diff --git a/gold/link/link.go b/gold/link/link.go
index 5a86541..19c7661 100644
--- a/gold/link/link.go
+++ b/gold/link/link.go
@@ -81,16 +81,16 @@ func (l *Link) Write(p *head.Packet, istransfer bool) (n int, err error) {
 	data := p.Data
 	totl := len(data)
 	i := 0
-	for ; totl > int(l.me.mtu); i += int(l.me.mtu) {
+	for ; totl-i > int(l.me.mtu); i += int(l.me.mtu) {
+		logrus.Infoln("[link] split frag", i, ":", i+int(l.me.mtu), ", remain:", totl-i)
 		packet := *p
-		packet.Data = data[i : i+int(l.me.mtu)]
+		packet.Data = data[:int(l.me.mtu)]
 		cnt, err := l.write(&packet, uint16(i), istransfer, true)
 		n += cnt
 		if err != nil {
 			return n, err
 		}
-		data = data[i+int(l.me.mtu):]
-		totl -= int(l.me.mtu)
+		data = data[int(l.me.mtu):]
 	}
 	p.Data = data
 	cnt, err := l.write(p, uint16(i), istransfer, false)
diff --git a/gold/link/me.go b/gold/link/me.go
index 69a00c8..97e1a14 100644
--- a/gold/link/me.go
+++ b/gold/link/me.go
@@ -71,7 +71,7 @@ func NewMe(privateKey *[32]byte, myipwithmask string, myEndpoint string, nopipei
 	m.loop = m.AddPeer(m.me.String(), nil, "127.0.0.1:56789", []string{myipwithmask}, 0, false, nopipeinlink)
 	m.srcport = srcport
 	m.dstport = dstport
-	m.mtu = mtu
+	m.mtu = mtu & 0xfff8
 	go m.initrecvpool()
 	return
 }