diff --git a/.gitignore b/.gitignore
index d5dbfd8..7c7feca 100644
--- a/.gitignore
+++ b/.gitignore
@@ -36,6 +36,7 @@ vendor/
 # IDE
 .vscode/
 agents.md
+*skill.md
 
 # For local development and testing create `local` directories.
 local
diff --git a/x/xnet/stack-async.go b/x/xnet/stack-async.go
index 9255637..0519ade 100644
--- a/x/xnet/stack-async.go
+++ b/x/xnet/stack-async.go
@@ -164,7 +164,7 @@ func (s *StackAsync) Reset(cfg StackConfig) error {
 		return err
 	}
 	s.link.SetAcceptMulticast(cfg.AcceptMulticast)
-	const ipNodes = 2 // UDP, TCP ports.
+	const ipNodes = 3 // 3 IP protocols possible: UDP, TCP, ICMP.
 	err = s.ip.Reset(addr, ipNodes)
 	if err != nil {
 		return err
diff --git a/x/xnet/xnet_fuzz_test.go b/x/xnet/xnet_fuzz_test.go
index 7029113..6ec6a33 100644
--- a/x/xnet/xnet_fuzz_test.go
+++ b/x/xnet/xnet_fuzz_test.go
@@ -75,6 +75,14 @@ func FuzzStackAsyncHTTP(f *testing.F) {
 	f.Fuzz(func(t *testing.T, pktnum int, a []byte) {
 		var buf [MTU + ethernet.MaxOverheadSize]byte
 		s1, s2, c1, c2 := newTCPStacks(t, seed, MTU)
+		err = s1.EnableICMP(true)
+		if err != nil {
+			t.Fatal(err)
+		}
+		err = s2.EnableICMP(true)
+		if err != nil {
+			t.Fatal(err)
+		}
 		err := s1.ListenTCP(c1, 80)
 		if err != nil {
 			t.Fatal(err)
diff --git a/x/xnet/xnet_test.go b/x/xnet/xnet_test.go
index 6697cc0..6085009 100644
--- a/x/xnet/xnet_test.go
+++ b/x/xnet/xnet_test.go
@@ -181,6 +181,7 @@ func newTCPStacks(t testing.TB, randSeed int64, mtu int) (s1, s2 *StackAsync, c1
 		MaxActiveTCPPorts: 1,
 		HardwareAddress:   [6]byte{0xbe, 0xef, 0, 0, 0, byte1},
 		MTU:               uint16(mtu),
+		ICMPQueueLimit:    2,
 	})
 	if err != nil {
 		t.Fatal(err)
@@ -194,6 +195,7 @@ func newTCPStacks(t testing.TB, randSeed int64, mtu int) (s1, s2 *StackAsync, c1
 		MaxActiveTCPPorts: 1,
 		HardwareAddress:   [6]byte{0xbe, 0xef, 0, 0, 0, byte2},
 		MTU:               uint16(mtu),
+		ICMPQueueLimit:    2,
 	})
 	if err != nil {
 		t.Fatal(err)