[rudedog]

a router will have 2 IP address.
Wan - or public IP address ( this is the one to give your friends)
LAN - private IP address ( the one your computer uses to connect to the router

Find out what your routers IP is by pointing your web browser to it's IP address. you will need it's username and password

you will also need to forward the correct ports. If all you want is your friends to play then just forward 12203. You will need to read your routers manual to figure out how to do this as it's different for every router.

If you want your computer to show up on gamespy and ASE then you need to forward all the ports or just place your computer in the routers DMZ. This will leave your computer open to the world but just for playing one or two games its not that big of deal. Just turn off file and printer sharing on your computer.

To find a list of ports, use the search button on top. Search for Dogmeat and ports

good luck