lwip-users
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [lwip-users] tcp_enqueue problem, using socket:


From: Piero 74
Subject: Re: [lwip-users] tcp_enqueue problem, using socket:
Date: Thu, 20 Mar 2008 11:33:31 +0100



2008/3/20, Jonathan Larmour <address@hidden>:
Piero 74 wrote:
> here i attached a wireshark file...
>
> I didn't understand what is the problem....
> Anyone can explain me??
>

> my ip board is 192.168.0.101 <http://192.168.0.101>
> pc ip is 192.169.0.1 <http://192.169.0.1>

Great! That's exactly what was needed. According to that, clearly the PC is
not ACKing the further sends, hence you eventually running out of send
buffer space.

Why is it not acking? According to my dump, the first unacked packet from
your ip board to the PC has a bad checksum:

09:28:34.359638 00:bd:33:02:64:24 (oui Unknown) > 00:c0:f0:52:fe:91 (oui
Unknown), ethertype IPv4 (0x0800), length 248: (tos 0x0, ttl 255, id 3,
offset 0, flags [none], proto: TCP (6), length: 234) 192.168.0.101.dnp >
192.168.0.1.4539: P, cksum 0x018f (incorrect (-> 0x3182), 195:389(194) ack
1 win 2048

Everything in the packet superficially looks ok (lengths, src and
destination IPs etc.) but either the packet has got corrupted, or somewhere
in your processing of the packet you have modified it without recalculating
the checksum.

Jifl... i use send function (socket).... i cannot change packet  in low level protocols
I'm thinking.... it could be possible a problem in my emac driver? but i don't know how i can debug this problem, if there is....
can you help me?

Piero

Jifl
--
eCosCentric Limited      http://www.eCosCentric.com/     The eCos experts
  **  Visit us at ESC Silicon Valley <http://www.embedded.com/esc/sv>  **
  **  April 15-17 2008, Booth 3012, San Jose McEnery Convention Center **
Barnwell House, Barnwell Drive, Cambridge, UK.       Tel: +44 1223 245571
Registered in England and Wales: Reg No 4422071.
------["Si fractum non sit, noli id reficere"]------       Opinions==mine


_______________________________________________

lwip-users mailing list
address@hidden
http://lists.nongnu.org/mailman/listinfo/lwip-users


reply via email to

[Prev in Thread] Current Thread [Next in Thread]