Debugging DHCP - how to do it?

[janeclements]

I wonder if any of you network guru's could shed some light on this....

I have a broadband connection that I have configured to eth1 with the dhclient program (dhcp3-client package).

For some reason it's stopped working and dhclient can't receive an ip address.

I've verified that the cable connections are fine, the modem is fine (they work on other computers). When the modem is put into standby, I can get to the built-in modem debug interface (192.68.100.1). And according to diagnostics there, the connection is great, reception is strong, etc.

I can do "ifconfig" and get my eth1 as well as lo for the localhost. But I can't get an ip address .... and it was just working yesterday!!!!

So what would make dhclient not be abpe to get a DHCP offer or find a working lease? What could I test/try? Can anybody walk me through this, I'm desperate!

Thanks!

[framp]

I'd use tcpdump to check whether you get a lease or there is a cable or provider problem.