I've disabled DCHP on the DD-WRT router as per these instructions. So now if I enter 192.168.1.1 in my browser, I directly access the modem.
The issue is that the modem has connected to the internet, but the computer is unable to.
This is resolved if on the individual computers you assign a static DNS ip of 8.8.8.8/8.8.4.4. Iphones are a OK without any modification.
This isn't ideal, as you need to set every computer up this way, and also our Wii won't connect.
Any ideas how to resolve this?
Here's a screen of the modem configuration:
