Comment 5 for bug 31273

Revision history for this message
Steven (steven3000) wrote :

I can confirm this bug.

I was trying to set up a DHCP server on Ubuntu Feisty Fawn and I notice that no responses were received from clients (also running Ubuntu), so I uses wireshark to capture packets and seems that UDP Checksum are incorrect, so offers get dropped.

I sent a message to dnsmasq mailing list and the answer was:

"The explanation for dhclient ignoring the DHCPOFFERS seems to be that
the UDP checksum is incorrect. Is the Ubuntu system the client, or the
server? The checksum problem seems to be originating on the server, and
if the server is running Ubuntu (or any Linux distro) then it's a kernel
problem: on Linux dnsmasq delegates UDP and IP header creation to the
kernel. [CUT]"

Link to the message: http://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2007q3/001501.html
Reply: http://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2007q3/001502.html

Look at the wireshark capture file: DHCPOFFER packets have an incorrect UDP Checksum, however DHCPDISCOVER packets are ok.

Server: Linux steven-desktop 2.6.20-16-generic #2 SMP Thu Jun 7 20:19:32 UTC 2007 i686 GNU/Linux
Client: Linux steven-laptop 2.6.20-16-generic #2 SMP Thu Jun 7 20:19:32 UTC 2007 i686 GNU/Linux