It's been one of those nights... I just set up a desktop with Ubuntu 8.10. The install went fine. The only thing that refuses to work is networking. I know the NIC and cable are fine because when this machine was running Windows earlier, it connected without any problems. I have a Linksys wireless router sitting between my computers and the cable modem. The router has DHCP enabled, and this Ubuntu machine was set to grab an IP using DHCP. No luck. I tried restarting dbus, I tried bringing eth0 down and up again, it absolutely refuses to pull an IP address. When I run ifconfig eth0, it shows no "inet addr" but it does have an "inet6 addr".
So next I tried a static IP address. It assigned okay, but I couldn't connect to anything.
Next, I bypassed the router entirely. I connected the Ubuntu machine directly to the cable modem, set eth0 back to DHCP, restarted dbus, brought eth0 down and up... still no IP address.
I have no idea why this isn't working. Help please?
Edit: I tried replacing the cable with another known good cable just for the sake of doing it. I get the same behavior. I even tried rebooting. When the system comes back up and I log in, the network status icon says "The network connection has been disconnected."