[lwip-users] Problem with recent port of lwip

[Bob Brusa]

Hi
I have downloaded a recent port (by Simon Kallweit) from
http://download.westlicht.ch/lwip-20090903.tar.gz. When running the
testprogram httpd_sequential.c it works - if lwip is configured for a
fixed address. But when I configure it to use DHCP, I run into a problem:
I then get no response from my board.

Using wireshark, I can see (see attachment 090921_1.out) that the there is
a hopeful beginning of the DHCP configuration process of my board. But
there is never a fitting answer from the ZyXEL P-661HW-D3 which implements
the DHCP-server on our LAN - at least as far as I see it, given my rather
limited experience with network issues.....

There is more: In the debug output of lwip I can see that my board
receives a packet from the ZyXEL which includes the IP address I am
expecting (see attachment packets.txt). But the package is dropped because
of a checksum error. Why? Short of memory? But even so, why can't I see
this packet on wiresharks output?

My system(s): Custom specific board based on at91sam7x256. Toolchain is
GNUARM

Has anyone out there a possible explanation what's going wrong here? Or a
hint in which direction to go for further debugging. Thanks for help.
--
   Robert

packets.txt
Description: Text document

090921_1.out
Description: Binary data