Network settings for bridged DD-WRT

[Morat]

I am trying to set up my upstairs Ubuntu 10.04 desktop to use my upstairs router (running DD-WRT v24-sp2) as a wireless bridge to my downstairs router.

I believe the routers are set up correctly. Ubuntu can see both routers but cannot make the final hop onto the internet.

I have followed the instructions in
http://www.youtube.com/watch?v=KjGGQoBElbY
http://www.dd-wrt.com/wiki/index.php/Wireless_Bridge
and all is as in the tutorials except when it comes to setting the desktop to obtain its IP and DNS automatically. I can do this in Windows but not in Linux. I assume it is this that is stopping me seeing the internet.

Any pointers?

--- Morat

[Morat]

Also, this was working earlier in the year, then it stopped working for a few weeks, then it worked again for a week or so (I had fiddled with it and finally got it working again but I don't know what I did to mend it), now it is broken again. I am not aware of changing any network settings before it breaks, I only fiddle with it when it has already stopped working.

It's really frustrating and does not help my general feeling that networking is voodoo!