Using Two Computers On The Same Modem

by on December 18, 2007

Q: Can two computers running Windows XP be connected to the same modem? The modem has an Ethernet and a USB connection and we would like to know if it would work without having to buy anything extra.

A: In order to connect two computers to the same modem, whether cable or DSL, you need to use a router. When a computer is connected directly to the modem the IP address is assigned to that machine which prevents you from simply swapping two computers on and off the modem without powering down the modem each time. When a router is connected to the modem the IP address is assigned to instead. At this point multiple computers can be used off of the same connection and/or swapped on and off. Unfortunately you cannot use the Ethernet connection for one computer and the USB for the other.

To use the router all you need to do is unplug your modem for a minute, connect the router to the modem with an Ethernet cable and plug the modem back in. When the modem is powered off it resets itself and reassigns the IP address to the router. Now you can plug both computers into the router and share the same connection. This works whether you are physically plugging in the computers to the router or using it wirelessly. If you are choosing to physically plug them in just remember that there is a difference between a switch and a router. A router is capable of storing an IP address a switch is not. You can buy a wired router for around $50.00 in most stores and a wireless one for around $70.00 for a G series. All wireless routers have the ports in the back for physical connections.