diff --git a/cmd/test.go b/cmd/test.go
index bd7d0e3d5..1d057b0d1 100644
--- a/cmd/test.go
+++ b/cmd/test.go
@@ -87,11 +87,12 @@ const (
 type testResultError struct{ error }
 
 type testResult struct {
-	Name        string
-	Verdict     testVerdict
-	Measurement string
-	Suggestion  string
-	Error       testResultError
+	Name         string
+	Verdict      testVerdict
+	Measurement  string
+	Suggestion   string
+	Error        testResultError
+	IsAcceptable bool
 }
 
 func (s *testResultError) UnmarshalText(data []byte) error {
@@ -101,6 +102,10 @@ func (s *testResultError) UnmarshalText(data []byte) error {
 
 // MarshalText implements encoding.TextMarshaler
 func (s testResultError) MarshalText() ([]byte, error) {
+	if s.error == nil {
+		return []byte{}, nil
+	}
+
 	return []byte(s.Error()), nil
 }
 
@@ -214,12 +219,18 @@ func calculateScore(results []testResult) categoryScore {
 	avg := 0
 	for _, t := range results {
 		switch t.Verdict {
-		case testVerdictBad, testVerdictFail:
+		case testVerdictBad:
 			return categoryScoreC
 		case testVerdictGood:
 			avg++
 		case testVerdictAvg:
 			avg--
+		case testVerdictFail:
+			if !t.IsAcceptable {
+				return categoryScoreC
+			}
+
+			continue
 		case testVerdictOk:
 			continue
 		}
diff --git a/cmd/testpeers.go b/cmd/testpeers.go
index 18106f6cd..d8d8f5296 100644
--- a/cmd/testpeers.go
+++ b/cmd/testpeers.go
@@ -10,6 +10,7 @@ import (
 	"io"
 	"math"
 	"math/rand"
+	"net"
 	"slices"
 	"strings"
 	"time"
@@ -99,7 +100,7 @@ func supportedPeerTestCases() map[testCaseName]testCasePeer {
 
 func supportedSelfTestCases() map[testCaseName]func(context.Context, *testPeersConfig) testResult {
 	return map[testCaseName]func(context.Context, *testPeersConfig) testResult{
-		{name: "natOpen", order: 1}: natOpenTest,
+		{name: "libp2pTCPPortOpenTest", order: 1}: libp2pTCPPortOpenTest,
 	}
 }
 
@@ -569,15 +570,49 @@ func peerPingLoadTest(ctx context.Context, conf *testPeersConfig, tcpNode host.H
 	return testRes
 }
 
-func natOpenTest(ctx context.Context, _ *testPeersConfig) testResult {
-	// TODO(kalo): implement real port check
-	select {
-	case <-ctx.Done():
-		return testResult{Verdict: testVerdictFail}
-	default:
-		return testResult{
-			Verdict: testVerdictFail,
-			Error:   errNotImplemented,
-		}
+func dialLibp2pTCPIP(ctx context.Context, address string) error {
+	d := net.Dialer{Timeout: time.Second}
+	conn, err := d.DialContext(ctx, "tcp", address)
+	if err != nil {
+		return errors.Wrap(err, "net dial")
+	}
+	defer conn.Close()
+	buf := new(strings.Builder)
+	_, err = io.CopyN(buf, conn, 19)
+	if err != nil {
+		return errors.Wrap(err, "io copy")
+	}
+	if !strings.Contains(buf.String(), "/multistream/1.0.0") {
+		return errors.New("multistream not found", z.Any("found", buf.String()), z.Any("address", address))
+	}
+
+	err = conn.Close()
+	if err != nil {
+		return errors.Wrap(err, "close conn")
 	}
+
+	return nil
+}
+
+func libp2pTCPPortOpenTest(ctx context.Context, cfg *testPeersConfig) testResult {
+	testRes := testResult{Name: "Libp2pTCPPortOpen"}
+
+	group, _ := errgroup.WithContext(ctx)
+
+	for _, addr := range cfg.P2P.TCPAddrs {
+		addrVal := addr
+		group.Go(func() error { return dialLibp2pTCPIP(ctx, addrVal) })
+	}
+
+	err := group.Wait()
+	if err != nil {
+		testRes.Verdict = testVerdictFail
+		testRes.Error = testResultError{err}
+
+		return testRes
+	}
+
+	testRes.Verdict = testVerdictOk
+
+	return testRes
 }
diff --git a/cmd/testpeers_internal_test.go b/cmd/testpeers_internal_test.go
index 3d1482c71..b33ad356e 100644
--- a/cmd/testpeers_internal_test.go
+++ b/cmd/testpeers_internal_test.go
@@ -51,7 +51,7 @@ func TestPeersTest(t *testing.T) {
 				CategoryName: "peers",
 				Targets: map[string][]testResult{
 					"self": {
-						{Name: "natOpen", Verdict: testVerdictFail, Measurement: "", Suggestion: "", Error: errNotImplemented},
+						{Name: "libp2pTCPPortOpenTest", Verdict: testVerdictOk, Measurement: "", Suggestion: "", Error: testResultError{nil}},
 					},
 					"frantic-colony - enr:-JG4QFI0llFYxSoTAHm24OrbgoVx77dL6Ehl1Ydys39JYoWcBhiHrRhtGXDTaygWNsEWFb1cL7a1Bk0klIdaNuXplKWGAYGv0Gt7gmlkgnY0gmlwhH8AAAGJc2VjcDI1NmsxoQL6bcis0tFXnbqG4KuywxT5BLhtmijPFApKCDJNl3mXFYN0Y3CCDhqDdWRwgg4u": {
 						{Name: "ping", Verdict: testVerdictFail, Measurement: "", Suggestion: "", Error: errTimeoutInterrupted},
@@ -87,7 +87,7 @@ func TestPeersTest(t *testing.T) {
 				CategoryName: "peers",
 				Targets: map[string][]testResult{
 					"self": {
-						{Name: "natOpen", Verdict: testVerdictFail, Measurement: "", Suggestion: "", Error: errNotImplemented},
+						{Name: "libp2pTCPPortOpenTest", Verdict: testVerdictOk, Measurement: "", Suggestion: "", Error: testResultError{nil}},
 					},
 					"frantic-colony - enr:-JG4QFI0llFYxSoTAHm24OrbgoVx77dL6Ehl1Ydys39JYoWcBhiHrRhtGXDTaygWNsEWFb1cL7a1Bk0klIdaNuXplKWGAYGv0Gt7gmlkgnY0gmlwhH8AAAGJc2VjcDI1NmsxoQL6bcis0tFXnbqG4KuywxT5BLhtmijPFApKCDJNl3mXFYN0Y3CCDhqDdWRwgg4u": {
 						{Name: "ping", Verdict: testVerdictFail, Measurement: "", Suggestion: "", Error: errTimeoutInterrupted},
@@ -175,7 +175,7 @@ func TestPeersTest(t *testing.T) {
 				CategoryName: "peers",
 				Targets: map[string][]testResult{
 					"self": {
-						{Name: "natOpen", Verdict: testVerdictFail, Measurement: "", Suggestion: "", Error: errNotImplemented},
+						{Name: "libp2pTCPPortOpenTest", Verdict: testVerdictOk, Measurement: "", Suggestion: "", Error: testResultError{nil}},
 					},
 					"frantic-colony - enr:-JG4QFI0llFYxSoTAHm24OrbgoVx77dL6Ehl1Ydys39JYoWcBhiHrRhtGXDTaygWNsEWFb1cL7a1Bk0klIdaNuXplKWGAYGv0Gt7gmlkgnY0gmlwhH8AAAGJc2VjcDI1NmsxoQL6bcis0tFXnbqG4KuywxT5BLhtmijPFApKCDJNl3mXFYN0Y3CCDhqDdWRwgg4u": {
 						{Name: "ping", Verdict: testVerdictFail, Measurement: "", Suggestion: "", Error: errTimeoutInterrupted},