RE: [lwip-devel] keep-alive not work

[bill]

It might have nothing to do with lwIP.  According to RFC 1122 – 4.2.3.6:

 

“Unfortunately, some misbehaved TCP implementations fail to respond to a segment with SEG.SEQ = SND.NXT-1 unless the segment contains data.”

 

Bill

 

 

From: address@hidden [mailto:address@hidden On Behalf Of Bandu
Sent: Tuesday, February 17, 2009 8:30 AM
To: address@hidden
Subject: [lwip-devel] keep-alive not work

 

Hi,

 

I'm trying to implement remote side network cable unplugging scenario by using keep-alive timer.

 

I set keep alive like:

pcb->so_options |= SOF_KEEPALIVE;

pcb->keep_idle = 15000;

pcb->keep_cnt = 1;

pcb->keep_intvl = 15000;

 

From wireshark, I can see my device is sending TCP keep alive packet. (Note: wireshark show with black color and marked as broken TCP.)

And remote side didn't ACK my keep-alive packet. (remote side is windows XP OS with telnet.exe running. my telnet implementation work fine)

so that my connection get keep-alive timed-out and disconnected.

 

Is anyone get lwip work with keep-alive feature?

Why remote side is not ACK-ing keep-alive packet?

 

 

thank you very much.

--
Bandu
address@hidden