[client] Add IPv6 support to ACL manager, USP filter, and forwarder (#5688)

2026-04-18 08:16:39 +00:00 · 2026-04-09 16:56:08 +08:00
parent a1e7db2713
commit 1c4e5e71d7
78 changed files with 3606 additions and 1071 deletions
--- a/client/internal/acl/manager.go
+++ b/client/internal/acl/manager.go
@@ -5,7 +5,6 @@ import (
 	"encoding/hex"
 	"errors"
 	"fmt"
-	"net"
 	"net/netip"
 	"strconv"
 	"sync"
@@ -19,6 +18,7 @@ import (
 	"github.com/netbirdio/netbird/client/internal/acl/id"
 	"github.com/netbirdio/netbird/shared/management/domain"
 	mgmProto "github.com/netbirdio/netbird/shared/management/proto"
+	"github.com/netbirdio/netbird/shared/netiputil"
 )

 var ErrSourceRangesEmpty = errors.New("sources range is empty")
@@ -105,6 +105,10 @@ func (d *DefaultManager) applyPeerACLs(networkMap *mgmProto.NetworkMap) {
 	newRulePairs := make(map[id.RuleID][]firewall.Rule)
 	ipsetByRuleSelectors := make(map[string]string)

+	// TODO: deny rules should be fatal: if a deny rule fails to apply, we must
+	// roll back all allow rules to avoid a fail-open where allowed traffic bypasses
+	// the missing deny. Currently we accumulate errors and continue.
+	var merr *multierror.Error
 	for _, r := range rules {
 		// if this rule is member of rule selection with more than DefaultIPsCountForSet
 		// it's IP address can be used in the ipset for firewall manager which supports it
@@ -117,9 +121,8 @@ func (d *DefaultManager) applyPeerACLs(networkMap *mgmProto.NetworkMap) {
 		}
 		pairID, rulePair, err := d.protoRuleToFirewallRule(r, ipsetName)
 		if err != nil {
-			log.Errorf("failed to apply firewall rule: %+v, %v", r, err)
-			d.rollBack(newRulePairs)
-			break
+			merr = multierror.Append(merr, fmt.Errorf("apply firewall rule: %w", err))
+			continue
 		}
 		if len(rulePair) > 0 {
 			d.peerRulesPairs[pairID] = rulePair
@@ -127,6 +130,10 @@ func (d *DefaultManager) applyPeerACLs(networkMap *mgmProto.NetworkMap) {
 		}
 	}

+	if merr != nil {
+		log.Errorf("failed to apply %d peer ACL rule(s): %v", merr.Len(), nberrors.FormatErrorOrNil(merr))
+	}
+
 	for pairID, rules := range d.peerRulesPairs {
 		if _, ok := newRulePairs[pairID]; !ok {
 			for _, rule := range rules {
@@ -216,10 +223,9 @@ func (d *DefaultManager) protoRuleToFirewallRule(
 	r *mgmProto.FirewallRule,
 	ipsetName string,
 ) (id.RuleID, []firewall.Rule, error) {
-	//nolint:staticcheck // PeerIP used for backward compatibility with old management
-	ip := net.ParseIP(r.PeerIP)
-	if ip == nil {
-		return "", nil, fmt.Errorf("invalid IP address, skipping firewall rule")
+	ip, err := extractRuleIP(r)
+	if err != nil {
+		return "", nil, err
 	}

 	protocol, err := convertToFirewallProtocol(r.Protocol)
@@ -290,13 +296,13 @@ func portInfoEmpty(portInfo *mgmProto.PortInfo) bool {

 func (d *DefaultManager) addInRules(
 	id []byte,
-	ip net.IP,
+	ip netip.Addr,
 	protocol firewall.Protocol,
 	port *firewall.Port,
 	action firewall.Action,
 	ipsetName string,
 ) ([]firewall.Rule, error) {
-	rule, err := d.firewall.AddPeerFiltering(id, ip, protocol, nil, port, action, ipsetName)
+	rule, err := d.firewall.AddPeerFiltering(id, ip.AsSlice(), protocol, nil, port, action, ipsetName)
 	if err != nil {
 		return nil, fmt.Errorf("add firewall rule: %w", err)
 	}
@@ -306,7 +312,7 @@ func (d *DefaultManager) addInRules(

 func (d *DefaultManager) addOutRules(
 	id []byte,
-	ip net.IP,
+	ip netip.Addr,
 	protocol firewall.Protocol,
 	port *firewall.Port,
 	action firewall.Action,
@@ -316,7 +322,7 @@ func (d *DefaultManager) addOutRules(
 		return nil, nil
 	}

-	rule, err := d.firewall.AddPeerFiltering(id, ip, protocol, port, nil, action, ipsetName)
+	rule, err := d.firewall.AddPeerFiltering(id, ip.AsSlice(), protocol, port, nil, action, ipsetName)
 	if err != nil {
 		return nil, fmt.Errorf("add firewall rule: %w", err)
 	}
@@ -324,9 +330,9 @@ func (d *DefaultManager) addOutRules(
 	return rule, nil
 }

-// getPeerRuleID() returns unique ID for the rule based on its parameters.
+// getPeerRuleID returns unique ID for the rule based on its parameters.
 func (d *DefaultManager) getPeerRuleID(
-	ip net.IP,
+	ip netip.Addr,
 	proto firewall.Protocol,
 	direction int,
 	port *firewall.Port,
@@ -345,15 +351,25 @@ func (d *DefaultManager) getRuleGroupingSelector(rule *mgmProto.FirewallRule) st
 	return fmt.Sprintf("%v:%v:%v:%s:%v", strconv.Itoa(int(rule.Direction)), rule.Action, rule.Protocol, rule.Port, rule.PortInfo)
 }

-func (d *DefaultManager) rollBack(newRulePairs map[id.RuleID][]firewall.Rule) {
-	log.Debugf("rollback ACL to previous state")
-	for _, rules := range newRulePairs {
-		for _, rule := range rules {
-			if err := d.firewall.DeletePeerRule(rule); err != nil {
-				log.Errorf("failed to delete new firewall rule (id: %v) during rollback: %v", rule.ID(), err)
-			}
+
+// extractRuleIP extracts the peer IP from a firewall rule.
+// If sourcePrefixes is populated (new management), decode the first entry and use its address.
+// Otherwise fall back to the deprecated PeerIP string field (old management).
+func extractRuleIP(r *mgmProto.FirewallRule) (netip.Addr, error) {
+	if len(r.SourcePrefixes) > 0 {
+		addr, err := netiputil.DecodeAddr(r.SourcePrefixes[0])
+		if err != nil {
+			return netip.Addr{}, fmt.Errorf("decode source prefix: %w", err)
 		}
+		return addr.Unmap(), nil
 	}
+
+	//nolint:staticcheck // PeerIP used for backward compatibility with old management
+	addr, err := netip.ParseAddr(r.PeerIP)
+	if err != nil {
+		return netip.Addr{}, fmt.Errorf("invalid IP address, skipping firewall rule")
+	}
+	return addr.Unmap(), nil
 }

 func convertToFirewallProtocol(protocol mgmProto.RuleProtocol) (firewall.Protocol, error) {
--- a/client/internal/debug/debug_test.go
+++ b/client/internal/debug/debug_test.go
@@ -430,8 +430,6 @@ func isInCGNATRange(ip net.IP) bool {
 }

 func TestAnonymizeFirewallRules(t *testing.T) {
-	// TODO: Add ipv6
-
 	// Example iptables-save output
 	iptablesSave := `# Generated by iptables-save v1.8.7 on Thu Dec 19 10:00:00 2024
 *filter
@@ -467,17 +465,31 @@ Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)
 Chain OUTPUT (policy ACCEPT 0 packets, 0 bytes)
    pkts bytes target     prot opt in     out     source               destination`

-	// Example nftables output
+	// Example ip6tables-save output
+	ip6tablesSave := `# Generated by ip6tables-save v1.8.7 on Thu Dec 19 10:00:00 2024
+*filter
+:INPUT ACCEPT [0:0]
+:FORWARD ACCEPT [0:0]
+:OUTPUT ACCEPT [0:0]
+-A INPUT -s fd00:1234::1/128 -j ACCEPT
+-A INPUT -s 2607:f8b0:4005::1/128 -j DROP
+-A FORWARD -s 2001:db8::/32 -d 2607:f8b0:4005::200e/128 -j ACCEPT
+COMMIT`
+
+	// Example nftables output with IPv6
 	nftablesRules := `table inet filter {
        chain input {
                type filter hook input priority filter; policy accept;
                ip saddr 192.168.1.1 accept
                ip saddr 44.192.140.1 drop
+                ip6 saddr 2607:f8b0:4005::1 drop
+                ip6 saddr fd00:1234::1 accept
        }
        chain forward {
                type filter hook forward priority filter; policy accept;
                ip saddr 10.0.0.0/8 drop
                ip saddr 44.192.140.0/24 ip daddr 52.84.12.34/24 accept
+                ip6 saddr 2001:db8::/32 ip6 daddr 2607:f8b0:4005::200e/128 accept
        }
    }`

@@ -540,4 +552,35 @@ Chain OUTPUT (policy ACCEPT 0 packets, 0 bytes)
 	assert.Contains(t, anonNftables, "table inet filter {")
 	assert.Contains(t, anonNftables, "chain input {")
 	assert.Contains(t, anonNftables, "type filter hook input priority filter; policy accept;")
+
+	// IPv6 public addresses in nftables should be anonymized
+	assert.NotContains(t, anonNftables, "2607:f8b0:4005::1")
+	assert.NotContains(t, anonNftables, "2607:f8b0:4005::200e")
+	assert.NotContains(t, anonNftables, "2001:db8::")
+	assert.Contains(t, anonNftables, "2001:db8:ffff::") // Default anonymous v6 range
+
+	// ULA addresses in nftables should remain unchanged (private)
+	assert.Contains(t, anonNftables, "fd00:1234::1")
+
+	// IPv6 nftables structure preserved
+	assert.Contains(t, anonNftables, "ip6 saddr")
+	assert.Contains(t, anonNftables, "ip6 daddr")
+
+	// Test ip6tables-save anonymization
+	anonIp6tablesSave := anonymizer.AnonymizeString(ip6tablesSave)
+
+	// ULA (private) IPv6 should remain unchanged
+	assert.Contains(t, anonIp6tablesSave, "fd00:1234::1/128")
+
+	// Public IPv6 addresses should be anonymized
+	assert.NotContains(t, anonIp6tablesSave, "2607:f8b0:4005::1")
+	assert.NotContains(t, anonIp6tablesSave, "2607:f8b0:4005::200e")
+	assert.NotContains(t, anonIp6tablesSave, "2001:db8::")
+	assert.Contains(t, anonIp6tablesSave, "2001:db8:ffff::") // Default anonymous v6 range
+
+	// Structure should be preserved
+	assert.Contains(t, anonIp6tablesSave, "*filter")
+	assert.Contains(t, anonIp6tablesSave, "COMMIT")
+	assert.Contains(t, anonIp6tablesSave, "-j DROP")
+	assert.Contains(t, anonIp6tablesSave, "-j ACCEPT")
 }
--- a/client/internal/dns/service_listener.go
+++ b/client/internal/dns/service_listener.go
@@ -189,10 +189,10 @@ func (s *serviceViaListener) RuntimeIP() netip.Addr {
 }


-// evalListenAddress figure out the listen address for the DNS server
-// first check the 53 port availability on WG interface or lo, if not success
-// pick a random port on WG interface for eBPF, if not success
-// check the 5053 port availability on WG interface or lo without eBPF usage,
+// evalListenAddress figures out the listen address for the DNS server.
+// IPv4-only: all peers have a v4 overlay address, and DNS config points to v4.
+// First checks port 53 on WG interface or lo, then tries eBPF on a random port,
+// then falls back to port 5053.
 func (s *serviceViaListener) evalListenAddress() (netip.Addr, uint16, error) {
 	if s.customAddr != nil {
 		return s.customAddr.Addr(), s.customAddr.Port(), nil
@@ -278,7 +278,7 @@ func (s *serviceViaListener) tryToUseeBPF() (ebpfMgr.Manager, uint16, bool) {
 	}

 	ebpfSrv := ebpf.GetEbpfManagerInstance()
-	err = ebpfSrv.LoadDNSFwd(s.wgInterface.Address().IP.String(), int(port))
+	err = ebpfSrv.LoadDNSFwd(s.wgInterface.Address().IP, int(port))
 	if err != nil {
 		log.Warnf("failed to load DNS forwarder eBPF program, error: %s", err)
 		return nil, 0, false
--- a/client/internal/dns/upstream.go
+++ b/client/internal/dns/upstream.go
@@ -21,6 +21,7 @@ import (
 	"golang.zx2c4.com/wireguard/tun/netstack"

 	"github.com/netbirdio/netbird/client/iface"
+	"github.com/netbirdio/netbird/client/iface/wgaddr"
 	"github.com/netbirdio/netbird/client/internal/dns/resutil"
 	"github.com/netbirdio/netbird/client/internal/dns/types"
 	"github.com/netbirdio/netbird/client/internal/peer"
@@ -29,6 +30,12 @@ import (

 var currentMTU uint16 = iface.DefaultMTU

+// privateClientIface is the subset of the WireGuard interface needed by GetClientPrivate.
+type privateClientIface interface {
+	Name() string
+	Address() wgaddr.Address
+}
+
 func SetCurrentMTU(mtu uint16) {
 	currentMTU = mtu
 }
--- a/client/internal/dns/upstream_android.go
+++ b/client/internal/dns/upstream_android.go
@@ -86,7 +86,7 @@ func (u *upstreamResolver) isLocalResolver(upstream string) bool {
 	return false
 }

-func GetClientPrivate(ip netip.Addr, interfaceName string, dialTimeout time.Duration) (*dns.Client, error) {
+func GetClientPrivate(_ privateClientIface, _ netip.Addr, dialTimeout time.Duration) (*dns.Client, error) {
 	return &dns.Client{
 		Timeout: dialTimeout,
 		Net:     "udp",
--- a/client/internal/dns/upstream_general.go
+++ b/client/internal/dns/upstream_general.go
@@ -52,7 +52,7 @@ func (u *upstreamResolver) exchange(ctx context.Context, upstream string, r *dns
 	return ExchangeWithFallback(ctx, client, r, upstream)
 }

-func GetClientPrivate(ip netip.Addr, interfaceName string, dialTimeout time.Duration) (*dns.Client, error) {
+func GetClientPrivate(_ privateClientIface, _ netip.Addr, dialTimeout time.Duration) (*dns.Client, error) {
 	return &dns.Client{
 		Timeout: dialTimeout,
 		Net:     "udp",
--- a/client/internal/dns/upstream_ios.go
+++ b/client/internal/dns/upstream_ios.go
@@ -19,11 +19,7 @@ import (

 type upstreamResolverIOS struct {
 	*upstreamResolverBase
-	lIP           netip.Addr
-	lNet          netip.Prefix
-	lIPv6         netip.Addr
-	lNetV6        netip.Prefix
-	interfaceName string
+	wgIface WGIface
 }

 func newUpstreamResolver(
@@ -37,11 +33,7 @@ func newUpstreamResolver(

 	ios := &upstreamResolverIOS{
 		upstreamResolverBase: upstreamResolverBase,
-		lIP:                  wgIface.Address().IP,
-		lNet:                 wgIface.Address().Network,
-		lIPv6:                wgIface.Address().IPv6,
-		lNetV6:               wgIface.Address().IPv6Net,
-		interfaceName:        wgIface.Name(),
+		wgIface:              wgIface,
 	}
 	ios.upstreamClient = ios

@@ -69,24 +61,15 @@ func (u *upstreamResolverIOS) exchange(ctx context.Context, upstream string, r *
 	} else {
 		upstreamIP = upstreamIP.Unmap()
 	}
-	needsPrivate := u.lNet.Contains(upstreamIP) ||
-		u.lNetV6.Contains(upstreamIP) ||
+	addr := u.wgIface.Address()
+	needsPrivate := addr.Network.Contains(upstreamIP) ||
+		addr.IPv6Net.Contains(upstreamIP) ||
 		(u.routeMatch != nil && u.routeMatch(upstreamIP))
 	if needsPrivate {
-		var bindIP netip.Addr
-		switch {
-		case upstreamIP.Is6() && u.lIPv6.IsValid():
-			bindIP = u.lIPv6
-		case upstreamIP.Is4() && u.lIP.IsValid():
-			bindIP = u.lIP
-		}
-
-		if bindIP.IsValid() {
-			log.Debugf("using private client to query %s via upstream %s", r.Question[0].Name, upstream)
-			client, err = GetClientPrivate(bindIP, u.interfaceName, timeout)
-			if err != nil {
-				return nil, 0, fmt.Errorf("create private client: %s", err)
-			}
+		log.Debugf("using private client to query %s via upstream %s", r.Question[0].Name, upstream)
+		client, err = GetClientPrivate(u.wgIface, upstreamIP, timeout)
+		if err != nil {
+			return nil, 0, fmt.Errorf("create private client: %s", err)
 		}
 	}

@@ -94,23 +77,29 @@ func (u *upstreamResolverIOS) exchange(ctx context.Context, upstream string, r *
 	return ExchangeWithFallback(nil, client, r, upstream)
 }

-// GetClientPrivate returns a new DNS client bound to the local IP address of the Netbird interface
-// This method is needed for iOS
-func GetClientPrivate(ip netip.Addr, interfaceName string, dialTimeout time.Duration) (*dns.Client, error) {
-	index, err := getInterfaceIndex(interfaceName)
+// GetClientPrivate returns a new DNS client bound to the local IP of the Netbird interface.
+// It selects the v6 bind address when the upstream is IPv6 and the interface has one, otherwise v4.
+func GetClientPrivate(iface privateClientIface, upstreamIP netip.Addr, dialTimeout time.Duration) (*dns.Client, error) {
+	index, err := getInterfaceIndex(iface.Name())
 	if err != nil {
-		log.Debugf("unable to get interface index for %s: %s", interfaceName, err)
+		log.Debugf("unable to get interface index for %s: %s", iface.Name(), err)
 		return nil, err
 	}

+	addr := iface.Address()
+	bindIP := addr.IP
+	if upstreamIP.Is6() && addr.HasIPv6() {
+		bindIP = addr.IPv6
+	}
+
 	proto, opt := unix.IPPROTO_IP, unix.IP_BOUND_IF
-	if ip.Is6() {
+	if bindIP.Is6() {
 		proto, opt = unix.IPPROTO_IPV6, unix.IPV6_BOUND_IF
 	}

 	dialer := &net.Dialer{
-		LocalAddr: net.UDPAddrFromAddrPort(netip.AddrPortFrom(ip, 0)),
-		Timeout: dialTimeout,
+		LocalAddr: net.UDPAddrFromAddrPort(netip.AddrPortFrom(bindIP, 0)),
+		Timeout:   dialTimeout,
 		Control: func(network, address string, c syscall.RawConn) error {
 			var operr error
 			fn := func(s uintptr) {
--- a/client/internal/dnsfwd/manager.go
+++ b/client/internal/dnsfwd/manager.go
@@ -80,6 +80,7 @@ func (m *Manager) Start(fwdEntries []*ForwarderEntry) error {
 		return err
 	}

+	// IPv4-only: peers reach the forwarder via its v4 overlay address.
 	localAddr := m.wgIface.Address().IP

 	if localAddr.IsValid() && m.firewall != nil {
--- a/client/internal/ebpf/ebpf/dns_fwd_linux.go
+++ b/client/internal/ebpf/ebpf/dns_fwd_linux.go
@@ -2,7 +2,8 @@ package ebpf

 import (
 	"encoding/binary"
-	"net"
+	"fmt"
+	"net/netip"

 	log "github.com/sirupsen/logrus"
 )
@@ -12,7 +13,7 @@ const (
 	mapKeyDNSPort uint32 = 1
 )

-func (tf *GeneralManager) LoadDNSFwd(ip string, dnsPort int) error {
+func (tf *GeneralManager) LoadDNSFwd(ip netip.Addr, dnsPort int) error {
 	log.Debugf("load eBPF DNS forwarder, watching addr: %s:53, redirect to port: %d", ip, dnsPort)
 	tf.lock.Lock()
 	defer tf.lock.Unlock()
@@ -22,7 +23,11 @@ func (tf *GeneralManager) LoadDNSFwd(ip string, dnsPort int) error {
 		return err
 	}

-	err = tf.bpfObjs.NbMapDnsIp.Put(mapKeyDNSIP, ip2int(ip))
+	if !ip.Is4() {
+		return fmt.Errorf("eBPF DNS forwarder only supports IPv4, got %s", ip)
+	}
+	ip4 := ip.As4()
+	err = tf.bpfObjs.NbMapDnsIp.Put(mapKeyDNSIP, binary.BigEndian.Uint32(ip4[:]))
 	if err != nil {
 		return err
 	}
@@ -45,7 +50,3 @@ func (tf *GeneralManager) FreeDNSFwd() error {
 	return tf.unsetFeatureFlag(featureFlagDnsForwarder)
 }

-func ip2int(ipString string) uint32 {
-	ip := net.ParseIP(ipString)
-	return binary.BigEndian.Uint32(ip.To4())
-}
--- a/client/internal/ebpf/manager/manager.go
+++ b/client/internal/ebpf/manager/manager.go
@@ -1,8 +1,10 @@
 package manager

+import "net/netip"
+
 // Manager is used to load multiple eBPF programs. E.g., current DNS programs and WireGuard proxy
 type Manager interface {
-	LoadDNSFwd(ip string, dnsPort int) error
+	LoadDNSFwd(ip netip.Addr, dnsPort int) error
 	FreeDNSFwd() error
 	LoadWgProxy(proxyPort, wgPort int) error
 	FreeWGProxy() error
--- a/client/internal/engine.go
+++ b/client/internal/engine.go
@@ -630,7 +630,7 @@ func (e *Engine) initFirewall() error {
 	rosenpassPort := e.rpManager.GetAddress().Port
 	port := firewallManager.Port{Values: []uint16{uint16(rosenpassPort)}}

-	// this rule is static and will be torn down on engine down by the firewall manager
+	// IPv4-only: rosenpass peers connect via AllowedIps[0] which is always v4.
 	if _, err := e.firewall.AddPeerFiltering(
 		nil,
 		net.IP{0, 0, 0, 0},
@@ -682,10 +682,15 @@ func (e *Engine) blockLanAccess() {

 	log.Infof("blocking route LAN access for networks: %v", toBlock)
 	v4 := netip.PrefixFrom(netip.IPv4Unspecified(), 0)
+	v6 := netip.PrefixFrom(netip.IPv6Unspecified(), 0)
 	for _, network := range toBlock {
+		source := v4
+		if network.Addr().Is6() {
+			source = v6
+		}
 		if _, err := e.firewall.AddRouteFiltering(
 			nil,
-			[]netip.Prefix{v4},
+			[]netip.Prefix{source},
 			firewallManager.Network{Prefix: network},
 			firewallManager.ProtocolALL,
 			nil,
@@ -1494,10 +1499,10 @@ func (e *Engine) updateOfflinePeers(offlinePeers []*mgmProto.RemotePeerConfig) {
 	replacement := make([]peer.State, len(offlinePeers))
 	for i, offlinePeer := range offlinePeers {
 		log.Debugf("added offline peer %s", offlinePeer.Fqdn)
-		v4, v6 := splitAllowedIPs(offlinePeer.GetAllowedIps(), e.wgInterface.Address().IPv6Net)
+		v4, v6 := overlayAddrsFromAllowedIPs(offlinePeer.GetAllowedIps(), e.wgInterface.Address().IPv6Net)
 		replacement[i] = peer.State{
-			IP:               v4,
-			IPv6:             v6,
+			IP:               addrToString(v4),
+			IPv6:             addrToString(v6),
 			PubKey:           offlinePeer.GetWgPubKey(),
 			FQDN:             offlinePeer.GetFqdn(),
 			ConnStatus:       peer.StatusIdle,
@@ -1508,30 +1513,37 @@ func (e *Engine) updateOfflinePeers(offlinePeers []*mgmProto.RemotePeerConfig) {
 	e.statusRecorder.ReplaceOfflinePeers(replacement)
 }

-// splitAllowedIPs separates the peer's overlay v4 (/32) and v6 (/128) addresses
-// from a list of AllowedIPs CIDRs. The v6 address is only matched if it falls
-// within ourV6Net (the local overlay v6 subnet), to avoid confusing routed /128
-// prefixes with the peer's overlay address.
-func splitAllowedIPs(allowedIPs []string, ourV6Net netip.Prefix) (v4, v6 string) {
+// overlayAddrsFromAllowedIPs extracts the peer's v4 and v6 overlay addresses
+// from AllowedIPs strings. Only host routes (/32, /128) are considered; v6 must
+// fall within ourV6Net to distinguish overlay addresses from routed prefixes.
+func overlayAddrsFromAllowedIPs(allowedIPs []string, ourV6Net netip.Prefix) (v4, v6 netip.Addr) {
 	for _, cidr := range allowedIPs {
 		prefix, err := netip.ParsePrefix(cidr)
 		if err != nil {
 			log.Warnf("failed to parse AllowedIP %q: %v", cidr, err)
 			continue
 		}
+		addr := prefix.Addr().Unmap()
 		switch {
-		case prefix.Addr().Is4() && prefix.Bits() == 32 && v4 == "":
-			v4 = prefix.Addr().String()
-		case prefix.Addr().Is6() && prefix.Bits() == 128 && ourV6Net.Contains(prefix.Addr()) && v6 == "":
-			v6 = prefix.Addr().String()
+		case addr.Is4() && prefix.Bits() == 32 && !v4.IsValid():
+			v4 = addr
+		case addr.Is6() && prefix.Bits() == 128 && ourV6Net.Contains(addr) && !v6.IsValid():
+			v6 = addr
 		}
-		if v4 != "" && v6 != "" {
+		if v4.IsValid() && v6.IsValid() {
 			break
 		}
 	}
 	return
 }

+func addrToString(addr netip.Addr) string {
+	if !addr.IsValid() {
+		return ""
+	}
+	return addr.String()
+}
+
 // addNewPeers adds peers that were not know before but arrived from the Management service with the update
 func (e *Engine) addNewPeers(peersUpdate []*mgmProto.RemotePeerConfig) error {
 	for _, p := range peersUpdate {
@@ -1572,8 +1584,8 @@ func (e *Engine) addNewPeer(peerConfig *mgmProto.RemotePeerConfig) error {
 		return fmt.Errorf("create peer connection: %w", err)
 	}

-	peerV4, peerV6 := splitAllowedIPs(peerConfig.GetAllowedIps(), e.wgInterface.Address().IPv6Net)
-	err = e.statusRecorder.AddPeer(peerKey, peerConfig.Fqdn, peerV4, peerV6)
+	peerV4, peerV6 := overlayAddrsFromAllowedIPs(peerConfig.GetAllowedIps(), e.wgInterface.Address().IPv6Net)
+	err = e.statusRecorder.AddPeer(peerKey, peerConfig.Fqdn, addrToString(peerV4), addrToString(peerV6))
 	if err != nil {
 		log.Warnf("error adding peer %s to status recorder, got error: %v", peerKey, err)
 	}
@@ -2355,8 +2367,7 @@ func getInterfacePrefixes() ([]netip.Prefix, error) {
 			prefix := netip.PrefixFrom(addr.Unmap(), ones).Masked()
 			ip := prefix.Addr()

-			// TODO: add IPv6
-			if !ip.Is4() || ip.IsLoopback() || ip.IsMulticast() || ip.IsLinkLocalUnicast() || ip.IsLinkLocalMulticast() {
+			if ip.IsLoopback() || ip.IsMulticast() || ip.IsLinkLocalUnicast() || ip.IsLinkLocalMulticast() {
 				continue
 			}

--- a/client/internal/engine_ssh.go
+++ b/client/internal/engine_ssh.go
@@ -145,13 +145,13 @@ func (e *Engine) extractPeerSSHInfo(remotePeers []*mgmProto.RemotePeerConfig) []
 			continue
 		}

-		peerIP, peerIPv6 := e.extractPeerIPs(peerConfig)
+		peerV4, peerV6 := overlayAddrsFromAllowedIPs(peerConfig.GetAllowedIps(), e.wgInterface.Address().IPv6Net)
 		hostname := e.extractHostname(peerConfig)

 		peerInfo = append(peerInfo, sshconfig.PeerSSHInfo{
 			Hostname: hostname,
-			IP:       peerIP,
-			IPv6:     peerIPv6,
+			IP:       peerV4,
+			IPv6:     peerV6,
 			FQDN:     peerConfig.GetFqdn(),
 		})
 	}
@@ -159,28 +159,6 @@ func (e *Engine) extractPeerSSHInfo(remotePeers []*mgmProto.RemotePeerConfig) []
 	return peerInfo
 }

-// extractPeerIPs extracts IPv4 and IPv6 overlay addresses from peer's allowed IPs.
-// Only considers host routes (/32, /128) within the overlay networks to avoid
-// picking up routed prefixes or static routes like 2620:fe::fe/128.
-func (e *Engine) extractPeerIPs(peerConfig *mgmProto.RemotePeerConfig) (v4, v6 netip.Addr) {
-	wgAddr := e.wgInterface.Address()
-	for _, allowedIP := range peerConfig.GetAllowedIps() {
-		prefix, err := netip.ParsePrefix(allowedIP)
-		if err != nil {
-			log.Warnf("failed to parse AllowedIP %q: %v", allowedIP, err)
-			continue
-		}
-		addr := prefix.Addr().Unmap()
-		switch {
-		case addr.Is4() && prefix.Bits() == 32 && wgAddr.Network.Contains(addr) && !v4.IsValid():
-			v4 = addr
-		case addr.Is6() && prefix.Bits() == 128 && wgAddr.IPv6Net.IsValid() && wgAddr.IPv6Net.Contains(addr) && !v6.IsValid():
-			v6 = addr
-		}
-	}
-	return v4, v6
-}
-
 // extractHostname extracts short hostname from FQDN
 func (e *Engine) extractHostname(peerConfig *mgmProto.RemotePeerConfig) string {
 	fqdn := peerConfig.GetFqdn()
--- a/client/internal/engine_test.go
+++ b/client/internal/engine_test.go
@@ -1837,7 +1837,7 @@ func TestFilterAllowedIPs(t *testing.T) {
 	}
 }

-func TestSplitAllowedIPs(t *testing.T) {
+func TestOverlayAddrsFromAllowedIPs(t *testing.T) {
 	ourV6Net := netip.MustParsePrefix("fd00:1234:5678:abcd::/64")

 	tests := []struct {
@@ -1900,9 +1900,17 @@ func TestSplitAllowedIPs(t *testing.T) {

 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			v4, v6 := splitAllowedIPs(tt.allowedIPs, tt.ourV6Net)
-			assert.Equal(t, tt.wantV4, v4, "v4")
-			assert.Equal(t, tt.wantV6, v6, "v6")
+			v4, v6 := overlayAddrsFromAllowedIPs(tt.allowedIPs, tt.ourV6Net)
+			if tt.wantV4 == "" {
+				assert.False(t, v4.IsValid(), "expected no v4")
+			} else {
+				assert.Equal(t, tt.wantV4, v4.String(), "v4")
+			}
+			if tt.wantV6 == "" {
+				assert.False(t, v6.IsValid(), "expected no v6")
+			} else {
+				assert.Equal(t, tt.wantV6, v6.String(), "v6")
+			}
 		})
 	}
 }
--- a/client/internal/lazyconn/activity/listener_bind.go
+++ b/client/internal/lazyconn/activity/listener_bind.go
@@ -57,6 +57,7 @@ func NewBindListener(wgIface WgInterface, bind device.EndpointManager, cfg lazyc
 // deriveFakeIP creates a deterministic fake IP for bind mode based on peer's NetBird IP.
 // Maps peer IP 100.64.x.y to fake IP 127.2.x.y (similar to relay proxy using 127.1.x.y).
 // It finds the peer's actual NetBird IP by checking which allowedIP is in the same subnet as our WG interface.
+// For IPv6-only peers, the last two bytes of the v6 address are used.
 func deriveFakeIP(wgIface WgInterface, allowedIPs []netip.Prefix) (netip.Addr, error) {
 	if len(allowedIPs) == 0 {
 		return netip.Addr{}, fmt.Errorf("no allowed IPs for peer")
@@ -64,6 +65,7 @@ func deriveFakeIP(wgIface WgInterface, allowedIPs []netip.Prefix) (netip.Addr, e

 	ourNetwork := wgIface.Address().Network

+	// Try v4 first (preferred: deterministic from overlay IP)
 	var peerIP netip.Addr
 	for _, allowedIP := range allowedIPs {
 		ip := allowedIP.Addr()
@@ -76,13 +78,24 @@ func deriveFakeIP(wgIface WgInterface, allowedIPs []netip.Prefix) (netip.Addr, e
 		}
 	}

-	if !peerIP.IsValid() {
-		return netip.Addr{}, fmt.Errorf("no peer NetBird IP found in allowed IPs")
+	if peerIP.IsValid() {
+		octets := peerIP.As4()
+		return netip.AddrFrom4([4]byte{127, 2, octets[2], octets[3]}), nil
 	}

-	octets := peerIP.As4()
-	fakeIP := netip.AddrFrom4([4]byte{127, 2, octets[2], octets[3]})
-	return fakeIP, nil
+	// Fallback: use last two bytes of first v6 overlay IP
+	addr := wgIface.Address()
+	if addr.IPv6Net.IsValid() {
+		for _, allowedIP := range allowedIPs {
+			ip := allowedIP.Addr()
+			if ip.Is6() && addr.IPv6Net.Contains(ip) {
+				raw := ip.As16()
+				return netip.AddrFrom4([4]byte{127, 2, raw[14], raw[15]}), nil
+			}
+		}
+	}
+
+	return netip.Addr{}, fmt.Errorf("no peer NetBird IP found in allowed IPs")
 }

 func (d *BindListener) setupLazyConn() error {
--- a/client/internal/peer/status.go
+++ b/client/internal/peer/status.go
@@ -1055,7 +1055,11 @@ func (d *Status) notifyPeerListChanged() {
 }

 func (d *Status) notifyAddressChanged() {
-	d.notifier.localAddressChanged(d.localPeer.FQDN, d.localPeer.IP)
+	addr := d.localPeer.IP
+	if d.localPeer.IPv6 != "" {
+		addr = addr + "\n" + d.localPeer.IPv6
+	}
+	d.notifier.localAddressChanged(d.localPeer.FQDN, addr)
 }

 func (d *Status) numOfPeers() int {
--- a/client/internal/routemanager/client/client.go
+++ b/client/internal/routemanager/client/client.go
@@ -3,9 +3,8 @@ package client
 import (
 	"context"
 	"fmt"
-	"net"
+	"net/netip"
 	"reflect"
-	"strconv"
 	"time"

 	log "github.com/sirupsen/logrus"
@@ -566,7 +565,7 @@ func HandlerFromRoute(params common.HandlerParams) RouteHandler {
 		return dnsinterceptor.New(params)
 	case handlerTypeDynamic:
 		dns := nbdns.NewServiceViaMemory(params.WgInterface)
-		dnsAddr := net.JoinHostPort(dns.RuntimeIP().String(), strconv.Itoa(dns.RuntimePort()))
+		dnsAddr := netip.AddrPortFrom(dns.RuntimeIP(), uint16(dns.RuntimePort()))
 		return dynamic.NewRoute(params, dnsAddr)
 	default:
 		return static.NewRoute(params)
--- a/client/internal/routemanager/dnsinterceptor/handler.go
+++ b/client/internal/routemanager/dnsinterceptor/handler.go
@@ -582,7 +582,7 @@ func (d *DnsInterceptor) queryUpstreamDNS(ctx context.Context, w dns.ResponseWri
 	if nsNet != nil {
 		reply, err = nbdns.ExchangeWithNetstack(ctx, nsNet, r, upstream)
 	} else {
-		client, clientErr := nbdns.GetClientPrivate(d.wgInterface.Address().IP, d.wgInterface.Name(), dnsTimeout)
+		client, clientErr := nbdns.GetClientPrivate(d.wgInterface, upstreamIP, dnsTimeout)
 		if clientErr != nil {
 			d.writeDNSError(w, r, logger, fmt.Sprintf("create DNS client: %v", clientErr))
 			return nil
--- a/client/internal/routemanager/dynamic/route.go
+++ b/client/internal/routemanager/dynamic/route.go
@@ -50,10 +50,10 @@ type Route struct {
 	cancel               context.CancelFunc
 	statusRecorder       *peer.Status
 	wgInterface          iface.WGIface
-	resolverAddr         string
+	resolverAddr         netip.AddrPort
 }

-func NewRoute(params common.HandlerParams, resolverAddr string) *Route {
+func NewRoute(params common.HandlerParams, resolverAddr netip.AddrPort) *Route {
 	return &Route{
 		route:                params.Route,
 		routeRefCounter:      params.RouteRefCounter,
--- a/client/internal/routemanager/dynamic/route_ios.go
+++ b/client/internal/routemanager/dynamic/route_ios.go
@@ -17,37 +17,47 @@ import (
 const dialTimeout = 10 * time.Second

 func (r *Route) getIPsFromResolver(domain domain.Domain) ([]net.IP, error) {
-	privateClient, err := nbdns.GetClientPrivate(r.wgInterface.Address().IP, r.wgInterface.Name(), dialTimeout)
+	privateClient, err := nbdns.GetClientPrivate(r.wgInterface, r.resolverAddr.Addr(), dialTimeout)
 	if err != nil {
 		return nil, fmt.Errorf("error while creating private client: %s", err)
 	}

-	msg := new(dns.Msg)
-	msg.SetQuestion(dns.Fqdn(domain.PunycodeString()), dns.TypeA)
-
+	fqdn := dns.Fqdn(domain.PunycodeString())
 	startTime := time.Now()

-	response, _, err := nbdns.ExchangeWithFallback(nil, privateClient, msg, r.resolverAddr)
-	if err != nil {
-		return nil, fmt.Errorf("DNS query for %s failed after %s: %s ", domain.SafeString(), time.Since(startTime), err)
-	}
+	var ips []net.IP
+	var queryErr error

-	if response.Rcode != dns.RcodeSuccess {
-		return nil, fmt.Errorf("dns response code: %s", dns.RcodeToString[response.Rcode])
-	}
+	for _, qtype := range []uint16{dns.TypeA, dns.TypeAAAA} {
+		msg := new(dns.Msg)
+		msg.SetQuestion(fqdn, qtype)

-	ips := make([]net.IP, 0)
-
-	for _, answ := range response.Answer {
-		if aRecord, ok := answ.(*dns.A); ok {
-			ips = append(ips, aRecord.A)
+		response, _, err := nbdns.ExchangeWithFallback(nil, privateClient, msg, r.resolverAddr.String())
+		if err != nil {
+			if queryErr == nil {
+				queryErr = fmt.Errorf("DNS query for %s (type %d) after %s: %w", domain.SafeString(), qtype, time.Since(startTime), err)
+			}
+			continue
 		}
-		if aaaaRecord, ok := answ.(*dns.AAAA); ok {
-			ips = append(ips, aaaaRecord.AAAA)
+
+		if response.Rcode != dns.RcodeSuccess {
+			continue
+		}
+
+		for _, answ := range response.Answer {
+			if aRecord, ok := answ.(*dns.A); ok {
+				ips = append(ips, aRecord.A)
+			}
+			if aaaaRecord, ok := answ.(*dns.AAAA); ok {
+				ips = append(ips, aaaaRecord.AAAA)
+			}
 		}
 	}

 	if len(ips) == 0 {
+		if queryErr != nil {
+			return nil, queryErr
+		}
 		return nil, fmt.Errorf("no A or AAAA records found for %s", domain.SafeString())
 	}

--- a/client/internal/routemanager/fakeip/fakeip.go
+++ b/client/internal/routemanager/fakeip/fakeip.go
@@ -1,93 +1,145 @@
 package fakeip

 import (
+	"errors"
 	"fmt"
 	"net/netip"
 	"sync"
 )

-// Manager manages allocation of fake IPs from the 240.0.0.0/8 block
-type Manager struct {
-	mu         sync.Mutex
-	nextIP     netip.Addr                // Next IP to allocate
+var (
+	// 240.0.0.1 - 240.255.255.254, block 240.0.0.0/8 (reserved, RFC 1112)
+	v4Base  = netip.AddrFrom4([4]byte{240, 0, 0, 1})
+	v4Max   = netip.AddrFrom4([4]byte{240, 255, 255, 254})
+	v4Block = netip.PrefixFrom(netip.AddrFrom4([4]byte{240, 0, 0, 0}), 8)
+
+	// 0100::1 - 0100::ffff:ffff:ffff:fffe, block 0100::/64 (discard, RFC 6666)
+	v6Base  = netip.AddrFrom16([16]byte{0x01, 0x00, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x01})
+	v6Max   = netip.AddrFrom16([16]byte{0x01, 0x00, 0, 0, 0, 0, 0, 0, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfe})
+	v6Block = netip.PrefixFrom(netip.AddrFrom16([16]byte{0x01, 0x00}), 64)
+)
+
+// fakeIPPool holds the allocation state for a single address family.
+type fakeIPPool struct {
+	nextIP     netip.Addr
+	baseIP     netip.Addr
+	maxIP      netip.Addr
+	block      netip.Prefix
 	allocated  map[netip.Addr]netip.Addr // real IP -> fake IP
 	fakeToReal map[netip.Addr]netip.Addr // fake IP -> real IP
-	baseIP     netip.Addr                // First usable IP: 240.0.0.1
-	maxIP      netip.Addr                // Last usable IP: 240.255.255.254
 }

-// NewManager creates a new fake IP manager using 240.0.0.0/8 block
-func NewManager() *Manager {
-	baseIP := netip.AddrFrom4([4]byte{240, 0, 0, 1})
-	maxIP := netip.AddrFrom4([4]byte{240, 255, 255, 254})
-
-	return &Manager{
-		nextIP:     baseIP,
+func newPool(base, maxAddr netip.Addr, block netip.Prefix) *fakeIPPool {
+	return &fakeIPPool{
+		nextIP:     base,
+		baseIP:     base,
+		maxIP:      maxAddr,
+		block:      block,
 		allocated:  make(map[netip.Addr]netip.Addr),
 		fakeToReal: make(map[netip.Addr]netip.Addr),
-		baseIP:     baseIP,
-		maxIP:      maxIP,
 	}
 }

-// AllocateFakeIP allocates a fake IP for the given real IP
-// Returns the fake IP, or existing fake IP if already allocated
-func (m *Manager) AllocateFakeIP(realIP netip.Addr) (netip.Addr, error) {
-	if !realIP.Is4() {
-		return netip.Addr{}, fmt.Errorf("only IPv4 addresses supported")
-	}
-
-	m.mu.Lock()
-	defer m.mu.Unlock()
-
-	if fakeIP, exists := m.allocated[realIP]; exists {
+// allocate allocates a fake IP for the given real IP.
+// Returns the existing fake IP if already allocated.
+func (p *fakeIPPool) allocate(realIP netip.Addr) (netip.Addr, error) {
+	if fakeIP, exists := p.allocated[realIP]; exists {
 		return fakeIP, nil
 	}

-	startIP := m.nextIP
+	startIP := p.nextIP
 	for {
-		currentIP := m.nextIP
+		currentIP := p.nextIP

 		// Advance to next IP, wrapping at boundary
-		if m.nextIP.Compare(m.maxIP) >= 0 {
-			m.nextIP = m.baseIP
+		if p.nextIP.Compare(p.maxIP) >= 0 {
+			p.nextIP = p.baseIP
 		} else {
-			m.nextIP = m.nextIP.Next()
+			p.nextIP = p.nextIP.Next()
 		}

-		// Check if current IP is available
-		if _, inUse := m.fakeToReal[currentIP]; !inUse {
-			m.allocated[realIP] = currentIP
-			m.fakeToReal[currentIP] = realIP
+		if _, inUse := p.fakeToReal[currentIP]; !inUse {
+			p.allocated[realIP] = currentIP
+			p.fakeToReal[currentIP] = realIP
 			return currentIP, nil
 		}

-		// Prevent infinite loop if all IPs exhausted
-		if m.nextIP.Compare(startIP) == 0 {
-			return netip.Addr{}, fmt.Errorf("no more fake IPs available in 240.0.0.0/8 block")
+		if p.nextIP.Compare(startIP) == 0 {
+			return netip.Addr{}, fmt.Errorf("no more fake IPs available in %s block", p.block)
 		}
 	}
 }

-// GetFakeIP returns the fake IP for a real IP if it exists
+// Manager manages allocation of fake IPs for dynamic DNS routes.
+// IPv4 uses 240.0.0.0/8 (reserved), IPv6 uses 0100::/64 (discard, RFC 6666).
+type Manager struct {
+	mu sync.Mutex
+	v4 *fakeIPPool
+	v6 *fakeIPPool
+}
+
+// NewManager creates a new fake IP manager.
+func NewManager() *Manager {
+	return &Manager{
+		v4: newPool(v4Base, v4Max, v4Block),
+		v6: newPool(v6Base, v6Max, v6Block),
+	}
+}
+
+func (m *Manager) pool(ip netip.Addr) *fakeIPPool {
+	if ip.Is6() {
+		return m.v6
+	}
+	return m.v4
+}
+
+// AllocateFakeIP allocates a fake IP for the given real IP.
+func (m *Manager) AllocateFakeIP(realIP netip.Addr) (netip.Addr, error) {
+	realIP = realIP.Unmap()
+	if !realIP.IsValid() {
+		return netip.Addr{}, errors.New("invalid IP address")
+	}
+
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+	return m.pool(realIP).allocate(realIP)
+}
+
+// GetFakeIP returns the fake IP for a real IP if it exists.
 func (m *Manager) GetFakeIP(realIP netip.Addr) (netip.Addr, bool) {
+	realIP = realIP.Unmap()
+	if !realIP.IsValid() {
+		return netip.Addr{}, false
+	}
+
 	m.mu.Lock()
 	defer m.mu.Unlock()

-	fakeIP, exists := m.allocated[realIP]
-	return fakeIP, exists
+	fakeIP, ok := m.pool(realIP).allocated[realIP]
+	return fakeIP, ok
 }

-// GetRealIP returns the real IP for a fake IP if it exists, otherwise false
+// GetRealIP returns the real IP for a fake IP if it exists.
 func (m *Manager) GetRealIP(fakeIP netip.Addr) (netip.Addr, bool) {
+	fakeIP = fakeIP.Unmap()
+	if !fakeIP.IsValid() {
+		return netip.Addr{}, false
+	}
+
 	m.mu.Lock()
 	defer m.mu.Unlock()

-	realIP, exists := m.fakeToReal[fakeIP]
-	return realIP, exists
+	realIP, ok := m.pool(fakeIP).fakeToReal[fakeIP]
+	return realIP, ok
 }

-// GetFakeIPBlock returns the fake IP block used by this manager
+// GetFakeIPBlock returns the v4 fake IP block used by this manager.
 func (m *Manager) GetFakeIPBlock() netip.Prefix {
-	return netip.MustParsePrefix("240.0.0.0/8")
+	return m.v4.block
+}
+
+// GetFakeIPv6Block returns the v6 fake IP block used by this manager.
+func (m *Manager) GetFakeIPv6Block() netip.Prefix {
+	return m.v6.block
 }
--- a/client/internal/routemanager/fakeip/fakeip_test.go
+++ b/client/internal/routemanager/fakeip/fakeip_test.go
@@ -9,16 +9,16 @@ import (
 func TestNewManager(t *testing.T) {
 	manager := NewManager()

-	if manager.baseIP.String() != "240.0.0.1" {
-		t.Errorf("Expected base IP 240.0.0.1, got %s", manager.baseIP.String())
+	if manager.v4.baseIP.String() != "240.0.0.1" {
+		t.Errorf("Expected v4 base IP 240.0.0.1, got %s", manager.v4.baseIP.String())
 	}

-	if manager.maxIP.String() != "240.255.255.254" {
-		t.Errorf("Expected max IP 240.255.255.254, got %s", manager.maxIP.String())
+	if manager.v4.maxIP.String() != "240.255.255.254" {
+		t.Errorf("Expected v4 max IP 240.255.255.254, got %s", manager.v4.maxIP.String())
 	}

-	if manager.nextIP.Compare(manager.baseIP) != 0 {
-		t.Errorf("Expected nextIP to start at baseIP")
+	if manager.v6.baseIP.String() != "100::1" {
+		t.Errorf("Expected v6 base IP 100::1, got %s", manager.v6.baseIP.String())
 	}
 }

@@ -35,7 +35,6 @@ func TestAllocateFakeIP(t *testing.T) {
 		t.Error("Fake IP should be IPv4")
 	}

-	// Check it's in the correct range
 	if fakeIP.As4()[0] != 240 {
 		t.Errorf("Fake IP should be in 240.0.0.0/8 range, got %s", fakeIP.String())
 	}
@@ -51,13 +50,31 @@ func TestAllocateFakeIP(t *testing.T) {
 	}
 }

-func TestAllocateFakeIPIPv6Rejection(t *testing.T) {
+func TestAllocateFakeIPv6(t *testing.T) {
 	manager := NewManager()
-	realIPv6 := netip.MustParseAddr("2001:db8::1")
+	realIP := netip.MustParseAddr("2001:db8::1")

-	_, err := manager.AllocateFakeIP(realIPv6)
-	if err == nil {
-		t.Error("Expected error for IPv6 address")
+	fakeIP, err := manager.AllocateFakeIP(realIP)
+	if err != nil {
+		t.Fatalf("Failed to allocate fake IPv6: %v", err)
+	}
+
+	if !fakeIP.Is6() {
+		t.Error("Fake IP should be IPv6")
+	}
+
+	if !netip.MustParsePrefix("100::/64").Contains(fakeIP) {
+		t.Errorf("Fake IP should be in 100::/64 range, got %s", fakeIP.String())
+	}
+
+	// Should return same fake IP for same real IP
+	fakeIP2, err := manager.AllocateFakeIP(realIP)
+	if err != nil {
+		t.Fatalf("Failed to get existing fake IPv6: %v", err)
+	}
+
+	if fakeIP.Compare(fakeIP2) != 0 {
+		t.Errorf("Expected same fake IP, got %s and %s", fakeIP.String(), fakeIP2.String())
 	}
 }

@@ -65,13 +82,11 @@ func TestGetFakeIP(t *testing.T) {
 	manager := NewManager()
 	realIP := netip.MustParseAddr("1.1.1.1")

-	// Should not exist initially
 	_, exists := manager.GetFakeIP(realIP)
 	if exists {
 		t.Error("Fake IP should not exist before allocation")
 	}

-	// Allocate and check
 	expectedFakeIP, err := manager.AllocateFakeIP(realIP)
 	if err != nil {
 		t.Fatalf("Failed to allocate: %v", err)
@@ -87,12 +102,30 @@ func TestGetFakeIP(t *testing.T) {
 	}
 }

+func TestGetRealIPv6(t *testing.T) {
+	manager := NewManager()
+	realIP := netip.MustParseAddr("2001:db8::1")
+
+	fakeIP, err := manager.AllocateFakeIP(realIP)
+	if err != nil {
+		t.Fatalf("Failed to allocate: %v", err)
+	}
+
+	gotReal, exists := manager.GetRealIP(fakeIP)
+	if !exists {
+		t.Error("Real IP should exist for allocated fake IP")
+	}
+
+	if gotReal.Compare(realIP) != 0 {
+		t.Errorf("Expected real IP %s, got %s", realIP, gotReal)
+	}
+}
+
 func TestMultipleAllocations(t *testing.T) {
 	manager := NewManager()

 	allocations := make(map[netip.Addr]netip.Addr)

-	// Allocate multiple IPs
 	for i := 1; i <= 100; i++ {
 		realIP := netip.AddrFrom4([4]byte{10, 0, byte(i / 256), byte(i % 256)})
 		fakeIP, err := manager.AllocateFakeIP(realIP)
@@ -100,7 +133,6 @@ func TestMultipleAllocations(t *testing.T) {
 			t.Fatalf("Failed to allocate fake IP for %s: %v", realIP.String(), err)
 		}

-		// Check for duplicates
 		for _, existingFake := range allocations {
 			if fakeIP.Compare(existingFake) == 0 {
 				t.Errorf("Duplicate fake IP allocated: %s", fakeIP.String())
@@ -110,7 +142,6 @@ func TestMultipleAllocations(t *testing.T) {
 		allocations[realIP] = fakeIP
 	}

-	// Verify all allocations can be retrieved
 	for realIP, expectedFake := range allocations {
 		actualFake, exists := manager.GetFakeIP(realIP)
 		if !exists {
@@ -124,11 +155,13 @@ func TestMultipleAllocations(t *testing.T) {

 func TestGetFakeIPBlock(t *testing.T) {
 	manager := NewManager()
-	block := manager.GetFakeIPBlock()

-	expected := "240.0.0.0/8"
-	if block.String() != expected {
-		t.Errorf("Expected %s, got %s", expected, block.String())
+	if block := manager.GetFakeIPBlock(); block.String() != "240.0.0.0/8" {
+		t.Errorf("Expected 240.0.0.0/8, got %s", block.String())
+	}
+
+	if block := manager.GetFakeIPv6Block(); block.String() != "100::/64" {
+		t.Errorf("Expected 100::/64, got %s", block.String())
 	}
 }

@@ -141,7 +174,6 @@ func TestConcurrentAccess(t *testing.T) {
 	var wg sync.WaitGroup
 	results := make(chan netip.Addr, numGoroutines*allocationsPerGoroutine)

-	// Concurrent allocations
 	for i := 0; i < numGoroutines; i++ {
 		wg.Add(1)
 		go func(goroutineID int) {
@@ -161,7 +193,6 @@ func TestConcurrentAccess(t *testing.T) {
 	wg.Wait()
 	close(results)

-	// Check for duplicates
 	seen := make(map[netip.Addr]bool)
 	count := 0
 	for fakeIP := range results {
@@ -178,47 +209,61 @@ func TestConcurrentAccess(t *testing.T) {
 }

 func TestIPExhaustion(t *testing.T) {
-	// Create a manager with limited range for testing
 	manager := &Manager{
-		nextIP:     netip.AddrFrom4([4]byte{240, 0, 0, 1}),
-		allocated:  make(map[netip.Addr]netip.Addr),
-		fakeToReal: make(map[netip.Addr]netip.Addr),
-		baseIP:     netip.AddrFrom4([4]byte{240, 0, 0, 1}),
-		maxIP:      netip.AddrFrom4([4]byte{240, 0, 0, 3}), // Only 3 IPs available
+		v4: newPool(
+			netip.AddrFrom4([4]byte{240, 0, 0, 1}),
+			netip.AddrFrom4([4]byte{240, 0, 0, 3}),
+			netip.MustParsePrefix("240.0.0.0/8"),
+		),
+		v6: newPool(
+			netip.MustParseAddr("100::1"),
+			netip.MustParseAddr("100::3"),
+			netip.MustParsePrefix("100::/64"),
+		),
 	}

-	// Allocate all available IPs
-	realIPs := []netip.Addr{
-		netip.MustParseAddr("1.0.0.1"),
-		netip.MustParseAddr("1.0.0.2"),
-		netip.MustParseAddr("1.0.0.3"),
-	}
-
-	for _, realIP := range realIPs {
-		_, err := manager.AllocateFakeIP(realIP)
+	for _, realIP := range []string{"1.0.0.1", "1.0.0.2", "1.0.0.3"} {
+		_, err := manager.AllocateFakeIP(netip.MustParseAddr(realIP))
 		if err != nil {
 			t.Fatalf("Failed to allocate fake IP: %v", err)
 		}
 	}

-	// Try to allocate one more - should fail
 	_, err := manager.AllocateFakeIP(netip.MustParseAddr("1.0.0.4"))
 	if err == nil {
-		t.Error("Expected exhaustion error")
+		t.Error("Expected v4 exhaustion error")
+	}
+
+	// Same for v6
+	for _, realIP := range []string{"2001:db8::1", "2001:db8::2", "2001:db8::3"} {
+		_, err := manager.AllocateFakeIP(netip.MustParseAddr(realIP))
+		if err != nil {
+			t.Fatalf("Failed to allocate fake IPv6: %v", err)
+		}
+	}
+
+	_, err = manager.AllocateFakeIP(netip.MustParseAddr("2001:db8::4"))
+	if err == nil {
+		t.Error("Expected v6 exhaustion error")
 	}
 }

 func TestWrapAround(t *testing.T) {
-	// Create manager starting near the end of range
 	manager := &Manager{
-		nextIP:     netip.AddrFrom4([4]byte{240, 0, 0, 254}),
-		allocated:  make(map[netip.Addr]netip.Addr),
-		fakeToReal: make(map[netip.Addr]netip.Addr),
-		baseIP:     netip.AddrFrom4([4]byte{240, 0, 0, 1}),
-		maxIP:      netip.AddrFrom4([4]byte{240, 0, 0, 254}),
+		v4: newPool(
+			netip.AddrFrom4([4]byte{240, 0, 0, 1}),
+			netip.AddrFrom4([4]byte{240, 0, 0, 254}),
+			netip.MustParsePrefix("240.0.0.0/8"),
+		),
+		v6: newPool(
+			netip.MustParseAddr("100::1"),
+			netip.MustParseAddr("100::ffff:ffff:ffff:fffe"),
+			netip.MustParsePrefix("100::/64"),
+		),
 	}
+	// Start near the end
+	manager.v4.nextIP = netip.AddrFrom4([4]byte{240, 0, 0, 254})

-	// Allocate the last IP
 	fakeIP1, err := manager.AllocateFakeIP(netip.MustParseAddr("1.0.0.1"))
 	if err != nil {
 		t.Fatalf("Failed to allocate first IP: %v", err)
@@ -228,7 +273,6 @@ func TestWrapAround(t *testing.T) {
 		t.Errorf("Expected 240.0.0.254, got %s", fakeIP1.String())
 	}

-	// Next allocation should wrap around to the beginning
 	fakeIP2, err := manager.AllocateFakeIP(netip.MustParseAddr("1.0.0.2"))
 	if err != nil {
 		t.Fatalf("Failed to allocate second IP: %v", err)
@@ -238,3 +282,32 @@ func TestWrapAround(t *testing.T) {
 		t.Errorf("Expected 240.0.0.1 after wrap, got %s", fakeIP2.String())
 	}
 }
+
+func TestMixedV4V6(t *testing.T) {
+	manager := NewManager()
+
+	v4Fake, err := manager.AllocateFakeIP(netip.MustParseAddr("8.8.8.8"))
+	if err != nil {
+		t.Fatalf("Failed to allocate v4: %v", err)
+	}
+
+	v6Fake, err := manager.AllocateFakeIP(netip.MustParseAddr("2001:db8::1"))
+	if err != nil {
+		t.Fatalf("Failed to allocate v6: %v", err)
+	}
+
+	if !v4Fake.Is4() || !v6Fake.Is6() {
+		t.Errorf("Wrong families: v4=%s v6=%s", v4Fake, v6Fake)
+	}
+
+	// Reverse lookups should work for both
+	gotV4, ok := manager.GetRealIP(v4Fake)
+	if !ok || gotV4.String() != "8.8.8.8" {
+		t.Errorf("v4 reverse lookup failed: got %s, ok=%v", gotV4, ok)
+	}
+
+	gotV6, ok := manager.GetRealIP(v6Fake)
+	if !ok || gotV6.String() != "2001:db8::1" {
+		t.Errorf("v6 reverse lookup failed: got %s, ok=%v", gotV6, ok)
+	}
+}
--- a/client/internal/routemanager/ipfwdstate/ipfwdstate.go
+++ b/client/internal/routemanager/ipfwdstate/ipfwdstate.go
@@ -9,7 +9,11 @@ import (
 )

 // IPForwardingState is a struct that keeps track of the IP forwarding state.
-// todo: read initial state of the IP forwarding from the system and reset the state based on it
+// todo: read initial state of the IP forwarding from the system and reset the state based on it.
+// todo: separate v4/v6 forwarding state, since the sysctls are independent
+// (net.ipv4.ip_forward vs net.ipv6.conf.all.forwarding). Currently the nftables
+// manager shares one instance between both routers, which works only because
+// EnableIPForwarding enables both sysctls in a single call.
 type IPForwardingState struct {
 	enabledCounter int
 }
--- a/client/internal/routemanager/manager.go
+++ b/client/internal/routemanager/manager.go
@@ -159,15 +159,23 @@ func (m *DefaultManager) setupAndroidRoutes(config ManagerConfig) {
 	if config.DNSFeatureFlag {
 		m.fakeIPManager = fakeip.NewManager()

-		id := uuid.NewString()
-		fakeIPRoute := &route.Route{
-			ID:          route.ID(id),
+		v4ID := uuid.NewString()
+		cr = append(cr, &route.Route{
+			ID:          route.ID(v4ID),
 			Network:     m.fakeIPManager.GetFakeIPBlock(),
-			NetID:       route.NetID(id),
+			NetID:       route.NetID(v4ID),
 			Peer:        m.pubKey,
 			NetworkType: route.IPv4Network,
-		}
-		cr = append(cr, fakeIPRoute)
+		})
+
+		v6ID := uuid.NewString()
+		cr = append(cr, &route.Route{
+			ID:          route.ID(v6ID),
+			Network:     m.fakeIPManager.GetFakeIPv6Block(),
+			NetID:       route.NetID(v6ID),
+			Peer:        m.pubKey,
+			NetworkType: route.IPv6Network,
+		})
 	}

 	m.notifier.SetInitialClientRoutes(cr, routesForComparison)
--- a/client/internal/routemanager/server/server.go
+++ b/client/internal/routemanager/server/server.go
@@ -146,8 +146,7 @@ func routeToRouterPair(route *route.Route, useNewDNSRoute bool) firewall.RouterP
 		if useNewDNSRoute {
 			destination.Set = firewall.NewDomainSet(route.Domains)
 		} else {
-			// TODO: add ipv6 additionally
-			destination = getDefaultPrefix(destination.Prefix)
+			destination = getDefaultPrefix(route.Network)
 		}
 	} else {
 		destination.Prefix = route.Network.Masked()
--- a/client/internal/routemanager/systemops/systemops.go
+++ b/client/internal/routemanager/systemops/systemops.go
@@ -107,8 +107,13 @@ func (r *SysOps) validateRoute(prefix netip.Prefix) error {
 		addr.IsInterfaceLocalMulticast(),
 		addr.IsMulticast(),
 		addr.IsUnspecified() && prefix.Bits() != 0,
-		r.wgInterface.Address().Network.Contains(addr):
+		r.isOwnAddress(addr):
 		return vars.ErrRouteNotAllowed
 	}
 	return nil
 }
+
+func (r *SysOps) isOwnAddress(addr netip.Addr) bool {
+	wgAddr := r.wgInterface.Address()
+	return wgAddr.Network.Contains(addr) || (wgAddr.IPv6Net.IsValid() && wgAddr.IPv6Net.Contains(addr))
+}
--- a/client/internal/routemanager/systemops/systemops_generic.go
+++ b/client/internal/routemanager/systemops/systemops_generic.go
@@ -222,30 +222,20 @@ func (r *SysOps) genericAddVPNRoute(prefix netip.Prefix, intf *net.Interface) er
 			return err
 		}

-		// TODO: remove once IPv6 is supported on the interface
-		if err := r.addToRouteTable(splitDefaultv6_1, nextHop); err != nil {
-			return fmt.Errorf("add unreachable route split 1: %w", err)
-		}
-		if err := r.addToRouteTable(splitDefaultv6_2, nextHop); err != nil {
-			if err2 := r.removeFromRouteTable(splitDefaultv6_1, nextHop); err2 != nil {
-				log.Warnf("Failed to rollback route addition: %s", err2)
+		// When the interface has no v6, add v6 split-default as blackhole so
+		// unroutable v6 goes to WG (dropped, no AllowedIPs) instead of leaking
+		// to the system default route. When v6 is active, management sends ::/0
+		// as a separate route that the dedicated handler adds.
+		// Soft-fail: v6 blackhole is best-effort, don't abort v4 routing on failure.
+		if !r.wgInterface.Address().HasIPv6() {
+			if err := r.addV6SplitDefault(nextHop); err != nil {
+				log.Warnf("failed to add v6 split-default blackhole: %s", err)
 			}
-			return fmt.Errorf("add unreachable route split 2: %w", err)
 		}

 		return nil
 	case vars.Defaultv6:
-		if err := r.addToRouteTable(splitDefaultv6_1, nextHop); err != nil {
-			return fmt.Errorf("add unreachable route split 1: %w", err)
-		}
-		if err := r.addToRouteTable(splitDefaultv6_2, nextHop); err != nil {
-			if err2 := r.removeFromRouteTable(splitDefaultv6_1, nextHop); err2 != nil {
-				log.Warnf("Failed to rollback route addition: %s", err2)
-			}
-			return fmt.Errorf("add unreachable route split 2: %w", err)
-		}
-
-		return nil
+		return r.addV6SplitDefault(nextHop)
 	}

 	return r.addToRouteTable(prefix, nextHop)
@@ -266,30 +256,42 @@ func (r *SysOps) genericRemoveVPNRoute(prefix netip.Prefix, intf *net.Interface)
 			result = multierror.Append(result, err)
 		}

-		// TODO: remove once IPv6 is supported on the interface
-		if err := r.removeFromRouteTable(splitDefaultv6_1, nextHop); err != nil {
-			result = multierror.Append(result, err)
-		}
-		if err := r.removeFromRouteTable(splitDefaultv6_2, nextHop); err != nil {
-			result = multierror.Append(result, err)
+		if !r.wgInterface.Address().HasIPv6() {
+			result = multierror.Append(result, r.removeV6SplitDefault(nextHop))
 		}

 		return nberrors.FormatErrorOrNil(result)
 	case vars.Defaultv6:
-		var result *multierror.Error
-		if err := r.removeFromRouteTable(splitDefaultv6_1, nextHop); err != nil {
-			result = multierror.Append(result, err)
-		}
-		if err := r.removeFromRouteTable(splitDefaultv6_2, nextHop); err != nil {
-			result = multierror.Append(result, err)
-		}
-
-		return nberrors.FormatErrorOrNil(result)
+		return nberrors.FormatErrorOrNil(r.removeV6SplitDefault(nextHop))
 	default:
 		return r.removeFromRouteTable(prefix, nextHop)
 	}
 }

+func (r *SysOps) addV6SplitDefault(nextHop Nexthop) error {
+	if err := r.addToRouteTable(splitDefaultv6_1, nextHop); err != nil {
+		return fmt.Errorf("add split 1: %w", err)
+	}
+	if err := r.addToRouteTable(splitDefaultv6_2, nextHop); err != nil {
+		if err2 := r.removeFromRouteTable(splitDefaultv6_1, nextHop); err2 != nil {
+			log.Warnf("Failed to rollback v6 split-default: %s", err2)
+		}
+		return fmt.Errorf("add split 2: %w", err)
+	}
+	return nil
+}
+
+func (r *SysOps) removeV6SplitDefault(nextHop Nexthop) *multierror.Error {
+	var result *multierror.Error
+	if err := r.removeFromRouteTable(splitDefaultv6_1, nextHop); err != nil {
+		result = multierror.Append(result, err)
+	}
+	if err := r.removeFromRouteTable(splitDefaultv6_2, nextHop); err != nil {
+		result = multierror.Append(result, err)
+	}
+	return result
+}
+
 func (r *SysOps) setupHooks(initAddresses []net.IP, stateManager *statemanager.Manager) error {
 	beforeHook := func(connID hooks.ConnectionID, prefix netip.Prefix) error {
 		if _, err := r.refCounter.IncrementWithID(string(connID), prefix, struct{}{}); err != nil {
--- a/client/internal/routemanager/systemops/systemops_linux.go
+++ b/client/internal/routemanager/systemops/systemops_linux.go
@@ -53,6 +53,8 @@ const (

 	// ipv4ForwardingPath is the path to the file containing the IP forwarding setting.
 	ipv4ForwardingPath = "net.ipv4.ip_forward"
+	// ipv6ForwardingPath is the path to the file containing the IPv6 forwarding setting.
+	ipv6ForwardingPath = "net.ipv6.conf.all.forwarding"
 )

 var ErrTableIDExists = errors.New("ID exists with different name")
@@ -185,10 +187,11 @@ func (r *SysOps) AddVPNRoute(prefix netip.Prefix, intf *net.Interface) error {

 	// No need to check if routes exist as main table takes precedence over the VPN table via Rule 1

-	// TODO remove this once we have ipv6 support
-	if prefix == vars.Defaultv4 {
+	// When the peer has no IPv6, blackhole v6 to prevent leaking.
+	// When IPv6 is enabled, management sends ::/0 as a separate route.
+	if prefix == vars.Defaultv4 && (r.wgInterface == nil || !r.wgInterface.Address().HasIPv6()) {
 		if err := addUnreachableRoute(vars.Defaultv6, NetbirdVPNTableID); err != nil {
-			return fmt.Errorf("add blackhole: %w", err)
+			return fmt.Errorf("add v6 blackhole: %w", err)
 		}
 	}
 	if err := addRoute(prefix, Nexthop{netip.Addr{}, intf}, NetbirdVPNTableID); err != nil {
@@ -206,10 +209,9 @@ func (r *SysOps) RemoveVPNRoute(prefix netip.Prefix, intf *net.Interface) error
 		return r.genericRemoveVPNRoute(prefix, intf)
 	}

-	// TODO remove this once we have ipv6 support
-	if prefix == vars.Defaultv4 {
+	if prefix == vars.Defaultv4 && (r.wgInterface == nil || !r.wgInterface.Address().HasIPv6()) {
 		if err := removeUnreachableRoute(vars.Defaultv6, NetbirdVPNTableID); err != nil {
-			return fmt.Errorf("remove unreachable route: %w", err)
+			log.Debugf("remove v6 blackhole: %v", err)
 		}
 	}
 	if err := removeRoute(prefix, Nexthop{netip.Addr{}, intf}, NetbirdVPNTableID); err != nil {
@@ -762,8 +764,13 @@ func flushRoutes(tableID, family int) error {
 }

 func EnableIPForwarding() error {
-	_, err := sysctl.Set(ipv4ForwardingPath, 1, false)
-	return err
+	if _, err := sysctl.Set(ipv4ForwardingPath, 1, false); err != nil {
+		return err
+	}
+	if _, err := sysctl.Set(ipv6ForwardingPath, 1, false); err != nil {
+		log.Warnf("failed to enable IPv6 forwarding: %v", err)
+	}
+	return nil
 }

 // entryExists checks if the specified ID or name already exists in the rt_tables file