Connecting a Linksys Wireless Router to a Comcast Modem

How to upgraded wireless home network from an old Netgear 802.11b router to a shiny new Linksys WRT120N router sporting the latest 802.11n technology, and a much sleeker design.

The network speed difference is very noticeable and significantly faster on the newer router, and the units were on sale for only $39 at Fry's so it seemed like a steal of a deal... until I tried to install it.

I have Comcast internet at home with a standard-issue Motorola cable modem, and it turns out that Linksys routers don't naturally connect directly with these modems.

The Network Magic software that comes with Linksys routers failed on the first setup screen with an "Error 321", claiming it could not detect my ethernet network adapter. Apparently the Linksys routers require you to connect through a separate router that sits between the Comcast modem and the Linksys router (or at least that's what I found hidden somewhere in the documentation) - and in fact, it worked fine if I connected through my old Netgear router to the Comcast modem.

I was also able to connect directly from my computer to the Linksys router, which I was able to verify by running ipconfig and seeing the IP address assigned by the router. I was also able to log into the router's admin console screens by opening a web browser and entering the IP address of the router - http://192.168.1.1 using admin/admin for the username/password (which is the default for Linksys routers).

So the culprit was the connection between the Linksys router and the Comcast modem, and the solution was to make the Linksys router clone my computer's MAC address (which made the Comcast modem think it was connecting directly to my computer instead of to a Linksys router).

Here are the steps to take to get a Linksys router to connect to a Comcast modem:

1. Unplug your computer from the cable modem and power down the cable modem (I even took the battery out from the backside, to make sure it was completely off).

2. Connect your computer with the Linksys router using the network cord, leaving the router unplugged from the cable modem.

3. Open a command prompt and enter "ipconfig /release" and then "ipconfig /renew" to get an IP address from the router.

4. Enter the router's admin console by pointing your web browser to http://192.168.1.1 (default IP address for Linksys routers). The default login for Linksys routers is admin for both username and password, if you haven't already configured an admin password.

5. Instruct the router to Clone your Mac Address, which is under the main "Setup" tab.

6. Connect the Linksys router to the Comcast cable modem.

7. In the Linksys router's admin console, request a new IP address from the cable modem. (This is the "Renew IP Address" button in the "Status" tab of the admin console)

The Comcast cable modem should now think it's connecting directly to your PC and your Linksys router should now be working.

As for the Network Magic software that came with the Linksys router - I tossed it.

As for Linksys technical support - also worthless. I spent about 15 minutes on hold, only to be disconnected.