I've spent hours today and the days prior trying to get both my Macs up on the internet at the same time. I can get either one to work independently through the router, but not together. My Vonage isn't working either, but that's another matter. So, a new Comcast approved Motorolla modem and Linkseys router (thanks to Mark) later, I'm still not getting both computers to work on the internet at the same time. (They used to, before our router went bad). We thought it was the modem so replaced it first. Here's the configuration: Comcast Cable into utility room > Cable Modem in said room > to wall outlet upstairs in kitchen > to router > to phone modem and upstairs and downstairs computers. Comcast hasn't been real helpful. They did come and determine that the router was the problem though. From my investigation I see that I cannot have an IP address beginning with 169. and that Comcast assigns an IP address each time I start up one of the computers. The router though is supposed to create a fake number so that the modem (or Comcast) only sees one computer. Something like that. Below are articles on it. So I took the IP and router address off the one computer I had the internet working on and manually put it on the other--keeping the router number the same but changing the IP to .13 at the end. The IP was .1, the router was .12. Then I shut off the computers, the router, the modem, and turned them all back on in opposite order (modem, etc.) Still same problem. I'm obviously missing something here. It all used to work fine so I don't know what has happened. How do I configure the router? One link said to configure the router to act as a "NAT" device so that it will appear that all traffic is coming from the router. Another person said this: "Who is your internet service provider? I know certain ones (including Comcast) require that the router clone the MAC address of your computer's ethernet port in order for the router to get an IP address. Most routers have a setting that will let you do this." Here's more about that direction (scroll down a bit): http://www.daniweb.com/forums/thread32833-2.html So I found this info on how to do this cloning, but I can't get the IP # suggested for Linksys in the browser window to load. Says "page can't be found." I'm not even sure that is the problem, because I can get either computer to work through the router, just not at the same time. Any advice?