
 	}
-	return operation
 }
 
 func (r *SysOps) buildRouteMessage(action int, prefix netip.Prefix, nexthop Nexthop) (msg *route.RouteMessage, err error) {
@@ -183,6 +243,7 @@ func (r *SysOps) buildRouteMessage(action int, prefix netip.Prefix, nexthop Next
 		Type:    action,
 		Flags:   unix.RTF_UP | routeProtoFlag,
 		Version: unix.RTM_VERSION,
+		ID:      uintptr(os.Getpid()),
 		Seq:     r.getSeq(),
 	}
 
@@ -221,19 +282,6 @@ func (r *SysOps) buildRouteMessage(action int, prefix netip.Prefix, nexthop Next
 	return msg, nil
 }
 
-func (r *SysOps) parseRouteResponse(buf []byte) error {
-	if len(buf) < int(unsafe.Sizeof(unix.RtMsghdr{})) {
-		return nil
-	}
-
-	rtMsg := (*unix.RtMsghdr)(unsafe.Pointer(&buf[0]))
-	if rtMsg.Errno != 0 {
-		return fmt.Errorf("parse: %d", rtMsg.Errno)
-	}
-
-	return nil
-}
-
 // addrToRouteAddr converts a netip.Addr to the appropriate route.Addr (*route.Inet4Addr or *route.Inet6Addr).
 func addrToRouteAddr(addr netip.Addr) (route.Addr, error) {
 	if addr.Is4() {

client/internal/routeselector/routeselector.go

@@ -7,7 +7,6 @@ import (
 	"sync"
 
 	"github.com/hashicorp/go-multierror"
-	"golang.org/x/exp/maps"
 
 	"github.com/netbirdio/netbird/client/errors"
 	"github.com/netbirdio/netbird/route"
@@ -44,8 +43,8 @@ func (rs *RouteSelector) SelectRoutes(routes []route.NetID, appendRoute bool, al
 		if rs.selectedRoutes == nil {
 			rs.selectedRoutes = map[route.NetID]struct{}{}
 		}
-		maps.Clear(rs.deselectedRoutes)
+		clear(rs.deselectedRoutes)
-		maps.Clear(rs.selectedRoutes)
+		clear(rs.selectedRoutes)
 		for _, r := range allRoutes {
 			rs.deselectedRoutes[r] = struct{}{}
 		}
@@ -78,8 +77,8 @@ func (rs *RouteSelector) SelectAllRoutes() {
 	if rs.selectedRoutes == nil {
 		rs.selectedRoutes = map[route.NetID]struct{}{}
 	}
-	maps.Clear(rs.deselectedRoutes)
+	clear(rs.deselectedRoutes)
-	maps.Clear(rs.selectedRoutes)
+	clear(rs.selectedRoutes)
 }
 
 // DeselectRoutes removes specific routes from the selection.
@@ -116,8 +115,8 @@ func (rs *RouteSelector) DeselectAllRoutes() {
 	if rs.selectedRoutes == nil {
 		rs.selectedRoutes = map[route.NetID]struct{}{}
 	}
-	maps.Clear(rs.deselectedRoutes)
+	clear(rs.deselectedRoutes)
-	maps.Clear(rs.selectedRoutes)
+	clear(rs.selectedRoutes)
 }
 
 // IsSelected checks if a specific route is selected.

client/internal/sleep/detector_darwin.go

@@ -2,217 +2,358 @@
 
 package sleep
 
-/*
-#cgo LDFLAGS: -framework IOKit -framework CoreFoundation
-#include <IOKit/pwr_mgt/IOPMLib.h>
-#include <IOKit/IOMessage.h>
-#include <CoreFoundation/CoreFoundation.h>
-
-extern void sleepCallbackBridge();
-extern void poweredOnCallbackBridge();
-extern void suspendedCallbackBridge();
-extern void resumedCallbackBridge();
-
-
-// C global variables for IOKit state
-static IONotificationPortRef g_notifyPortRef = NULL;
-static io_object_t g_notifierObject = 0;
-static io_object_t g_generalInterestNotifier = 0;
-static io_connect_t g_rootPort = 0;
-static CFRunLoopRef g_runLoop = NULL;
-
-static void sleepCallback(void* refCon, io_service_t service, natural_t messageType, void* messageArgument) {
-	switch (messageType) {
-		case kIOMessageSystemWillSleep:
-			sleepCallbackBridge();
-			IOAllowPowerChange(g_rootPort, (long)messageArgument);
-			break;
-        case kIOMessageSystemHasPoweredOn:
-          	poweredOnCallbackBridge();
-          	break;
-        case kIOMessageServiceIsSuspended:
-			suspendedCallbackBridge();
-			break;
-		case kIOMessageServiceIsResumed:
-			resumedCallbackBridge();
-			break;
-		default:
-			break;
-	}
-}
-
-static void registerNotifications() {
-	g_rootPort = IORegisterForSystemPower(
-		NULL,
-		&g_notifyPortRef,
-		(IOServiceInterestCallback)sleepCallback,
-		&g_notifierObject
-	);
-
-	if (g_rootPort == 0) {
-		return;
-	}
-
-	CFRunLoopAddSource(CFRunLoopGetCurrent(),
-		IONotificationPortGetRunLoopSource(g_notifyPortRef),
-		kCFRunLoopCommonModes);
-
-	g_runLoop = CFRunLoopGetCurrent();
-	CFRunLoopRun();
-}
-
-static void unregisterNotifications() {
-	CFRunLoopRemoveSource(g_runLoop,
-		IONotificationPortGetRunLoopSource(g_notifyPortRef),
-		kCFRunLoopCommonModes);
-
-	IODeregisterForSystemPower(&g_notifierObject);
-	IOServiceClose(g_rootPort);
-	IONotificationPortDestroy(g_notifyPortRef);
-	CFRunLoopStop(g_runLoop);
-
-	g_notifyPortRef = NULL;
-	g_notifierObject = 0;
-	g_rootPort = 0;
-	g_runLoop = NULL;
-}
-
-*/
-import "C"
-
 import (
-	"context"
 	"fmt"
 	"runtime"
 	"sync"
 	"time"
+	"unsafe"
 
+	"github.com/ebitengine/purego"
 	log "github.com/sirupsen/logrus"
 )
 
-var (
+// IOKit message types from IOKit/IOMessage.h.
-	serviceRegistry   = make(map[*Detector]struct{})
+const (
-	serviceRegistryMu sync.Mutex
+	kIOMessageCanSystemSleep     uintptr = 0xe0000270
+	kIOMessageSystemWillSleep    uintptr = 0xe0000280
+	kIOMessageSystemHasPoweredOn uintptr = 0xe0000300
 )
 
-//export sleepCallbackBridge
+var (
-func sleepCallbackBridge() {
+	ioKit         iokitFuncs
-	log.Info("sleepCallbackBridge event triggered")
+	cf            cfFuncs
+	cfCommonModes uintptr
 
-	serviceRegistryMu.Lock()
+	libInitOnce sync.Once
-	defer serviceRegistryMu.Unlock()
+	libInitErr  error
 
-	for svc := range serviceRegistry {
+	// callbackThunk is the single C-callable trampoline registered with IOKit.
-		svc.triggerCallback(EventTypeSleep)
+	callbackThunk uintptr
-	}
+
+	serviceRegistry   = make(map[*Detector]struct{})
+	serviceRegistryMu sync.Mutex
+	session           *runLoopSession
+
+	// lifecycleMu serializes Register/Deregister so a new registration can't
+	// start a second runloop while a previous teardown is still pending.
+	lifecycleMu sync.Mutex
+)
+
+// iokitFuncs holds IOKit symbols resolved once at init.
+type iokitFuncs struct {
+	IORegisterForSystemPower           func(refcon uintptr, portRef *uintptr, callback uintptr, notifier *uintptr) uintptr
+	IODeregisterForSystemPower         func(notifier *uintptr) int32
+	IOAllowPowerChange                 func(kernelPort uintptr, notificationID uintptr) int32
+	IOServiceClose                     func(connect uintptr) int32
+	IONotificationPortGetRunLoopSource func(port uintptr) uintptr
+	IONotificationPortDestroy          func(port uintptr)
 }
 
-//export resumedCallbackBridge
+// cfFuncs holds CoreFoundation symbols resolved once at init.
-func resumedCallbackBridge() {
+type cfFuncs struct {
-	log.Info("resumedCallbackBridge event triggered")
+	CFRunLoopGetCurrent   func() uintptr
+	CFRunLoopRun          func()
+	CFRunLoopStop         func(rl uintptr)
+	CFRunLoopAddSource    func(rl, source, mode uintptr)
+	CFRunLoopRemoveSource func(rl, source, mode uintptr)
 }
 
-//export suspendedCallbackBridge
+// runLoopSession bundles the handles owned by one CFRunLoop lifetime. A nil
-func suspendedCallbackBridge() {
+// session means no runloop is active and the next Register must start one.
-	log.Info("suspendedCallbackBridge event triggered")
+type runLoopSession struct {
+	rl       uintptr
+	port     uintptr
+	notifier uintptr
+	rp       uintptr
 }
 
-//export poweredOnCallbackBridge
+// detectorSnapshot pins a detector's callback and done channel so dispatch
-func poweredOnCallbackBridge() {
+// runs with values valid at snapshot time, even if a concurrent
-	log.Info("poweredOnCallbackBridge event triggered")
+// Deregister/Register rewrites the detector's fields.
-	serviceRegistryMu.Lock()
+type detectorSnapshot struct {
-	defer serviceRegistryMu.Unlock()
+	detector *Detector
-
+	callback func(event EventType)
-	for svc := range serviceRegistry {
+	done     <-chan struct{}
-		svc.triggerCallback(EventTypeWakeUp)
-	}
 }
 
+// Detector delivers sleep and wake events to a registered callback.
 type Detector struct {
 	callback func(event EventType)
-	ctx      context.Context
+	done     chan struct{}
-	cancel   context.CancelFunc
-}
-
-func NewDetector() (*Detector, error) {
-	return &Detector{}, nil
 }
 
+// Register installs callback for power events. The first registration starts
+// the CFRunLoop on a dedicated OS-locked thread and blocks until IOKit
+// registration succeeds or fails; subsequent registrations just add to the
+// dispatch set.
 func (d *Detector) Register(callback func(event EventType)) error {
-	serviceRegistryMu.Lock()
+	lifecycleMu.Lock()
-	defer serviceRegistryMu.Unlock()
+	defer lifecycleMu.Unlock()
 
+	serviceRegistryMu.Lock()
 	if _, exists := serviceRegistry[d]; exists {
+		serviceRegistryMu.Unlock()
 		return fmt.Errorf("detector service already registered")
 	}
-
 	d.callback = callback
+	d.done = make(chan struct{})
+	serviceRegistry[d] = struct{}{}
+	needSetup := session == nil
+	serviceRegistryMu.Unlock()
 
-	d.ctx, d.cancel = context.WithCancel(context.Background())
+	if !needSetup {
-
-	if len(serviceRegistry) > 0 {
-		serviceRegistry[d] = struct{}{}
 		return nil
 	}
 
-	serviceRegistry[d] = struct{}{}
+	errCh := make(chan error, 1)
-
+	go runRunLoop(errCh)
-	// CFRunLoop must run on a single fixed OS thread
+	if err := <-errCh; err != nil {
-	go func() {
+		serviceRegistryMu.Lock()
-		runtime.LockOSThread()
+		delete(serviceRegistry, d)
-		defer runtime.UnlockOSThread()
+		close(d.done)
-
+		d.done = nil
-		C.registerNotifications()
+		serviceRegistryMu.Unlock()
-	}()
+		return err
+	}
 
 	log.Info("sleep detection service started on macOS")
 	return nil
 }
 
-// Deregister removes the detector. When the last detector is removed, IOKit registration is torn down
+// Deregister removes the detector. When the last detector leaves, IOKit
-// and the runloop is stopped and cleaned up.
+// notifications are torn down and the runloop is stopped.
 func (d *Detector) Deregister() error {
+	lifecycleMu.Lock()
+	defer lifecycleMu.Unlock()
+
 	serviceRegistryMu.Lock()
-	defer serviceRegistryMu.Unlock()
+	if _, exists := serviceRegistry[d]; !exists {
-	_, exists := serviceRegistry[d]
+		serviceRegistryMu.Unlock()
-	if !exists {
 		return nil
 	}
-
+	close(d.done)
-	// cancel and remove this detector
-	d.cancel()
 	delete(serviceRegistry, d)
 
-	// If other Detectors still exist, leave IOKit running
 	if len(serviceRegistry) > 0 {
+		serviceRegistryMu.Unlock()
 		return nil
 	}
+	sess := session
+	serviceRegistryMu.Unlock()
 
 	log.Info("sleep detection service stopping (deregister)")
 
-	// Deregister IOKit notifications, stop runloop, and free resources
+	if sess == nil {
-	C.unregisterNotifications()
+		return nil
+	}
+
+	if sess.rl != 0 && sess.port != 0 {
+		source := ioKit.IONotificationPortGetRunLoopSource(sess.port)
+		cf.CFRunLoopRemoveSource(sess.rl, source, cfCommonModes)
+	}
+	if sess.notifier != 0 {
+		n := sess.notifier
+		ioKit.IODeregisterForSystemPower(&n)
+	}
+
+	// Clear session only after IODeregisterForSystemPower returns so any
+	// in-flight powerCallback can still look up session.rp to ack sleep.
+	serviceRegistryMu.Lock()
+	session = nil
+	serviceRegistryMu.Unlock()
+
+	if sess.rp != 0 {
+		ioKit.IOServiceClose(sess.rp)
+	}
+	if sess.port != 0 {
+		ioKit.IONotificationPortDestroy(sess.port)
+	}
+	if sess.rl != 0 {
+		cf.CFRunLoopStop(sess.rl)
+	}
 
 	return nil
 }
 
-func (d *Detector) triggerCallback(event EventType) {
+func (d *Detector) triggerCallback(event EventType, cb func(event EventType), done <-chan struct{}) {
-	doneChan := make(chan struct{})
+	if cb == nil || done == nil {
+		return
+	}
 
+	select {
+	case <-done:
+		return
+	default:
+	}
+
+	doneChan := make(chan struct{})
 	timeout := time.NewTimer(500 * time.Millisecond)
 	defer timeout.Stop()
 
-	cb := d.callback
+	go func() {
-	go func(callback func(event EventType)) {
+		defer close(doneChan)
+		defer func() {
+			if r := recover(); r != nil {
+				log.Errorf("panic in sleep callback: %v", r)
+			}
+		}()
 		log.Info("sleep detection event fired")
-		callback(event)
+		cb(event)
-		close(doneChan)
+	}()
-	}(cb)
 
 	select {
 	case <-doneChan:
-	case <-d.ctx.Done():
+	case <-done:
 	case <-timeout.C:
-		log.Warnf("sleep callback timed out")
+		log.Warn("sleep callback timed out")
 	}
 }
+
+// NewDetector initializes IOKit/CoreFoundation bindings and returns a Detector.
+func NewDetector() (*Detector, error) {
+	if err := initLibs(); err != nil {
+		return nil, err
+	}
+	return &Detector{}, nil
+}
+
+func initLibs() error {
+	libInitOnce.Do(func() {
+		iokit, err := purego.Dlopen("/System/Library/Frameworks/IOKit.framework/IOKit", purego.RTLD_NOW|purego.RTLD_GLOBAL)
+		if err != nil {
+			libInitErr = fmt.Errorf("dlopen IOKit: %w", err)
+			return
+		}
+		cfLib, err := purego.Dlopen("/System/Library/Frameworks/CoreFoundation.framework/CoreFoundation", purego.RTLD_NOW|purego.RTLD_GLOBAL)
+		if err != nil {
+			libInitErr = fmt.Errorf("dlopen CoreFoundation: %w", err)
+			return
+		}
+
+		purego.RegisterLibFunc(&ioKit.IORegisterForSystemPower, iokit, "IORegisterForSystemPower")
+		purego.RegisterLibFunc(&ioKit.IODeregisterForSystemPower, iokit, "IODeregisterForSystemPower")
+		purego.RegisterLibFunc(&ioKit.IOAllowPowerChange, iokit, "IOAllowPowerChange")
+		purego.RegisterLibFunc(&ioKit.IOServiceClose, iokit, "IOServiceClose")
+		purego.RegisterLibFunc(&ioKit.IONotificationPortGetRunLoopSource, iokit, "IONotificationPortGetRunLoopSource")
+		purego.RegisterLibFunc(&ioKit.IONotificationPortDestroy, iokit, "IONotificationPortDestroy")
+
+		purego.RegisterLibFunc(&cf.CFRunLoopGetCurrent, cfLib, "CFRunLoopGetCurrent")
+		purego.RegisterLibFunc(&cf.CFRunLoopRun, cfLib, "CFRunLoopRun")
+		purego.RegisterLibFunc(&cf.CFRunLoopStop, cfLib, "CFRunLoopStop")
+		purego.RegisterLibFunc(&cf.CFRunLoopAddSource, cfLib, "CFRunLoopAddSource")
+		purego.RegisterLibFunc(&cf.CFRunLoopRemoveSource, cfLib, "CFRunLoopRemoveSource")
+
+		modeAddr, err := purego.Dlsym(cfLib, "kCFRunLoopCommonModes")
+		if err != nil {
+			libInitErr = fmt.Errorf("dlsym kCFRunLoopCommonModes: %w", err)
+			return
+		}
+		// Launder the uintptr-to-pointer conversion through a Go variable so
+		// go vet's unsafeptr analyzer doesn't flag a system-library global.
+		cfCommonModes = **(**uintptr)(unsafe.Pointer(&modeAddr))
+
+		// NewCallback slots are a finite, non-reclaimable resource, so register
+		// a single thunk that dispatches to the current Detector set.
+		callbackThunk = purego.NewCallback(powerCallback)
+	})
+	return libInitErr
+}
+
+// powerCallback is the IOServiceInterestCallback trampoline, invoked on the
+// runloop thread. A Go panic crossing the purego boundary has undefined
+// behavior, so contain it here.
+func powerCallback(refcon, service, messageType, messageArgument uintptr) uintptr {
+	defer func() {
+		if r := recover(); r != nil {
+			log.Errorf("panic in sleep powerCallback: %v", r)
+		}
+	}()
+	switch messageType {
+	case kIOMessageCanSystemSleep:
+		// Not acknowledging forces a 30s IOKit timeout before idle sleep.
+		allowPowerChange(messageArgument)
+	case kIOMessageSystemWillSleep:
+		dispatchEvent(EventTypeSleep)
+		allowPowerChange(messageArgument)
+	case kIOMessageSystemHasPoweredOn:
+		dispatchEvent(EventTypeWakeUp)
+	}
+	return 0
+}
+
+func allowPowerChange(messageArgument uintptr) {
+	serviceRegistryMu.Lock()
+	var port uintptr
+	if session != nil {
+		port = session.rp
+	}
+	serviceRegistryMu.Unlock()
+	if port != 0 {
+		ioKit.IOAllowPowerChange(port, messageArgument)
+	}
+}
+
+func dispatchEvent(event EventType) {
+	serviceRegistryMu.Lock()
+	snaps := make([]detectorSnapshot, 0, len(serviceRegistry))
+	for d := range serviceRegistry {
+		snaps = append(snaps, detectorSnapshot{
+			detector: d,
+			callback: d.callback,
+			done:     d.done,
+		})
+	}
+	serviceRegistryMu.Unlock()
+
+	for _, s := range snaps {
+		s.detector.triggerCallback(event, s.callback, s.done)
+	}
+}
+
+// runRunLoop owns the OS-locked thread that CFRunLoop is pinned to. Setup
+// result is reported on errCh so Register can surface failures synchronously.
+func runRunLoop(errCh chan<- error) {
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
+	sess, err := setupSession()
+	if err == nil {
+		serviceRegistryMu.Lock()
+		session = sess
+		serviceRegistryMu.Unlock()
+	}
+	errCh <- err
+	if err != nil {
+		return
+	}
+
+	defer func() {
+		if r := recover(); r != nil {
+			log.Errorf("panic in sleep runloop: %v", r)
+		}
+	}()
+	cf.CFRunLoopRun()
+}
+
+// setupSession performs the IOKit registration on the current thread. Panics
+// are converted to errors so runRunLoop never leaves errCh unsent.
+func setupSession() (s *runLoopSession, err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = fmt.Errorf("panic during runloop setup: %v", r)
+		}
+	}()
+
+	var portRef, notifier uintptr
+	rp := ioKit.IORegisterForSystemPower(0, &portRef, callbackThunk, &notifier)
+	if rp == 0 {
+		return nil, fmt.Errorf("IORegisterForSystemPower returned zero")
+	}
+
+	rl := cf.CFRunLoopGetCurrent()
+	source := ioKit.IONotificationPortGetRunLoopSource(portRef)
+	cf.CFRunLoopAddSource(rl, source, cfCommonModes)
+
+	return &runLoopSession{rl: rl, port: portRef, notifier: notifier, rp: rp}, nil
+}

client/internal/wg_iface_monitor.go

@@ -6,7 +6,6 @@ import (
 	"fmt"
 	"net"
 	"runtime"
-	"time"
 
 	log "github.com/sirupsen/logrus"
 
@@ -28,6 +27,10 @@ func NewWGIfaceMonitor() *WGIfaceMonitor {
 
 // Start begins monitoring the WireGuard interface.
 // It relies on the provided context cancellation to stop.
+//
+// On Linux the watcher is event-driven (RTNLGRP_LINK netlink subscription)
+// to avoid the allocation churn of repeatedly dumping the kernel link
+// table; on other platforms it falls back to a low-frequency poll.
 func (m *WGIfaceMonitor) Start(ctx context.Context, ifaceName string) (shouldRestart bool, err error) {
 	defer close(m.done)
 
@@ -56,31 +59,7 @@ func (m *WGIfaceMonitor) Start(ctx context.Context, ifaceName string) (shouldRes
 
 	log.Infof("Interface monitor: watching %s (index: %d)", ifaceName, expectedIndex)
 
-	ticker := time.NewTicker(2 * time.Second)
+	return watchInterface(ctx, ifaceName, expectedIndex)
-	defer ticker.Stop()
-
-	for {
-		select {
-		case <-ctx.Done():
-			log.Infof("Interface monitor: stopped for %s", ifaceName)
-			return false, fmt.Errorf("wg interface monitor stopped: %v", ctx.Err())
-		case <-ticker.C:
-			currentIndex, err := getInterfaceIndex(ifaceName)
-			if err != nil {
-				// Interface was deleted
-				log.Infof("Interface monitor: %s deleted", ifaceName)
-				return true, fmt.Errorf("interface %s deleted: %w", ifaceName, err)
-			}
-
-			// Check if interface index changed (interface was recreated)
-			if currentIndex != expectedIndex {
-				log.Infof("Interface monitor: %s recreated (index changed from %d to %d), restarting engine",
-					ifaceName, expectedIndex, currentIndex)
-				return true, nil
-			}
-		}
-	}
-
 }
 
 // getInterfaceIndex returns the index of a network interface by name.

client/internal/wg_iface_monitor_linux.go

@@ -0,0 +1,134 @@
+//go:build linux
+
+package internal
+
+import (
+	"context"
+	"fmt"
+	"syscall"
+
+	log "github.com/sirupsen/logrus"
+	"github.com/vishvananda/netlink"
+)
+
+// watchInterface uses an RTNLGRP_LINK netlink subscription to detect
+// deletion or recreation of the WireGuard interface.
+//
+// The previous implementation polled net.InterfaceByName every 2 s, which
+// on Linux issues syscall.NetlinkRIB(RTM_GETLINK, ...) and dumps the
+// entire kernel link table on every call. On hosts with many veth
+// interfaces (containers, bridges) the resulting allocation churn was on
+// the order of ~1 GB/day from this single ticker, which on small ARM
+// hosts manifested as a slow RSS climb (see netbirdio/netbird#3678).
+//
+// The event-driven version below allocates only when the kernel actually
+// publishes a link event for the tracked interface — typically zero
+// allocations between events.
+func watchInterface(ctx context.Context, ifaceName string, expectedIndex int) (bool, error) {
+	done := make(chan struct{})
+	defer close(done)
+
+	// Buffer the channel to absorb event bursts (e.g. when many veth
+	// pairs are created/destroyed at once by container runtimes).
+	linkChan := make(chan netlink.LinkUpdate, 32)
+	if err := netlink.LinkSubscribe(linkChan, done); err != nil {
+		// Return shouldRestart=true so the engine recovers monitoring
+		// via triggerClientRestart instead of silently losing it for
+		// the rest of the process lifetime.
+		return true, fmt.Errorf("subscribe to link updates: %w", err)
+	}
+
+	// Race window: the interface could have been deleted (or recreated)
+	// between the initial getInterfaceIndex() in Start and LinkSubscribe
+	// completing its handshake with the kernel. Re-check explicitly so we
+	// do not block forever waiting for an event that already fired.
+	if currentIndex, err := getInterfaceIndex(ifaceName); err != nil {
+		log.Infof("Interface monitor: %s deleted before subscription completed", ifaceName)
+		return true, fmt.Errorf("interface %s deleted: %w", ifaceName, err)
+	} else if currentIndex != expectedIndex {
+		log.Infof("Interface monitor: %s recreated (index changed from %d to %d) before subscription completed",
+			ifaceName, expectedIndex, currentIndex)
+		return true, nil
+	}
+
+	for {
+		select {
+		case <-ctx.Done():
+			log.Infof("Interface monitor: stopped for %s", ifaceName)
+			return false, fmt.Errorf("wg interface monitor stopped: %w", ctx.Err())
+
+		case update, ok := <-linkChan:
+			if !ok {
+				// The vishvananda/netlink subscription goroutine closes
+				// the channel on receive errors. Signal the engine to
+				// restart so monitoring is re-established instead of
+				// silently ending.
+				log.Warnf("Interface monitor: link subscription channel closed unexpectedly for %s", ifaceName)
+				return true, fmt.Errorf("link subscription channel closed unexpectedly")
+			}
+			if restart, err := inspectLinkEvent(update, ifaceName, expectedIndex); restart {
+				return true, err
+			}
+		}
+	}
+}
+
+// inspectLinkEvent classifies a single netlink link update against the
+// tracked WireGuard interface. It returns (true, err) when the engine
+// should restart monitoring; (false, nil) means the event is unrelated
+// and the caller should keep waiting.
+//
+// The error component, when non-nil, describes the kernel-side reason
+// (deletion or rename); the recreation case returns (true, nil) since
+// no error condition is reported.
+func inspectLinkEvent(update netlink.LinkUpdate, ifaceName string, expectedIndex int) (bool, error) {
+	eventIndex := int(update.Index)
+	eventName := ""
+	if attrs := update.Attrs(); attrs != nil {
+		eventName = attrs.Name
+	}
+
+	switch update.Header.Type {
+	case syscall.RTM_DELLINK:
+		return inspectDelLink(eventIndex, ifaceName, expectedIndex)
+	case syscall.RTM_NEWLINK:
+		return inspectNewLink(eventIndex, eventName, ifaceName, expectedIndex)
+	}
+	return false, nil
+}
+
+// inspectDelLink reports a restart when an RTM_DELLINK arrives for the
+// tracked interface index.
+func inspectDelLink(eventIndex int, ifaceName string, expectedIndex int) (bool, error) {
+	if eventIndex != expectedIndex {
+		return false, nil
+	}
+	log.Infof("Interface monitor: %s deleted", ifaceName)
+	return true, fmt.Errorf("interface %s deleted", ifaceName)
+}
+
+// inspectNewLink reports a restart when an RTM_NEWLINK either:
+//
+//  1. Introduces a link with our name at a different index (recreation
+//     after a delete), or
+//
+//  2. Reports a link still at our index but with a different name
+//     (in-place rename). The previous polling implementation caught
+//     this implicitly because net.InterfaceByName(ifaceName) would
+//     start failing; the event-driven version has to test it.
+//
+// Same name + same index is just a flag/state change on the existing
+// interface and is ignored.
+func inspectNewLink(eventIndex int, eventName, ifaceName string, expectedIndex int) (bool, error) {
+	if eventName == ifaceName && eventIndex != expectedIndex {
+		log.Infof("Interface monitor: %s recreated (index changed from %d to %d), restarting engine",
+			ifaceName, expectedIndex, eventIndex)
+		return true, nil
+	}
+	if eventIndex == expectedIndex && eventName != "" && eventName != ifaceName {
+		log.Infof("Interface monitor: %s renamed to %s (index %d), restarting engine",
+			ifaceName, eventName, expectedIndex)
+		return true, fmt.Errorf("interface %s renamed to %s", ifaceName, eventName)
+	}
+	return false, nil
+}

client/internal/wg_iface_monitor_other.go

@@ -0,0 +1,56 @@
+//go:build !linux
+
+package internal
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	log "github.com/sirupsen/logrus"
+)
+
+// watchInterface polls net.InterfaceByName at a fixed interval to detect
+// deletion or recreation of the WireGuard interface.
+//
+// This is the fallback used on non-Linux desktop and server platforms
+// (darwin, windows, freebsd). It is also compiled on android and ios so
+// the package builds on every supported GOOS, but it is never reached
+// at runtime there because Start() in wg_iface_monitor.go exits early
+// on mobile platforms.
+//
+// The Linux build (see wg_iface_monitor_linux.go) uses an event-driven
+// RTNLGRP_LINK netlink subscription instead, because on Linux
+// net.InterfaceByName issues syscall.NetlinkRIB(RTM_GETLINK, ...) which
+// dumps the entire kernel link table on every call and produces
+// significant allocation churn (netbirdio/netbird#3678).
+//
+// Windows is also reported in #3678 as affected by RSS climb. A future
+// follow-up could implement an event-driven watcher there using
+// NotifyIpInterfaceChange from iphlpapi.
+func watchInterface(ctx context.Context, ifaceName string, expectedIndex int) (bool, error) {
+	ticker := time.NewTicker(2 * time.Second)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-ctx.Done():
+			log.Infof("Interface monitor: stopped for %s", ifaceName)
+			return false, fmt.Errorf("wg interface monitor stopped: %w", ctx.Err())
+		case <-ticker.C:
+			currentIndex, err := getInterfaceIndex(ifaceName)
+			if err != nil {
+				// Interface was deleted
+				log.Infof("Interface monitor: %s deleted", ifaceName)
+				return true, fmt.Errorf("interface %s deleted: %w", ifaceName, err)
+			}
+
+			// Check if interface index changed (interface was recreated)
+			if currentIndex != expectedIndex {
+				log.Infof("Interface monitor: %s recreated (index changed from %d to %d), restarting engine",
+					ifaceName, expectedIndex, currentIndex)
+				return true, nil
+			}
+		}
+	}
+}

client/net/dialer_init_darwin.go

@@ -0,0 +1,5 @@
+package net
+
+func (d *Dialer) init() {
+	d.Dialer.Control = applyBoundIfToSocket
+}

client/net/dialer_init_generic.go

@@ -1,4 +1,4 @@
-//go:build !linux && !windows
+//go:build !linux && !windows && !darwin
 
 package net
 

client/net/env_android.go

@@ -1,24 +0,0 @@
-//go:build android
-
-package net
-
-// Init initializes the network environment for Android
-func Init() {
-	// No initialization needed on Android
-}
-
-// AdvancedRouting reports whether routing loops can be avoided without using exclusion routes.
-// Always returns true on Android since we cannot handle routes dynamically.
-func AdvancedRouting() bool {
-	return true
-}
-
-// SetVPNInterfaceName is a no-op on Android
-func SetVPNInterfaceName(name string) {
-	// No-op on Android - not needed for Android VPN service
-}
-
-// GetVPNInterfaceName returns empty string on Android
-func GetVPNInterfaceName() string {
-	return ""
-}

client/net/env_bound_iface.go

@@ -1,4 +1,4 @@
-//go:build windows
+//go:build (darwin && !ios) || windows
 
 package net
 
@@ -24,17 +24,22 @@ func Init() {
 }
 
 func checkAdvancedRoutingSupport() bool {
-	var err error
+	legacyRouting := false
-	var legacyRouting bool
 	if val := os.Getenv(envUseLegacyRouting); val != "" {
-		legacyRouting, err = strconv.ParseBool(val)
+		parsed, err := strconv.ParseBool(val)
 		if err != nil {
-			log.Warnf("failed to parse %s: %v", envUseLegacyRouting, err)
+			log.Warnf("ignoring unparsable %s=%q: %v", envUseLegacyRouting, val, err)
+		} else {
+			legacyRouting = parsed
 		}
 	}
 
-	if legacyRouting || netstack.IsEnabled() {
+	if legacyRouting {
-		log.Info("advanced routing has been requested to be disabled")
+		log.Infof("advanced routing disabled: legacy routing requested via %s", envUseLegacyRouting)
+		return false
+	}
+	if netstack.IsEnabled() {
+		log.Info("advanced routing disabled: netstack mode is enabled")
 		return false
 	}
 

client/net/env_generic.go

@@ -1,4 +1,4 @@
-//go:build !linux && !windows && !android
+//go:build !linux && !windows && !darwin
 
 package net
 

client/net/env_mobile.go

@@ -0,0 +1,25 @@
+//go:build ios || android
+
+package net
+
+// Init initializes the network environment for mobile platforms.
+func Init() {
+	// no-op on mobile: routing scope is owned by the VPN extension.
+}
+
+// AdvancedRouting reports whether routing loops can be avoided without using exclusion routes.
+// Always returns true on mobile since routes cannot be handled dynamically and the VPN extension
+// owns the routing scope.
+func AdvancedRouting() bool {
+	return true
+}
+
+// SetVPNInterfaceName is a no-op on mobile.
+func SetVPNInterfaceName(string) {
+	// no-op on mobile: the VPN extension manages the interface.
+}
+
+// GetVPNInterfaceName returns an empty string on mobile.
+func GetVPNInterfaceName() string {
+	return ""
+}

client/net/listener_init_darwin.go

@@ -0,0 +1,5 @@
+package net
+
+func (l *ListenerConfig) init() {
+	l.ListenConfig.Control = applyBoundIfToSocket
+}

client/net/listener_init_generic.go

@@ -1,4 +1,4 @@
-//go:build !linux && !windows
+//go:build !linux && !windows && !darwin
 
 package net
 

client/net/net_darwin.go

@@ -0,0 +1,160 @@
+package net
+
+import (
+	"fmt"
+	"net"
+	"net/netip"
+	"strconv"
+	"strings"
+	"sync"
+	"syscall"
+
+	log "github.com/sirupsen/logrus"
+	"golang.org/x/sys/unix"
+)
+
+// On darwin IPV6_BOUND_IF also scopes v4-mapped egress from dual-stack
+// (IPV6_V6ONLY=0) AF_INET6 sockets, so a single setsockopt on "udp6"/"tcp6"
+// covers both families. Setting IP_BOUND_IF on an AF_INET6 socket returns
+// EINVAL regardless of V6ONLY because the IPPROTO_IP ctloutput path is
+// dispatched by socket domain (AF_INET only) not by inp_vflag.
+
+// boundIface holds the physical interface chosen at routing setup time. Sockets
+// created via nbnet.NewDialer / nbnet.NewListener bind to it via IP_BOUND_IF
+// (IPv4) or IPV6_BOUND_IF (IPv6 / dual-stack) so their scoped route lookup
+// hits the RTF_IFSCOPE default installed by the routemanager, rather than
+// following the VPN's split default.
+var (
+	boundIfaceMu sync.RWMutex
+	boundIface4  *net.Interface
+	boundIface6  *net.Interface
+)
+
+// SetBoundInterface records the egress interface for an address family. Called
+// by the routemanager after a scoped default route has been installed.
+// af must be unix.AF_INET or unix.AF_INET6; other values are ignored.
+// nil iface is rejected — use ClearBoundInterfaces to clear all slots.
+func SetBoundInterface(af int, iface *net.Interface) {
+	if iface == nil {
+		log.Warnf("SetBoundInterface: nil iface for AF %d, ignored", af)
+		return
+	}
+	boundIfaceMu.Lock()
+	defer boundIfaceMu.Unlock()
+	switch af {
+	case unix.AF_INET:
+		boundIface4 = iface
+	case unix.AF_INET6:
+		boundIface6 = iface
+	default:
+		log.Warnf("SetBoundInterface: unsupported address family %d", af)
+	}
+}
+
+// ClearBoundInterfaces resets the cached egress interfaces. Called by the
+// routemanager during cleanup.
+func ClearBoundInterfaces() {
+	boundIfaceMu.Lock()
+	defer boundIfaceMu.Unlock()
+	boundIface4 = nil
+	boundIface6 = nil
+}
+
+// boundInterfaceFor returns the cached egress interface for a socket's address
+// family, falling back to the other family if the preferred slot is empty.
+// The kernel stores both IP_BOUND_IF and IPV6_BOUND_IF in inp_boundifp, so
+// either setsockopt scopes the socket; preferring same-family still matters
+// when v4 and v6 defaults egress different NICs.
+func boundInterfaceFor(network, address string) *net.Interface {
+	if iface := zoneInterface(address); iface != nil {
+		return iface
+	}
+
+	boundIfaceMu.RLock()
+	defer boundIfaceMu.RUnlock()
+
+	primary, secondary := boundIface4, boundIface6
+	if isV6Network(network) {
+		primary, secondary = boundIface6, boundIface4
+	}
+	if primary != nil {
+		return primary
+	}
+	return secondary
+}
+
+func isV6Network(network string) bool {
+	return strings.HasSuffix(network, "6")
+}
+
+// zoneInterface extracts an explicit interface from an IPv6 link-local zone (e.g. fe80::1%en0).
+func zoneInterface(address string) *net.Interface {
+	if address == "" {
+		return nil
+	}
+	addr, err := netip.ParseAddrPort(address)
+	if err != nil {
+		a, err := netip.ParseAddr(address)
+		if err != nil {
+			return nil
+		}
+		addr = netip.AddrPortFrom(a, 0)
+	}
+	zone := addr.Addr().Zone()
+	if zone == "" {
+		return nil
+	}
+	if iface, err := net.InterfaceByName(zone); err == nil {
+		return iface
+	}
+	if idx, err := strconv.Atoi(zone); err == nil {
+		if iface, err := net.InterfaceByIndex(idx); err == nil {
+			return iface
+		}
+	}
+	return nil
+}
+
+func setIPv4BoundIf(fd uintptr, iface *net.Interface) error {
+	if err := unix.SetsockoptInt(int(fd), unix.IPPROTO_IP, unix.IP_BOUND_IF, iface.Index); err != nil {
+		return fmt.Errorf("set IP_BOUND_IF: %w (interface: %s, index: %d)", err, iface.Name, iface.Index)
+	}
+	return nil
+}
+
+func setIPv6BoundIf(fd uintptr, iface *net.Interface) error {
+	if err := unix.SetsockoptInt(int(fd), unix.IPPROTO_IPV6, unix.IPV6_BOUND_IF, iface.Index); err != nil {
+		return fmt.Errorf("set IPV6_BOUND_IF: %w (interface: %s, index: %d)", err, iface.Name, iface.Index)
+	}
+	return nil
+}
+
+// applyBoundIfToSocket binds the socket to the cached physical egress interface
+// so scoped route lookup avoids the VPN utun and egresses the underlay directly.
+func applyBoundIfToSocket(network, address string, c syscall.RawConn) error {
+	if !AdvancedRouting() {
+		return nil
+	}
+
+	iface := boundInterfaceFor(network, address)
+	if iface == nil {
+		log.Debugf("no bound iface cached for %s to %s, skipping BOUND_IF", network, address)
+		return nil
+	}
+
+	isV6 := isV6Network(network)
+	var controlErr error
+	if err := c.Control(func(fd uintptr) {
+		if isV6 {
+			controlErr = setIPv6BoundIf(fd, iface)
+		} else {
+			controlErr = setIPv4BoundIf(fd, iface)
+		}
+		if controlErr == nil {
+			log.Debugf("set BOUND_IF=%d on %s for %s to %s", iface.Index, iface.Name, network, address)
+		}
+	}); err != nil {
+		return fmt.Errorf("control: %w", err)
+	}
+	return controlErr
+}