Re: [lwip-users] LWIP 1.2 issue.

[Kieran Mansley]

On Mon, 2007-04-16 at 10:39 -0400, Robert Morse wrote:
> Hi,
>       Maybe some one can point me at a place to look at for the following 
> issue I am seeing.
> 
> I have have ported LWIP to an Turbo186, I have the stack up and 
> running, but seeing some
> strange problems.
> 
> Looking at wireshark/Ethereal  I see the following: (pcap file attached)
> 
> [Client]      -- SYN
> [LWIP]   -- SYN ACK
> [Client] -- ACK
> [Client] -- Sends Soap Message.
> [LWIP] -- TCP Window Update to 2448
> [LWIP] -- TCP Window Update to 3072
> [LWIP] -- Responds with answer to Soap Message
> [CLIENT] -- FIN, ACK
> [LWIP] -- FIN, ACK
> [CLIENT] -- ACK
> [LWIP] -- ACK
> [LWIP] -- DUP ACK (About 2 MS after ACK).

That is a bit odd.  I can't see any reason for the duplicate ACK.  

> Also I am getting the following Messages: (I have some debugging turned 
> on).
> 
> tpc_listen_input: ACK in LISTEN, sending reset.
> tcp_rst: seqno 5984823 ackno 3514939349.

This suggests that packets are being sent or delivered to the listening
socket when there should obviously be none other than SYNs going there.
If you can get a packet capture of one of these that might through some
light on it.  

Kieran