This is my router, a Pipline 75, made by Ascend. I am using Network Address Translation (NAT) on my router, so that the computers on my LAN can get to the internet. In a nutshell, my LAN ip addresses are non-routable 10.x.x.x, and my router has the IP given to me by my ISP. If any of the computers on my LAN makes a request from the internet, the router gets it, and makes sure it gets back to the computer that made the request. This setup is pretty slick, and affords a lot of security from outside attacks.