diff --git a/TCPProtocol/mnhv1.go b/TCPProtocol/mnhv1.go
index 613898c..3703909 100644
--- a/TCPProtocol/mnhv1.go
+++ b/TCPProtocol/mnhv1.go
@@ -1,12 +1,14 @@
 package TCPProtocol
 
 import (
+	"errors"
 	"net"
 	"sync"
 	"time"
 
 	"github.com/hzyitc/mnh/TCPMode"
 	"github.com/hzyitc/mnh/log"
+	"github.com/hzyitc/netutils"
 )
 
 type mnhv1 struct {
@@ -61,7 +63,12 @@ func (s *mnhv1) keepalive(duration time.Duration, timeout time.Duration) {
 }
 
 func NewMnhv1(m TCPMode.Interface, server string, id string) (Interface, error) {
-	conn, err := m.Dial(server)
+	addr, err := netutils.ResolveAddr("tcp", server, "mnhv1", 6641)
+	if err != nil {
+		return nil, err
+	}
+
+	conn, err := m.Dial(addr.String())
 	if err != nil {
 		return nil, err
 	}
@@ -80,10 +87,10 @@ func NewMnhv1(m TCPMode.Interface, server string, id string) (Interface, error)
 	}
 	msg := string(buf[:n])
 
-	holeAddr, err := net.ResolveTCPAddr("tcp", msg)
-	if err != nil {
+	holeAddr := netutils.ParseAddr("", msg)
+	if holeAddr == nil {
 		conn.Close()
-		return nil, err
+		return nil, errors.New("fail to parse \"" + msg + "\"")
 	}
 
 	s := &mnhv1{
diff --git a/UDPProtocol/mnhv1.go b/UDPProtocol/mnhv1.go
index 021b0d8..2eefaf2 100644
--- a/UDPProtocol/mnhv1.go
+++ b/UDPProtocol/mnhv1.go
@@ -1,12 +1,14 @@
 package UDPProtocol
 
 import (
+	"errors"
 	"net"
 	"sync"
 	"time"
 
 	"github.com/hzyitc/mnh/UDPMode"
 	"github.com/hzyitc/mnh/log"
+	"github.com/hzyitc/netutils"
 )
 
 type mnhv1 struct {
@@ -61,7 +63,12 @@ func (s *mnhv1) keepalive(duration time.Duration, timeout time.Duration) {
 }
 
 func NewMnhv1(m UDPMode.Interface, server string, id string) (Interface, error) {
-	conn, err := m.Dial(server)
+	addr, err := netutils.ResolveAddr("udp", server, "mnhv1", 6641)
+	if err != nil {
+		return nil, err
+	}
+
+	conn, err := m.Dial(addr.String())
 	if err != nil {
 		return nil, err
 	}
@@ -81,10 +88,10 @@ func NewMnhv1(m UDPMode.Interface, server string, id string) (Interface, error)
 	}
 	msg := string(buf[:n])
 
-	holeAddr, err := net.ResolveUDPAddr("udp", msg)
+	holeAddr := netutils.ParseAddr("", msg)
 	if err != nil {
 		conn.Close()
-		return nil, err
+		return nil, errors.New("fail to parse \"" + msg + "\"")
 	}
 
 	s := &mnhv1{
diff --git a/go.mod b/go.mod
index 38650ae..b254d4e 100644
--- a/go.mod
+++ b/go.mod
@@ -3,6 +3,7 @@ module github.com/hzyitc/mnh
 go 1.16
 
 require (
+	github.com/hzyitc/netutils v0.1.0
 	github.com/libp2p/go-reuseport v0.0.2
 	github.com/spf13/cobra v1.1.3
 	gitlab.com/NebulousLabs/go-upnp v0.0.0-20210414172302-67b91c9a5c03
diff --git a/go.sum b/go.sum
index 041e6cd..8eff63c 100644
--- a/go.sum
+++ b/go.sum
@@ -89,6 +89,8 @@ github.com/hashicorp/logutils v1.0.0/go.mod h1:QIAnNjmIWmVIIkWDTG1z5v++HQmx9WQRO
 github.com/hashicorp/mdns v1.0.0/go.mod h1:tL+uN++7HEJ6SQLQ2/p+z2pH24WQKWjBPkE0mNTz8vQ=
 github.com/hashicorp/memberlist v0.1.3/go.mod h1:ajVTdAv/9Im8oMAAj5G31PhhMCZJV2pPBoIllUwCN7I=
 github.com/hashicorp/serf v0.8.2/go.mod h1:6hOLApaqBFA1NXqRQAsxw9QxuDEvNxSQRwA/JwenrHc=
+github.com/hzyitc/netutils v0.1.0 h1:jnOu0GOWUlGjGbz8P6bt5uFpFyB0v904r08Ke8vhLAI=
+github.com/hzyitc/netutils v0.1.0/go.mod h1:DUOpn7k1pRfmS6bXThgrWVTyXHM8R7GCVfKnYQcq1U4=
 github.com/inconshreveable/mousetrap v1.0.0 h1:Z8tu5sraLXCXIcARxBp/8cbvlwVa7Z1NHg9XEKhtSvM=
 github.com/inconshreveable/mousetrap v1.0.0/go.mod h1:PxqpIevigyE2G7u3NXJIT2ANytuPF1OarO4DADm73n8=
 github.com/jonboulle/clockwork v0.1.0/go.mod h1:Ii8DK3G1RaLaWxj9trq07+26W01tbo22gdxWY5EU2bo=