What's involved: A WRT54G v8, original firmware, hooked to cable modem. Another WRT54G v8, using dd-wrt* acting as a dd-wrt client wireless bridge. DD-WRT v24 RC-4 (10/10/07) micro - build 8151M
The offending desktop is connected to the dd-wrt wireless bridge. It is running an ancient pre-SP1 version of XP Home, which has a nauseatingly incorrect IP stack. Very NT.
What I have found is that this works:1) Hook up wired to the backhaul router. 2) Do the DHCP thing. 3) Disconnect from the backhaul router. 4) Reboot workstation, connected to the wireless client bridge. 5) Workstation gets the same IP address.
So, we add another (modern) workstation with a USB 802.11G thumb drive which carps the IP address of the old computer.
The workstation does not appear to get a DHCP response back and shrugs, chooses a 184.108.40.206 appropriate address.
I tried this with the horrible old XP version but I also got exactly the same results with a Knoppix boot-from-CD. The DHCP response times out.
I conclude that the dd-wrt wireless bridge does not forward broadcasts* to the main wireless router, and DHCP cannot be made to work properly over this arrangement. Yes, the answer is a fixed IP, and I'll do it as soon as I have backed up all 16 GB of stuff off the offending machine.*I'm not sure of the layer, but I think it's a clue.
Once I have my story straight, I'll ply the waters of the dd-wrt community again.
-- Les Cargill