Saturday, April 10, 2010

How to make Windows XP as a Router | IP Forwarding on Windows XP Professional

The benefit using Windows XP Professional as a Router is you don't have to buy additional router and so can save some money. This approach is not so common practiced in Windows XP, but it works.

As an example, let say you have 10 computers and 2 network switches, and need to create 2 networks that can access Internet, so how to do it? Some more information, one of the computers is equipped with 2 network cards and one of the network cards is connected to cable / DSL modem to access Internet, so this computer will act as a router!

Configure the network cards on the router with following information.

Router (Must Windows XP Professional)

Network Card A (connect to Internet via cable / dsl connection)
This information will be based on the Internet connection service which you have subscribed.
Gateway (GW):

Network Card B (connect to network A):
Gateway (GW): [leave it blank]

Configure all the computers in network B with following information.

Network B
Gateway (GW):

1. Go to Start and click Run…, then type in regedit to run registry editor.

Note: Please note that only System Administrator can run registry editor.

2. Registry editor window will appear. Browse for the following registry key at the left hand side window:


Right click IPEnableRouter registry object, and click Modify.

Note: Be extra careful when you deal with registry editor, wrong editing will crash you Windows OS.

3. The IPEnableRouter window will appear. Type 1 as Value data and click OK.

4. Close the regisrty editor and reboot the computer. After rebooting, all the computers should be able to access Internet and also share the file/printer between network A and B.

Note: When I did the test, IP forwarding will only work after rebooting the computer. So don't forget to do it.