Try running a command from the computer that is plugged in via Cat[x] cable, after you have established a good connection to the internet [and can surf].
Go the start menu and select "Run"
Type "command" and hit enter to bring up the command prompt [a DOS window]. [you can also just find "command prompt" in the start menu somewhere instead]
Type "tracert supramania.com" and hit enter.
This will trace your route/hops from your computer to supramania.com
There are other ways to do this, but I thought this related well to our site.
The first address that came up for me was my gateway/router config address
http://192.168.xxx.xxx/
You will want to take note of the first address that is displayed; write it down or something.
Open up a web browser and type the address in, and hit enter.
If I type those numbers it will bring me to my router configuration page.