Merge remote-tracking branch 'origin/main' into netmap_progressive_alignment

# Conflicts:
#	client/internal/engine.go

client/iface/wgproxy/bind/proxy.go

@@ -136,6 +136,11 @@ func (p *ProxyBind) CloseConn() error {
 	return p.close()
 }
 
+// InjectPacket is a no-op for the userspace proxy: first-packet reinjection is kernel-only.
+func (p *ProxyBind) InjectPacket(_ []byte) error {
+	return nil
+}
+
 func (p *ProxyBind) close() error {
 	if p.remoteConn == nil {
 		return nil

client/iface/wgproxy/ebpf/wrapper.go

@@ -219,6 +219,17 @@ func (p *ProxyWrapper) RedirectAs(endpoint *net.UDPAddr) {
 	p.pausedCond.L.Unlock()
 }
 
+// InjectPacket writes b to the remote peer over the underlying transport.
+func (p *ProxyWrapper) InjectPacket(b []byte) error {
+	if p.remoteConn == nil {
+		return errors.New("proxy not started")
+	}
+	if _, err := p.remoteConn.Write(b); err != nil {
+		return err
+	}
+	return nil
+}
+
 // CloseConn close the remoteConn and automatically remove the conn instance from the map
 func (p *ProxyWrapper) CloseConn() error {
 	if p.cancel == nil {

client/iface/wgproxy/proxy.go

@@ -18,4 +18,9 @@ type Proxy interface {
 	RedirectAs(endpoint *net.UDPAddr)
 	CloseConn() error
 	SetDisconnectListener(disconnected func())
+
+	// InjectPacket writes a raw packet directly to the remote peer over the underlying transport,
+	// bypassing WireGuard. Used to replay the captured lazyconn handshake initiation. Only the
+	// kernel-mode proxies act on it; the userspace proxy is a no-op since reinjection is kernel-only.
+	InjectPacket(b []byte) error
 }

client/iface/wgproxy/udp/proxy.go

@@ -147,6 +147,17 @@ func (p *WGUDPProxy) RedirectAs(endpoint *net.UDPAddr) {
 	p.sendPkg = p.srcFakerConn.SendPkg
 }
 
+// InjectPacket writes b to the remote peer over the underlying transport.
+func (p *WGUDPProxy) InjectPacket(b []byte) error {
+	if p.remoteConn == nil {
+		return errors.New("proxy not started")
+	}
+	if _, err := p.remoteConn.Write(b); err != nil {
+		return err
+	}
+	return nil
+}
+
 // CloseConn close the localConn
 func (p *WGUDPProxy) CloseConn() error {
 	if p.cancel == nil {

client/internal/acl/manager.go

@@ -11,6 +11,7 @@ import (
 	"time"
 
 	"github.com/hashicorp/go-multierror"
+	"github.com/mitchellh/hashstructure/v2"
 	log "github.com/sirupsen/logrus"
 
 	nberrors "github.com/netbirdio/netbird/client/errors"
@@ -30,11 +31,13 @@ type Manager interface {
 
 // DefaultManager uses firewall manager to handle
 type DefaultManager struct {
-	firewall       firewall.Manager
-	ipsetCounter   int
-	peerRulesPairs map[id.RuleID][]firewall.Rule
-	routeRules     map[id.RuleID]struct{}
-	mutex          sync.Mutex
+	firewall           firewall.Manager
+	ipsetCounter       int
+	peerRulesPairs     map[id.RuleID][]firewall.Rule
+	routeRules         map[id.RuleID]struct{}
+	previousConfigHash uint64
+	hasAppliedConfig   bool
+	mutex              sync.Mutex
 }
 
 func NewDefaultManager(fm firewall.Manager) *DefaultManager {
@@ -57,6 +60,23 @@ func (d *DefaultManager) ApplyFiltering(networkMap *mgmProto.NetworkMap, dnsRout
 		return
 	}
 
+	// Skip the full rebuild + flush when the inputs that drive the firewall
+	// state are byte-for-byte identical to the last successfully applied
+	// update. Management re-sends the same network map far more often than it
+	// actually changes (account-wide updates, peer meta churn), and rebuilding
+	// every peer/route ACL and flushing the firewall on every such sync is the
+	// dominant client-side cost when nothing changed. Mirrors the same guard the
+	// DNS server already uses (previousConfigHash). Only the fields ApplyFiltering
+	// consumes participate in the hash, so an unrelated map change cannot mask a
+	// real ACL change.
+	hash, err := d.firewallConfigHash(networkMap, dnsRouteFeatureFlag)
+	if err != nil {
+		log.Errorf("unable to hash firewall configuration, applying unconditionally: %v", err)
+	} else if d.hasAppliedConfig && d.previousConfigHash == hash {
+		log.Debugf("not applying the firewall configuration update as there is nothing new (hash: %d)", hash)
+		return
+	}
+
 	start := time.Now()
 	defer func() {
 		total := 0
@@ -70,13 +90,49 @@ func (d *DefaultManager) ApplyFiltering(networkMap *mgmProto.NetworkMap, dnsRout
 
 	d.applyPeerACLs(networkMap)
 
-	if err := d.applyRouteACLs(networkMap.RoutesFirewallRules, dnsRouteFeatureFlag); err != nil {
-		log.Errorf("Failed to apply route ACLs: %v", err)
+	routeErr := d.applyRouteACLs(networkMap.RoutesFirewallRules, dnsRouteFeatureFlag)
+	if routeErr != nil {
+		log.Errorf("Failed to apply route ACLs: %v", routeErr)
 	}
 
-	if err := d.firewall.Flush(); err != nil {
-		log.Error("failed to flush firewall rules: ", err)
+	flushErr := d.firewall.Flush()
+	if flushErr != nil {
+		log.Error("failed to flush firewall rules: ", flushErr)
 	}
+
+	// Only remember the hash once the firewall actually reflects this config.
+	// If applying or flushing failed, leave the previous hash untouched so the
+	// next (possibly identical) update is not skipped and gets a chance to
+	// reconcile the firewall state.
+	if err == nil && routeErr == nil && flushErr == nil {
+		d.previousConfigHash = hash
+		d.hasAppliedConfig = true
+	} else {
+		d.hasAppliedConfig = false
+	}
+}
+
+// firewallConfigHash hashes exactly the inputs ApplyFiltering uses to build the
+// firewall state, so an identical hash means an identical resulting ruleset.
+func (d *DefaultManager) firewallConfigHash(networkMap *mgmProto.NetworkMap, dnsRouteFeatureFlag bool) (uint64, error) {
+	return hashstructure.Hash(struct {
+		PeerRules            []*mgmProto.FirewallRule
+		PeerRulesIsEmpty     bool
+		RouteRules           []*mgmProto.RouteFirewallRule
+		RouteRulesIsEmpty    bool
+		DNSRouteFeatureFlag  bool
+	}{
+		PeerRules:           networkMap.GetFirewallRules(),
+		PeerRulesIsEmpty:    networkMap.GetFirewallRulesIsEmpty(),
+		RouteRules:          networkMap.GetRoutesFirewallRules(),
+		RouteRulesIsEmpty:   networkMap.GetRoutesFirewallRulesIsEmpty(),
+		DNSRouteFeatureFlag: dnsRouteFeatureFlag,
+	}, hashstructure.FormatV2, &hashstructure.HashOptions{
+		ZeroNil:         true,
+		IgnoreZeroValue: true,
+		SlicesAsSets:    true,
+		UseStringer:     true,
+	})
 }
 
 func (d *DefaultManager) applyPeerACLs(networkMap *mgmProto.NetworkMap) {

client/internal/acl/manager_test.go

@@ -1,6 +1,7 @@
 package acl
 
 import (
+	"fmt"
 	"net/netip"
 	"testing"
 
@@ -485,3 +486,149 @@ func TestPortInfoEmpty(t *testing.T) {
 		})
 	}
 }
+
+// TestApplyFilteringSkipsUnchangedConfig verifies that an identical network map
+// re-applied is recognized as a no-op (hash unchanged), while a real change to
+// any firewall-relevant input forces a re-apply (hash changes). This is the
+// guard that prevents a full ruleset rebuild + flush on every redundant sync.
+func TestApplyFilteringSkipsUnchangedConfig(t *testing.T) {
+	t.Setenv("NB_WG_KERNEL_DISABLED", "true")
+	t.Setenv(firewall.EnvForceUserspaceFirewall, "true")
+
+	ctrl := gomock.NewController(t)
+	defer ctrl.Finish()
+
+	ifaceMock := mocks.NewMockIFaceMapper(ctrl)
+	ifaceMock.EXPECT().IsUserspaceBind().Return(true).AnyTimes()
+	ifaceMock.EXPECT().SetFilter(gomock.Any())
+	network := netip.MustParsePrefix("172.0.0.1/32")
+	ifaceMock.EXPECT().Name().Return("lo").AnyTimes()
+	ifaceMock.EXPECT().Address().Return(wgaddr.Address{
+		IP:      network.Addr(),
+		Network: network,
+	}).AnyTimes()
+	ifaceMock.EXPECT().GetWGDevice().Return(nil).AnyTimes()
+
+	fw, err := firewall.NewFirewall(ifaceMock, nil, flowLogger, false, iface.DefaultMTU)
+	require.NoError(t, err)
+	defer func() {
+		require.NoError(t, fw.Close(nil))
+	}()
+
+	acl := NewDefaultManager(fw)
+
+	networkMap := &mgmProto.NetworkMap{
+		FirewallRules: []*mgmProto.FirewallRule{
+			{
+				PeerIP:    "10.93.0.1",
+				Direction: mgmProto.RuleDirection_IN,
+				Action:    mgmProto.RuleAction_ACCEPT,
+				Protocol:  mgmProto.RuleProtocol_TCP,
+				Port:      "22",
+			},
+		},
+		FirewallRulesIsEmpty: false,
+	}
+
+	acl.ApplyFiltering(networkMap, false)
+	require.True(t, acl.hasAppliedConfig, "config should be marked applied after first apply")
+	firstHash := acl.previousConfigHash
+	require.NotZero(t, firstHash)
+
+	// Re-applying the identical map must not change the recorded hash: the
+	// expensive rebuild path was skipped.
+	acl.ApplyFiltering(networkMap, false)
+	assert.Equal(t, firstHash, acl.previousConfigHash,
+		"identical re-apply must be a no-op (hash unchanged)")
+
+	// A real change must produce a different hash and re-apply.
+	networkMap.FirewallRules[0].Action = mgmProto.RuleAction_DROP
+	acl.ApplyFiltering(networkMap, false)
+	assert.NotEqual(t, firstHash, acl.previousConfigHash,
+		"changing a rule's action must force a re-apply (hash changed)")
+
+	// The dnsRouteFeatureFlag also participates in the hash.
+	changedHash := acl.previousConfigHash
+	acl.ApplyFiltering(networkMap, true)
+	assert.NotEqual(t, changedHash, acl.previousConfigHash,
+		"flipping dnsRouteFeatureFlag must force a re-apply (hash changed)")
+}
+
+func buildNetworkMap(peerRules, routeRules int) *mgmProto.NetworkMap {
+	nm := &mgmProto.NetworkMap{
+		FirewallRulesIsEmpty:      peerRules == 0,
+		RoutesFirewallRulesIsEmpty: routeRules == 0,
+	}
+	for i := range peerRules {
+		nm.FirewallRules = append(nm.FirewallRules, &mgmProto.FirewallRule{
+			PeerIP:    fmt.Sprintf("10.%d.%d.%d", i>>16&0xff, i>>8&0xff, i&0xff),
+			Direction: mgmProto.RuleDirection_IN,
+			Action:    mgmProto.RuleAction_ACCEPT,
+			Protocol:  mgmProto.RuleProtocol_TCP,
+			Port:      fmt.Sprintf("%d", 1024+i%64511),
+		})
+	}
+	for i := range routeRules {
+		nm.RoutesFirewallRules = append(nm.RoutesFirewallRules, &mgmProto.RouteFirewallRule{
+			Destination:  fmt.Sprintf("192.168.%d.0/24", i%256),
+			SourceRanges: []string{fmt.Sprintf("10.0.%d.0/24", i%256)},
+			Action:       mgmProto.RuleAction_ACCEPT,
+			Protocol:     mgmProto.RuleProtocol_ALL,
+		})
+	}
+	return nm
+}
+
+func BenchmarkFirewallConfigHash_Small(b *testing.B) {
+	d := &DefaultManager{}
+	nm := buildNetworkMap(10, 5)
+	b.ResetTimer()
+	for b.Loop() {
+		_, _ = d.firewallConfigHash(nm, false)
+	}
+}
+
+func BenchmarkFirewallConfigHash_Medium(b *testing.B) {
+	d := &DefaultManager{}
+	nm := buildNetworkMap(100, 50)
+	b.ResetTimer()
+	for b.Loop() {
+		_, _ = d.firewallConfigHash(nm, false)
+	}
+}
+
+func BenchmarkFirewallConfigHash_Large(b *testing.B) {
+	d := &DefaultManager{}
+	nm := buildNetworkMap(1000, 200)
+	b.ResetTimer()
+	for b.Loop() {
+		_, _ = d.firewallConfigHash(nm, false)
+	}
+}
+
+// TestFirewallConfigHashDeterministic verifies the hash is stable for equal
+// inputs and order-independent for the rule slices (management does not
+// guarantee rule order).
+func TestFirewallConfigHashDeterministic(t *testing.T) {
+	d := &DefaultManager{}
+
+	nm1 := &mgmProto.NetworkMap{
+		FirewallRules: []*mgmProto.FirewallRule{
+			{PeerIP: "10.0.0.1", Direction: mgmProto.RuleDirection_IN, Action: mgmProto.RuleAction_ACCEPT, Protocol: mgmProto.RuleProtocol_TCP, Port: "22"},
+			{PeerIP: "10.0.0.2", Direction: mgmProto.RuleDirection_IN, Action: mgmProto.RuleAction_DROP, Protocol: mgmProto.RuleProtocol_TCP, Port: "80"},
+		},
+	}
+	// Same rules, reversed order.
+	nm2 := &mgmProto.NetworkMap{
+		FirewallRules: []*mgmProto.FirewallRule{
+			nm1.FirewallRules[1],
+			nm1.FirewallRules[0],
+		},
+	}
+
+	h1, err := d.firewallConfigHash(nm1, false)
+	require.NoError(t, err)
+	h2, err := d.firewallConfigHash(nm2, false)
+	require.NoError(t, err)
+	assert.Equal(t, h1, h2, "hash must be order-independent for rule slices")
+}

client/internal/dns/resutil/resolve.go

@@ -8,6 +8,7 @@ import (
 	"errors"
 	"net"
 	"net/netip"
+	"slices"
 	"strings"
 
 	"github.com/miekg/dns"
@@ -167,7 +168,10 @@ func getRcodeForNotFound(ctx context.Context, r resolver, domain string, origina
 	case dns.TypeA:
 		alternativeNetwork = "ip6"
 	default:
-		return dns.RcodeNameError
+		// Non-address types reach LookupIP only unexpectedly; without an
+		// address pair to probe we cannot prove the name is absent, so answer
+		// NODATA rather than a poisoning NXDOMAIN.
+		return dns.RcodeSuccess
 	}
 
 	if _, err := r.LookupNetIP(ctx, alternativeNetwork, domain); err != nil {
@@ -184,6 +188,230 @@ func getRcodeForNotFound(ctx context.Context, r resolver, domain string, origina
 	return dns.RcodeSuccess
 }
 
+// RecordResolver is the host resolver surface used to forward non-address
+// record queries. net.DefaultResolver satisfies it.
+type RecordResolver interface {
+	LookupMX(ctx context.Context, name string) ([]*net.MX, error)
+	LookupTXT(ctx context.Context, name string) ([]string, error)
+	LookupNS(ctx context.Context, name string) ([]*net.NS, error)
+	LookupSRV(ctx context.Context, service, proto, name string) (string, []*net.SRV, error)
+	LookupCNAME(ctx context.Context, host string) (string, error)
+	LookupAddr(ctx context.Context, addr string) ([]string, error)
+}
+
+// LookupRecords resolves a non-address DNS record type through the host
+// resolver and returns the resource records and the DNS rcode. Types the host
+// resolver cannot answer (anything not covered by the net.Resolver Lookup*
+// methods) yield NODATA so that a routed name is never poisoned with NXDOMAIN
+// for an unsupported type.
+func LookupRecords(ctx context.Context, r RecordResolver, name string, qtype uint16, ttl uint32) ([]dns.RR, int) {
+	fqdn := dns.Fqdn(name)
+
+	switch qtype {
+	case dns.TypeMX:
+		return lookupMX(ctx, r, name, fqdn, ttl)
+	case dns.TypeTXT:
+		return lookupTXT(ctx, r, name, fqdn, ttl)
+	case dns.TypeNS:
+		return lookupNS(ctx, r, name, fqdn, ttl)
+	case dns.TypeSRV:
+		return lookupSRV(ctx, r, name, fqdn, ttl)
+	case dns.TypeCNAME:
+		return lookupCNAME(ctx, r, name, fqdn, ttl)
+	case dns.TypePTR:
+		return lookupPTR(ctx, r, name, fqdn, ttl)
+	default:
+		return nil, dns.RcodeSuccess
+	}
+}
+
+func recordHeader(fqdn string, rrtype uint16, ttl uint32) dns.RR_Header {
+	return dns.RR_Header{Name: fqdn, Rrtype: rrtype, Class: dns.ClassINET, Ttl: ttl}
+}
+
+func lookupMX(ctx context.Context, r RecordResolver, name, fqdn string, ttl uint32) ([]dns.RR, int) {
+	recs, err := r.LookupMX(ctx, name)
+	if err != nil {
+		return nil, rcodeForRecordError(err)
+	}
+	rrs := make([]dns.RR, 0, len(recs))
+	for _, mx := range recs {
+		rrs = append(rrs, &dns.MX{
+			Hdr:        recordHeader(fqdn, dns.TypeMX, ttl),
+			Preference: mx.Pref,
+			Mx:         dns.Fqdn(mx.Host),
+		})
+	}
+	return rrs, dns.RcodeSuccess
+}
+
+func lookupTXT(ctx context.Context, r RecordResolver, name, fqdn string, ttl uint32) ([]dns.RR, int) {
+	recs, err := r.LookupTXT(ctx, name)
+	if err != nil {
+		return nil, rcodeForRecordError(err)
+	}
+	rrs := make([]dns.RR, 0, len(recs))
+	for _, txt := range recs {
+		rrs = append(rrs, &dns.TXT{
+			Hdr: recordHeader(fqdn, dns.TypeTXT, ttl),
+			Txt: chunkTXT(txt),
+		})
+	}
+	return rrs, dns.RcodeSuccess
+}
+
+func lookupNS(ctx context.Context, r RecordResolver, name, fqdn string, ttl uint32) ([]dns.RR, int) {
+	recs, err := r.LookupNS(ctx, name)
+	if err != nil {
+		return nil, rcodeForRecordError(err)
+	}
+	rrs := make([]dns.RR, 0, len(recs))
+	for _, ns := range recs {
+		rrs = append(rrs, &dns.NS{
+			Hdr: recordHeader(fqdn, dns.TypeNS, ttl),
+			Ns:  dns.Fqdn(ns.Host),
+		})
+	}
+	return rrs, dns.RcodeSuccess
+}
+
+func lookupSRV(ctx context.Context, r RecordResolver, name, fqdn string, ttl uint32) ([]dns.RR, int) {
+	_, recs, err := r.LookupSRV(ctx, "", "", name)
+	if err != nil {
+		return nil, rcodeForRecordError(err)
+	}
+	rrs := make([]dns.RR, 0, len(recs))
+	for _, srv := range recs {
+		rrs = append(rrs, &dns.SRV{
+			Hdr:      recordHeader(fqdn, dns.TypeSRV, ttl),
+			Priority: srv.Priority,
+			Weight:   srv.Weight,
+			Port:     srv.Port,
+			Target:   dns.Fqdn(srv.Target),
+		})
+	}
+	return rrs, dns.RcodeSuccess
+}
+
+func lookupCNAME(ctx context.Context, r RecordResolver, name, fqdn string, ttl uint32) ([]dns.RR, int) {
+	cname, err := r.LookupCNAME(ctx, name)
+	if err != nil {
+		return nil, rcodeForRecordError(err)
+	}
+	// LookupCNAME returns the queried name itself when the name resolves but
+	// has no CNAME record; that is a NODATA result, not a CNAME.
+	if strings.EqualFold(dns.Fqdn(cname), fqdn) {
+		return nil, dns.RcodeSuccess
+	}
+	return []dns.RR{&dns.CNAME{
+		Hdr:    recordHeader(fqdn, dns.TypeCNAME, ttl),
+		Target: dns.Fqdn(cname),
+	}}, dns.RcodeSuccess
+}
+
+func lookupPTR(ctx context.Context, r RecordResolver, name, fqdn string, ttl uint32) ([]dns.RR, int) {
+	addr, ok := ptrQueryAddr(name)
+	if !ok {
+		return nil, dns.RcodeSuccess
+	}
+	names, err := r.LookupAddr(ctx, addr)
+	if err != nil {
+		return nil, rcodeForRecordError(err)
+	}
+	rrs := make([]dns.RR, 0, len(names))
+	for _, n := range names {
+		rrs = append(rrs, &dns.PTR{
+			Hdr: recordHeader(fqdn, dns.TypePTR, ttl),
+			Ptr: dns.Fqdn(n),
+		})
+	}
+	return rrs, dns.RcodeSuccess
+}
+
+// ptrQueryAddr converts a reverse-DNS query name (in-addr.arpa or ip6.arpa)
+// into the address string expected by net.Resolver.LookupAddr. It reports false
+// when the name is not a well-formed reverse name.
+func ptrQueryAddr(qname string) (string, bool) {
+	name := strings.TrimSuffix(strings.ToLower(dns.Fqdn(qname)), ".")
+
+	switch {
+	case strings.HasSuffix(name, ".in-addr.arpa"):
+		return parseInAddrArpa(strings.TrimSuffix(name, ".in-addr.arpa"))
+	case strings.HasSuffix(name, ".ip6.arpa"):
+		return parseIP6Arpa(strings.TrimSuffix(name, ".ip6.arpa"))
+	default:
+		return "", false
+	}
+}
+
+// parseInAddrArpa turns the label portion of an in-addr.arpa name into an IPv4
+// address string, reporting false when it is not a well-formed reverse name.
+func parseInAddrArpa(labelPart string) (string, bool) {
+	labels := strings.Split(labelPart, ".")
+	if len(labels) != 4 {
+		return "", false
+	}
+	slices.Reverse(labels)
+	addr, err := netip.ParseAddr(strings.Join(labels, "."))
+	if err != nil || !addr.Is4() {
+		return "", false
+	}
+	return addr.String(), true
+}
+
+// parseIP6Arpa turns the nibble portion of an ip6.arpa name into an IPv6
+// address string, reporting false when it is not a well-formed reverse name.
+func parseIP6Arpa(nibblePart string) (string, bool) {
+	nibbles := strings.Split(nibblePart, ".")
+	if len(nibbles) != 32 {
+		return "", false
+	}
+	slices.Reverse(nibbles)
+	var sb strings.Builder
+	for i, n := range nibbles {
+		if i > 0 && i%4 == 0 {
+			sb.WriteByte(':')
+		}
+		sb.WriteString(n)
+	}
+	addr, err := netip.ParseAddr(sb.String())
+	if err != nil || !addr.Is6() {
+		return "", false
+	}
+	return addr.String(), true
+}
+
+// rcodeForRecordError maps a non-address lookup error to a DNS rcode. A
+// not-found result becomes NODATA rather than NXDOMAIN: net.DNSError.IsNotFound
+// does not distinguish a missing name from a name that exists only with records
+// of other types, so the name cannot be proven absent and must not be poisoned.
+func rcodeForRecordError(err error) int {
+	var dnsErr *net.DNSError
+	if errors.As(err, &dnsErr) && dnsErr.IsNotFound {
+		return dns.RcodeSuccess
+	}
+	return dns.RcodeServerFailure
+}
+
+// chunkTXT splits a TXT string into character-strings no longer than 255 bytes
+// so the record can be packed. The chunks form one TXT resource record.
+func chunkTXT(s string) []string {
+	const maxLen = 255
+	if len(s) <= maxLen {
+		return []string{s}
+	}
+
+	var chunks []string
+	for len(s) > maxLen {
+		chunks = append(chunks, s[:maxLen])
+		s = s[maxLen:]
+	}
+	if len(s) > 0 {
+		chunks = append(chunks, s)
+	}
+	return chunks
+}
+
 // FormatAnswers formats DNS resource records for logging.
 func FormatAnswers(answers []dns.RR) string {
 	if len(answers) == 0 {

client/internal/dns/resutil/resolve_test.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"net"
 	"net/netip"
+	"strings"
 	"testing"
 
 	"github.com/miekg/dns"
@@ -121,6 +122,164 @@ func TestLookupIP_DNSErrorNotIsNotFound(t *testing.T) {
 	assert.Equal(t, dns.RcodeServerFailure, result.Rcode, "upstream failure should map to SERVFAIL")
 }
 
+func TestPtrQueryAddr(t *testing.T) {
+	tests := []struct {
+		name   string
+		qname  string
+		want   string
+		wantOK bool
+	}{
+		{name: "ipv4", qname: "4.3.2.1.in-addr.arpa.", want: "1.2.3.4", wantOK: true},
+		{name: "ipv4 no trailing dot", qname: "1.0.0.127.in-addr.arpa", want: "127.0.0.1", wantOK: true},
+		{
+			name:   "ipv6",
+			qname:  "1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.b.d.0.1.0.0.2.ip6.arpa.",
+			want:   "2001:db8::1",
+			wantOK: true,
+		},
+		{name: "ipv4 wrong label count", qname: "2.1.in-addr.arpa.", wantOK: false},
+		{name: "ipv6 wrong nibble count", qname: "1.0.ip6.arpa.", wantOK: false},
+		{name: "not a reverse name", qname: "example.com.", wantOK: false},
+		{name: "ipv4 bad octet", qname: "4.3.2.999.in-addr.arpa.", wantOK: false},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, ok := ptrQueryAddr(tt.qname)
+			assert.Equal(t, tt.wantOK, ok, "parse success mismatch")
+			if tt.wantOK {
+				assert.Equal(t, tt.want, got, "parsed address mismatch")
+			}
+		})
+	}
+}
+
+type mockRecordResolver struct {
+	mx    []*net.MX
+	txt   []string
+	ns    []*net.NS
+	srv   []*net.SRV
+	cname string
+	ptr   []string
+	err   error
+}
+
+func (m *mockRecordResolver) LookupMX(context.Context, string) ([]*net.MX, error) {
+	return m.mx, m.err
+}
+func (m *mockRecordResolver) LookupTXT(context.Context, string) ([]string, error) {
+	return m.txt, m.err
+}
+func (m *mockRecordResolver) LookupNS(context.Context, string) ([]*net.NS, error) {
+	return m.ns, m.err
+}
+func (m *mockRecordResolver) LookupSRV(context.Context, string, string, string) (string, []*net.SRV, error) {
+	return "", m.srv, m.err
+}
+func (m *mockRecordResolver) LookupCNAME(context.Context, string) (string, error) {
+	return m.cname, m.err
+}
+func (m *mockRecordResolver) LookupAddr(context.Context, string) ([]string, error) {
+	return m.ptr, m.err
+}
+
+func TestLookupRecords(t *testing.T) {
+	notFound := &net.DNSError{IsNotFound: true, Name: "example.com."}
+
+	t.Run("MX success", func(t *testing.T) {
+		r := &mockRecordResolver{mx: []*net.MX{{Host: "mail.example.com.", Pref: 10}}}
+		rrs, rcode := LookupRecords(context.Background(), r, "example.com.", dns.TypeMX, 300)
+		assert.Equal(t, dns.RcodeSuccess, rcode)
+		require.Len(t, rrs, 1)
+		assert.Equal(t, "mail.example.com.", rrs[0].(*dns.MX).Mx)
+	})
+
+	t.Run("TXT short string is one character-string", func(t *testing.T) {
+		r := &mockRecordResolver{txt: []string{"v=spf1 -all"}}
+		rrs, rcode := LookupRecords(context.Background(), r, "example.com.", dns.TypeTXT, 300)
+		assert.Equal(t, dns.RcodeSuccess, rcode)
+		require.Len(t, rrs, 1)
+		assert.Equal(t, []string{"v=spf1 -all"}, rrs[0].(*dns.TXT).Txt)
+	})
+
+	t.Run("TXT chunks long strings", func(t *testing.T) {
+		long := strings.Repeat("a", 300)
+		r := &mockRecordResolver{txt: []string{long}}
+		rrs, rcode := LookupRecords(context.Background(), r, "example.com.", dns.TypeTXT, 300)
+		assert.Equal(t, dns.RcodeSuccess, rcode)
+		require.Len(t, rrs, 1)
+		txt := rrs[0].(*dns.TXT).Txt
+		require.Len(t, txt, 2, "300-byte string should split into two character-strings")
+		assert.Equal(t, 255, len(txt[0]))
+		assert.Equal(t, 45, len(txt[1]))
+	})
+
+	t.Run("NS success", func(t *testing.T) {
+		r := &mockRecordResolver{ns: []*net.NS{{Host: "ns1.example.com."}}}
+		rrs, rcode := LookupRecords(context.Background(), r, "example.com.", dns.TypeNS, 300)
+		assert.Equal(t, dns.RcodeSuccess, rcode)
+		require.Len(t, rrs, 1)
+		assert.Equal(t, "ns1.example.com.", rrs[0].(*dns.NS).Ns)
+	})
+
+	t.Run("SRV success", func(t *testing.T) {
+		r := &mockRecordResolver{srv: []*net.SRV{{Target: "sip.example.com.", Port: 5060}}}
+		rrs, rcode := LookupRecords(context.Background(), r, "_sip._tcp.example.com.", dns.TypeSRV, 300)
+		assert.Equal(t, dns.RcodeSuccess, rcode)
+		require.Len(t, rrs, 1)
+		assert.Equal(t, uint16(5060), rrs[0].(*dns.SRV).Port)
+	})
+
+	t.Run("CNAME success", func(t *testing.T) {
+		r := &mockRecordResolver{cname: "target.example.com."}
+		rrs, rcode := LookupRecords(context.Background(), r, "www.example.com.", dns.TypeCNAME, 300)
+		assert.Equal(t, dns.RcodeSuccess, rcode)
+		require.Len(t, rrs, 1)
+		assert.Equal(t, "target.example.com.", rrs[0].(*dns.CNAME).Target)
+	})
+
+	t.Run("CNAME equal to name is NODATA", func(t *testing.T) {
+		r := &mockRecordResolver{cname: "example.com."}
+		rrs, rcode := LookupRecords(context.Background(), r, "example.com.", dns.TypeCNAME, 300)
+		assert.Equal(t, dns.RcodeSuccess, rcode)
+		assert.Empty(t, rrs, "self-referential CNAME is NODATA")
+	})
+
+	t.Run("PTR success", func(t *testing.T) {
+		r := &mockRecordResolver{ptr: []string{"host.example.com."}}
+		rrs, rcode := LookupRecords(context.Background(), r, "4.3.2.1.in-addr.arpa.", dns.TypePTR, 300)
+		assert.Equal(t, dns.RcodeSuccess, rcode)
+		require.Len(t, rrs, 1)
+		assert.Equal(t, "host.example.com.", rrs[0].(*dns.PTR).Ptr)
+	})
+
+	t.Run("PTR malformed name is NODATA", func(t *testing.T) {
+		r := &mockRecordResolver{}
+		rrs, rcode := LookupRecords(context.Background(), r, "example.com.", dns.TypePTR, 300)
+		assert.Equal(t, dns.RcodeSuccess, rcode)
+		assert.Empty(t, rrs)
+	})
+
+	t.Run("not found is NODATA never NXDOMAIN", func(t *testing.T) {
+		r := &mockRecordResolver{err: notFound}
+		_, rcode := LookupRecords(context.Background(), r, "example.com.", dns.TypeMX, 300)
+		assert.Equal(t, dns.RcodeSuccess, rcode, "missing record must not poison the name")
+	})
+
+	t.Run("server failure maps to SERVFAIL", func(t *testing.T) {
+		r := &mockRecordResolver{err: &net.DNSError{Err: "server misbehaving", IsTemporary: true}}
+		_, rcode := LookupRecords(context.Background(), r, "example.com.", dns.TypeMX, 300)
+		assert.Equal(t, dns.RcodeServerFailure, rcode)
+	})
+
+	t.Run("unsupported type is NODATA", func(t *testing.T) {
+		r := &mockRecordResolver{}
+		rrs, rcode := LookupRecords(context.Background(), r, "example.com.", dns.TypeCAA, 300)
+		assert.Equal(t, dns.RcodeSuccess, rcode)
+		assert.Empty(t, rrs)
+	})
+}
+
 func TestStripOPT(t *testing.T) {
 	rm := &dns.Msg{
 		Extra: []dns.RR{

client/internal/dnsfwd/forwarder.go

@@ -37,6 +37,12 @@ const (
 
 type resolver interface {
 	LookupNetIP(ctx context.Context, network, host string) ([]netip.Addr, error)
+	LookupMX(ctx context.Context, name string) ([]*net.MX, error)
+	LookupTXT(ctx context.Context, name string) ([]string, error)
+	LookupNS(ctx context.Context, name string) ([]*net.NS, error)
+	LookupSRV(ctx context.Context, service, proto, name string) (string, []*net.SRV, error)
+	LookupCNAME(ctx context.Context, host string) (string, error)
+	LookupAddr(ctx context.Context, addr string) ([]string, error)
 }
 
 type firewaller interface {
@@ -210,12 +216,6 @@ func (f *DNSForwarder) handleDNSQuery(logger *log.Entry, w dns.ResponseWriter, q
 		qname, dns.TypeToString[question.Qtype], dns.ClassToString[question.Qclass])
 
 	resp := query.SetReply(query)
-	network := resutil.NetworkForQtype(question.Qtype)
-	if network == "" {
-		resp.Rcode = dns.RcodeNotImplemented
-		f.writeResponse(logger, w, resp, qname, startTime)
-		return
-	}
 
 	mostSpecificResId, matchingEntries := f.getMatchingEntries(strings.TrimSuffix(qname, "."))
 	if mostSpecificResId == "" {
@@ -227,9 +227,46 @@ func (f *DNSForwarder) handleDNSQuery(logger *log.Entry, w dns.ResponseWriter, q
 	ctx, cancel := context.WithTimeout(context.Background(), upstreamTimeout)
 	defer cancel()
 
+	reqHasEdns := query.IsEdns0() != nil
+
+	switch question.Qtype {
+	case dns.TypeA, dns.TypeAAAA:
+		f.handleAddressQuery(ctx, logger, w, resp, mostSpecificResId, matchingEntries, reqHasEdns, startTime)
+	case dns.TypeMX, dns.TypeTXT, dns.TypeNS, dns.TypeSRV, dns.TypeCNAME, dns.TypePTR:
+		f.handleRecordQuery(ctx, logger, w, resp, startTime)
+	default:
+		// The domain is routed here, so any other type is answered NODATA
+		// (NOERROR, empty answer) rather than falling back to a resolver that
+		// would poison the name with NXDOMAIN. The Extended DNS Error lets a
+		// client tell this capability-driven NODATA apart from an
+		// authoritative one. The OPT pseudo-record must not appear unless the
+		// query advertised EDNS0.
+		if reqHasEdns {
+			attachEDE(resp, dns.ExtendedErrorCodeNotSupported, "netbird forwarder: unsupported query type")
+		}
+		f.writeResponse(logger, w, resp, qname, startTime)
+	}
+}
+
+// handleAddressQuery resolves A/AAAA queries, programs the firewall sets and
+// resolved-IP state, and caches the answer for resilience on upstream failure.
+func (f *DNSForwarder) handleAddressQuery(
+	ctx context.Context,
+	logger *log.Entry,
+	w dns.ResponseWriter,
+	resp *dns.Msg,
+	mostSpecificResId route.ResID,
+	matchingEntries []*ForwarderEntry,
+	reqHasEdns bool,
+	startTime time.Time,
+) {
+	question := resp.Question[0]
+	qname := strings.ToLower(question.Name)
+
+	network := resutil.NetworkForQtype(question.Qtype)
 	result := resutil.LookupIP(ctx, f.resolver, network, qname, question.Qtype)
 	if result.Err != nil {
-		f.handleDNSError(ctx, logger, w, question, resp, qname, result, query.IsEdns0() != nil, startTime)
+		f.handleDNSError(ctx, logger, w, question, resp, qname, result, reqHasEdns, startTime)
 		return
 	}
 
@@ -240,6 +277,25 @@ func (f *DNSForwarder) handleDNSQuery(logger *log.Entry, w dns.ResponseWriter, q
 	f.writeResponse(logger, w, resp, qname, startTime)
 }
 
+// handleRecordQuery resolves non-address record types (MX, TXT, NS, SRV,
+// CNAME, PTR) through the host resolver. Missing records are answered NODATA so
+// the routed name is never poisoned with NXDOMAIN.
+func (f *DNSForwarder) handleRecordQuery(
+	ctx context.Context,
+	logger *log.Entry,
+	w dns.ResponseWriter,
+	resp *dns.Msg,
+	startTime time.Time,
+) {
+	question := resp.Question[0]
+	qname := strings.ToLower(question.Name)
+
+	records, rcode := resutil.LookupRecords(ctx, f.resolver, qname, question.Qtype, f.ttl)
+	resp.Rcode = rcode
+	resp.Answer = append(resp.Answer, records...)
+	f.writeResponse(logger, w, resp, qname, startTime)
+}
+
 func (f *DNSForwarder) writeResponse(logger *log.Entry, w dns.ResponseWriter, resp *dns.Msg, qname string, startTime time.Time) {
 	if err := w.WriteMsg(resp); err != nil {
 		logger.Errorf("failed to write DNS response: %v", err)

client/internal/dnsfwd/forwarder_test.go

@@ -133,6 +133,41 @@ func (m *MockResolver) LookupNetIP(ctx context.Context, network, host string) ([
 	return args.Get(0).([]netip.Addr), args.Error(1)
 }
 
+func (m *MockResolver) LookupMX(ctx context.Context, name string) ([]*net.MX, error) {
+	args := m.Called(ctx, name)
+	recs, _ := args.Get(0).([]*net.MX)
+	return recs, args.Error(1)
+}
+
+func (m *MockResolver) LookupTXT(ctx context.Context, name string) ([]string, error) {
+	args := m.Called(ctx, name)
+	recs, _ := args.Get(0).([]string)
+	return recs, args.Error(1)
+}
+
+func (m *MockResolver) LookupNS(ctx context.Context, name string) ([]*net.NS, error) {
+	args := m.Called(ctx, name)
+	recs, _ := args.Get(0).([]*net.NS)
+	return recs, args.Error(1)
+}
+
+func (m *MockResolver) LookupSRV(ctx context.Context, service, proto, name string) (string, []*net.SRV, error) {
+	args := m.Called(ctx, service, proto, name)
+	recs, _ := args.Get(1).([]*net.SRV)
+	return args.String(0), recs, args.Error(2)
+}
+
+func (m *MockResolver) LookupCNAME(ctx context.Context, host string) (string, error) {
+	args := m.Called(ctx, host)
+	return args.String(0), args.Error(1)
+}
+
+func (m *MockResolver) LookupAddr(ctx context.Context, addr string) ([]string, error) {
+	args := m.Called(ctx, addr)
+	recs, _ := args.Get(0).([]string)
+	return recs, args.Error(1)
+}
+
 func TestDNSForwarder_SubdomainAccessLogic(t *testing.T) {
 	tests := []struct {
 		name             string
@@ -545,12 +580,15 @@ func TestDNSForwarder_MultipleIPsInSingleUpdate(t *testing.T) {
 }
 
 func TestDNSForwarder_ResponseCodes(t *testing.T) {
+	// A type with no net.Resolver Lookup method (CAA) must answer NODATA
+	// (NOERROR, empty) rather than NXDOMAIN/NOTIMP to avoid poisoning the name.
 	tests := []struct {
 		name         string
 		queryType    uint16
 		queryDomain  string
 		configured   string
 		expectedCode int
+		expectEDE    bool
 		description  string
 	}{
 		{
@@ -562,28 +600,13 @@ func TestDNSForwarder_ResponseCodes(t *testing.T) {
 			description:  "RFC compliant REFUSED for unauthorized queries",
 		},
 		{
-			name:         "unsupported query type returns NOTIMP",
-			queryType:    dns.TypeMX,
+			name:         "unsupported query type returns NODATA",
+			queryType:    dns.TypeCAA,
 			queryDomain:  "example.com",
 			configured:   "example.com",
-			expectedCode: dns.RcodeNotImplemented,
-			description:  "RFC compliant NOTIMP for unsupported types",
-		},
-		{
-			name:         "CNAME query returns NOTIMP",
-			queryType:    dns.TypeCNAME,
-			queryDomain:  "example.com",
-			configured:   "example.com",
-			expectedCode: dns.RcodeNotImplemented,
-			description:  "CNAME queries not supported",
-		},
-		{
-			name:         "TXT query returns NOTIMP",
-			queryType:    dns.TypeTXT,
-			queryDomain:  "example.com",
-			configured:   "example.com",
-			expectedCode: dns.RcodeNotImplemented,
-			description:  "TXT queries not supported",
+			expectedCode: dns.RcodeSuccess,
+			expectEDE:    true,
+			description:  "Unsupported types answer NODATA, not NXDOMAIN/NOTIMP",
 		},
 	}
 
@@ -599,6 +622,7 @@ func TestDNSForwarder_ResponseCodes(t *testing.T) {
 
 			query := &dns.Msg{}
 			query.SetQuestion(dns.Fqdn(tt.queryDomain), tt.queryType)
+			query.SetEdns0(dns.DefaultMsgSize, false)
 
 			// Capture the written response
 			var writtenResp *dns.Msg
@@ -614,10 +638,213 @@ func TestDNSForwarder_ResponseCodes(t *testing.T) {
 			// Check the response written to the writer
 			require.NotNil(t, writtenResp, "Expected response to be written")
 			assert.Equal(t, tt.expectedCode, writtenResp.Rcode, tt.description)
+			assert.Empty(t, writtenResp.Answer, "Non-address response should carry no answers")
+
+			if tt.expectEDE {
+				require.NotNil(t, writtenResp.IsEdns0(), "EDNS0 client should get an OPT in the reply")
+				assert.True(t, hasEDE(writtenResp, dns.ExtendedErrorCodeNotSupported),
+					"unsupported type NODATA should carry EDE Not Supported")
+			}
 		})
 	}
 }
 
+func hasEDE(m *dns.Msg, code uint16) bool {
+	opt := m.IsEdns0()
+	if opt == nil {
+		return false
+	}
+	for _, o := range opt.Option {
+		if ede, ok := o.(*dns.EDNS0_EDE); ok && ede.InfoCode == code {
+			return true
+		}
+	}
+	return false
+}
+
+func TestDNSForwarder_RecordQueries(t *testing.T) {
+	notFound := &net.DNSError{IsNotFound: true, Name: "example.com"}
+
+	t.Run("MX records are forwarded", func(t *testing.T) {
+		mockResolver := &MockResolver{}
+		forwarder := newRecordTestForwarder(t, mockResolver, "example.com")
+
+		mockResolver.On("LookupMX", mock.Anything, "example.com.").
+			Return([]*net.MX{{Host: "mail.example.com.", Pref: 10}}, nil).Once()
+
+		resp := runRecordQuery(t, forwarder, "example.com", dns.TypeMX)
+		require.Equal(t, dns.RcodeSuccess, resp.Rcode)
+		require.Len(t, resp.Answer, 1)
+		mx, ok := resp.Answer[0].(*dns.MX)
+		require.True(t, ok, "answer should be an MX record")
+		assert.Equal(t, uint16(10), mx.Preference)
+		assert.Equal(t, "mail.example.com.", mx.Mx)
+		mockResolver.AssertExpectations(t)
+	})
+
+	t.Run("missing MX is NODATA not NXDOMAIN", func(t *testing.T) {
+		mockResolver := &MockResolver{}
+		forwarder := newRecordTestForwarder(t, mockResolver, "example.com")
+
+		// A not-found cannot prove the name is absent (it may exist with only
+		// other record types), so it must answer NODATA, never NXDOMAIN.
+		mockResolver.On("LookupMX", mock.Anything, "example.com.").
+			Return(nil, notFound).Once()
+
+		resp := runRecordQuery(t, forwarder, "example.com", dns.TypeMX)
+		assert.Equal(t, dns.RcodeSuccess, resp.Rcode, "missing record must be NODATA")
+		assert.Empty(t, resp.Answer)
+		mockResolver.AssertExpectations(t)
+	})
+
+	t.Run("NS records are forwarded", func(t *testing.T) {
+		mockResolver := &MockResolver{}
+		forwarder := newRecordTestForwarder(t, mockResolver, "example.com")
+
+		mockResolver.On("LookupNS", mock.Anything, "example.com.").
+			Return([]*net.NS{{Host: "ns1.example.com."}}, nil).Once()
+
+		resp := runRecordQuery(t, forwarder, "example.com", dns.TypeNS)
+		require.Equal(t, dns.RcodeSuccess, resp.Rcode)
+		require.Len(t, resp.Answer, 1)
+		ns, ok := resp.Answer[0].(*dns.NS)
+		require.True(t, ok, "answer should be an NS record")
+		assert.Equal(t, "ns1.example.com.", ns.Ns)
+		mockResolver.AssertExpectations(t)
+	})
+
+	t.Run("missing NS is NODATA", func(t *testing.T) {
+		mockResolver := &MockResolver{}
+		forwarder := newRecordTestForwarder(t, mockResolver, "example.com")
+
+		mockResolver.On("LookupNS", mock.Anything, "example.com.").
+			Return(nil, notFound).Once()
+
+		resp := runRecordQuery(t, forwarder, "example.com", dns.TypeNS)
+		assert.Equal(t, dns.RcodeSuccess, resp.Rcode)
+		assert.Empty(t, resp.Answer)
+		mockResolver.AssertExpectations(t)
+	})
+
+	t.Run("SRV records are forwarded", func(t *testing.T) {
+		mockResolver := &MockResolver{}
+		forwarder := newRecordTestForwarder(t, mockResolver, "_sip._tcp.example.com")
+
+		mockResolver.On("LookupSRV", mock.Anything, "", "", "_sip._tcp.example.com.").
+			Return("", []*net.SRV{{Target: "sip.example.com.", Port: 5060, Priority: 10, Weight: 5}}, nil).Once()
+
+		resp := runRecordQuery(t, forwarder, "_sip._tcp.example.com", dns.TypeSRV)
+		require.Equal(t, dns.RcodeSuccess, resp.Rcode)
+		require.Len(t, resp.Answer, 1)
+		srv, ok := resp.Answer[0].(*dns.SRV)
+		require.True(t, ok, "answer should be an SRV record")
+		assert.Equal(t, "sip.example.com.", srv.Target)
+		assert.Equal(t, uint16(5060), srv.Port)
+		assert.Equal(t, uint16(10), srv.Priority)
+		mockResolver.AssertExpectations(t)
+	})
+
+	t.Run("missing SRV is NODATA", func(t *testing.T) {
+		mockResolver := &MockResolver{}
+		forwarder := newRecordTestForwarder(t, mockResolver, "_sip._tcp.example.com")
+
+		mockResolver.On("LookupSRV", mock.Anything, "", "", "_sip._tcp.example.com.").
+			Return("", nil, notFound).Once()
+
+		resp := runRecordQuery(t, forwarder, "_sip._tcp.example.com", dns.TypeSRV)
+		assert.Equal(t, dns.RcodeSuccess, resp.Rcode)
+		assert.Empty(t, resp.Answer)
+		mockResolver.AssertExpectations(t)
+	})
+
+	t.Run("TXT records are forwarded", func(t *testing.T) {
+		mockResolver := &MockResolver{}
+		forwarder := newRecordTestForwarder(t, mockResolver, "example.com")
+
+		mockResolver.On("LookupTXT", mock.Anything, "example.com.").
+			Return([]string{"v=spf1 -all"}, nil).Once()
+
+		resp := runRecordQuery(t, forwarder, "example.com", dns.TypeTXT)
+		require.Equal(t, dns.RcodeSuccess, resp.Rcode)
+		require.Len(t, resp.Answer, 1)
+		txt, ok := resp.Answer[0].(*dns.TXT)
+		require.True(t, ok, "answer should be a TXT record")
+		assert.Equal(t, []string{"v=spf1 -all"}, txt.Txt)
+		mockResolver.AssertExpectations(t)
+	})
+
+	t.Run("CNAME record is forwarded", func(t *testing.T) {
+		mockResolver := &MockResolver{}
+		forwarder := newRecordTestForwarder(t, mockResolver, "www.example.com")
+
+		mockResolver.On("LookupCNAME", mock.Anything, "www.example.com.").
+			Return("target.example.com.", nil).Once()
+
+		resp := runRecordQuery(t, forwarder, "www.example.com", dns.TypeCNAME)
+		require.Equal(t, dns.RcodeSuccess, resp.Rcode)
+		require.Len(t, resp.Answer, 1)
+		cname, ok := resp.Answer[0].(*dns.CNAME)
+		require.True(t, ok, "answer should be a CNAME record")
+		assert.Equal(t, "target.example.com.", cname.Target)
+		mockResolver.AssertExpectations(t)
+	})
+
+	t.Run("CNAME equal to the name is NODATA", func(t *testing.T) {
+		mockResolver := &MockResolver{}
+		forwarder := newRecordTestForwarder(t, mockResolver, "example.com")
+
+		// No CNAME exists: LookupCNAME echoes the queried name back.
+		mockResolver.On("LookupCNAME", mock.Anything, "example.com.").
+			Return("example.com.", nil).Once()
+
+		resp := runRecordQuery(t, forwarder, "example.com", dns.TypeCNAME)
+		assert.Equal(t, dns.RcodeSuccess, resp.Rcode)
+		assert.Empty(t, resp.Answer, "self-referential CNAME means no CNAME record")
+		mockResolver.AssertExpectations(t)
+	})
+
+	t.Run("PTR record is forwarded", func(t *testing.T) {
+		mockResolver := &MockResolver{}
+		forwarder := newRecordTestForwarder(t, mockResolver, "*.in-addr.arpa")
+
+		// The reverse name is parsed back to the address LookupAddr expects.
+		mockResolver.On("LookupAddr", mock.Anything, "1.2.3.4").
+			Return([]string{"host.example.com."}, nil).Once()
+
+		resp := runRecordQuery(t, forwarder, "4.3.2.1.in-addr.arpa", dns.TypePTR)
+		require.Equal(t, dns.RcodeSuccess, resp.Rcode)
+		require.Len(t, resp.Answer, 1)
+		ptr, ok := resp.Answer[0].(*dns.PTR)
+		require.True(t, ok, "answer should be a PTR record")
+		assert.Equal(t, "host.example.com.", ptr.Ptr)
+		mockResolver.AssertExpectations(t)
+	})
+}
+
+func newRecordTestForwarder(t *testing.T, r resolver, configured string) *DNSForwarder {
+	t.Helper()
+	forwarder := NewDNSForwarder(netip.MustParseAddrPort("127.0.0.1:0"), 300, nil, &peer.Status{}, nil)
+	forwarder.resolver = r
+
+	d, err := domain.FromString(configured)
+	require.NoError(t, err)
+	forwarder.UpdateDomains([]*ForwarderEntry{{Domain: d, ResID: "test-res"}})
+	return forwarder
+}
+
+func runRecordQuery(t *testing.T, forwarder *DNSForwarder, qname string, qtype uint16) *dns.Msg {
+	t.Helper()
+	query := &dns.Msg{}
+	query.SetQuestion(dns.Fqdn(qname), qtype)
+
+	mockWriter := &test.MockResponseWriter{}
+	forwarder.handleDNSQuery(log.NewEntry(log.StandardLogger()), mockWriter, query, time.Now())
+
+	resp := mockWriter.GetLastResponse()
+	require.NotNil(t, resp, "expected response to be written")
+	return resp
+}
+
 func TestDNSForwarder_UpstreamFailureEDE(t *testing.T) {
 	tests := []struct {
 		name        string

client/internal/engine.go

@@ -82,6 +82,12 @@ const (
 	PeerConnectionTimeoutMax = 45000 // ms
 	PeerConnectionTimeoutMin = 30000 // ms
 	disableAutoUpdate        = "disabled"
+
+	// systemInfoTimeout bounds how long the sync loop waits for system info / posture
+	// check gathering. The gathering runs uncancellable system calls (process scan,
+	// exec, os.Stat); without this bound a single stuck call freezes handleSync, and
+	// thus syncMsgMux, for as long as the call hangs (observed multi-minute freezes).
+	systemInfoTimeout = 15 * time.Second
 )
 
 var ErrResetConnection = fmt.Errorf("reset connection")
@@ -920,6 +926,16 @@ func (e *Engine) handleAutoUpdateVersion(autoUpdateSettings *mgmProto.AutoUpdate
 	e.updateManager.SetVersion(autoUpdateSettings.Version, autoUpdateSettings.AlwaysUpdate)
 }
 
+// phase times a sync sub-phase: it returns a function that records the elapsed
+// duration when called. Starting the timer at the call site keeps inter-phase
+// glue code out of the measurement.
+func (e *Engine) phase(name string) func() {
+	start := time.Now()
+	return func() {
+		e.clientMetrics.RecordSyncPhase(e.ctx, name, time.Since(start))
+	}
+}
+
 // applySyncPass applies one bounded pass of the sync update under syncMsgMux and
 // returns true if more peers remained than the per-pass cap. It is driven by the
 // mapStateManager, which re-invokes it (releasing the lock between passes) until
@@ -937,7 +953,10 @@ func (e *Engine) applySyncPass(update *mgmProto.SyncResponse, firstPass bool) (b
 		e.handleAutoUpdateVersion(update.NetworkMap.PeerConfig.AutoUpdate)
 	}
 
-	if err := e.updateNetbirdConfig(update.GetNetbirdConfig()); err != nil {
+	done := e.phase("netbird_config")
+	err := e.updateNetbirdConfig(update.GetNetbirdConfig())
+	done()
+	if err != nil {
 		return false, err
 	}
 
@@ -951,7 +970,10 @@ func (e *Engine) applySyncPass(update *mgmProto.SyncResponse, firstPass bool) (b
 		return false, nil
 	}
 
-	if err := e.updateChecksIfNew(update.Checks); err != nil {
+	done = e.phase("checks")
+	err = e.updateChecksIfNew(update.Checks)
+	done()
+	if err != nil {
 		return false, err
 	}
 
@@ -1095,11 +1117,22 @@ func (e *Engine) updateChecksIfNew(checks []*mgmProto.Checks) error {
 	}
 	e.checks = checks
 
-	info, err := system.GetInfoWithChecks(e.ctx, checks, e.overlayAddresses()...)
-	if err != nil {
-		log.Warnf("failed to get system info with checks: %v", err)
-		info = system.GetInfo(e.ctx)
+	info, ok := system.GetInfoWithChecksTimeout(e.ctx, systemInfoTimeout, checks, e.overlayAddresses()...)
+	if !ok {
+		// Gathering timed out; skip the meta sync this cycle rather than blocking the
+		// sync loop (and syncMsgMux) on a stuck system call. A later sync will retry.
+		return nil
 	}
+	e.applyInfoFlags(info)
+
+	if err := e.mgmClient.SyncMeta(info); err != nil {
+		return fmt.Errorf("could not sync meta: error %s", err)
+	}
+	return nil
+}
+
+// applyInfoFlags sets the engine's config-derived feature flags on the gathered system info.
+func (e *Engine) applyInfoFlags(info *system.Info) {
 	info.SetFlags(
 		e.config.RosenpassEnabled,
 		e.config.RosenpassPermissive,
@@ -1118,12 +1151,6 @@ func (e *Engine) updateChecksIfNew(checks []*mgmProto.Checks) error {
 		e.config.EnableSSHRemotePortForwarding,
 		e.config.DisableSSHAuth,
 	)
-
-	if err := e.mgmClient.SyncMeta(info); err != nil {
-		log.Errorf("could not sync meta: error %s", err)
-		return err
-	}
-	return nil
 }
 
 // overlayAddresses returns our own WireGuard overlay address (v4 and v6) so it
@@ -1283,33 +1310,22 @@ func (e *Engine) receiveManagementEvents() {
 	e.shutdownWg.Add(1)
 	go func() {
 		defer e.shutdownWg.Done()
-		info, err := system.GetInfoWithChecks(e.ctx, e.checks, e.overlayAddresses()...)
-		if err != nil {
-			log.Warnf("failed to get system info with checks: %v", err)
+		info, ok := system.GetInfoWithChecksTimeout(e.ctx, systemInfoTimeout, e.checks, e.overlayAddresses()...)
+		if !ok {
+			// Gathering timed out; connect the stream with base info so management
+			// connectivity still comes up rather than blocking here.
 			info = system.GetInfo(e.ctx)
 		}
-		info.SetFlags(
-			e.config.RosenpassEnabled,
-			e.config.RosenpassPermissive,
-			&e.config.ServerSSHAllowed,
-			e.config.DisableClientRoutes,
-			e.config.DisableServerRoutes,
-			e.config.DisableDNS,
-			e.config.DisableFirewall,
-			e.config.BlockLANAccess,
-			e.config.BlockInbound,
-			e.config.DisableIPv6,
-			e.config.LazyConnectionEnabled,
-			e.config.EnableSSHRoot,
-			e.config.EnableSSHSFTP,
-			e.config.EnableSSHLocalPortForwarding,
-			e.config.EnableSSHRemotePortForwarding,
-			e.config.DisableSSHAuth,
-		)
+		e.applyInfoFlags(info)
 
 		// The map-state manager converges the latest update in the background in
 		// bounded passes; the stream callback only hands it the newest target.
-		manager := newMapStateManager(e.applySyncPass, e.persistSyncResponse, func(d time.Duration) {
+		persist := func(u *mgmProto.SyncResponse) {
+			done := e.phase("persist")
+			e.persistSyncResponse(u)
+			done()
+		}
+		manager := newMapStateManager(e.applySyncPass, persist, func(d time.Duration) {
 			log.Infof("sync finished in %s", d)
 			e.clientMetrics.RecordSyncDuration(e.ctx, d)
 		})
@@ -1319,7 +1335,7 @@ func (e *Engine) receiveManagementEvents() {
 			manager.run(e.ctx)
 		}()
 
-		err = e.mgmClient.Sync(e.ctx, info, manager.SetTarget)
+		err := e.mgmClient.Sync(e.ctx, info, manager.SetTarget)
 		if err != nil {
 			// happens if management is unavailable for a long time.
 			// We want to cancel the operation of the whole client
@@ -1399,7 +1415,9 @@ func (e *Engine) updateNetworkMap(networkMap *mgmProto.NetworkMap, maxBatch int,
 
 	log.Debugf("got peers update from Management Service, total peers to connect to = %d", len(networkMap.GetRemotePeers()))
 
+	doneOffline := e.phase("offline_peers")
 	e.updateOfflinePeers(networkMap.GetOfflinePeers())
+	doneOffline()
 
 	// Filter out own peer from the remote peers list
 	localPubKey := e.config.WgPrivateKey.PublicKey().String()
@@ -1421,17 +1439,23 @@ func (e *Engine) updateNetworkMap(networkMap *mgmProto.NetworkMap, maxBatch int,
 			return false, err
 		}
 	} else {
+		doneRemoved := e.phase("removed_peers")
 		removeMore, err := e.removePeers(remotePeers, maxBatch)
+		doneRemoved()
 		if err != nil {
 			return false, err
 		}
 
+		doneModified := e.phase("modified_peers")
 		modifyMore, err := e.modifyPeers(remotePeers, maxBatch)
+		doneModified()
 		if err != nil {
 			return false, err
 		}
 
+		doneAdded := e.phase("added_peers")
 		addMore, err := e.addNewPeers(remotePeers, maxBatch)
+		doneAdded()
 		if err != nil {
 			return false, err
 		}
@@ -1453,8 +1477,10 @@ func (e *Engine) updateNetworkMap(networkMap *mgmProto.NetworkMap, maxBatch int,
 	// the last batch). It needs all target peers present in the store, and
 	// ExcludePeer has replace-semantics — a partial set mid-convergence would be wrong.
 	if !needMore {
+		doneLazy := e.phase("lazy_exclude")
 		excludedLazyPeers := e.toExcludedLazyPeers(e.forwardingRules, remotePeers)
 		e.connMgr.SetExcludeList(e.ctx, excludedLazyPeers)
+		doneLazy()
 	}
 
 	e.networkSerial = serial
@@ -1495,13 +1521,16 @@ func (e *Engine) applyWholesale(networkMap *mgmProto.NetworkMap, serial uint64)
 
 	dnsConfig := toDNSConfig(protoDNSConfig, e.wgInterface.Address())
 
+	done := e.phase("dns_server")
 	if err := e.dnsServer.UpdateDNSServer(serial, dnsConfig); err != nil {
 		log.Errorf("failed to update dns server, err: %v", err)
 	}
+	done()
 
 	e.routeManager.SetDNSForwarderPort(dnsConfig.ForwarderPort)
 
 	// apply routes first, route related actions might depend on routing being enabled
+	done = e.phase("routes_classify")
 	routes := toRoutes(networkMap.GetRoutes())
 	serverRoutes, clientRoutes := e.routeManager.ClassifyRoutes(routes)
 
@@ -1510,24 +1539,33 @@ func (e *Engine) applyWholesale(networkMap *mgmProto.NetworkMap, serial uint64)
 		e.connMgr.UpdateRouteHAMap(clientRoutes)
 		log.Debugf("updated lazy connection manager with %d HA groups", len(clientRoutes))
 	}
+	done()
 
+	done = e.phase("routes_apply")
 	dnsRouteFeatureFlag := toDNSFeatureFlag(networkMap)
 	if err := e.routeManager.UpdateRoutes(serial, serverRoutes, clientRoutes, dnsRouteFeatureFlag); err != nil {
 		log.Errorf("failed to update routes: %v", err)
 	}
+	done()
 
+	done = e.phase("filtering")
 	if e.acl != nil {
 		e.acl.ApplyFiltering(networkMap, dnsRouteFeatureFlag)
 	}
+	done()
 
+	done = e.phase("dns_forwarder")
 	fwdEntries := toRouteDomains(e.config.WgPrivateKey.PublicKey().String(), routes)
 	e.updateDNSForwarder(dnsRouteFeatureFlag, fwdEntries)
+	done()
 
 	// Ingress forward rules
+	done = e.phase("forward_rules")
 	forwardingRules, err := e.updateForwardRules(networkMap.GetForwardingRules())
 	if err != nil {
 		log.Errorf("failed to update forward rules, err: %v", err)
 	}
+	done()
 	e.forwardingRules = forwardingRules
 }
 

client/internal/engine_test.go

@@ -178,6 +178,10 @@ func (m *MockWGIface) LastActivities() map[string]monotime.Time {
 	return nil
 }
 
+func (m *MockWGIface) MTU() uint16 {
+	return 1280
+}
+
 func (m *MockWGIface) SetPresharedKey(peerKey string, psk wgtypes.Key, updateOnly bool) error {
 	return nil
 }

client/internal/iface_common.go

@@ -44,4 +44,5 @@ type wgIfaceBase interface {
 	FullStats() (*configurer.Stats, error)
 	LastActivities() map[string]monotime.Time
 	SetPresharedKey(peerKey string, psk wgtypes.Key, updateOnly bool) error
+	MTU() uint16
 }

client/internal/lazyconn/activity/listener_bind.go

@@ -124,6 +124,11 @@ func (d *BindListener) ReadPackets() {
 	d.done.Done()
 }
 
+// CapturedPacket is unused in userspace bind mode: first-packet reinjection is kernel-only.
+func (d *BindListener) CapturedPacket() []byte {
+	return nil
+}
+
 // Close stops the listener and cleans up resources.
 func (d *BindListener) Close() {
 	d.peerCfg.Log.Infof("closing activity listener (LazyConn)")

client/internal/lazyconn/activity/listener_bind_test.go

@@ -45,10 +45,6 @@ type MockWGIfaceBind struct {
 	endpointMgr *mockEndpointManager
 }
 
-func (m *MockWGIfaceBind) RemovePeer(string) error {
-	return nil
-}
-
 func (m *MockWGIfaceBind) UpdatePeer(string, []netip.Prefix, time.Duration, *net.UDPAddr, *wgtypes.Key) error {
 	return nil
 }
@@ -68,6 +64,10 @@ func (m *MockWGIfaceBind) GetBind() device.EndpointManager {
 	return m.endpointMgr
 }
 
+func (m *MockWGIfaceBind) MTU() uint16 {
+	return 1280
+}
+
 func TestBindListener_Creation(t *testing.T) {
 	mockEndpointMgr := newMockEndpointManager()
 	mockIface := &MockWGIfaceBind{endpointMgr: mockEndpointMgr}
@@ -207,8 +207,9 @@ func TestManager_BindMode(t *testing.T) {
 	require.NoError(t, err)
 
 	select {
-	case peerConnID := <-mgr.OnActivityChan:
-		assert.Equal(t, cfg.PeerConnID, peerConnID, "Received peer connection ID should match")
+	case ev := <-mgr.OnActivityChan:
+		assert.Equal(t, cfg.PeerConnID, ev.PeerConnID, "Received peer connection ID should match")
+		assert.Nil(t, ev.FirstPacket, "Bind mode does not capture packets: reinjection is kernel-only")
 	case <-time.After(2 * time.Second):
 		t.Fatal("timeout waiting for activity notification")
 	}
@@ -266,8 +267,8 @@ func TestManager_BindMode_MultiplePeers(t *testing.T) {
 	receivedPeers := make(map[peerid.ConnID]bool)
 	for i := 0; i < 2; i++ {
 		select {
-		case peerConnID := <-mgr.OnActivityChan:
-			receivedPeers[peerConnID] = true
+		case ev := <-mgr.OnActivityChan:
+			receivedPeers[ev.PeerConnID] = true
 		case <-time.After(2 * time.Second):
 			t.Fatal("timeout waiting for activity notifications")
 		}

client/internal/lazyconn/activity/listener_udp.go

@@ -3,11 +3,13 @@ package activity
 import (
 	"fmt"
 	"net"
+	"slices"
 	"sync"
 	"sync/atomic"
 
 	log "github.com/sirupsen/logrus"
 
+	"github.com/netbirdio/netbird/client/iface/bufsize"
 	"github.com/netbirdio/netbird/client/internal/lazyconn"
 )
 
@@ -20,6 +22,8 @@ type UDPListener struct {
 	done     sync.Mutex
 
 	isClosed atomic.Bool
+
+	capturedPacket []byte
 }
 
 // NewUDPListener creates a listener that detects activity via UDP socket reads.
@@ -46,9 +50,13 @@ func NewUDPListener(wgIface WgInterface, cfg lazyconn.PeerConfig) (*UDPListener,
 }
 
 // ReadPackets blocks reading from the UDP socket until activity is detected or the listener is closed.
+// The first packet that triggers activity is captured so it can be reinjected through the real
+// transport once it is established. Without this, kernel WireGuard's handshake initiation would be
+// dropped and WG would only retry after REKEY_TIMEOUT.
 func (d *UDPListener) ReadPackets() {
 	for {
-		n, remoteAddr, err := d.conn.ReadFromUDP(make([]byte, 1))
+		buf := make([]byte, int(d.wgIface.MTU())+bufsize.WGBufferOverhead)
+		n, remoteAddr, err := d.conn.ReadFromUDP(buf)
 		if err != nil {
 			if d.isClosed.Load() {
 				d.peerCfg.Log.Infof("exit from activity listener")
@@ -62,20 +70,24 @@ func (d *UDPListener) ReadPackets() {
 			d.peerCfg.Log.Warnf("received %d bytes from %s, too short", n, remoteAddr)
 			continue
 		}
-		d.peerCfg.Log.Infof("activity detected")
+		d.capturedPacket = slices.Clone(buf[:n])
+		d.peerCfg.Log.Infof("activity detected, captured %d bytes for reinjection", n)
 		break
 	}
 
-	d.peerCfg.Log.Debugf("removing lazy endpoint: %s", d.endpoint.String())
-	if err := d.wgIface.RemovePeer(d.peerCfg.PublicKey); err != nil {
-		d.peerCfg.Log.Errorf("failed to remove endpoint: %s", err)
-	}
-
-	// Ignore close error as it may return "use of closed network connection" if already closed.
+	// Leave the peer in place. ConfigureWGEndpoint will UpdatePeer with the real endpoint;
+	// removing the peer here wipes kernel WG's staged queue and drops the user packet that
+	// triggered activation.
 	_ = d.conn.Close()
 	d.done.Unlock()
 }
 
+// CapturedPacket returns the first packet that triggered activity, or nil if none was captured.
+// Safe to call after ReadPackets returns.
+func (d *UDPListener) CapturedPacket() []byte {
+	return d.capturedPacket
+}
+
 // Close stops the listener and cleans up resources.
 func (d *UDPListener) Close() {
 	d.peerCfg.Log.Infof("closing activity listener: %s", d.conn.LocalAddr().String())

client/internal/lazyconn/activity/manager.go

@@ -19,17 +19,25 @@ import (
 type listener interface {
 	ReadPackets()
 	Close()
+	CapturedPacket() []byte
+}
+
+// Event reports activity on a managed peer. FirstPacket is the bytes that triggered activation,
+// captured for reinjection through the real transport.
+type Event struct {
+	PeerConnID  peerid.ConnID
+	FirstPacket []byte
 }
 
 type WgInterface interface {
-	RemovePeer(peerKey string) error
 	UpdatePeer(peerKey string, allowedIps []netip.Prefix, keepAlive time.Duration, endpoint *net.UDPAddr, preSharedKey *wgtypes.Key) error
 	IsUserspaceBind() bool
 	Address() wgaddr.Address
+	MTU() uint16
 }
 
 type Manager struct {
-	OnActivityChan chan peerid.ConnID
+	OnActivityChan chan Event
 
 	wgIface WgInterface
 
@@ -41,7 +49,7 @@ type Manager struct {
 
 func NewManager(wgIface WgInterface) *Manager {
 	m := &Manager{
-		OnActivityChan: make(chan peerid.ConnID, 1),
+		OnActivityChan: make(chan Event, 1),
 		wgIface:        wgIface,
 		peers:          make(map[peerid.ConnID]listener),
 		done:           make(chan struct{}),
@@ -116,12 +124,12 @@ func (m *Manager) waitForTraffic(l listener, peerConnID peerid.ConnID) {
 	delete(m.peers, peerConnID)
 	m.mu.Unlock()
 
-	m.notify(peerConnID)
+	m.notify(Event{PeerConnID: peerConnID, FirstPacket: l.CapturedPacket()})
 }
 
-func (m *Manager) notify(peerConnID peerid.ConnID) {
+func (m *Manager) notify(ev Event) {
 	select {
 	case <-m.done:
-	case m.OnActivityChan <- peerConnID:
+	case m.OnActivityChan <- ev:
 	}
 }

client/internal/lazyconn/activity/manager_test.go

@@ -1,6 +1,7 @@
 package activity
 
 import (
+	"bytes"
 	"net"
 	"net/netip"
 	"testing"
@@ -25,10 +26,6 @@ func (m *MocPeer) ConnID() peerid.ConnID {
 type MocWGIface struct {
 }
 
-func (m MocWGIface) RemovePeer(string) error {
-	return nil
-}
-
 func (m MocWGIface) UpdatePeer(string, []netip.Prefix, time.Duration, *net.UDPAddr, *wgtypes.Key) error {
 	return nil
 }
@@ -44,6 +41,10 @@ func (m MocWGIface) Address() wgaddr.Address {
 	}
 }
 
+func (m MocWGIface) MTU() uint16 {
+	return 1280
+}
+
 // GetPeerListener is a test helper to access listeners
 func (m *Manager) GetPeerListener(peerConnID peerid.ConnID) (listener, bool) {
 	m.mu.Lock()
@@ -86,11 +87,15 @@ func TestManager_MonitorPeerActivity(t *testing.T) {
 	}
 
 	select {
-	case peerConnID := <-mgr.OnActivityChan:
-		if peerConnID != peerCfg1.PeerConnID {
-			t.Fatalf("unexpected peerConnID: %v", peerConnID)
+	case ev := <-mgr.OnActivityChan:
+		if ev.PeerConnID != peerCfg1.PeerConnID {
+			t.Fatalf("unexpected peerConnID: %v", ev.PeerConnID)
+		}
+		if !bytes.Equal(ev.FirstPacket, []byte{0x01, 0x02, 0x03, 0x04, 0x05}) {
+			t.Fatalf("unexpected first packet: %v", ev.FirstPacket)
 		}
 	case <-time.After(1 * time.Second):
+		t.Fatal("timed out waiting for activity")
 	}
 }
 

client/internal/lazyconn/manager/manager.go

@@ -130,8 +130,8 @@ func (m *Manager) Start(ctx context.Context) {
 		select {
 		case <-ctx.Done():
 			return
-		case peerConnID := <-m.activityManager.OnActivityChan:
-			m.onPeerActivity(peerConnID)
+		case ev := <-m.activityManager.OnActivityChan:
+			m.onPeerActivity(ev)
 		case peerIDs := <-m.inactivityManager.InactivePeersChan():
 			m.onPeerInactivityTimedOut(peerIDs)
 		}
@@ -513,13 +513,13 @@ func (m *Manager) checkHaGroupActivity(haGroup route.HAUniqueID, peerID string,
 	return false
 }
 
-func (m *Manager) onPeerActivity(peerConnID peerid.ConnID) {
+func (m *Manager) onPeerActivity(ev activity.Event) {
 	m.managedPeersMu.Lock()
 	defer m.managedPeersMu.Unlock()
 
-	mp, ok := m.managedPeersByConnID[peerConnID]
+	mp, ok := m.managedPeersByConnID[ev.PeerConnID]
 	if !ok {
-		log.Errorf("peer not found by conn id: %v", peerConnID)
+		log.Errorf("peer not found by conn id: %v", ev.PeerConnID)
 		return
 	}
 
@@ -536,7 +536,7 @@ func (m *Manager) onPeerActivity(peerConnID peerid.ConnID) {
 
 	m.activateHAGroupPeers(mp.peerCfg)
 
-	m.peerStore.PeerConnOpen(m.engineCtx, mp.peerCfg.PublicKey)
+	m.peerStore.PeerConnOpenWithFirstPacket(m.engineCtx, mp.peerCfg.PublicKey, ev.FirstPacket)
 }
 
 func (m *Manager) onPeerInactivityTimedOut(peerIDs map[string]struct{}) {

client/internal/lazyconn/wgiface.go

@@ -17,4 +17,5 @@ type WGIface interface {
 	IsUserspaceBind() bool
 	Address() wgaddr.Address
 	LastActivities() map[string]monotime.Time
+	MTU() uint16
 }

client/internal/metrics/influxdb.go

@@ -120,6 +120,30 @@ func (m *influxDBMetrics) RecordSyncDuration(_ context.Context, agentInfo AgentI
 	m.trimLocked()
 }
 
+func (m *influxDBMetrics) RecordSyncPhase(_ context.Context, agentInfo AgentInfo, phase string, duration time.Duration) {
+	tags := fmt.Sprintf("deployment_type=%s,version=%s,os=%s,arch=%s,peer_id=%s,phase=%s",
+		agentInfo.DeploymentType.String(),
+		agentInfo.Version,
+		agentInfo.OS,
+		agentInfo.Arch,
+		agentInfo.peerID,
+		phase,
+	)
+
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+	m.samples = append(m.samples, influxSample{
+		measurement: "netbird_sync_phase",
+		tags:        tags,
+		fields: map[string]float64{
+			"duration_seconds": duration.Seconds(),
+		},
+		timestamp: time.Now(),
+	})
+	m.trimLocked()
+}
+
 func (m *influxDBMetrics) RecordLoginDuration(_ context.Context, agentInfo AgentInfo, duration time.Duration, success bool) {
 	result := "success"
 	if !success {

client/internal/metrics/infra/README.md

@@ -78,6 +78,25 @@ Tags:
 - `os`: Operating system (linux, darwin, windows, android, ios, etc.)
 - `arch`: CPU architecture (amd64, arm64, etc.)
 
+### Sync Phase Timing
+
+Measurement: `netbird_sync_phase`
+
+Breaks down where time goes inside a single sync, so the total `netbird_sync` duration can be attributed to the sub-step that dominates.
+
+| Field | Description |
+|-------|-------------|
+| `duration_seconds` | Time spent in one sub-phase of sync processing |
+
+Tags:
+- `phase`: the sub-phase — `netbird_config`, `checks`, `persist`, `dns_server`, `routes_classify`, `routes_apply`, `filtering`, `dns_forwarder`, `forward_rules`, `offline_peers`, `removed_peers`, `modified_peers`, `added_peers`, `lazy_exclude`
+- `deployment_type`: "cloud" | "selfhosted" | "unknown"
+- `version`: NetBird version string
+- `os`: Operating system (linux, darwin, windows, android, ios, etc.)
+- `arch`: CPU architecture (amd64, arm64, etc.)
+
+**Note:** this is wall-time per phase — it includes both CPU work and time spent waiting on locks. A slow phase points to *where* the time goes, not *why*; pair it with lock-wait metrics to tell contention apart from real work.
+
 ### Login Duration
 
 Measurement: `netbird_login`
@@ -191,4 +210,52 @@ docker compose exec influxdb influx query \
 
 # Check ingest server health
 curl http://localhost:8087/health
-```
+```
+
+## Analyzing a Debug Bundle
+
+Metrics collection is always on, so every debug bundle ships a `metrics.txt` in InfluxDB line protocol — a timestamped time series of all recorded events (sync durations, sync phases, connection stages, login). You can replay it into the local stack and graph it, without a running client.
+
+The bundle's `metrics.txt` is a rolling window (capped at 5 days / ~20k samples, see [Buffer Limits](#buffer-limits)). For a connection incident the relevant window is short (connection setup is seconds), so a bundle captured during the issue is enough.
+
+### 1. Start the stack
+
+```bash
+# From this directory (client/internal/metrics/infra)
+INFLUXDB_ADMIN_TOKEN=admin123 INFLUXDB_ADMIN_PASSWORD=admin123 GRAFANA_ADMIN_PASSWORD=admin123 \
+  docker compose up -d
+```
+
+(`admin123` are throwaway local credentials — fine for offline analysis.)
+
+### 2. Clear any previous data
+
+So you only see this bundle:
+
+```bash
+docker exec influxdb influx delete --org netbird --bucket metrics --token admin123 \
+  --start 1970-01-01T00:00:00Z --stop 2100-01-01T00:00:00Z
+```
+
+### 3. Import the bundle's metrics.txt
+
+InfluxDB is not exposed on the host, so import inside the container:
+
+```bash
+docker cp /path/to/bundle/metrics.txt influxdb:/tmp/m.txt
+docker exec influxdb influx write --org netbird --bucket metrics --precision ns \
+  --token admin123 --file /tmp/m.txt
+```
+
+Re-importing the same file is idempotent (same measurement+tags+timestamp overwrites).
+
+### 4. View the dashboards
+
+Grafana on http://localhost:3001 (login `admin` / `admin123`), datasource pre-provisioned:
+
+- **Where sync time goes:** http://localhost:3001/d/netbird-sync-phases/netbird-sync-phases-where-time-goes
+- **General client metrics:** http://localhost:3001/d/netbird-influxdb-metrics
+
+**Set the time range** to cover the bundle's timestamps (e.g. "Last 7 days" or an absolute range matching when the bundle was taken) — with the default short range the panels look empty.
+
+Bundles are distinguishable by the `version` tag; add a tag at import time (e.g. `sed 's/^netbird_\([a-z_]*\),/netbird_\1,bundle=mycase,/' metrics.txt`) if you want to compare several side by side.

client/internal/metrics/infra/grafana/provisioning/dashboards/json/netbird-sync-phases.json

@@ -0,0 +1,259 @@
+{
+  "annotations": {
+    "list": []
+  },
+  "editable": true,
+  "fiscalYearStartMonth": 0,
+  "graphTooltip": 1,
+  "links": [],
+  "refresh": "",
+  "schemaVersion": 39,
+  "tags": [
+    "netbird",
+    "sync"
+  ],
+  "templating": {
+    "list": [
+      {
+        "current": {
+          "text": "All",
+          "value": "$__all"
+        },
+        "datasource": {
+          "type": "influxdb",
+          "uid": "influxdb"
+        },
+        "definition": "import \"influxdata/influxdb/schema\"\nschema.tagValues(bucket: \"metrics\", tag: \"version\")",
+        "includeAll": true,
+        "label": "version",
+        "multi": true,
+        "name": "version",
+        "query": "import \"influxdata/influxdb/schema\"\nschema.tagValues(bucket: \"metrics\", tag: \"version\")",
+        "refresh": 2,
+        "type": "query",
+        "allValue": ".*"
+      }
+    ]
+  },
+  "time": {
+    "from": "now-2d",
+    "to": "now"
+  },
+  "timepicker": {},
+  "timezone": "",
+  "title": "NetBird Sync Phases (where time goes)",
+  "uid": "netbird-sync-phases",
+  "version": 1,
+  "panels": [
+    {
+      "id": 1,
+      "title": "Time per phase over time (stacked, ms)",
+      "type": "timeseries",
+      "datasource": {
+        "type": "influxdb",
+        "uid": "influxdb"
+      },
+      "gridPos": {
+        "h": 10,
+        "w": 24,
+        "x": 0,
+        "y": 0
+      },
+      "fieldConfig": {
+        "defaults": {
+          "unit": "ms",
+          "custom": {
+            "drawStyle": "bars",
+            "stacking": {
+              "mode": "normal",
+              "group": "A"
+            },
+            "fillOpacity": 80,
+            "lineWidth": 0
+          }
+        },
+        "overrides": []
+      },
+      "options": {
+        "legend": {
+          "displayMode": "table",
+          "placement": "right",
+          "calcs": [
+            "max",
+            "mean"
+          ]
+        },
+        "tooltip": {
+          "mode": "multi",
+          "sort": "desc"
+        }
+      },
+      "targets": [
+        {
+          "refId": "A",
+          "datasource": {
+            "type": "influxdb",
+            "uid": "influxdb"
+          },
+          "query": "from(bucket: \"metrics\")\n  |> range(start: v.timeRangeStart, stop: v.timeRangeStop)\n  |> filter(fn: (r) => r._measurement == \"netbird_sync_phase\" and r._field == \"duration_seconds\")\n  |> filter(fn: (r) => r.version =~ /${version:regex}/)\n  |> map(fn: (r) => ({ r with _value: r._value * 1000.0 }))\n  |> keep(columns: [\"_time\", \"_value\", \"phase\"])\n  |> group(columns: [\"phase\"])"
+        }
+      ]
+    },
+    {
+      "id": 2,
+      "title": "p95 per phase (ms)",
+      "type": "bargauge",
+      "datasource": {
+        "type": "influxdb",
+        "uid": "influxdb"
+      },
+      "gridPos": {
+        "h": 11,
+        "w": 12,
+        "x": 0,
+        "y": 10
+      },
+      "fieldConfig": {
+        "defaults": {
+          "unit": "ms",
+          "color": {
+            "mode": "continuous-GrYlRd"
+          }
+        },
+        "overrides": []
+      },
+      "options": {
+        "displayMode": "gradient",
+        "orientation": "horizontal",
+        "reduceOptions": {
+          "calcs": [
+            "lastNotNull"
+          ],
+          "fields": "",
+          "values": false
+        },
+        "showUnfilled": true
+      },
+      "targets": [
+        {
+          "refId": "A",
+          "datasource": {
+            "type": "influxdb",
+            "uid": "influxdb"
+          },
+          "query": "from(bucket: \"metrics\")\n  |> range(start: v.timeRangeStart, stop: v.timeRangeStop)\n  |> filter(fn: (r) => r._measurement == \"netbird_sync_phase\" and r._field == \"duration_seconds\")\n  |> filter(fn: (r) => r.version =~ /${version:regex}/)\n  |> map(fn: (r) => ({ r with _value: r._value * 1000.0 }))\n  |> group(columns: [\"phase\"])\n  |> quantile(q: 0.95)\n  |> group()\n  |> sort(columns: [\"_value\"], desc: true)"
+        }
+      ]
+    },
+    {
+      "id": 3,
+      "title": "Per-phase stats (ms): mean / p95 / max",
+      "type": "table",
+      "datasource": {
+        "type": "influxdb",
+        "uid": "influxdb"
+      },
+      "gridPos": {
+        "h": 11,
+        "w": 12,
+        "x": 12,
+        "y": 10
+      },
+      "fieldConfig": {
+        "defaults": {
+          "unit": "ms"
+        },
+        "overrides": []
+      },
+      "options": {
+        "showHeader": true,
+        "sortBy": [
+          {
+            "displayName": "max",
+            "desc": true
+          }
+        ]
+      },
+      "transformations": [
+        {
+          "id": "merge",
+          "options": {}
+        }
+      ],
+      "targets": [
+        {
+          "refId": "mean",
+          "datasource": {
+            "type": "influxdb",
+            "uid": "influxdb"
+          },
+          "query": "from(bucket: \"metrics\")\n  |> range(start: v.timeRangeStart, stop: v.timeRangeStop)\n  |> filter(fn: (r) => r._measurement == \"netbird_sync_phase\" and r._field == \"duration_seconds\")\n  |> filter(fn: (r) => r.version =~ /${version:regex}/)\n  |> map(fn: (r) => ({ r with _value: r._value * 1000.0 }))\n  |> group(columns: [\"phase\"])\n  |> mean()\n  |> group()\n  |> keep(columns: [\"phase\", \"_value\"])\n  |> rename(columns: {_value: \"mean\"})"
+        },
+        {
+          "refId": "p95",
+          "datasource": {
+            "type": "influxdb",
+            "uid": "influxdb"
+          },
+          "query": "from(bucket: \"metrics\")\n  |> range(start: v.timeRangeStart, stop: v.timeRangeStop)\n  |> filter(fn: (r) => r._measurement == \"netbird_sync_phase\" and r._field == \"duration_seconds\")\n  |> filter(fn: (r) => r.version =~ /${version:regex}/)\n  |> map(fn: (r) => ({ r with _value: r._value * 1000.0 }))\n  |> group(columns: [\"phase\"])\n  |> quantile(q: 0.95)\n  |> group()\n  |> keep(columns: [\"phase\", \"_value\"])\n  |> rename(columns: {_value: \"p95\"})"
+        },
+        {
+          "refId": "max",
+          "datasource": {
+            "type": "influxdb",
+            "uid": "influxdb"
+          },
+          "query": "from(bucket: \"metrics\")\n  |> range(start: v.timeRangeStart, stop: v.timeRangeStop)\n  |> filter(fn: (r) => r._measurement == \"netbird_sync_phase\" and r._field == \"duration_seconds\")\n  |> filter(fn: (r) => r.version =~ /${version:regex}/)\n  |> map(fn: (r) => ({ r with _value: r._value * 1000.0 }))\n  |> group(columns: [\"phase\"])\n  |> max()\n  |> group()\n  |> keep(columns: [\"phase\", \"_value\"])\n  |> rename(columns: {_value: \"max\"})"
+        }
+      ]
+    },
+    {
+      "id": 4,
+      "title": "Total sync duration (netbird_sync, ms) \u2014 reference",
+      "type": "timeseries",
+      "datasource": {
+        "type": "influxdb",
+        "uid": "influxdb"
+      },
+      "gridPos": {
+        "h": 8,
+        "w": 24,
+        "x": 0,
+        "y": 21
+      },
+      "fieldConfig": {
+        "defaults": {
+          "unit": "ms",
+          "custom": {
+            "drawStyle": "points",
+            "pointSize": 5
+          }
+        },
+        "overrides": []
+      },
+      "options": {
+        "legend": {
+          "displayMode": "table",
+          "placement": "right",
+          "calcs": [
+            "max",
+            "mean"
+          ]
+        },
+        "tooltip": {
+          "mode": "single"
+        }
+      },
+      "targets": [
+        {
+          "refId": "A",
+          "datasource": {
+            "type": "influxdb",
+            "uid": "influxdb"
+          },
+          "query": "from(bucket: \"metrics\")\n  |> range(start: v.timeRangeStart, stop: v.timeRangeStop)\n  |> filter(fn: (r) => r._measurement == \"netbird_sync\" and r._field == \"duration_seconds\")\n  |> filter(fn: (r) => r.version =~ /${version:regex}/)\n  |> map(fn: (r) => ({ r with _value: r._value * 1000.0 }))\n  |> keep(columns: [\"_time\", \"_value\", \"version\"])\n  |> group(columns: [\"version\"])"
+        }
+      ]
+    }
+  ]
+}

client/internal/metrics/infra/ingest/main.go

@@ -19,7 +19,7 @@ const (
 	defaultListenAddr  = ":8087"
 	defaultInfluxDBURL = "http://influxdb:8086/api/v2/write?org=netbird&bucket=metrics&precision=ns"
 	maxBodySize        = 50 * 1024 * 1024 // 50 MB max request body
-	maxDurationSeconds = 300.0            // reject any duration field > 5 minutes
+	maxDurationSeconds = 86400.0          // reject any duration field > 24 hours
 	peerIDLength       = 16               // truncated SHA-256: 8 bytes = 16 hex chars
 	maxTagValueLength  = 64               // reject tag values longer than this
 )
@@ -59,6 +59,19 @@ var allowedMeasurements = map[string]measurementSpec{
 			"peer_id":         true,
 		},
 	},
+	"netbird_sync_phase": {
+		allowedFields: map[string]bool{
+			"duration_seconds": true,
+		},
+		allowedTags: map[string]bool{
+			"deployment_type": true,
+			"version":         true,
+			"os":              true,
+			"arch":            true,
+			"peer_id":         true,
+			"phase":           true,
+		},
+	},
 	"netbird_login": {
 		allowedFields: map[string]bool{
 			"duration_seconds": true,

client/internal/metrics/infra/ingest/main_test.go

@@ -53,14 +53,14 @@ func TestValidateLine_NegativeValue(t *testing.T) {
 }
 
 func TestValidateLine_DurationTooLarge(t *testing.T) {
-	line := `netbird_sync,deployment_type=cloud,version=1.0.0,os=linux,arch=amd64,peer_id=abc duration_seconds=999 1234567890`
+	line := `netbird_sync,deployment_type=cloud,version=1.0.0,os=linux,arch=amd64,peer_id=abc duration_seconds=100000 1234567890`
 	err := validateLine(line)
 	require.Error(t, err)
 	assert.Contains(t, err.Error(), "too large")
 }
 
 func TestValidateLine_TotalSecondsTooLarge(t *testing.T) {
-	line := `netbird_peer_connection,deployment_type=cloud,connection_type=ice,attempt_type=initial,version=1.0.0,os=linux,arch=amd64,peer_id=abc,connection_pair_id=pair total_seconds=500 1234567890`
+	line := `netbird_peer_connection,deployment_type=cloud,connection_type=ice,attempt_type=initial,version=1.0.0,os=linux,arch=amd64,peer_id=abc,connection_pair_id=pair total_seconds=100000 1234567890`
 	err := validateLine(line)
 	require.Error(t, err)
 	assert.Contains(t, err.Error(), "too large")

client/internal/metrics/metrics.go

@@ -56,6 +56,9 @@ type metricsImplementation interface {
 	// RecordSyncDuration records how long it took to process a sync message
 	RecordSyncDuration(ctx context.Context, agentInfo AgentInfo, duration time.Duration)
 
+	// RecordSyncPhase records how long a single sub-phase of sync processing took
+	RecordSyncPhase(ctx context.Context, agentInfo AgentInfo, phase string, duration time.Duration)
+
 	// RecordLoginDuration records how long the login to management took
 	RecordLoginDuration(ctx context.Context, agentInfo AgentInfo, duration time.Duration, success bool)
 
@@ -127,6 +130,18 @@ func (c *ClientMetrics) RecordSyncDuration(ctx context.Context, duration time.Du
 	c.impl.RecordSyncDuration(ctx, agentInfo, duration)
 }
 
+// RecordSyncPhase records the duration of a single sub-phase of sync processing
+func (c *ClientMetrics) RecordSyncPhase(ctx context.Context, phase string, duration time.Duration) {
+	if c == nil {
+		return
+	}
+	c.mu.RLock()
+	agentInfo := c.agentInfo
+	c.mu.RUnlock()
+
+	c.impl.RecordSyncPhase(ctx, agentInfo, phase, duration)
+}
+
 // RecordLoginDuration records how long the login to management server took
 func (c *ClientMetrics) RecordLoginDuration(ctx context.Context, duration time.Duration, success bool) {
 	if c == nil {

client/internal/metrics/push_test.go

@@ -70,6 +70,9 @@ func (m *mockMetrics) RecordConnectionStages(_ context.Context, _ AgentInfo, _ s
 func (m *mockMetrics) RecordSyncDuration(_ context.Context, _ AgentInfo, _ time.Duration) {
 }
 
+func (m *mockMetrics) RecordSyncPhase(_ context.Context, _ AgentInfo, _ string, _ time.Duration) {
+}
+
 func (m *mockMetrics) RecordLoginDuration(_ context.Context, _ AgentInfo, _ time.Duration, _ bool) {
 }
 

client/internal/peer/conn.go

@@ -6,6 +6,7 @@ import (
 	"net"
 	"net/netip"
 	"runtime"
+	"slices"
 	"sync"
 	"time"
 
@@ -136,6 +137,39 @@ type Conn struct {
 	// Connection stage timestamps for metrics
 	metricsRecorder MetricsRecorder
 	metricsStages   *MetricsStages
+
+	// pendingFirstPacket is the lazyconn-captured handshake init, replayed once the real
+	// transport is up.
+	pendingFirstPacket []byte
+}
+
+// injectPendingFirstPacket replays the captured handshake through the proxy if present, else
+// directly through the ICE conn. The packet is cleared only after a successful write, so a failed
+// or transport-less attempt leaves it available for a later reinjection. Caller must hold conn.mu.
+func (conn *Conn) injectPendingFirstPacket(proxy wgproxy.Proxy, directConn net.Conn) {
+	pkt := conn.pendingFirstPacket
+	if len(pkt) == 0 {
+		return
+	}
+
+	switch {
+	case proxy != nil:
+		if err := proxy.InjectPacket(pkt); err != nil {
+			conn.Log.Debugf("failed to reinject captured first packet via proxy: %v", err)
+			return
+		}
+	case directConn != nil:
+		if _, err := directConn.Write(pkt); err != nil {
+			conn.Log.Debugf("failed to reinject captured first packet via direct conn: %v", err)
+			return
+		}
+	default:
+		conn.Log.Debugf("no transport available to reinject captured first packet")
+		return
+	}
+
+	conn.pendingFirstPacket = nil
+	conn.Log.Debugf("reinjected captured first packet (%d bytes)", len(pkt))
 }
 
 // NewConn creates a new not opened Conn to the remote peer.
@@ -172,6 +206,16 @@ func NewConn(config ConnConfig, services ServiceDependencies) (*Conn, error) {
 // It will try to establish a connection using ICE and in parallel with relay. The higher priority connection type will
 // be used.
 func (conn *Conn) Open(engineCtx context.Context) error {
+	return conn.open(engineCtx, nil)
+}
+
+// OpenWithFirstPacket opens the connection like Open and stashes firstPacket to be replayed once
+// the real transport is established. The packet is retained only on a successful open.
+func (conn *Conn) OpenWithFirstPacket(engineCtx context.Context, firstPacket []byte) error {
+	return conn.open(engineCtx, firstPacket)
+}
+
+func (conn *Conn) open(engineCtx context.Context, firstPacket []byte) error {
 	conn.mu.Lock()
 	defer conn.mu.Unlock()
 
@@ -227,6 +271,9 @@ func (conn *Conn) Open(engineCtx context.Context) error {
 		defer conn.wg.Done()
 		conn.guard.Start(conn.ctx, conn.onGuardEvent)
 	}()
+	if len(firstPacket) > 0 {
+		conn.pendingFirstPacket = slices.Clone(firstPacket)
+	}
 	conn.opened = true
 	return nil
 }
@@ -423,6 +470,8 @@ func (conn *Conn) onICEConnectionIsReady(priority conntype.ConnPriority, iceConn
 		conn.wgProxyRelay.RedirectAs(ep)
 	}
 
+	conn.injectPendingFirstPacket(wgProxy, iceConnInfo.RemoteConn)
+
 	conn.currentConnPriority = priority
 	conn.statusICE.SetConnected()
 	conn.updateIceState(iceConnInfo, updateTime)
@@ -546,6 +595,8 @@ func (conn *Conn) onRelayConnectionIsReady(rci RelayConnInfo) {
 
 	wgConfigWorkaround()
 
+	conn.injectPendingFirstPacket(wgProxy, nil)
+
 	conn.rosenpassRemoteKey = rci.rosenpassPubKey
 	conn.currentConnPriority = conntype.Relay
 	conn.statusRelay.SetConnected()

client/internal/peerstore/store.go

@@ -88,11 +88,24 @@ func (s *Store) PeerConnOpen(ctx context.Context, pubKey string) {
 	if !ok {
 		return
 	}
-	// this can be blocked because of the connect open limiter semaphore
 	if err := p.Open(ctx); err != nil {
 		p.Log.Errorf("failed to open peer connection: %v", err)
 	}
+}
 
+// PeerConnOpenWithFirstPacket opens the peer connection and stashes a first packet to be
+// reinjected once the real transport is established.
+func (s *Store) PeerConnOpenWithFirstPacket(ctx context.Context, pubKey string, firstPacket []byte) {
+	s.peerConnsMu.RLock()
+	defer s.peerConnsMu.RUnlock()
+
+	p, ok := s.peerConns[pubKey]
+	if !ok {
+		return
+	}
+	if err := p.OpenWithFirstPacket(ctx, firstPacket); err != nil {
+		p.Log.Errorf("failed to open peer connection: %v", err)
+	}
 }
 
 func (s *Store) PeerConnIdle(pubKey string) {

client/internal/routemanager/dnsinterceptor/handler.go

@@ -226,12 +226,11 @@ func (d *DnsInterceptor) ServeDNS(w dns.ResponseWriter, r *dns.Msg) {
 		return
 	}
 
-	// pass if non A/AAAA query
-	if r.Question[0].Qtype != dns.TypeA && r.Question[0].Qtype != dns.TypeAAAA {
-		d.continueToNextHandler(w, r, logger, "non A/AAAA query")
-		return
-	}
-
+	// All query types for an intercepted domain are forwarded to the peer's
+	// DNS forwarder, which owns the name. Falling through to the system
+	// resolver would let it answer NXDOMAIN for a name it isn't authoritative
+	// for, poisoning the whole name (including the A/AAAA records the route
+	// does serve). The forwarder answers NODATA for types it cannot resolve.
 	d.mu.RLock()
 	peerKey := d.currentPeerKey
 	d.mu.RUnlock()
@@ -293,19 +292,6 @@ func (d *DnsInterceptor) writeDNSError(w dns.ResponseWriter, r *dns.Msg, logger
 	}
 }
 
-// continueToNextHandler signals the handler chain to try the next handler
-func (d *DnsInterceptor) continueToNextHandler(w dns.ResponseWriter, r *dns.Msg, logger *log.Entry, reason string) {
-	logger.Tracef("continuing to next handler for domain=%s reason=%s", r.Question[0].Name, reason)
-
-	resp := new(dns.Msg)
-	resp.SetRcode(r, dns.RcodeNameError)
-	// Set Zero bit to signal handler chain to continue
-	resp.MsgHdr.Zero = true
-	if err := w.WriteMsg(resp); err != nil {
-		logger.Errorf("failed writing DNS continue response: %v", err)
-	}
-}
-
 func (d *DnsInterceptor) getUpstreamIP(peerKey string) (netip.Addr, error) {
 	peerAllowedIP, exists := d.peerStore.AllowedIP(peerKey)
 	if !exists {

client/system/info.go

@@ -2,9 +2,11 @@ package system
 
 import (
 	"context"
+	"errors"
 	"net/netip"
 	"slices"
 	"strings"
+	"time"
 
 	log "github.com/sirupsen/logrus"
 	"google.golang.org/grpc/metadata"
@@ -174,7 +176,7 @@ func GetInfoWithChecks(ctx context.Context, checks []*proto.Checks, excludeIPs .
 		processCheckPaths = append(processCheckPaths, check.GetFiles()...)
 	}
 
-	files, err := checkFileAndProcess(processCheckPaths)
+	files, err := checkFileAndProcess(ctx, processCheckPaths)
 	if err != nil {
 		return nil, err
 	}
@@ -187,3 +189,43 @@ func GetInfoWithChecks(ctx context.Context, checks []*proto.Checks, excludeIPs .
 	log.Debugf("all system information gathered successfully")
 	return info, nil
 }
+
+// GetInfoWithChecksTimeout is GetInfoWithChecks bounded by timeout. Posture-check gathering
+// runs uncancellable system calls (process enumeration, os.Stat), so calling it inline can
+// block the caller for as long as such a call hangs. It runs in a goroutine instead: if it
+// does not return within timeout the caller gets (nil, false) and should proceed with
+// degraded behavior rather than block. On a gathering error it falls back to base GetInfo.
+//
+// The buffered channel lets the abandoned goroutine finish and exit once its blocking call
+// returns, so it does not leak beyond the duration of that call.
+func GetInfoWithChecksTimeout(ctx context.Context, timeout time.Duration, checks []*proto.Checks, excludeIPs ...netip.Addr) (*Info, bool) {
+	ctx, cancel := context.WithTimeout(ctx, timeout)
+	defer cancel()
+
+	infoCh := make(chan *Info, 1)
+	go func() {
+		info, err := GetInfoWithChecks(ctx, checks, excludeIPs...)
+		if err != nil {
+			if ctx.Err() != nil {
+				return
+			}
+			log.Warnf("failed to get system info with checks: %v", err)
+			info = GetInfo(ctx)
+			info.removeAddresses(excludeIPs...)
+		}
+		infoCh <- info
+	}()
+
+	select {
+	case info := <-infoCh:
+		return info, true
+	case <-ctx.Done():
+		if errors.Is(ctx.Err(), context.DeadlineExceeded) {
+			log.Warnf("gathering system info with checks timed out after %s", timeout)
+		} else {
+			// Parent context canceled (e.g. shutdown), not a timeout.
+			log.Warnf("gathering system info with checks canceled: %v", ctx.Err())
+		}
+		return nil, false
+	}
+}

client/system/info_android.go

@@ -50,7 +50,7 @@ func GetInfo(ctx context.Context) *Info {
 }
 
 // checkFileAndProcess checks if the file path exists and if a process is running at that path.
-func checkFileAndProcess(paths []string) ([]File, error) {
+func checkFileAndProcess(_ context.Context, _ []string) ([]File, error) {
 	return []File{}, nil
 }
 

client/system/info_darwin.go

@@ -32,7 +32,7 @@ func GetInfo(ctx context.Context) *Info {
 	sysName := string(bytes.Split(utsname.Sysname[:], []byte{0})[0])
 	machine := string(bytes.Split(utsname.Machine[:], []byte{0})[0])
 	release := string(bytes.Split(utsname.Release[:], []byte{0})[0])
-	swVersion, err := exec.Command("sw_vers", "-productVersion").Output()
+	swVersion, err := exec.CommandContext(ctx, "sw_vers", "-productVersion").Output()
 	if err != nil {
 		log.Warnf("got an error while retrieving macOS version with sw_vers, error: %s. Using darwin version instead.\n", err)
 		swVersion = []byte(release)

client/system/info_ios.go

@@ -105,7 +105,7 @@ func isDuplicated(addresses []NetworkAddress, addr NetworkAddress) bool {
 }
 
 // checkFileAndProcess checks if the file path exists and if a process is running at that path.
-func checkFileAndProcess(paths []string) ([]File, error) {
+func checkFileAndProcess(_ context.Context, _ []string) ([]File, error) {
 	return []File{}, nil
 }
 

client/system/info_js.go

@@ -103,7 +103,7 @@ func collectLocationInfo(info *Info) {
 	}
 }
 
-func checkFileAndProcess(_ []string) ([]File, error) {
+func checkFileAndProcess(_ context.Context, _ []string) ([]File, error) {
 	return []File{}, nil
 }
 

client/system/info_test.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"net/netip"
 	"testing"
+	"time"
 
 	"github.com/stretchr/testify/assert"
 	"google.golang.org/grpc/metadata"
@@ -35,6 +36,20 @@ func Test_CustomHostname(t *testing.T) {
 	assert.Equal(t, want, got.Hostname)
 }
 
+func TestGetInfoWithChecksTimeout_Success(t *testing.T) {
+	info, ok := GetInfoWithChecksTimeout(context.Background(), 30*time.Second, nil)
+	assert.True(t, ok, "expected gathering to complete within the timeout")
+	assert.NotNil(t, info)
+}
+
+func TestGetInfoWithChecksTimeout_Timeout(t *testing.T) {
+	// A 1ns budget expires before the (real) system-info gathering can finish, so the
+	// caller must get (nil, false) instead of blocking on the in-flight goroutine.
+	info, ok := GetInfoWithChecksTimeout(context.Background(), time.Nanosecond, nil)
+	assert.False(t, ok, "expected timeout to be reported")
+	assert.Nil(t, info)
+}
+
 func Test_NetAddresses(t *testing.T) {
 	addr, err := networkAddresses()
 	if err != nil {

client/system/process.go

@@ -3,24 +3,30 @@
 package system
 
 import (
+	"context"
 	"os"
 	"slices"
 
 	"github.com/shirou/gopsutil/v3/process"
 )
 
-// getRunningProcesses returns a list of running process paths.
-func getRunningProcesses() ([]string, error) {
-	processIDs, err := process.Pids()
+// getRunningProcesses returns a list of running process paths. The context bounds the work:
+// the per-PID loop bails as soon as ctx is done, and the gopsutil calls honor it where they
+// can, so a stuck enumeration cannot run unbounded.
+func getRunningProcesses(ctx context.Context) ([]string, error) {
+	processIDs, err := process.PidsWithContext(ctx)
 	if err != nil {
 		return nil, err
 	}
 
 	processMap := make(map[string]bool)
 	for _, pID := range processIDs {
+		if err := ctx.Err(); err != nil {
+			return nil, err
+		}
 		p := &process.Process{Pid: pID}
 
-		path, _ := p.Exe()
+		path, _ := p.ExeWithContext(ctx)
 		if path != "" {
 			processMap[path] = false
 		}
@@ -35,18 +41,21 @@ func getRunningProcesses() ([]string, error) {
 }
 
 // checkFileAndProcess checks if the file path exists and if a process is running at that path.
-func checkFileAndProcess(paths []string) ([]File, error) {
+func checkFileAndProcess(ctx context.Context, paths []string) ([]File, error) {
 	files := make([]File, len(paths))
 	if len(paths) == 0 {
 		return files, nil
 	}
 
-	runningProcesses, err := getRunningProcesses()
+	runningProcesses, err := getRunningProcesses(ctx)
 	if err != nil {
 		return nil, err
 	}
 
 	for i, path := range paths {
+		if err := ctx.Err(); err != nil {
+			return nil, err
+		}
 		file := File{Path: path}
 
 		_, err := os.Stat(path)

client/system/process_test.go

@@ -1,6 +1,7 @@
 package system
 
 import (
+	"context"
 	"testing"
 
 	"github.com/shirou/gopsutil/v3/process"
@@ -9,7 +10,7 @@ import (
 func Benchmark_getRunningProcesses(b *testing.B) {
 	b.Run("getRunningProcesses new", func(b *testing.B) {
 		for i := 0; i < b.N; i++ {
-			ps, err := getRunningProcesses()
+			ps, err := getRunningProcesses(context.Background())
 			if err != nil {
 				b.Fatalf("unexpected error: %v", err)
 			}
@@ -29,12 +30,38 @@ func Benchmark_getRunningProcesses(b *testing.B) {
 			}
 		}
 	})
-	s, _ := getRunningProcesses()
+	s, _ := getRunningProcesses(context.Background())
 	b.Logf("getRunningProcesses returned %d processes", len(s))
 	s, _ = getRunningProcessesOld()
 	b.Logf("getRunningProcessesOld returned %d processes", len(s))
 }
 
+func TestCheckFileAndProcess_ContextCanceled(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel()
+
+	// With a canceled context and non-empty paths the gathering must bail with an error
+	// instead of running the (potentially blocking) process scan / stat loop.
+	if _, err := checkFileAndProcess(ctx, []string{"/does/not/exist"}); err == nil {
+		t.Fatal("expected error on canceled context, got nil")
+	}
+}
+
+func TestCheckFileAndProcess_EmptyPaths(t *testing.T) {
+	// No check paths means no work to do: it must return immediately with no error,
+	// even on a canceled context (nothing to scan or stat).
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel()
+
+	files, err := checkFileAndProcess(ctx, nil)
+	if err != nil {
+		t.Fatalf("unexpected error for empty paths: %v", err)
+	}
+	if len(files) != 0 {
+		t.Fatalf("expected no files, got %d", len(files))
+	}
+}
+
 func getRunningProcessesOld() ([]string, error) {
 	processes, err := process.Processes()
 	if err != nil {