diff --git a/gold/head/packet.go b/gold/head/packet.go
index 5e5fed4..69b1efc 100644
--- a/gold/head/packet.go
+++ b/gold/head/packet.go
@@ -86,7 +86,9 @@ func (p *Packet) Marshal(src net.IP) []byte {
 	}
 
 	p.DataSZ = uint32(len(p.Data))
-	p.Src = src
+	if src != nil {
+		p.Src = src
+	}
 
 	packet := make([]byte, 52+len(p.Data))
 	binary.LittleEndian.PutUint32(packet[:4], p.DataSZ)
diff --git a/gold/link/link.go b/gold/link/link.go
index cc148a0..8476e3f 100644
--- a/gold/link/link.go
+++ b/gold/link/link.go
@@ -72,10 +72,15 @@ func (l *Link) Read() *head.Packet {
 }
 
 // Write 向 peer 发包
-func (l *Link) Write(p *head.Packet) (n int, err error) {
+func (l *Link) Write(p *head.Packet, istransfer bool) (n int, err error) {
 	p.FillHash()
 	p.Data = l.Encode(p.Data)
-	d := p.Marshal(l.me.me)
+	var d []byte
+	if istransfer {
+		d = p.Marshal(nil)
+	} else {
+		d = p.Marshal(l.me.me)
+	}
 	if d == nil {
 		return 0, errors.New("[link] ttl exceeded")
 	}
diff --git a/gold/link/listen.go b/gold/link/listen.go
index 4fc5828..6d8e670 100644
--- a/gold/link/listen.go
+++ b/gold/link/listen.go
@@ -46,7 +46,7 @@ func (m *Me) listen() (conn *net.UDPConn, err error) {
 									case head.ProtoHello:
 										switch p.status {
 										case LINK_STATUS_DOWN:
-											_, _ = p.Write(head.NewPacket(head.ProtoHello, 0, p.peerip, 0, nil))
+											_, _ = p.Write(head.NewPacket(head.ProtoHello, 0, p.peerip, 0, nil), false)
 											logrus.Infoln("[link] send hello ack packet")
 											p.status = LINK_STATUS_HALFUP
 										case LINK_STATUS_HALFUP:
@@ -77,7 +77,7 @@ func (m *Me) listen() (conn *net.UDPConn, err error) {
 							} else if p.Accept(packet.Dst) {
 								if p.allowtrans {
 									// 转发
-									p.Write(&packet)
+									p.Write(&packet, true)
 									logrus.Infoln("[link] trans packet to", packet.Dst.String()+":"+strconv.Itoa(int(packet.DstPort)))
 								} else {
 									logrus.Warnln("[link] refused to trans packet to", packet.Dst.String()+":"+strconv.Itoa(int(packet.DstPort)))
diff --git a/gold/link/nat.go b/gold/link/nat.go
index 29dadaf..23065c1 100644
--- a/gold/link/nat.go
+++ b/gold/link/nat.go
@@ -15,7 +15,7 @@ func (l *Link) keepAlive() {
 		go func() {
 			t := time.NewTicker(time.Second * time.Duration(l.keepalive))
 			for range t.C {
-				_, _ = l.Write(head.NewPacket(head.ProtoHello, 0, l.peerip, 0, nil))
+				_, _ = l.Write(head.NewPacket(head.ProtoHello, 0, l.peerip, 0, nil), false)
 				logrus.Infoln("[link.nat] send keep alive packet")
 			}
 		}()
diff --git a/gold/link/query.go b/gold/link/query.go
index 31fde36..6b2b4b2 100644
--- a/gold/link/query.go
+++ b/gold/link/query.go
@@ -27,6 +27,6 @@ func (l *Link) SendQuery(peers ...string) error {
 	if err != nil {
 		return err
 	}
-	_, err = l.Write(head.NewPacket(head.ProtoQuery, 0, l.peerip, 0, data))
+	_, err = l.Write(head.NewPacket(head.ProtoQuery, 0, l.peerip, 0, data), false)
 	return err
 }
diff --git a/lower/nic.go b/lower/nic.go
index 2cb5111..ed76e1b 100644
--- a/lower/nic.go
+++ b/lower/nic.go
@@ -79,7 +79,7 @@ func (nc *NIC) Start(m *link.Me) {
 			logrus.Warnln("[lower] connect to peer", dst.String(), "err:", err)
 			continue
 		}
-		lnk.Write(head.NewPacket(head.ProtoData, srcport, dst, dstport, packet))
+		lnk.Write(head.NewPacket(head.ProtoData, srcport, dst, dstport, packet), false)
 	}
 }
 
diff --git a/upper/services/tunnel/tunnel.go b/upper/services/tunnel/tunnel.go
index 71987ed..1ee3f65 100644
--- a/upper/services/tunnel/tunnel.go
+++ b/upper/services/tunnel/tunnel.go
@@ -79,7 +79,7 @@ func (s *Tunnel) handleWrite() {
 		logrus.Debugln("[tunnel] writing", len(b), "bytes...")
 		for len(b) > int(s.mtu) {
 			logrus.Infoln("[tunnel] split buffer")
-			_, err := s.l.Write(head.NewPacket(head.ProtoData, s.src, s.peerip, s.dest, b[:s.mtu]))
+			_, err := s.l.Write(head.NewPacket(head.ProtoData, s.src, s.peerip, s.dest, b[:s.mtu]), false)
 			if err != nil {
 				logrus.Errorln("[tunnel] write err:", err)
 				return
@@ -87,7 +87,7 @@ func (s *Tunnel) handleWrite() {
 			logrus.Debugln("[tunnel] write succeeded")
 			b = b[s.mtu:]
 		}
-		_, err := s.l.Write(head.NewPacket(head.ProtoData, s.src, s.peerip, s.dest, b))
+		_, err := s.l.Write(head.NewPacket(head.ProtoData, s.src, s.peerip, s.dest, b), false)
 		if err != nil {
 			logrus.Errorln("[tunnel] write err:", err)
 			break