diff --git a/gold/head/packet.go b/gold/head/packet.go
index af4bfa0..2842cc6 100644
--- a/gold/head/packet.go
+++ b/gold/head/packet.go
@@ -97,7 +97,6 @@ func (p *Packet) Marshal(src net.IP, datasz uint32, offset uint16, dontfrag, has
 	if src != nil {
 		p.DataSZ = datasz
 		p.Src = src
-		offset >>= 3
 		if dontfrag {
 			offset |= 0x4000
 		}
diff --git a/gold/link/link.go b/gold/link/link.go
index 7e8813b..5df85f0 100644
--- a/gold/link/link.go
+++ b/gold/link/link.go
@@ -93,7 +93,7 @@ func (l *Link) Write(p *head.Packet, istransfer bool) (n int, err error) {
 		logrus.Infoln("[link] split frag", i, ":", i+int(l.me.mtu), ", remain:", int(totl)-i-int(l.me.mtu))
 		packet := *p
 		packet.Data = data[:int(l.me.mtu)]
-		cnt, err := l.write(&packet, totl, uint16(i), istransfer, true)
+		cnt, err := l.write(&packet, totl, uint16(uint(i)>>3), istransfer, true)
 		n += cnt
 		if err != nil {
 			return n, err
@@ -101,7 +101,7 @@ func (l *Link) Write(p *head.Packet, istransfer bool) (n int, err error) {
 		data = data[int(l.me.mtu):]
 	}
 	p.Data = data
-	cnt, err := l.write(p, totl, uint16(i), istransfer, false)
+	cnt, err := l.write(p, totl, uint16(uint(i)>>3), istransfer, false)
 	n += cnt
 	if err != nil {
 		return n, err
diff --git a/gold/link/recv.go b/gold/link/recv.go
index 407bb05..9c58c26 100644
--- a/gold/link/recv.go
+++ b/gold/link/recv.go
@@ -39,6 +39,7 @@ func (m *Me) initrecvpool() {
 
 func (m *Me) wait(data []byte) *head.Packet {
 	flags := binary.LittleEndian.Uint16(data[10:12])
+	logrus.Infoln("[recv]", len(data), "bytes data with flag", hex.EncodeToString(data[10:12]))
 	if flags == 0 || flags == 0x4000 {
 		h := &head.Packet{}
 		_, err := h.Unmarshal(data)