[client] Set up firewall rules for dns routes dynamically based on dns response (#3702)

client/firewall/iptables/manager_linux.go

@@ -113,17 +113,16 @@ func (m *Manager) AddPeerFiltering(
 func (m *Manager) AddRouteFiltering(
 	id []byte,
 	sources []netip.Prefix,
-	destination netip.Prefix,
+	destination firewall.Network,
 	proto firewall.Protocol,
-	sPort *firewall.Port,
-	dPort *firewall.Port,
+	sPort, dPort *firewall.Port,
 	action firewall.Action,
 ) (firewall.Rule, error) {
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
 
-	if !destination.Addr().Is4() {
-		return nil, fmt.Errorf("unsupported IP version: %s", destination.Addr().String())
+	if destination.IsPrefix() && !destination.Prefix.Addr().Is4() {
+		return nil, fmt.Errorf("unsupported IP version: %s", destination.Prefix.Addr().String())
 	}
 
 	return m.router.AddRouteFiltering(id, sources, destination, proto, sPort, dPort, action)
@@ -243,6 +242,14 @@ func (m *Manager) DeleteDNATRule(rule firewall.Rule) error {
 	return m.router.DeleteDNATRule(rule)
 }
 
+// UpdateSet updates the set with the given prefixes
+func (m *Manager) UpdateSet(set firewall.Set, prefixes []netip.Prefix) error {
+	m.mutex.Lock()
+	defer m.mutex.Unlock()
+
+	return m.router.UpdateSet(set, prefixes)
+}
+
 func getConntrackEstablished() []string {
 	return []string{"-m", "conntrack", "--ctstate", "RELATED,ESTABLISHED", "-j", "ACCEPT"}
 }

client/firewall/iptables/router_linux.go

@@ -57,18 +57,18 @@ type ruleInfo struct {
 }
 
 type routeFilteringRuleParams struct {
-	Sources     []netip.Prefix
-	Destination netip.Prefix
+	Source      firewall.Network
+	Destination firewall.Network
 	Proto       firewall.Protocol
 	SPort       *firewall.Port
 	DPort       *firewall.Port
 	Direction   firewall.RuleDirection
 	Action      firewall.Action
-	SetName     string
 }
 
 type routeRules map[string][]string
 
+// the ipset library currently does not support comments, so we use the name only (string)
 type ipsetCounter = refcounter.Counter[string, []netip.Prefix, struct{}]
 
 type router struct {
@@ -129,7 +129,7 @@ func (r *router) init(stateManager *statemanager.Manager) error {
 func (r *router) AddRouteFiltering(
 	id []byte,
 	sources []netip.Prefix,
-	destination netip.Prefix,
+	destination firewall.Network,
 	proto firewall.Protocol,
 	sPort *firewall.Port,
 	dPort *firewall.Port,
@@ -140,27 +140,28 @@ func (r *router) AddRouteFiltering(
 		return ruleKey, nil
 	}
 
-	var setName string
+	var source firewall.Network
 	if len(sources) > 1 {
-		setName = firewall.GenerateSetName(sources)
-		if _, err := r.ipsetCounter.Increment(setName, sources); err != nil {
-			return nil, fmt.Errorf("create or get ipset: %w", err)
-		}
+		source.Set = firewall.NewPrefixSet(sources)
+	} else if len(sources) > 0 {
+		source.Prefix = sources[0]
 	}
 
 	params := routeFilteringRuleParams{
-		Sources:     sources,
+		Source:      source,
 		Destination: destination,
 		Proto:       proto,
 		SPort:       sPort,
 		DPort:       dPort,
 		Action:      action,
-		SetName:     setName,
 	}
 
-	rule := genRouteFilteringRuleSpec(params)
+	rule, err := r.genRouteRuleSpec(params, sources)
+	if err != nil {
+		return nil, fmt.Errorf("generate route rule spec: %w", err)
+	}
+
 	// Insert DROP rules at the beginning, append ACCEPT rules at the end
-	var err error
 	if action == firewall.ActionDrop {
 		// after the established rule
 		err = r.iptablesClient.Insert(tableFilter, chainRTFWDIN, 2, rule...)
@@ -183,17 +184,13 @@ func (r *router) DeleteRouteRule(rule firewall.Rule) error {
 	ruleKey := rule.ID()
 
 	if rule, exists := r.rules[ruleKey]; exists {
-		setName := r.findSetNameInRule(rule)
-
 		if err := r.iptablesClient.Delete(tableFilter, chainRTFWDIN, rule...); err != nil {
 			return fmt.Errorf("delete route rule: %v", err)
 		}
 		delete(r.rules, ruleKey)
 
-		if setName != "" {
-			if _, err := r.ipsetCounter.Decrement(setName); err != nil {
-				return fmt.Errorf("failed to remove ipset: %w", err)
-			}
+		if err := r.decrementSetCounter(rule); err != nil {
+			return fmt.Errorf("decrement ipset counter: %w", err)
 		}
 	} else {
 		log.Debugf("route rule %s not found", ruleKey)
@@ -204,13 +201,26 @@ func (r *router) DeleteRouteRule(rule firewall.Rule) error {
 	return nil
 }
 
-func (r *router) findSetNameInRule(rule []string) string {
-	for i, arg := range rule {
-		if arg == "-m" && i+3 < len(rule) && rule[i+1] == "set" && rule[i+2] == matchSet {
-			return rule[i+3]
+func (r *router) decrementSetCounter(rule []string) error {
+	sets := r.findSets(rule)
+	var merr *multierror.Error
+	for _, setName := range sets {
+		if _, err := r.ipsetCounter.Decrement(setName); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("decrement counter: %w", err))
 		}
 	}
-	return ""
+
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+func (r *router) findSets(rule []string) []string {
+	var sets []string
+	for i, arg := range rule {
+		if arg == "-m" && i+3 < len(rule) && rule[i+1] == "set" && rule[i+2] == matchSet {
+			sets = append(sets, rule[i+3])
+		}
+	}
+	return sets
 }
 
 func (r *router) createIpSet(setName string, sources []netip.Prefix) error {
@@ -231,6 +241,8 @@ func (r *router) deleteIpSet(setName string) error {
 	if err := ipset.Destroy(setName); err != nil {
 		return fmt.Errorf("destroy set %s: %w", setName, err)
 	}
+
+	log.Debugf("Deleted unused ipset %s", setName)
 	return nil
 }
 
@@ -270,12 +282,14 @@ func (r *router) RemoveNatRule(pair firewall.RouterPair) error {
 		log.Errorf("%v", err)
 	}
 
-	if err := r.removeNatRule(pair); err != nil {
-		return fmt.Errorf("remove nat rule: %w", err)
-	}
+	if pair.Masquerade {
+		if err := r.removeNatRule(pair); err != nil {
+			return fmt.Errorf("remove nat rule: %w", err)
+		}
 
-	if err := r.removeNatRule(firewall.GetInversePair(pair)); err != nil {
-		return fmt.Errorf("remove inverse nat rule: %w", err)
+		if err := r.removeNatRule(firewall.GetInversePair(pair)); err != nil {
+			return fmt.Errorf("remove inverse nat rule: %w", err)
+		}
 	}
 
 	if err := r.removeLegacyRouteRule(pair); err != nil {
@@ -313,8 +327,10 @@ func (r *router) removeLegacyRouteRule(pair firewall.RouterPair) error {
 			return fmt.Errorf("remove legacy forwarding rule %s -> %s: %v", pair.Source, pair.Destination, err)
 		}
 		delete(r.rules, ruleKey)
-	} else {
-		log.Debugf("legacy forwarding rule %s not found", ruleKey)
+
+		if err := r.decrementSetCounter(rule); err != nil {
+			return fmt.Errorf("decrement ipset counter: %w", err)
+		}
 	}
 
 	return nil
@@ -599,12 +615,24 @@ func (r *router) addNatRule(pair firewall.RouterPair) error {
 	rule = append(rule,
 		"-m", "conntrack",
 		"--ctstate", "NEW",
-		"-s", pair.Source.String(),
-		"-d", pair.Destination.String(),
+	)
+	sourceExp, err := r.applyNetwork("-s", pair.Source, nil)
+	if err != nil {
+		return fmt.Errorf("apply network -s: %w", err)
+	}
+	destExp, err := r.applyNetwork("-d", pair.Destination, nil)
+	if err != nil {
+		return fmt.Errorf("apply network -d: %w", err)
+	}
+
+	rule = append(rule, sourceExp...)
+	rule = append(rule, destExp...)
+	rule = append(rule,
 		"-j", "MARK", "--set-mark", fmt.Sprintf("%#x", markValue),
 	)
 
 	if err := r.iptablesClient.Append(tableMangle, chainRTPRE, rule...); err != nil {
+		// TODO: rollback ipset counter
 		return fmt.Errorf("error while adding marking rule for %s: %v", pair.Destination, err)
 	}
 
@@ -622,6 +650,10 @@ func (r *router) removeNatRule(pair firewall.RouterPair) error {
 			return fmt.Errorf("error while removing marking rule for %s: %v", pair.Destination, err)
 		}
 		delete(r.rules, ruleKey)
+
+		if err := r.decrementSetCounter(rule); err != nil {
+			return fmt.Errorf("decrement ipset counter: %w", err)
+		}
 	} else {
 		log.Debugf("marking rule %s not found", ruleKey)
 	}
@@ -787,17 +819,21 @@ func (r *router) DeleteDNATRule(rule firewall.Rule) error {
 	return nberrors.FormatErrorOrNil(merr)
 }
 
-func genRouteFilteringRuleSpec(params routeFilteringRuleParams) []string {
+func (r *router) genRouteRuleSpec(params routeFilteringRuleParams, sources []netip.Prefix) ([]string, error) {
 	var rule []string
 
-	if params.SetName != "" {
-		rule = append(rule, "-m", "set", matchSet, params.SetName, "src")
-	} else if len(params.Sources) > 0 {
-		source := params.Sources[0]
-		rule = append(rule, "-s", source.String())
+	sourceExp, err := r.applyNetwork("-s", params.Source, sources)
+	if err != nil {
+		return nil, fmt.Errorf("apply network -s: %w", err)
+
+	}
+	destExp, err := r.applyNetwork("-d", params.Destination, nil)
+	if err != nil {
+		return nil, fmt.Errorf("apply network -d: %w", err)
 	}
 
-	rule = append(rule, "-d", params.Destination.String())
+	rule = append(rule, sourceExp...)
+	rule = append(rule, destExp...)
 
 	if params.Proto != firewall.ProtocolALL {
 		rule = append(rule, "-p", strings.ToLower(string(params.Proto)))
@@ -807,7 +843,47 @@ func genRouteFilteringRuleSpec(params routeFilteringRuleParams) []string {
 
 	rule = append(rule, "-j", actionToStr(params.Action))
 
-	return rule
+	return rule, nil
+}
+
+func (r *router) applyNetwork(flag string, network firewall.Network, prefixes []netip.Prefix) ([]string, error) {
+	direction := "src"
+	if flag == "-d" {
+		direction = "dst"
+	}
+
+	if network.IsSet() {
+		if _, err := r.ipsetCounter.Increment(network.Set.HashedName(), prefixes); err != nil {
+			return nil, fmt.Errorf("create or get ipset: %w", err)
+		}
+
+		return []string{"-m", "set", matchSet, network.Set.HashedName(), direction}, nil
+	}
+	if network.IsPrefix() {
+		return []string{flag, network.Prefix.String()}, nil
+	}
+
+	// nolint:nilnil
+	return nil, nil
+}
+
+func (r *router) UpdateSet(set firewall.Set, prefixes []netip.Prefix) error {
+	var merr *multierror.Error
+	for _, prefix := range prefixes {
+		// TODO: Implement IPv6 support
+		if prefix.Addr().Is6() {
+			log.Tracef("skipping IPv6 prefix %s: IPv6 support not yet implemented", prefix)
+			continue
+		}
+		if err := ipset.AddPrefix(set.HashedName(), prefix); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("increment ipset counter: %w", err))
+		}
+	}
+	if merr == nil {
+		log.Debugf("updated set %s with prefixes %v", set.HashedName(), prefixes)
+	}
+
+	return nberrors.FormatErrorOrNil(merr)
 }
 
 func applyPort(flag string, port *firewall.Port) []string {

client/firewall/iptables/router_linux_test.go

@@ -60,8 +60,8 @@ func TestIptablesManager_RestoreOrCreateContainers(t *testing.T) {
 
 	pair := firewall.RouterPair{
 		ID:          "abc",
-		Source:      netip.MustParsePrefix("100.100.100.1/32"),
-		Destination: netip.MustParsePrefix("100.100.100.0/24"),
+		Source:      firewall.Network{Prefix: netip.MustParsePrefix("100.100.100.1/32")},
+		Destination: firewall.Network{Prefix: netip.MustParsePrefix("100.100.100.0/24")},
 		Masquerade:  true,
 	}
 
@@ -332,7 +332,7 @@ func TestRouter_AddRouteFiltering(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			ruleKey, err := r.AddRouteFiltering(nil, tt.sources, tt.destination, tt.proto, tt.sPort, tt.dPort, tt.action)
+			ruleKey, err := r.AddRouteFiltering(nil, tt.sources, firewall.Network{Prefix: tt.destination}, tt.proto, tt.sPort, tt.dPort, tt.action)
 			require.NoError(t, err, "AddRouteFiltering failed")
 
 			// Check if the rule is in the internal map
@@ -347,23 +347,29 @@ func TestRouter_AddRouteFiltering(t *testing.T) {
 			assert.NoError(t, err, "Failed to check rule existence")
 			assert.True(t, exists, "Rule not found in iptables")
 
+			var source firewall.Network
+			if len(tt.sources) > 1 {
+				source.Set = firewall.NewPrefixSet(tt.sources)
+			} else if len(tt.sources) > 0 {
+				source.Prefix = tt.sources[0]
+			}
 			// Verify rule content
 			params := routeFilteringRuleParams{
-				Sources:     tt.sources,
-				Destination: tt.destination,
+				Source:      source,
+				Destination: firewall.Network{Prefix: tt.destination},
 				Proto:       tt.proto,
 				SPort:       tt.sPort,
 				DPort:       tt.dPort,
 				Action:      tt.action,
-				SetName:     "",
 			}
 
-			expectedRule := genRouteFilteringRuleSpec(params)
+			expectedRule, err := r.genRouteRuleSpec(params, nil)
+			require.NoError(t, err, "Failed to generate expected rule spec")
 
 			if tt.expectSet {
-				setName := firewall.GenerateSetName(tt.sources)
-				params.SetName = setName
-				expectedRule = genRouteFilteringRuleSpec(params)
+				setName := firewall.NewPrefixSet(tt.sources).HashedName()
+				expectedRule, err = r.genRouteRuleSpec(params, nil)
+				require.NoError(t, err, "Failed to generate expected rule spec with set")
 
 				// Check if the set was created
 				_, exists := r.ipsetCounter.Get(setName)
@@ -378,3 +384,62 @@ func TestRouter_AddRouteFiltering(t *testing.T) {
 		})
 	}
 }
+
+func TestFindSetNameInRule(t *testing.T) {
+	r := &router{}
+
+	testCases := []struct {
+		name     string
+		rule     []string
+		expected []string
+	}{
+		{
+			name: "Basic rule with two sets",
+			rule: []string{
+				"-A", "NETBIRD-RT-FWD-IN", "-p", "tcp", "-m", "set", "--match-set", "nb-2e5a2a05", "src",
+				"-m", "set", "--match-set", "nb-349ae051", "dst", "-m", "tcp", "--dport", "8080", "-j", "ACCEPT",
+			},
+			expected: []string{"nb-2e5a2a05", "nb-349ae051"},
+		},
+		{
+			name:     "No sets",
+			rule:     []string{"-A", "NETBIRD-RT-FWD-IN", "-p", "tcp", "-j", "ACCEPT"},
+			expected: []string{},
+		},
+		{
+			name: "Multiple sets with different positions",
+			rule: []string{
+				"-m", "set", "--match-set", "set1", "src", "-p", "tcp",
+				"-m", "set", "--match-set", "set-abc123", "dst", "-j", "ACCEPT",
+			},
+			expected: []string{"set1", "set-abc123"},
+		},
+		{
+			name:     "Boundary case - sequence appears at end",
+			rule:     []string{"-p", "tcp", "-m", "set", "--match-set", "final-set"},
+			expected: []string{"final-set"},
+		},
+		{
+			name:     "Incomplete pattern - missing set name",
+			rule:     []string{"-p", "tcp", "-m", "set", "--match-set"},
+			expected: []string{},
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			result := r.findSets(tc.rule)
+
+			if len(result) != len(tc.expected) {
+				t.Errorf("Expected %d sets, got %d. Sets found: %v", len(tc.expected), len(result), result)
+				return
+			}
+
+			for i, set := range result {
+				if set != tc.expected[i] {
+					t.Errorf("Expected set %q at position %d, got %q", tc.expected[i], i, set)
+				}
+			}
+		})
+	}
+}

client/firewall/manager/firewall.go

@@ -1,13 +1,10 @@
 package manager
 
 import (
-	"crypto/sha256"
-	"encoding/hex"
 	"fmt"
 	"net"
 	"net/netip"
 	"sort"
-	"strings"
 
 	log "github.com/sirupsen/logrus"
 
@@ -43,6 +40,18 @@ const (
 // Action is the action to be taken on a rule
 type Action int
 
+// String returns the string representation of the action
+func (a Action) String() string {
+	switch a {
+	case ActionAccept:
+		return "accept"
+	case ActionDrop:
+		return "drop"
+	default:
+		return "unknown"
+	}
+}
+
 const (
 	// ActionAccept is the action to accept a packet
 	ActionAccept Action = iota
@@ -50,6 +59,33 @@ const (
 	ActionDrop
 )
 
+// Network is a rule destination, either a set or a prefix
+type Network struct {
+	Set    Set
+	Prefix netip.Prefix
+}
+
+// String returns the string representation of the destination
+func (d Network) String() string {
+	if d.Prefix.IsValid() {
+		return d.Prefix.String()
+	}
+	if d.IsSet() {
+		return d.Set.HashedName()
+	}
+	return "<invalid network>"
+}
+
+// IsSet returns true if the destination is a set
+func (d Network) IsSet() bool {
+	return d.Set != Set{}
+}
+
+// IsPrefix returns true if the destination is a valid prefix
+func (d Network) IsPrefix() bool {
+	return d.Prefix.IsValid()
+}
+
 // Manager is the high level abstraction of a firewall manager
 //
 // It declares methods which handle actions required by the
@@ -83,10 +119,9 @@ type Manager interface {
 	AddRouteFiltering(
 		id []byte,
 		sources []netip.Prefix,
-		destination netip.Prefix,
+		destination Network,
 		proto Protocol,
-		sPort *Port,
-		dPort *Port,
+		sPort, dPort *Port,
 		action Action,
 	) (Rule, error)
 
@@ -119,6 +154,9 @@ type Manager interface {
 
 	// DeleteDNATRule deletes a DNAT rule
 	DeleteDNATRule(Rule) error
+
+	// UpdateSet updates the set with the given prefixes
+	UpdateSet(hash Set, prefixes []netip.Prefix) error
 }
 
 func GenKey(format string, pair RouterPair) string {
@@ -153,22 +191,6 @@ func SetLegacyManagement(router LegacyManager, isLegacy bool) error {
 	return nil
 }
 
-// GenerateSetName generates a unique name for an ipset based on the given sources.
-func GenerateSetName(sources []netip.Prefix) string {
-	// sort for consistent naming
-	SortPrefixes(sources)
-
-	var sourcesStr strings.Builder
-	for _, src := range sources {
-		sourcesStr.WriteString(src.String())
-	}
-
-	hash := sha256.Sum256([]byte(sourcesStr.String()))
-	shortHash := hex.EncodeToString(hash[:])[:8]
-
-	return fmt.Sprintf("nb-%s", shortHash)
-}
-
 // MergeIPRanges merges overlapping IP ranges and returns a slice of non-overlapping netip.Prefix
 func MergeIPRanges(prefixes []netip.Prefix) []netip.Prefix {
 	if len(prefixes) == 0 {

client/firewall/manager/firewall_test.go

@@ -20,8 +20,8 @@ func TestGenerateSetName(t *testing.T) {
 			netip.MustParsePrefix("192.168.1.0/24"),
 		}
 
-		result1 := manager.GenerateSetName(prefixes1)
-		result2 := manager.GenerateSetName(prefixes2)
+		result1 := manager.NewPrefixSet(prefixes1)
+		result2 := manager.NewPrefixSet(prefixes2)
 
 		if result1 != result2 {
 			t.Errorf("Different orders produced different hashes: %s != %s", result1, result2)
@@ -34,9 +34,9 @@ func TestGenerateSetName(t *testing.T) {
 			netip.MustParsePrefix("10.0.0.0/8"),
 		}
 
-		result := manager.GenerateSetName(prefixes)
+		result := manager.NewPrefixSet(prefixes)
 
-		matched, err := regexp.MatchString(`^nb-[0-9a-f]{8}$`, result)
+		matched, err := regexp.MatchString(`^nb-[0-9a-f]{8}$`, result.HashedName())
 		if err != nil {
 			t.Fatalf("Error matching regex: %v", err)
 		}
@@ -46,8 +46,8 @@ func TestGenerateSetName(t *testing.T) {
 	})
 
 	t.Run("Empty input produces consistent result", func(t *testing.T) {
-		result1 := manager.GenerateSetName([]netip.Prefix{})
-		result2 := manager.GenerateSetName([]netip.Prefix{})
+		result1 := manager.NewPrefixSet([]netip.Prefix{})
+		result2 := manager.NewPrefixSet([]netip.Prefix{})
 
 		if result1 != result2 {
 			t.Errorf("Empty input produced inconsistent results: %s != %s", result1, result2)
@@ -64,8 +64,8 @@ func TestGenerateSetName(t *testing.T) {
 			netip.MustParsePrefix("192.168.1.0/24"),
 		}
 
-		result1 := manager.GenerateSetName(prefixes1)
-		result2 := manager.GenerateSetName(prefixes2)
+		result1 := manager.NewPrefixSet(prefixes1)
+		result2 := manager.NewPrefixSet(prefixes2)
 
 		if result1 != result2 {
 			t.Errorf("Different orders of IPv4 and IPv6 produced different hashes: %s != %s", result1, result2)

client/firewall/manager/routerpair.go

@@ -1,15 +1,13 @@
 package manager
 
 import (
-	"net/netip"
-
 	"github.com/netbirdio/netbird/route"
 )
 
 type RouterPair struct {
 	ID          route.ID
-	Source      netip.Prefix
-	Destination netip.Prefix
+	Source      Network
+	Destination Network
 	Masquerade  bool
 	Inverse     bool
 }

client/firewall/manager/set.go

@@ -0,0 +1,74 @@
+package manager
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+	"fmt"
+	"net/netip"
+	"slices"
+
+	log "github.com/sirupsen/logrus"
+
+	"github.com/netbirdio/netbird/management/domain"
+)
+
+type Set struct {
+	hash    [4]byte
+	comment string
+}
+
+// String returns the string representation of the set: hashed name and comment
+func (h Set) String() string {
+	if h.comment == "" {
+		return h.HashedName()
+	}
+	return h.HashedName() + ": " + h.comment
+}
+
+// HashedName returns the string representation of the hash
+func (h Set) HashedName() string {
+	return fmt.Sprintf(
+		"nb-%s",
+		hex.EncodeToString(h.hash[:]),
+	)
+}
+
+// Comment returns the comment of the set
+func (h Set) Comment() string {
+	return h.comment
+}
+
+// NewPrefixSet generates a unique name for an ipset based on the given prefixes.
+func NewPrefixSet(prefixes []netip.Prefix) Set {
+	// sort for consistent naming
+	SortPrefixes(prefixes)
+
+	hash := sha256.New()
+	for _, src := range prefixes {
+		bytes, err := src.MarshalBinary()
+		if err != nil {
+			log.Warnf("failed to marshal prefix %s: %v", src, err)
+		}
+		hash.Write(bytes)
+	}
+	var set Set
+	copy(set.hash[:], hash.Sum(nil)[:4])
+
+	return set
+}
+
+// NewDomainSet generates a unique name for an ipset based on the given domains.
+func NewDomainSet(domains domain.List) Set {
+	slices.Sort(domains)
+
+	hash := sha256.New()
+	for _, d := range domains {
+		hash.Write([]byte(d.PunycodeString()))
+	}
+	set := Set{
+		comment: domains.SafeString(),
+	}
+	copy(set.hash[:], hash.Sum(nil)[:4])
+
+	return set
+}

client/firewall/nftables/manager_linux.go

@@ -135,17 +135,16 @@ func (m *Manager) AddPeerFiltering(
 func (m *Manager) AddRouteFiltering(
 	id []byte,
 	sources []netip.Prefix,
-	destination netip.Prefix,
+	destination firewall.Network,
 	proto firewall.Protocol,
-	sPort *firewall.Port,
-	dPort *firewall.Port,
+	sPort, dPort *firewall.Port,
 	action firewall.Action,
 ) (firewall.Rule, error) {
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
 
-	if !destination.Addr().Is4() {
-		return nil, fmt.Errorf("unsupported IP version: %s", destination.Addr().String())
+	if destination.IsPrefix() && !destination.Prefix.Addr().Is4() {
+		return nil, fmt.Errorf("unsupported IP version: %s", destination.Prefix.Addr().String())
 	}
 
 	return m.router.AddRouteFiltering(id, sources, destination, proto, sPort, dPort, action)
@@ -242,7 +241,7 @@ func (m *Manager) SetLegacyManagement(isLegacy bool) error {
 	return firewall.SetLegacyManagement(m.router, isLegacy)
 }
 
-// Reset firewall to the default state
+// Close closes the firewall manager
 func (m *Manager) Close(stateManager *statemanager.Manager) error {
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
@@ -359,6 +358,14 @@ func (m *Manager) DeleteDNATRule(rule firewall.Rule) error {
 	return m.router.DeleteDNATRule(rule)
 }
 
+// UpdateSet updates the set with the given prefixes
+func (m *Manager) UpdateSet(set firewall.Set, prefixes []netip.Prefix) error {
+	m.mutex.Lock()
+	defer m.mutex.Unlock()
+
+	return m.router.UpdateSet(set, prefixes)
+}
+
 func (m *Manager) createWorkTable() (*nftables.Table, error) {
 	tables, err := m.rConn.ListTablesOfFamily(nftables.TableFamilyIPv4)
 	if err != nil {

client/firewall/nftables/manager_linux_test.go

@@ -289,7 +289,7 @@ func TestNftablesManagerCompatibilityWithIptables(t *testing.T) {
 	_, err = manager.AddRouteFiltering(
 		nil,
 		[]netip.Prefix{netip.MustParsePrefix("192.168.2.0/24")},
-		netip.MustParsePrefix("10.1.0.0/24"),
+		fw.Network{Prefix: netip.MustParsePrefix("10.1.0.0/24")},
 		fw.ProtocolTCP,
 		nil,
 		&fw.Port{Values: []uint16{443}},
@@ -298,8 +298,8 @@ func TestNftablesManagerCompatibilityWithIptables(t *testing.T) {
 	require.NoError(t, err, "failed to add route filtering rule")
 
 	pair := fw.RouterPair{
-		Source:      netip.MustParsePrefix("192.168.1.0/24"),
-		Destination: netip.MustParsePrefix("10.0.0.0/24"),
+		Source:      fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
+		Destination: fw.Network{Prefix: netip.MustParsePrefix("10.0.0.0/24")},
 		Masquerade:  true,
 	}
 	err = manager.AddNatRule(pair)

client/firewall/nftables/router_linux.go

@@ -10,7 +10,6 @@ import (
 	"strings"
 
 	"github.com/coreos/go-iptables/iptables"
-	"github.com/davecgh/go-spew/spew"
 	"github.com/google/nftables"
 	"github.com/google/nftables/binaryutil"
 	"github.com/google/nftables/expr"
@@ -44,9 +43,14 @@ const (
 const refreshRulesMapError = "refresh rules map: %w"
 
 var (
-	errFilterTableNotFound = fmt.Errorf("nftables: 'filter' table not found")
+	errFilterTableNotFound = fmt.Errorf("'filter' table not found")
 )
 
+type setInput struct {
+	set      firewall.Set
+	prefixes []netip.Prefix
+}
+
 type router struct {
 	conn        *nftables.Conn
 	workTable   *nftables.Table
@@ -54,7 +58,7 @@ type router struct {
 	chains      map[string]*nftables.Chain
 	// rules is useful to avoid duplicates and to get missing attributes that we don't have when adding new rules
 	rules        map[string]*nftables.Rule
-	ipsetCounter *refcounter.Counter[string, []netip.Prefix, *nftables.Set]
+	ipsetCounter *refcounter.Counter[string, setInput, *nftables.Set]
 
 	wgIface          iFaceMapper
 	ipFwdState       *ipfwdstate.IPForwardingState
@@ -163,7 +167,7 @@ func (r *router) removeNatPreroutingRules() error {
 func (r *router) loadFilterTable() (*nftables.Table, error) {
 	tables, err := r.conn.ListTablesOfFamily(nftables.TableFamilyIPv4)
 	if err != nil {
-		return nil, fmt.Errorf("nftables: unable to list tables: %v", err)
+		return nil, fmt.Errorf("unable to list tables: %v", err)
 	}
 
 	for _, table := range tables {
@@ -316,7 +320,7 @@ func (r *router) setupDataPlaneMark() error {
 func (r *router) AddRouteFiltering(
 	id []byte,
 	sources []netip.Prefix,
-	destination netip.Prefix,
+	destination firewall.Network,
 	proto firewall.Protocol,
 	sPort *firewall.Port,
 	dPort *firewall.Port,
@@ -331,23 +335,29 @@ func (r *router) AddRouteFiltering(
 	chain := r.chains[chainNameRoutingFw]
 	var exprs []expr.Any
 
+	var source firewall.Network
 	switch {
 	case len(sources) == 1 && sources[0].Bits() == 0:
 		// If it's 0.0.0.0/0, we don't need to add any source matching
 	case len(sources) == 1:
 		// If there's only one source, we can use it directly
-		exprs = append(exprs, generateCIDRMatcherExpressions(true, sources[0])...)
+		source.Prefix = sources[0]
 	default:
-		// If there are multiple sources, create or get an ipset
-		var err error
-		exprs, err = r.getIpSetExprs(sources, exprs)
-		if err != nil {
-			return nil, fmt.Errorf("get ipset expressions: %w", err)
-		}
+		// If there are multiple sources, use a set
+		source.Set = firewall.NewPrefixSet(sources)
 	}
 
-	// Handle destination
-	exprs = append(exprs, generateCIDRMatcherExpressions(false, destination)...)
+	sourceExp, err := r.applyNetwork(source, sources, true)
+	if err != nil {
+		return nil, fmt.Errorf("apply source: %w", err)
+	}
+	exprs = append(exprs, sourceExp...)
+
+	destExp, err := r.applyNetwork(destination, nil, false)
+	if err != nil {
+		return nil, fmt.Errorf("apply destination: %w", err)
+	}
+	exprs = append(exprs, destExp...)
 
 	// Handle protocol
 	if proto != firewall.ProtocolALL {
@@ -391,39 +401,27 @@ func (r *router) AddRouteFiltering(
 		rule = r.conn.AddRule(rule)
 	}
 
-	log.Tracef("Adding route rule %s", spew.Sdump(rule))
 	if err := r.conn.Flush(); err != nil {
 		return nil, fmt.Errorf(flushError, err)
 	}
 
 	r.rules[string(ruleKey)] = rule
 
-	log.Debugf("nftables: added route rule: sources=%v, destination=%v, proto=%v, sPort=%v, dPort=%v, action=%v", sources, destination, proto, sPort, dPort, action)
+	log.Debugf("added route rule: sources=%v, destination=%v, proto=%v, sPort=%v, dPort=%v, action=%v", sources, destination, proto, sPort, dPort, action)
 
 	return ruleKey, nil
 }
 
-func (r *router) getIpSetExprs(sources []netip.Prefix, exprs []expr.Any) ([]expr.Any, error) {
-	setName := firewall.GenerateSetName(sources)
-	ref, err := r.ipsetCounter.Increment(setName, sources)
+func (r *router) getIpSet(set firewall.Set, prefixes []netip.Prefix, isSource bool) ([]expr.Any, error) {
+	ref, err := r.ipsetCounter.Increment(set.HashedName(), setInput{
+		set:      set,
+		prefixes: prefixes,
+	})
 	if err != nil {
-		return nil, fmt.Errorf("create or get ipset for sources: %w", err)
+		return nil, fmt.Errorf("create or get ipset: %w", err)
 	}
 
-	exprs = append(exprs,
-		&expr.Payload{
-			DestRegister: 1,
-			Base:         expr.PayloadBaseNetworkHeader,
-			Offset:       12,
-			Len:          4,
-		},
-		&expr.Lookup{
-			SourceRegister: 1,
-			SetName:        ref.Out.Name,
-			SetID:          ref.Out.ID,
-		},
-	)
-	return exprs, nil
+	return getIpSetExprs(ref, isSource)
 }
 
 func (r *router) DeleteRouteRule(rule firewall.Rule) error {
@@ -442,42 +440,54 @@ func (r *router) DeleteRouteRule(rule firewall.Rule) error {
 		return fmt.Errorf("route rule %s has no handle", ruleKey)
 	}
 
-	setName := r.findSetNameInRule(nftRule)
-
 	if err := r.deleteNftRule(nftRule, ruleKey); err != nil {
 		return fmt.Errorf("delete: %w", err)
 	}
 
-	if setName != "" {
-		if _, err := r.ipsetCounter.Decrement(setName); err != nil {
-			return fmt.Errorf("decrement ipset reference: %w", err)
-		}
-	}
-
 	if err := r.conn.Flush(); err != nil {
 		return fmt.Errorf(flushError, err)
 	}
 
+	if err := r.decrementSetCounter(nftRule); err != nil {
+		return fmt.Errorf("decrement set counter: %w", err)
+	}
+
 	return nil
 }
 
-func (r *router) createIpSet(setName string, sources []netip.Prefix) (*nftables.Set, error) {
+func (r *router) createIpSet(setName string, input setInput) (*nftables.Set, error) {
 	// overlapping prefixes will result in an error, so we need to merge them
-	sources = firewall.MergeIPRanges(sources)
+	prefixes := firewall.MergeIPRanges(input.prefixes)
 
-	set := &nftables.Set{
-		Name:  setName,
-		Table: r.workTable,
+	nfset := &nftables.Set{
+		Name:    setName,
+		Comment: input.set.Comment(),
+		Table:   r.workTable,
 		// required for prefixes
 		Interval: true,
 		KeyType:  nftables.TypeIPAddr,
 	}
 
+	elements := convertPrefixesToSet(prefixes)
+	if err := r.conn.AddSet(nfset, elements); err != nil {
+		return nil, fmt.Errorf("error adding elements to set %s: %w", setName, err)
+	}
+
+	if err := r.conn.Flush(); err != nil {
+		return nil, fmt.Errorf("flush error: %w", err)
+	}
+
+	log.Printf("Created new ipset: %s with %d elements", setName, len(elements)/2)
+
+	return nfset, nil
+}
+
+func convertPrefixesToSet(prefixes []netip.Prefix) []nftables.SetElement {
 	var elements []nftables.SetElement
-	for _, prefix := range sources {
+	for _, prefix := range prefixes {
 		// TODO: Implement IPv6 support
 		if prefix.Addr().Is6() {
-			log.Printf("Skipping IPv6 prefix %s: IPv6 support not yet implemented", prefix)
+			log.Tracef("skipping IPv6 prefix %s: IPv6 support not yet implemented", prefix)
 			continue
 		}
 
@@ -493,18 +503,7 @@ func (r *router) createIpSet(setName string, sources []netip.Prefix) (*nftables.
 			nftables.SetElement{Key: lastIP.AsSlice(), IntervalEnd: true},
 		)
 	}
-
-	if err := r.conn.AddSet(set, elements); err != nil {
-		return nil, fmt.Errorf("error adding elements to set %s: %w", setName, err)
-	}
-
-	if err := r.conn.Flush(); err != nil {
-		return nil, fmt.Errorf("flush error: %w", err)
-	}
-
-	log.Printf("Created new ipset: %s with %d elements", setName, len(elements)/2)
-
-	return set, nil
+	return elements
 }
 
 // calculateLastIP determines the last IP in a given prefix.
@@ -528,8 +527,8 @@ func uint32ToBytes(ip uint32) [4]byte {
 	return b
 }
 
-func (r *router) deleteIpSet(setName string, set *nftables.Set) error {
-	r.conn.DelSet(set)
+func (r *router) deleteIpSet(setName string, nfset *nftables.Set) error {
+	r.conn.DelSet(nfset)
 	if err := r.conn.Flush(); err != nil {
 		return fmt.Errorf(flushError, err)
 	}
@@ -538,13 +537,27 @@ func (r *router) deleteIpSet(setName string, set *nftables.Set) error {
 	return nil
 }
 
-func (r *router) findSetNameInRule(rule *nftables.Rule) string {
-	for _, e := range rule.Exprs {
-		if lookup, ok := e.(*expr.Lookup); ok {
-			return lookup.SetName
+func (r *router) decrementSetCounter(rule *nftables.Rule) error {
+	sets := r.findSets(rule)
+
+	var merr *multierror.Error
+	for _, setName := range sets {
+		if _, err := r.ipsetCounter.Decrement(setName); err != nil {
+			merr = multierror.Append(merr, fmt.Errorf("decrement set counter: %w", err))
 		}
 	}
-	return ""
+
+	return nberrors.FormatErrorOrNil(merr)
+}
+
+func (r *router) findSets(rule *nftables.Rule) []string {
+	var sets []string
+	for _, e := range rule.Exprs {
+		if lookup, ok := e.(*expr.Lookup); ok {
+			sets = append(sets, lookup.SetName)
+		}
+	}
+	return sets
 }
 
 func (r *router) deleteNftRule(rule *nftables.Rule, ruleKey string) error {
@@ -586,7 +599,8 @@ func (r *router) AddNatRule(pair firewall.RouterPair) error {
 	}
 
 	if err := r.conn.Flush(); err != nil {
-		return fmt.Errorf("nftables: insert rules for %s: %v", pair.Destination, err)
+		// TODO: rollback ipset counter
+		return fmt.Errorf("insert rules for %s: %v", pair.Destination, err)
 	}
 
 	return nil
@@ -594,19 +608,22 @@ func (r *router) AddNatRule(pair firewall.RouterPair) error {
 
 // addNatRule inserts a nftables rule to the conn client flush queue
 func (r *router) addNatRule(pair firewall.RouterPair) error {
-	sourceExp := generateCIDRMatcherExpressions(true, pair.Source)
-	destExp := generateCIDRMatcherExpressions(false, pair.Destination)
+	sourceExp, err := r.applyNetwork(pair.Source, nil, true)
+	if err != nil {
+		return fmt.Errorf("apply source: %w", err)
+	}
+
+	destExp, err := r.applyNetwork(pair.Destination, nil, false)
+	if err != nil {
+		return fmt.Errorf("apply destination: %w", err)
+	}
 
 	op := expr.CmpOpEq
 	if pair.Inverse {
 		op = expr.CmpOpNeq
 	}
 
-	// We only care about NEW connections to mark them and later identify them in the postrouting chain for masquerading.
-	// Masquerading will take care of the conntrack state, which means we won't need to mark established connections.
-	exprs := getCtNewExprs()
-	exprs = append(exprs,
-		// interface matching
+	exprs := []expr.Any{
 		&expr.Meta{
 			Key:      expr.MetaKeyIIFNAME,
 			Register: 1,
@@ -616,7 +633,10 @@ func (r *router) addNatRule(pair firewall.RouterPair) error {
 			Register: 1,
 			Data:     ifname(r.wgIface.Name()),
 		},
-	)
+	}
+	// We only care about NEW connections to mark them and later identify them in the postrouting chain for masquerading.
+	// Masquerading will take care of the conntrack state, which means we won't need to mark established connections.
+	exprs = append(exprs, getCtNewExprs()...)
 
 	exprs = append(exprs, sourceExp...)
 	exprs = append(exprs, destExp...)
@@ -729,8 +749,15 @@ func (r *router) addPostroutingRules() error {
 
 // addLegacyRouteRule adds a legacy routing rule for mgmt servers pre route acls
 func (r *router) addLegacyRouteRule(pair firewall.RouterPair) error {
-	sourceExp := generateCIDRMatcherExpressions(true, pair.Source)
-	destExp := generateCIDRMatcherExpressions(false, pair.Destination)
+	sourceExp, err := r.applyNetwork(pair.Source, nil, true)
+	if err != nil {
+		return fmt.Errorf("apply source: %w", err)
+	}
+
+	destExp, err := r.applyNetwork(pair.Destination, nil, false)
+	if err != nil {
+		return fmt.Errorf("apply destination: %w", err)
+	}
 
 	exprs := []expr.Any{
 		&expr.Counter{},
@@ -739,7 +766,8 @@ func (r *router) addLegacyRouteRule(pair firewall.RouterPair) error {
 		},
 	}
 
-	expression := append(sourceExp, append(destExp, exprs...)...) // nolint:gocritic
+	exprs = append(exprs, sourceExp...)
+	exprs = append(exprs, destExp...)
 
 	ruleKey := firewall.GenKey(firewall.ForwardingFormat, pair)
 
@@ -752,7 +780,7 @@ func (r *router) addLegacyRouteRule(pair firewall.RouterPair) error {
 	r.rules[ruleKey] = r.conn.AddRule(&nftables.Rule{
 		Table:    r.workTable,
 		Chain:    r.chains[chainNameRoutingFw],
-		Exprs:    expression,
+		Exprs:    exprs,
 		UserData: []byte(ruleKey),
 	})
 	return nil
@@ -767,11 +795,13 @@ func (r *router) removeLegacyRouteRule(pair firewall.RouterPair) error {
 			return fmt.Errorf("remove legacy forwarding rule %s -> %s: %v", pair.Source, pair.Destination, err)
 		}
 
-		log.Debugf("nftables: removed legacy forwarding rule %s -> %s", pair.Source, pair.Destination)
+		log.Debugf("removed legacy forwarding rule %s -> %s", pair.Source, pair.Destination)
 
 		delete(r.rules, ruleKey)
-	} else {
-		log.Debugf("nftables: legacy forwarding rule %s not found", ruleKey)
+
+		if err := r.decrementSetCounter(rule); err != nil {
+			return fmt.Errorf("decrement set counter: %w", err)
+		}
 	}
 
 	return nil
@@ -982,12 +1012,14 @@ func (r *router) RemoveNatRule(pair firewall.RouterPair) error {
 		return fmt.Errorf(refreshRulesMapError, err)
 	}
 
-	if err := r.removeNatRule(pair); err != nil {
-		return fmt.Errorf("remove prerouting rule: %w", err)
-	}
+	if pair.Masquerade {
+		if err := r.removeNatRule(pair); err != nil {
+			return fmt.Errorf("remove prerouting rule: %w", err)
+		}
 
-	if err := r.removeNatRule(firewall.GetInversePair(pair)); err != nil {
-		return fmt.Errorf("remove inverse prerouting rule: %w", err)
+		if err := r.removeNatRule(firewall.GetInversePair(pair)); err != nil {
+			return fmt.Errorf("remove inverse prerouting rule: %w", err)
+		}
 	}
 
 	if err := r.removeLegacyRouteRule(pair); err != nil {
@@ -995,10 +1027,10 @@ func (r *router) RemoveNatRule(pair firewall.RouterPair) error {
 	}
 
 	if err := r.conn.Flush(); err != nil {
-		return fmt.Errorf("nftables: received error while applying rule removal for %s: %v", pair.Destination, err)
+		// TODO: rollback set counter
+		return fmt.Errorf("remove nat rules rule %s: %v", pair.Destination, err)
 	}
 
-	log.Debugf("nftables: removed nat rules for %s", pair.Destination)
 	return nil
 }
 
@@ -1006,16 +1038,19 @@ func (r *router) removeNatRule(pair firewall.RouterPair) error {
 	ruleKey := firewall.GenKey(firewall.PreroutingFormat, pair)
 
 	if rule, exists := r.rules[ruleKey]; exists {
-		err := r.conn.DelRule(rule)
-		if err != nil {
+		if err := r.conn.DelRule(rule); err != nil {
 			return fmt.Errorf("remove prerouting rule %s -> %s: %v", pair.Source, pair.Destination, err)
 		}
 
-		log.Debugf("nftables: removed prerouting rule %s -> %s", pair.Source, pair.Destination)
+		log.Debugf("removed prerouting rule %s -> %s", pair.Source, pair.Destination)
 
 		delete(r.rules, ruleKey)
+
+		if err := r.decrementSetCounter(rule); err != nil {
+			return fmt.Errorf("decrement set counter: %w", err)
+		}
 	} else {
-		log.Debugf("nftables: prerouting rule %s not found", ruleKey)
+		log.Debugf("prerouting rule %s not found", ruleKey)
 	}
 
 	return nil
@@ -1027,7 +1062,7 @@ func (r *router) refreshRulesMap() error {
 	for _, chain := range r.chains {
 		rules, err := r.conn.GetRules(chain.Table, chain)
 		if err != nil {
-			return fmt.Errorf("nftables: unable to list rules: %v", err)
+			return fmt.Errorf(" unable to list rules: %v", err)
 		}
 		for _, rule := range rules {
 			if len(rule.UserData) > 0 {
@@ -1301,13 +1336,54 @@ func (r *router) DeleteDNATRule(rule firewall.Rule) error {
 	return nberrors.FormatErrorOrNil(merr)
 }
 
-// generateCIDRMatcherExpressions generates nftables expressions that matches a CIDR
-func generateCIDRMatcherExpressions(source bool, prefix netip.Prefix) []expr.Any {
-	var offset uint32
-	if source {
-		offset = 12 // src offset
-	} else {
-		offset = 16 // dst offset
+func (r *router) UpdateSet(set firewall.Set, prefixes []netip.Prefix) error {
+	nfset, err := r.conn.GetSetByName(r.workTable, set.HashedName())
+	if err != nil {
+		return fmt.Errorf("get set %s: %w", set.HashedName(), err)
+	}
+
+	elements := convertPrefixesToSet(prefixes)
+	if err := r.conn.SetAddElements(nfset, elements); err != nil {
+		return fmt.Errorf("add elements to set %s: %w", set.HashedName(), err)
+	}
+
+	if err := r.conn.Flush(); err != nil {
+		return fmt.Errorf(flushError, err)
+	}
+
+	log.Debugf("updated set %s with prefixes %v", set.HashedName(), prefixes)
+
+	return nil
+}
+
+// applyNetwork generates nftables expressions for networks (CIDR) or sets
+func (r *router) applyNetwork(
+	network firewall.Network,
+	setPrefixes []netip.Prefix,
+	isSource bool,
+) ([]expr.Any, error) {
+	if network.IsSet() {
+		exprs, err := r.getIpSet(network.Set, setPrefixes, isSource)
+		if err != nil {
+			return nil, fmt.Errorf("source: %w", err)
+		}
+		return exprs, nil
+	}
+
+	if network.IsPrefix() {
+		return applyPrefix(network.Prefix, isSource), nil
+	}
+
+	return nil, nil
+}
+
+// applyPrefix generates nftables expressions for a CIDR prefix
+func applyPrefix(prefix netip.Prefix, isSource bool) []expr.Any {
+	// dst offset
+	offset := uint32(16)
+	if isSource {
+		// src offset
+		offset = 12
 	}
 
 	ones := prefix.Bits()
@@ -1415,3 +1491,27 @@ func getCtNewExprs() []expr.Any {
 		},
 	}
 }
+
+func getIpSetExprs(ref refcounter.Ref[*nftables.Set], isSource bool) ([]expr.Any, error) {
+
+	// dst offset
+	offset := uint32(16)
+	if isSource {
+		// src offset
+		offset = 12
+	}
+
+	return []expr.Any{
+		&expr.Payload{
+			DestRegister: 1,
+			Base:         expr.PayloadBaseNetworkHeader,
+			Offset:       offset,
+			Len:          4,
+		},
+		&expr.Lookup{
+			SourceRegister: 1,
+			SetName:        ref.Out.Name,
+			SetID:          ref.Out.ID,
+		},
+	}, nil
+}

client/firewall/nftables/router_linux_test.go

@@ -88,8 +88,8 @@ func TestNftablesManager_AddNatRule(t *testing.T) {
 				}
 
 				// Build CIDR matching expressions
-				sourceExp := generateCIDRMatcherExpressions(true, testCase.InputPair.Source)
-				destExp := generateCIDRMatcherExpressions(false, testCase.InputPair.Destination)
+				sourceExp := applyPrefix(testCase.InputPair.Source.Prefix, true)
+				destExp := applyPrefix(testCase.InputPair.Destination.Prefix, false)
 
 				// Combine all expressions in the correct order
 				// nolint:gocritic
@@ -311,7 +311,7 @@ func TestRouter_AddRouteFiltering(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			ruleKey, err := r.AddRouteFiltering(nil, tt.sources, tt.destination, tt.proto, tt.sPort, tt.dPort, tt.action)
+			ruleKey, err := r.AddRouteFiltering(nil, tt.sources, firewall.Network{Prefix: tt.destination}, tt.proto, tt.sPort, tt.dPort, tt.action)
 			require.NoError(t, err, "AddRouteFiltering failed")
 
 			t.Cleanup(func() {
@@ -441,8 +441,8 @@ func TestNftablesCreateIpSet(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			setName := firewall.GenerateSetName(tt.sources)
-			set, err := r.createIpSet(setName, tt.sources)
+			setName := firewall.NewPrefixSet(tt.sources).HashedName()
+			set, err := r.createIpSet(setName, setInput{prefixes: tt.sources})
 			if err != nil {
 				t.Logf("Failed to create IP set: %v", err)
 				printNftSets()

client/firewall/test/cases_linux.go

@@ -15,8 +15,8 @@ var (
 			Name: "Insert Forwarding IPV4 Rule",
 			InputPair: firewall.RouterPair{
 				ID:          "zxa",
-				Source:      netip.MustParsePrefix("100.100.100.1/32"),
-				Destination: netip.MustParsePrefix("100.100.200.0/24"),
+				Source:      firewall.Network{Prefix: netip.MustParsePrefix("100.100.100.1/32")},
+				Destination: firewall.Network{Prefix: netip.MustParsePrefix("100.100.200.0/24")},
 				Masquerade:  false,
 			},
 		},
@@ -24,8 +24,8 @@ var (
 			Name: "Insert Forwarding And Nat IPV4 Rules",
 			InputPair: firewall.RouterPair{
 				ID:          "zxa",
-				Source:      netip.MustParsePrefix("100.100.100.1/32"),
-				Destination: netip.MustParsePrefix("100.100.200.0/24"),
+				Source:      firewall.Network{Prefix: netip.MustParsePrefix("100.100.100.1/32")},
+				Destination: firewall.Network{Prefix: netip.MustParsePrefix("100.100.200.0/24")},
 				Masquerade:  true,
 			},
 		},
@@ -40,8 +40,8 @@ var (
 			Name: "Remove Forwarding And Nat IPV4 Rules",
 			InputPair: firewall.RouterPair{
 				ID:          "zxa",
-				Source:      netip.MustParsePrefix("100.100.100.1/32"),
-				Destination: netip.MustParsePrefix("100.100.200.0/24"),
+				Source:      firewall.Network{Prefix: netip.MustParsePrefix("100.100.100.1/32")},
+				Destination: firewall.Network{Prefix: netip.MustParsePrefix("100.100.200.0/24")},
 				Masquerade:  true,
 			},
 		},

client/firewall/uspfilter/allow_netbird.go

@@ -12,7 +12,7 @@ import (
 	"github.com/netbirdio/netbird/client/internal/statemanager"
 )
 
-// Reset firewall to the default state
+// Close cleans up the firewall manager by removing all rules and closing trackers
 func (m *Manager) Close(stateManager *statemanager.Manager) error {
 	m.mutex.Lock()
 	defer m.mutex.Unlock()

client/firewall/uspfilter/allow_netbird_windows.go

@@ -10,7 +10,6 @@ import (
 
 	log "github.com/sirupsen/logrus"
 
-	"github.com/netbirdio/netbird/client/firewall/uspfilter/conntrack"
 	"github.com/netbirdio/netbird/client/internal/statemanager"
 )
 
@@ -22,7 +21,7 @@ const (
 	firewallRuleName        = "Netbird"
 )
 
-// Reset firewall to the default state
+// Close cleans up the firewall manager by removing all rules and closing trackers
 func (m *Manager) Close(*statemanager.Manager) error {
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
@@ -32,17 +31,14 @@ func (m *Manager) Close(*statemanager.Manager) error {
 
 	if m.udpTracker != nil {
 		m.udpTracker.Close()
-		m.udpTracker = conntrack.NewUDPTracker(conntrack.DefaultUDPTimeout, m.logger, m.flowLogger)
 	}
 
 	if m.icmpTracker != nil {
 		m.icmpTracker.Close()
-		m.icmpTracker = conntrack.NewICMPTracker(conntrack.DefaultICMPTimeout, m.logger, m.flowLogger)
 	}
 
 	if m.tcpTracker != nil {
 		m.tcpTracker.Close()
-		m.tcpTracker = conntrack.NewTCPTracker(conntrack.DefaultTCPTimeout, m.logger, m.flowLogger)
 	}
 
 	if fwder := m.forwarder.Load(); fwder != nil {

client/firewall/uspfilter/rule.go

@@ -29,14 +29,15 @@ func (r *PeerRule) ID() string {
 }
 
 type RouteRule struct {
-	id          string
-	mgmtId      []byte
-	sources     []netip.Prefix
-	destination netip.Prefix
-	proto       firewall.Protocol
-	srcPort     *firewall.Port
-	dstPort     *firewall.Port
-	action      firewall.Action
+	id           string
+	mgmtId       []byte
+	sources      []netip.Prefix
+	dstSet       firewall.Set
+	destinations []netip.Prefix
+	proto        firewall.Protocol
+	srcPort      *firewall.Port
+	dstPort      *firewall.Port
+	action       firewall.Action
 }
 
 // ID returns the rule id

client/firewall/uspfilter/tracer_test.go

@@ -199,7 +199,7 @@ func TestTracePacket(t *testing.T) {
 
 				src := netip.PrefixFrom(netip.AddrFrom4([4]byte{1, 1, 1, 1}), 32)
 				dst := netip.PrefixFrom(netip.AddrFrom4([4]byte{172, 17, 0, 2}), 32)
-				_, err := m.AddRouteFiltering(nil, []netip.Prefix{src}, dst, fw.ProtocolTCP, nil, &fw.Port{Values: []uint16{80}}, fw.ActionAccept)
+				_, err := m.AddRouteFiltering(nil, []netip.Prefix{src}, fw.Network{Prefix: dst}, fw.ProtocolTCP, nil, &fw.Port{Values: []uint16{80}}, fw.ActionAccept)
 				require.NoError(t, err)
 			},
 			packetBuilder: func() *PacketBuilder {
@@ -223,7 +223,7 @@ func TestTracePacket(t *testing.T) {
 
 				src := netip.PrefixFrom(netip.AddrFrom4([4]byte{1, 1, 1, 1}), 32)
 				dst := netip.PrefixFrom(netip.AddrFrom4([4]byte{172, 17, 0, 2}), 32)
-				_, err := m.AddRouteFiltering(nil, []netip.Prefix{src}, dst, fw.ProtocolTCP, nil, &fw.Port{Values: []uint16{80}}, fw.ActionDrop)
+				_, err := m.AddRouteFiltering(nil, []netip.Prefix{src}, fw.Network{Prefix: dst}, fw.ProtocolTCP, nil, &fw.Port{Values: []uint16{80}}, fw.ActionDrop)
 				require.NoError(t, err)
 			},
 			packetBuilder: func() *PacketBuilder {

client/firewall/uspfilter/uspfilter.go

@@ -49,10 +49,10 @@ var errNatNotSupported = errors.New("nat not supported with userspace firewall")
 // RuleSet is a set of rules grouped by a string key
 type RuleSet map[string]PeerRule
 
-type RouteRules []RouteRule
+type RouteRules []*RouteRule
 
 func (r RouteRules) Sort() {
-	slices.SortStableFunc(r, func(a, b RouteRule) int {
+	slices.SortStableFunc(r, func(a, b *RouteRule) int {
 		// Deny rules come first
 		if a.action == firewall.ActionDrop && b.action != firewall.ActionDrop {
 			return -1
@@ -99,6 +99,8 @@ type Manager struct {
 	forwarder   atomic.Pointer[forwarder.Forwarder]
 	logger      *nblog.Logger
 	flowLogger  nftypes.FlowLogger
+
+	blockRule firewall.Rule
 }
 
 // decoder for packages
@@ -201,41 +203,35 @@ func create(iface common.IFaceMapper, nativeFirewall firewall.Manager, disableSe
 		}
 	}
 
-	if err := m.blockInvalidRouted(iface); err != nil {
-		log.Errorf("failed to block invalid routed traffic: %v", err)
-	}
-
 	if err := iface.SetFilter(m); err != nil {
 		return nil, fmt.Errorf("set filter: %w", err)
 	}
 	return m, nil
 }
 
-func (m *Manager) blockInvalidRouted(iface common.IFaceMapper) error {
-	if m.forwarder.Load() == nil {
-		return nil
-	}
+func (m *Manager) blockInvalidRouted(iface common.IFaceMapper) (firewall.Rule, error) {
 	wgPrefix, err := netip.ParsePrefix(iface.Address().Network.String())
 	if err != nil {
-		return fmt.Errorf("parse wireguard network: %w", err)
+		return nil, fmt.Errorf("parse wireguard network: %w", err)
 	}
 	log.Debugf("blocking invalid routed traffic for %s", wgPrefix)
 
-	if _, err := m.AddRouteFiltering(
+	rule, err := m.addRouteFiltering(
 		nil,
 		[]netip.Prefix{netip.PrefixFrom(netip.IPv4Unspecified(), 0)},
-		wgPrefix,
+		firewall.Network{Prefix: wgPrefix},
 		firewall.ProtocolALL,
 		nil,
 		nil,
 		firewall.ActionDrop,
-	); err != nil {
-		return fmt.Errorf("block wg nte : %w", err)
+	)
+	if err != nil {
+		return nil, fmt.Errorf("block wg nte : %w", err)
 	}
 
 	// TODO: Block networks that we're a client of
 
-	return nil
+	return rule, nil
 }
 
 func (m *Manager) determineRouting() error {
@@ -413,10 +409,23 @@ func (m *Manager) AddPeerFiltering(
 func (m *Manager) AddRouteFiltering(
 	id []byte,
 	sources []netip.Prefix,
-	destination netip.Prefix,
+	destination firewall.Network,
 	proto firewall.Protocol,
-	sPort *firewall.Port,
-	dPort *firewall.Port,
+	sPort, dPort *firewall.Port,
+	action firewall.Action,
+) (firewall.Rule, error) {
+	m.mutex.Lock()
+	defer m.mutex.Unlock()
+
+	return m.addRouteFiltering(id, sources, destination, proto, sPort, dPort, action)
+}
+
+func (m *Manager) addRouteFiltering(
+	id []byte,
+	sources []netip.Prefix,
+	destination firewall.Network,
+	proto firewall.Protocol,
+	sPort, dPort *firewall.Port,
 	action firewall.Action,
 ) (firewall.Rule, error) {
 	if m.nativeRouter.Load() && m.nativeFirewall != nil {
@@ -426,34 +435,39 @@ func (m *Manager) AddRouteFiltering(
 	ruleID := uuid.New().String()
 	rule := RouteRule{
 		// TODO: consolidate these IDs
-		id:          ruleID,
-		mgmtId:      id,
-		sources:     sources,
-		destination: destination,
-		proto:       proto,
-		srcPort:     sPort,
-		dstPort:     dPort,
-		action:      action,
+		id:      ruleID,
+		mgmtId:  id,
+		sources: sources,
+		dstSet:  destination.Set,
+		proto:   proto,
+		srcPort: sPort,
+		dstPort: dPort,
+		action:  action,
+	}
+	if destination.IsPrefix() {
+		rule.destinations = []netip.Prefix{destination.Prefix}
 	}
 
-	m.mutex.Lock()
-	m.routeRules = append(m.routeRules, rule)
+	m.routeRules = append(m.routeRules, &rule)
 	m.routeRules.Sort()
-	m.mutex.Unlock()
 
 	return &rule, nil
 }
 
 func (m *Manager) DeleteRouteRule(rule firewall.Rule) error {
+	m.mutex.Lock()
+	defer m.mutex.Unlock()
+
+	return m.deleteRouteRule(rule)
+}
+
+func (m *Manager) deleteRouteRule(rule firewall.Rule) error {
 	if m.nativeRouter.Load() && m.nativeFirewall != nil {
 		return m.nativeFirewall.DeleteRouteRule(rule)
 	}
 
-	m.mutex.Lock()
-	defer m.mutex.Unlock()
-
 	ruleID := rule.ID()
-	idx := slices.IndexFunc(m.routeRules, func(r RouteRule) bool {
+	idx := slices.IndexFunc(m.routeRules, func(r *RouteRule) bool {
 		return r.id == ruleID
 	})
 	if idx < 0 {
@@ -509,6 +523,52 @@ func (m *Manager) DeleteDNATRule(rule firewall.Rule) error {
 	return m.nativeFirewall.DeleteDNATRule(rule)
 }
 
+// UpdateSet updates the rule destinations associated with the given set
+// by merging the existing prefixes with the new ones, then deduplicating.
+func (m *Manager) UpdateSet(set firewall.Set, prefixes []netip.Prefix) error {
+	if m.nativeRouter.Load() && m.nativeFirewall != nil {
+		return m.nativeFirewall.UpdateSet(set, prefixes)
+	}
+
+	m.mutex.Lock()
+	defer m.mutex.Unlock()
+
+	var matches []*RouteRule
+	for _, rule := range m.routeRules {
+		if rule.dstSet == set {
+			matches = append(matches, rule)
+		}
+	}
+
+	if len(matches) == 0 {
+		return fmt.Errorf("no route rule found for set: %s", set)
+	}
+
+	destinations := matches[0].destinations
+	for _, prefix := range prefixes {
+		if prefix.Addr().Is4() {
+			destinations = append(destinations, prefix)
+		}
+	}
+
+	slices.SortFunc(destinations, func(a, b netip.Prefix) int {
+		cmp := a.Addr().Compare(b.Addr())
+		if cmp != 0 {
+			return cmp
+		}
+		return a.Bits() - b.Bits()
+	})
+
+	destinations = slices.Compact(destinations)
+
+	for _, rule := range matches {
+		rule.destinations = destinations
+	}
+	log.Debugf("updated set %s to prefixes %v", set.HashedName(), destinations)
+
+	return nil
+}
+
 // DropOutgoing filter outgoing packets
 func (m *Manager) DropOutgoing(packetData []byte, size int) bool {
 	return m.processOutgoingHooks(packetData, size)
@@ -988,8 +1048,15 @@ func (m *Manager) routeACLsPass(srcIP, dstIP netip.Addr, proto firewall.Protocol
 	return nil, false
 }
 
-func (m *Manager) ruleMatches(rule RouteRule, srcAddr, dstAddr netip.Addr, proto firewall.Protocol, srcPort, dstPort uint16) bool {
-	if !rule.destination.Contains(dstAddr) {
+func (m *Manager) ruleMatches(rule *RouteRule, srcAddr, dstAddr netip.Addr, proto firewall.Protocol, srcPort, dstPort uint16) bool {
+	destMatched := false
+	for _, dst := range rule.destinations {
+		if dst.Contains(dstAddr) {
+			destMatched = true
+			break
+		}
+	}
+	if !destMatched {
 		return false
 	}
 
@@ -1091,7 +1158,22 @@ func (m *Manager) EnableRouting() error {
 	m.mutex.Lock()
 	defer m.mutex.Unlock()
 
-	return m.determineRouting()
+	if err := m.determineRouting(); err != nil {
+		return fmt.Errorf("determine routing: %w", err)
+	}
+
+	if m.forwarder.Load() == nil {
+		return nil
+	}
+
+	rule, err := m.blockInvalidRouted(m.wgIface)
+	if err != nil {
+		return fmt.Errorf("block invalid routed: %w", err)
+	}
+
+	m.blockRule = rule
+
+	return nil
 }
 
 func (m *Manager) DisableRouting() error {
@@ -1116,5 +1198,12 @@ func (m *Manager) DisableRouting() error {
 
 	log.Debug("forwarder stopped")
 
+	if m.blockRule != nil {
+		if err := m.deleteRouteRule(m.blockRule); err != nil {
+			return fmt.Errorf("delete block rule: %w", err)
+		}
+		m.blockRule = nil
+	}
+
 	return nil
 }

client/firewall/uspfilter/uspfilter_filter_test.go

@@ -15,6 +15,7 @@ import (
 	"github.com/netbirdio/netbird/client/iface/device"
 	"github.com/netbirdio/netbird/client/iface/mocks"
 	"github.com/netbirdio/netbird/client/iface/wgaddr"
+	"github.com/netbirdio/netbird/management/domain"
 )
 
 func TestPeerACLFiltering(t *testing.T) {
@@ -600,8 +601,8 @@ func setupRoutedManager(tb testing.TB, network string) *Manager {
 	}
 
 	manager, err := Create(ifaceMock, false, flowLogger)
-	require.NoError(tb, manager.EnableRouting())
 	require.NoError(tb, err)
+	require.NoError(tb, manager.EnableRouting())
 	require.NotNil(tb, manager)
 	require.True(tb, manager.routingEnabled.Load())
 	require.False(tb, manager.nativeRouter.Load())
@@ -618,7 +619,7 @@ func TestRouteACLFiltering(t *testing.T) {
 
 	type rule struct {
 		sources []netip.Prefix
-		dest    netip.Prefix
+		dest    fw.Network
 		proto   fw.Protocol
 		srcPort *fw.Port
 		dstPort *fw.Port
@@ -644,7 +645,7 @@ func TestRouteACLFiltering(t *testing.T) {
 			dstPort: 443,
 			rule: rule{
 				sources: []netip.Prefix{netip.MustParsePrefix("100.10.0.0/16")},
-				dest:    netip.MustParsePrefix("192.168.1.0/24"),
+				dest:    fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
 				proto:   fw.ProtocolTCP,
 				dstPort: &fw.Port{Values: []uint16{443}},
 				action:  fw.ActionAccept,
@@ -660,7 +661,7 @@ func TestRouteACLFiltering(t *testing.T) {
 			dstPort: 443,
 			rule: rule{
 				sources: []netip.Prefix{netip.MustParsePrefix("0.0.0.0/0")},
-				dest:    netip.MustParsePrefix("192.168.1.0/24"),
+				dest:    fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
 				proto:   fw.ProtocolTCP,
 				dstPort: &fw.Port{Values: []uint16{443}},
 				action:  fw.ActionAccept,
@@ -676,7 +677,7 @@ func TestRouteACLFiltering(t *testing.T) {
 			dstPort: 443,
 			rule: rule{
 				sources: []netip.Prefix{netip.MustParsePrefix("0.0.0.0/0")},
-				dest:    netip.MustParsePrefix("0.0.0.0/0"),
+				dest:    fw.Network{Prefix: netip.MustParsePrefix("0.0.0.0/0")},
 				proto:   fw.ProtocolTCP,
 				dstPort: &fw.Port{Values: []uint16{443}},
 				action:  fw.ActionAccept,
@@ -692,7 +693,7 @@ func TestRouteACLFiltering(t *testing.T) {
 			dstPort: 53,
 			rule: rule{
 				sources: []netip.Prefix{netip.MustParsePrefix("100.10.0.0/16")},
-				dest:    netip.MustParsePrefix("192.168.1.0/24"),
+				dest:    fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
 				proto:   fw.ProtocolUDP,
 				dstPort: &fw.Port{Values: []uint16{53}},
 				action:  fw.ActionAccept,
@@ -706,7 +707,7 @@ func TestRouteACLFiltering(t *testing.T) {
 			proto: fw.ProtocolICMP,
 			rule: rule{
 				sources: []netip.Prefix{netip.MustParsePrefix("100.10.0.0/16")},
-				dest:    netip.MustParsePrefix("0.0.0.0/0"),
+				dest:    fw.Network{Prefix: netip.MustParsePrefix("0.0.0.0/0")},
 				proto:   fw.ProtocolICMP,
 				action:  fw.ActionAccept,
 			},
@@ -721,7 +722,7 @@ func TestRouteACLFiltering(t *testing.T) {
 			dstPort: 80,
 			rule: rule{
 				sources: []netip.Prefix{netip.MustParsePrefix("100.10.0.0/16")},
-				dest:    netip.MustParsePrefix("192.168.1.0/24"),
+				dest:    fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
 				proto:   fw.ProtocolALL,
 				dstPort: &fw.Port{Values: []uint16{80}},
 				action:  fw.ActionAccept,
@@ -737,7 +738,7 @@ func TestRouteACLFiltering(t *testing.T) {
 			dstPort: 8080,
 			rule: rule{
 				sources: []netip.Prefix{netip.MustParsePrefix("100.10.0.0/16")},
-				dest:    netip.MustParsePrefix("192.168.1.0/24"),
+				dest:    fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
 				proto:   fw.ProtocolTCP,
 				dstPort: &fw.Port{Values: []uint16{80}},
 				action:  fw.ActionAccept,
@@ -753,7 +754,7 @@ func TestRouteACLFiltering(t *testing.T) {
 			dstPort: 80,
 			rule: rule{
 				sources: []netip.Prefix{netip.MustParsePrefix("100.10.0.0/16")},
-				dest:    netip.MustParsePrefix("192.168.1.0/24"),
+				dest:    fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
 				proto:   fw.ProtocolTCP,
 				dstPort: &fw.Port{Values: []uint16{80}},
 				action:  fw.ActionAccept,
@@ -769,7 +770,7 @@ func TestRouteACLFiltering(t *testing.T) {
 			dstPort: 80,
 			rule: rule{
 				sources: []netip.Prefix{netip.MustParsePrefix("100.10.0.0/16")},
-				dest:    netip.MustParsePrefix("192.168.1.0/24"),
+				dest:    fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
 				proto:   fw.ProtocolTCP,
 				dstPort: &fw.Port{Values: []uint16{80}},
 				action:  fw.ActionAccept,
@@ -785,7 +786,7 @@ func TestRouteACLFiltering(t *testing.T) {
 			dstPort: 80,
 			rule: rule{
 				sources: []netip.Prefix{netip.MustParsePrefix("100.10.0.0/16")},
-				dest:    netip.MustParsePrefix("192.168.1.0/24"),
+				dest:    fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
 				proto:   fw.ProtocolTCP,
 				srcPort: &fw.Port{Values: []uint16{12345}},
 				action:  fw.ActionAccept,
@@ -804,7 +805,7 @@ func TestRouteACLFiltering(t *testing.T) {
 					netip.MustParsePrefix("100.10.0.0/16"),
 					netip.MustParsePrefix("172.16.0.0/16"),
 				},
-				dest:    netip.MustParsePrefix("192.168.1.0/24"),
+				dest:    fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
 				proto:   fw.ProtocolTCP,
 				dstPort: &fw.Port{Values: []uint16{80}},
 				action:  fw.ActionAccept,
@@ -818,7 +819,7 @@ func TestRouteACLFiltering(t *testing.T) {
 			proto: fw.ProtocolICMP,
 			rule: rule{
 				sources: []netip.Prefix{netip.MustParsePrefix("100.10.0.0/16")},
-				dest:    netip.MustParsePrefix("192.168.1.0/24"),
+				dest:    fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
 				proto:   fw.ProtocolALL,
 				action:  fw.ActionAccept,
 			},
@@ -833,7 +834,7 @@ func TestRouteACLFiltering(t *testing.T) {
 			dstPort: 80,
 			rule: rule{
 				sources: []netip.Prefix{netip.MustParsePrefix("100.10.0.0/16")},
-				dest:    netip.MustParsePrefix("192.168.1.0/24"),
+				dest:    fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
 				proto:   fw.ProtocolALL,
 				dstPort: &fw.Port{Values: []uint16{80}},
 				action:  fw.ActionAccept,
@@ -849,7 +850,7 @@ func TestRouteACLFiltering(t *testing.T) {
 			dstPort: 8080,
 			rule: rule{
 				sources: []netip.Prefix{netip.MustParsePrefix("100.10.0.0/16")},
-				dest:    netip.MustParsePrefix("192.168.1.0/24"),
+				dest:    fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
 				proto:   fw.ProtocolTCP,
 				dstPort: &fw.Port{Values: []uint16{80, 8080, 443}},
 				action:  fw.ActionAccept,
@@ -865,7 +866,7 @@ func TestRouteACLFiltering(t *testing.T) {
 			dstPort: 80,
 			rule: rule{
 				sources: []netip.Prefix{netip.MustParsePrefix("100.10.0.0/16")},
-				dest:    netip.MustParsePrefix("192.168.1.0/24"),
+				dest:    fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
 				proto:   fw.ProtocolTCP,
 				srcPort: &fw.Port{Values: []uint16{12345, 12346, 12347}},
 				action:  fw.ActionAccept,
@@ -881,7 +882,7 @@ func TestRouteACLFiltering(t *testing.T) {
 			dstPort: 80,
 			rule: rule{
 				sources: []netip.Prefix{netip.MustParsePrefix("100.10.0.0/16")},
-				dest:    netip.MustParsePrefix("192.168.1.0/24"),
+				dest:    fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
 				proto:   fw.ProtocolALL,
 				srcPort: &fw.Port{Values: []uint16{12345}},
 				dstPort: &fw.Port{Values: []uint16{80}},
@@ -898,7 +899,7 @@ func TestRouteACLFiltering(t *testing.T) {
 			dstPort: 8080,
 			rule: rule{
 				sources: []netip.Prefix{netip.MustParsePrefix("100.10.0.0/16")},
-				dest:    netip.MustParsePrefix("192.168.1.0/24"),
+				dest:    fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
 				proto:   fw.ProtocolTCP,
 				dstPort: &fw.Port{
 					IsRange: true,
@@ -917,7 +918,7 @@ func TestRouteACLFiltering(t *testing.T) {
 			dstPort: 7999,
 			rule: rule{
 				sources: []netip.Prefix{netip.MustParsePrefix("100.10.0.0/16")},
-				dest:    netip.MustParsePrefix("192.168.1.0/24"),
+				dest:    fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
 				proto:   fw.ProtocolTCP,
 				dstPort: &fw.Port{
 					IsRange: true,
@@ -936,7 +937,7 @@ func TestRouteACLFiltering(t *testing.T) {
 			dstPort: 80,
 			rule: rule{
 				sources: []netip.Prefix{netip.MustParsePrefix("100.10.0.0/16")},
-				dest:    netip.MustParsePrefix("192.168.1.0/24"),
+				dest:    fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
 				proto:   fw.ProtocolTCP,
 				srcPort: &fw.Port{
 					IsRange: true,
@@ -955,7 +956,7 @@ func TestRouteACLFiltering(t *testing.T) {
 			dstPort: 443,
 			rule: rule{
 				sources: []netip.Prefix{netip.MustParsePrefix("100.10.0.0/16")},
-				dest:    netip.MustParsePrefix("192.168.1.0/24"),
+				dest:    fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
 				proto:   fw.ProtocolTCP,
 				srcPort: &fw.Port{
 					IsRange: true,
@@ -977,7 +978,7 @@ func TestRouteACLFiltering(t *testing.T) {
 			dstPort: 8100,
 			rule: rule{
 				sources: []netip.Prefix{netip.MustParsePrefix("100.10.0.0/16")},
-				dest:    netip.MustParsePrefix("192.168.1.0/24"),
+				dest:    fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
 				proto:   fw.ProtocolTCP,
 				dstPort: &fw.Port{
 					IsRange: true,
@@ -996,7 +997,7 @@ func TestRouteACLFiltering(t *testing.T) {
 			dstPort: 5060,
 			rule: rule{
 				sources: []netip.Prefix{netip.MustParsePrefix("100.10.0.0/16")},
-				dest:    netip.MustParsePrefix("192.168.1.0/24"),
+				dest:    fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
 				proto:   fw.ProtocolUDP,
 				dstPort: &fw.Port{
 					IsRange: true,
@@ -1015,7 +1016,7 @@ func TestRouteACLFiltering(t *testing.T) {
 			dstPort: 8080,
 			rule: rule{
 				sources: []netip.Prefix{netip.MustParsePrefix("100.10.0.0/16")},
-				dest:    netip.MustParsePrefix("192.168.1.0/24"),
+				dest:    fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
 				proto:   fw.ProtocolALL,
 				dstPort: &fw.Port{
 					IsRange: true,
@@ -1034,7 +1035,7 @@ func TestRouteACLFiltering(t *testing.T) {
 			dstPort: 443,
 			rule: rule{
 				sources: []netip.Prefix{netip.MustParsePrefix("100.10.0.0/16")},
-				dest:    netip.MustParsePrefix("192.168.1.0/24"),
+				dest:    fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
 				proto:   fw.ProtocolTCP,
 				dstPort: &fw.Port{Values: []uint16{443}},
 				action:  fw.ActionDrop,
@@ -1050,7 +1051,7 @@ func TestRouteACLFiltering(t *testing.T) {
 			dstPort: 80,
 			rule: rule{
 				sources: []netip.Prefix{netip.MustParsePrefix("100.10.0.0/16")},
-				dest:    netip.MustParsePrefix("192.168.1.0/24"),
+				dest:    fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
 				proto:   fw.ProtocolALL,
 				action:  fw.ActionDrop,
 			},
@@ -1068,13 +1069,32 @@ func TestRouteACLFiltering(t *testing.T) {
 					netip.MustParsePrefix("100.10.0.0/16"),
 					netip.MustParsePrefix("172.16.0.0/16"),
 				},
-				dest:    netip.MustParsePrefix("192.168.1.0/24"),
+				dest:    fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
 				proto:   fw.ProtocolTCP,
 				dstPort: &fw.Port{Values: []uint16{80}},
 				action:  fw.ActionDrop,
 			},
 			shouldPass: false,
 		},
+
+		{
+			name:    "Drop empty destination set",
+			srcIP:   "172.16.0.1",
+			dstIP:   "192.168.1.100",
+			proto:   fw.ProtocolTCP,
+			srcPort: 12345,
+			dstPort: 80,
+			rule: rule{
+				sources: []netip.Prefix{
+					netip.MustParsePrefix("172.16.0.0/16"),
+				},
+				dest:    fw.Network{Set: fw.Set{}},
+				proto:   fw.ProtocolTCP,
+				dstPort: &fw.Port{Values: []uint16{80}},
+				action:  fw.ActionAccept,
+			},
+			shouldPass: false,
+		},
 		{
 			name:    "Accept TCP traffic outside drop port range",
 			srcIP:   "100.10.0.1",
@@ -1084,7 +1104,7 @@ func TestRouteACLFiltering(t *testing.T) {
 			dstPort: 7999,
 			rule: rule{
 				sources: []netip.Prefix{netip.MustParsePrefix("100.10.0.0/16")},
-				dest:    netip.MustParsePrefix("192.168.1.0/24"),
+				dest:    fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
 				proto:   fw.ProtocolTCP,
 				dstPort: &fw.Port{IsRange: true, Values: []uint16{8000, 8100}},
 				action:  fw.ActionDrop,
@@ -1100,7 +1120,7 @@ func TestRouteACLFiltering(t *testing.T) {
 			dstPort: 443,
 			rule: rule{
 				sources: []netip.Prefix{netip.MustParsePrefix("100.10.0.0/16")},
-				dest:    netip.MustParsePrefix("192.168.1.0/24"),
+				dest:    fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
 				proto:   fw.ProtocolTCP,
 				action:  fw.ActionAccept,
 			},
@@ -1115,7 +1135,7 @@ func TestRouteACLFiltering(t *testing.T) {
 			dstPort: 53,
 			rule: rule{
 				sources: []netip.Prefix{netip.MustParsePrefix("100.10.0.0/16")},
-				dest:    netip.MustParsePrefix("192.168.1.0/24"),
+				dest:    fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
 				proto:   fw.ProtocolUDP,
 				action:  fw.ActionAccept,
 			},
@@ -1130,7 +1150,7 @@ func TestRouteACLFiltering(t *testing.T) {
 			dstPort: 80,
 			rule: rule{
 				sources: []netip.Prefix{netip.MustParsePrefix("100.10.0.0/16")},
-				dest:    netip.MustParsePrefix("192.168.1.0/24"),
+				dest:    fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
 				proto:   fw.ProtocolUDP,
 				dstPort: &fw.Port{Values: []uint16{80}},
 				action:  fw.ActionAccept,
@@ -1146,7 +1166,7 @@ func TestRouteACLFiltering(t *testing.T) {
 			dstPort: 80,
 			rule: rule{
 				sources: []netip.Prefix{netip.MustParsePrefix("100.10.0.0/16")},
-				dest:    netip.MustParsePrefix("192.168.1.0/24"),
+				dest:    fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
 				proto:   fw.ProtocolTCP,
 				dstPort: &fw.Port{Values: []uint16{80}},
 				action:  fw.ActionAccept,
@@ -1160,7 +1180,7 @@ func TestRouteACLFiltering(t *testing.T) {
 			proto: fw.ProtocolICMP,
 			rule: rule{
 				sources: []netip.Prefix{netip.MustParsePrefix("100.10.0.0/16")},
-				dest:    netip.MustParsePrefix("192.168.1.0/24"),
+				dest:    fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
 				proto:   fw.ProtocolTCP,
 				action:  fw.ActionAccept,
 			},
@@ -1173,7 +1193,7 @@ func TestRouteACLFiltering(t *testing.T) {
 			proto: fw.ProtocolICMP,
 			rule: rule{
 				sources: []netip.Prefix{netip.MustParsePrefix("100.10.0.0/16")},
-				dest:    netip.MustParsePrefix("192.168.1.0/24"),
+				dest:    fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
 				proto:   fw.ProtocolUDP,
 				action:  fw.ActionAccept,
 			},
@@ -1188,7 +1208,7 @@ func TestRouteACLFiltering(t *testing.T) {
 				rule, err := manager.AddRouteFiltering(
 					nil,
 					[]netip.Prefix{netip.MustParsePrefix("0.0.0.0/0")},
-					netip.MustParsePrefix("0.0.0.0/0"),
+					fw.Network{Prefix: netip.MustParsePrefix("0.0.0.0/0")},
 					fw.ProtocolALL,
 					nil,
 					nil,
@@ -1235,7 +1255,7 @@ func TestRouteACLOrder(t *testing.T) {
 		name  string
 		rules []struct {
 			sources []netip.Prefix
-			dest    netip.Prefix
+			dest    fw.Network
 			proto   fw.Protocol
 			srcPort *fw.Port
 			dstPort *fw.Port
@@ -1256,7 +1276,7 @@ func TestRouteACLOrder(t *testing.T) {
 			name: "Drop rules take precedence over accept",
 			rules: []struct {
 				sources []netip.Prefix
-				dest    netip.Prefix
+				dest    fw.Network
 				proto   fw.Protocol
 				srcPort *fw.Port
 				dstPort *fw.Port
@@ -1265,7 +1285,7 @@ func TestRouteACLOrder(t *testing.T) {
 				{
 					// Accept rule added first
 					sources: []netip.Prefix{netip.MustParsePrefix("100.10.0.0/16")},
-					dest:    netip.MustParsePrefix("192.168.1.0/24"),
+					dest:    fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
 					proto:   fw.ProtocolTCP,
 					dstPort: &fw.Port{Values: []uint16{80, 443}},
 					action:  fw.ActionAccept,
@@ -1273,7 +1293,7 @@ func TestRouteACLOrder(t *testing.T) {
 				{
 					// Drop rule added second but should be evaluated first
 					sources: []netip.Prefix{netip.MustParsePrefix("100.10.0.0/16")},
-					dest:    netip.MustParsePrefix("192.168.1.0/24"),
+					dest:    fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
 					proto:   fw.ProtocolTCP,
 					dstPort: &fw.Port{Values: []uint16{443}},
 					action:  fw.ActionDrop,
@@ -1311,7 +1331,7 @@ func TestRouteACLOrder(t *testing.T) {
 			name: "Multiple drop rules take precedence",
 			rules: []struct {
 				sources []netip.Prefix
-				dest    netip.Prefix
+				dest    fw.Network
 				proto   fw.Protocol
 				srcPort *fw.Port
 				dstPort *fw.Port
@@ -1320,14 +1340,14 @@ func TestRouteACLOrder(t *testing.T) {
 				{
 					// Accept all
 					sources: []netip.Prefix{netip.MustParsePrefix("0.0.0.0/0")},
-					dest:    netip.MustParsePrefix("0.0.0.0/0"),
+					dest:    fw.Network{Prefix: netip.MustParsePrefix("0.0.0.0/0")},
 					proto:   fw.ProtocolALL,
 					action:  fw.ActionAccept,
 				},
 				{
 					// Drop specific port
 					sources: []netip.Prefix{netip.MustParsePrefix("100.10.0.0/16")},
-					dest:    netip.MustParsePrefix("192.168.1.0/24"),
+					dest:    fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
 					proto:   fw.ProtocolTCP,
 					dstPort: &fw.Port{Values: []uint16{443}},
 					action:  fw.ActionDrop,
@@ -1335,7 +1355,7 @@ func TestRouteACLOrder(t *testing.T) {
 				{
 					// Drop different port
 					sources: []netip.Prefix{netip.MustParsePrefix("100.10.0.0/16")},
-					dest:    netip.MustParsePrefix("192.168.1.0/24"),
+					dest:    fw.Network{Prefix: netip.MustParsePrefix("192.168.1.0/24")},
 					proto:   fw.ProtocolTCP,
 					dstPort: &fw.Port{Values: []uint16{80}},
 					action:  fw.ActionDrop,
@@ -1414,3 +1434,53 @@ func TestRouteACLOrder(t *testing.T) {
 		})
 	}
 }
+
+func TestRouteACLSet(t *testing.T) {
+	ifaceMock := &IFaceMock{
+		SetFilterFunc: func(device.PacketFilter) error { return nil },
+		AddressFunc: func() wgaddr.Address {
+			return wgaddr.Address{
+				IP: net.ParseIP("100.10.0.100"),
+				Network: &net.IPNet{
+					IP:   net.ParseIP("100.10.0.0"),
+					Mask: net.CIDRMask(16, 32),
+				},
+			}
+		},
+	}
+
+	manager, err := Create(ifaceMock, false, flowLogger)
+	require.NoError(t, err)
+	t.Cleanup(func() {
+		require.NoError(t, manager.Close(nil))
+	})
+
+	set := fw.NewDomainSet(domain.List{"example.org"})
+
+	// Add rule that uses the set (initially empty)
+	rule, err := manager.AddRouteFiltering(
+		nil,
+		[]netip.Prefix{netip.MustParsePrefix("0.0.0.0/0")},
+		fw.Network{Set: set},
+		fw.ProtocolTCP,
+		nil,
+		nil,
+		fw.ActionAccept,
+	)
+	require.NoError(t, err)
+	require.NotNil(t, rule)
+
+	srcIP := netip.MustParseAddr("100.10.0.1")
+	dstIP := netip.MustParseAddr("192.168.1.100")
+
+	// Check that traffic is dropped (empty set shouldn't match anything)
+	_, isAllowed := manager.routeACLsPass(srcIP, dstIP, fw.ProtocolTCP, 12345, 80)
+	require.False(t, isAllowed, "Empty set should not allow any traffic")
+
+	err = manager.UpdateSet(set, []netip.Prefix{netip.MustParsePrefix("192.168.1.0/24")})
+	require.NoError(t, err)
+
+	// Now the packet should be allowed
+	_, isAllowed = manager.routeACLsPass(srcIP, dstIP, fw.ProtocolTCP, 12345, 80)
+	require.True(t, isAllowed, "After set update, traffic to the added network should be allowed")
+}

client/firewall/uspfilter/uspfilter_test.go

@@ -20,6 +20,7 @@ import (
 	"github.com/netbirdio/netbird/client/iface/device"
 	"github.com/netbirdio/netbird/client/iface/wgaddr"
 	"github.com/netbirdio/netbird/client/internal/netflow"
+	"github.com/netbirdio/netbird/management/domain"
 )
 
 var logger = log.NewFromLogrus(logrus.StandardLogger())
@@ -711,3 +712,203 @@ func TestStatefulFirewall_UDPTracking(t *testing.T) {
 		})
 	}
 }
+
+func TestUpdateSetMerge(t *testing.T) {
+	ifaceMock := &IFaceMock{
+		SetFilterFunc: func(device.PacketFilter) error { return nil },
+	}
+
+	manager, err := Create(ifaceMock, false, flowLogger)
+	require.NoError(t, err)
+	t.Cleanup(func() {
+		require.NoError(t, manager.Close(nil))
+	})
+
+	set := fw.NewDomainSet(domain.List{"example.org"})
+
+	initialPrefixes := []netip.Prefix{
+		netip.MustParsePrefix("10.0.0.0/24"),
+		netip.MustParsePrefix("192.168.1.0/24"),
+	}
+
+	rule, err := manager.AddRouteFiltering(
+		nil,
+		[]netip.Prefix{netip.MustParsePrefix("0.0.0.0/0")},
+		fw.Network{Set: set},
+		fw.ProtocolTCP,
+		nil,
+		nil,
+		fw.ActionAccept,
+	)
+	require.NoError(t, err)
+	require.NotNil(t, rule)
+
+	// Update the set with initial prefixes
+	err = manager.UpdateSet(set, initialPrefixes)
+	require.NoError(t, err)
+
+	// Test initial prefixes work
+	srcIP := netip.MustParseAddr("100.10.0.1")
+	dstIP1 := netip.MustParseAddr("10.0.0.100")
+	dstIP2 := netip.MustParseAddr("192.168.1.100")
+	dstIP3 := netip.MustParseAddr("172.16.0.100")
+
+	_, isAllowed1 := manager.routeACLsPass(srcIP, dstIP1, fw.ProtocolTCP, 12345, 80)
+	_, isAllowed2 := manager.routeACLsPass(srcIP, dstIP2, fw.ProtocolTCP, 12345, 80)
+	_, isAllowed3 := manager.routeACLsPass(srcIP, dstIP3, fw.ProtocolTCP, 12345, 80)
+
+	require.True(t, isAllowed1, "Traffic to 10.0.0.100 should be allowed")
+	require.True(t, isAllowed2, "Traffic to 192.168.1.100 should be allowed")
+	require.False(t, isAllowed3, "Traffic to 172.16.0.100 should be denied")
+
+	newPrefixes := []netip.Prefix{
+		netip.MustParsePrefix("172.16.0.0/16"),
+		netip.MustParsePrefix("10.1.0.0/24"),
+	}
+
+	err = manager.UpdateSet(set, newPrefixes)
+	require.NoError(t, err)
+
+	// Check that all original prefixes are still included
+	_, isAllowed1 = manager.routeACLsPass(srcIP, dstIP1, fw.ProtocolTCP, 12345, 80)
+	_, isAllowed2 = manager.routeACLsPass(srcIP, dstIP2, fw.ProtocolTCP, 12345, 80)
+	require.True(t, isAllowed1, "Traffic to 10.0.0.100 should still be allowed after update")
+	require.True(t, isAllowed2, "Traffic to 192.168.1.100 should still be allowed after update")
+
+	// Check that new prefixes are included
+	dstIP4 := netip.MustParseAddr("172.16.1.100")
+	dstIP5 := netip.MustParseAddr("10.1.0.50")
+
+	_, isAllowed4 := manager.routeACLsPass(srcIP, dstIP4, fw.ProtocolTCP, 12345, 80)
+	_, isAllowed5 := manager.routeACLsPass(srcIP, dstIP5, fw.ProtocolTCP, 12345, 80)
+
+	require.True(t, isAllowed4, "Traffic to new prefix 172.16.0.0/16 should be allowed")
+	require.True(t, isAllowed5, "Traffic to new prefix 10.1.0.0/24 should be allowed")
+
+	// Verify the rule has all prefixes
+	manager.mutex.RLock()
+	foundRule := false
+	for _, r := range manager.routeRules {
+		if r.id == rule.ID() {
+			foundRule = true
+			require.Len(t, r.destinations, len(initialPrefixes)+len(newPrefixes),
+				"Rule should have all prefixes merged")
+		}
+	}
+	manager.mutex.RUnlock()
+	require.True(t, foundRule, "Rule should be found")
+}
+
+func TestUpdateSetDeduplication(t *testing.T) {
+	ifaceMock := &IFaceMock{
+		SetFilterFunc: func(device.PacketFilter) error { return nil },
+	}
+
+	manager, err := Create(ifaceMock, false, flowLogger)
+	require.NoError(t, err)
+	t.Cleanup(func() {
+		require.NoError(t, manager.Close(nil))
+	})
+
+	set := fw.NewDomainSet(domain.List{"example.org"})
+
+	rule, err := manager.AddRouteFiltering(
+		nil,
+		[]netip.Prefix{netip.MustParsePrefix("0.0.0.0/0")},
+		fw.Network{Set: set},
+		fw.ProtocolTCP,
+		nil,
+		nil,
+		fw.ActionAccept,
+	)
+	require.NoError(t, err)
+	require.NotNil(t, rule)
+
+	initialPrefixes := []netip.Prefix{
+		netip.MustParsePrefix("10.0.0.0/24"),
+		netip.MustParsePrefix("10.0.0.0/24"), // Duplicate
+		netip.MustParsePrefix("192.168.1.0/24"),
+		netip.MustParsePrefix("192.168.1.0/24"), // Duplicate
+	}
+
+	err = manager.UpdateSet(set, initialPrefixes)
+	require.NoError(t, err)
+
+	// Check the internal state for deduplication
+	manager.mutex.RLock()
+	foundRule := false
+	for _, r := range manager.routeRules {
+		if r.id == rule.ID() {
+			foundRule = true
+			// Should have deduplicated to 2 prefixes
+			require.Len(t, r.destinations, 2, "Duplicate prefixes should be removed")
+
+			// Check the prefixes are correct
+			expectedPrefixes := []netip.Prefix{
+				netip.MustParsePrefix("10.0.0.0/24"),
+				netip.MustParsePrefix("192.168.1.0/24"),
+			}
+			for i, prefix := range expectedPrefixes {
+				require.True(t, r.destinations[i] == prefix,
+					"Prefix should match expected value")
+			}
+		}
+	}
+	manager.mutex.RUnlock()
+	require.True(t, foundRule, "Rule should be found")
+
+	// Test with overlapping prefixes of different sizes
+	overlappingPrefixes := []netip.Prefix{
+		netip.MustParsePrefix("10.0.0.0/16"),    // More general
+		netip.MustParsePrefix("10.0.0.0/24"),    // More specific (already exists)
+		netip.MustParsePrefix("192.168.0.0/16"), // More general
+		netip.MustParsePrefix("192.168.1.0/24"), // More specific (already exists)
+	}
+
+	err = manager.UpdateSet(set, overlappingPrefixes)
+	require.NoError(t, err)
+
+	// Check that all prefixes are included (no deduplication of overlapping prefixes)
+	manager.mutex.RLock()
+	for _, r := range manager.routeRules {
+		if r.id == rule.ID() {
+			// Should have all 4 prefixes (2 original + 2 new more general ones)
+			require.Len(t, r.destinations, 4,
+				"Overlapping prefixes should not be deduplicated")
+
+			// Verify they're sorted correctly (more specific prefixes should come first)
+			prefixes := make([]string, 0, len(r.destinations))
+			for _, p := range r.destinations {
+				prefixes = append(prefixes, p.String())
+			}
+
+			// Check sorted order
+			require.Equal(t, []string{
+				"10.0.0.0/16",
+				"10.0.0.0/24",
+				"192.168.0.0/16",
+				"192.168.1.0/24",
+			}, prefixes, "Prefixes should be sorted")
+		}
+	}
+	manager.mutex.RUnlock()
+
+	// Test functionality with all prefixes
+	testCases := []struct {
+		dstIP    netip.Addr
+		expected bool
+		desc     string
+	}{
+		{netip.MustParseAddr("10.0.0.100"), true, "IP in both /16 and /24"},
+		{netip.MustParseAddr("10.0.1.100"), true, "IP only in /16"},
+		{netip.MustParseAddr("192.168.1.100"), true, "IP in both /16 and /24"},
+		{netip.MustParseAddr("192.168.2.100"), true, "IP only in /16"},
+		{netip.MustParseAddr("172.16.0.100"), false, "IP not in any prefix"},
+	}
+
+	srcIP := netip.MustParseAddr("100.10.0.1")
+	for _, tc := range testCases {
+		_, isAllowed := manager.routeACLsPass(srcIP, tc.dstIP, fw.ProtocolTCP, 12345, 80)
+		require.Equal(t, tc.expected, isAllowed, tc.desc)
+	}
+}