I run a simple TCP client on machine A and a simple TCP server on machine B (machine B is a Planetlab node while machine A is not).
Then the client establishes a tcp connection with machine B and send some data.
I
capture packets on both A and B, on A the wireshark shows that it is a
normal 3-Way handshaking, but on B, it shows as below:1 0.000000 138.46.116.22 138.46.201.109 TCP 74 54000 > 57182 [SYN, ACK] Seq=0 Ack=0 Win=5792 Len=0 MSS=1460 SACK_PERM=1 TSval=1751648211 TSecr=1119925943 WS=128 0.000000
2 -0.000062 138.46.201.109 138.46.116.22 TCP 74 [TCP Port numbers reused] 57182 > 54000 [SYN] Seq=0 Win=14600 Len=0 MSS=1460 SACK_PERM=1 TSval=1119925943 TSecr=0 WS=128 -0.000062
3 0.000308 138.46.201.109 138.46.116.22 TCP 66 57181 > 54000 [ACK] Seq=1 Ack=1 Win=14720 Len=0 TSval=1119737278 TSecr=1751459556 0.000308
while I see on machine B, actually the tcp connection is established.
before the client sends the SYN and ACK, I checked machine B and found no TCP connection
netstat -tnp
(Not all processes could be identified, non-owned process info will not be shown, you would have to be root to see it all.)
Active Internet connections (w/o servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 138.46.116.22:54000 138.46.201.109:57181 ESTABLISHED 17879/tcp_server
anyway, I can send data to the tcp server and it receives it correctly.
why wireshark shows TCP Port numbers reused? and the time is '-0.000062'?
