With the d-link firmware I just connected the router and it worked, as is expected when using DHCP, but with dd-wrt I have no internet access.

It is configured with DHCP, and dd-wrt's wan status page reports that it is connected and that it has an ip address. Yet it is impossible to reach the internet.

If I disconnect the router and plugs the cable directly into my computer I get internet access, so it's obviously the dd-wrt software that isn't doing its job. However, I have no previous experience with the dd-wrt software and have no clue what to look for. I thought it would just work.

By the way, the power led is orange, the internet led is off, and wireless+lan1 is green. They all used to be green with the d-link firmware. Not sure if it's relevant, but now you know.

Does anyone have any idea what I should do to get internet access (besides reinstalling d-link's firmware)?

EDIT: It's a version B1. I read that it is very different from the A1 version, so I thought it may be relevant.