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Improvising Your Own Wireless Router

by Wei-Meng Lee, author of Windows XP Unwired
10/31/2003

Most homes today have a broadband connection to the Internet. Contrary to what the ISPs want you to believe, you can actually share the connection with multiple computers at home by using a router. If you're a wireless user, simply buy a wireless router and it will enable you to share the connection with multiple computers wirelessly.

However, you might not want to invest money in another piece of equipment, especially in this economically trying time. So, in this article, I will show you how to use the Internet Connection Sharing (ICS) feature available in Windows XP to improvise a wireless router so that you can share the Internet connection wirelessly.

Windows XP Unwired

Related Reading

Windows XP Unwired
A Guide for Home, Office, and the Road
By Wei-Meng Lee

What You Need

First, I assume you have a broadband connection, like a cable or ADSL/DSL connection. I would also assume you have more than one computer, since your motive is to share the Internet connection with multiple PCs.

Next, designate the PC you want to act as the "wireless router." This PC must be connected to the broadband connection, that is, to the cable or ADSL/DSL modem. This PC must also have a wireless adapter connected. In my case, I connect the Linksys WUSB11 USB wireless adapter (see Figure 1) to my PC.

Figure 1. The Linksys WUSB11

Figure 2 shows the proposed settings for sharing the Internet connection:

Figure 2. The proposed setup for ICS

Configuring the Wireless Adapter

First, let's configure the wireless adapter. In the Tray on the Taskbar, locate the wireless adapter icon and right click on it. Select "View Available Wireless Networks" (see Figure 3). The Wireless Network Connection window will display.

Figure 3. Configuring the wireless adapter

Click on Advanced, and the Wireless Network Connection Properties window will appear. Select the Wireless Networks tab. Under the Preferred networks group, click on Add.(see Figure 4).

Figure 4. Adding a new wireless network

Enter a network name (or SSID), such as MyWirelessNetwork. Uncheck the Data encryption (WEP-enabled) checkbox if you do not wish to enable WEP. Click on OK (see Figure 5).

Figure 5. Specifying a wireless network name

Back to the Wireless Network Connection Properties window, click on Advanced and select the option "Computer-to-computer to non-preferred networks only" (see Figure 6).

Figure 6. Selecting the ad hoc networks option

Basically, I am configuring an ad hoc network using my wireless adapter. All computers wishing to share the Internet connection would need to establish a peer-to-peer network connection with this wireless adapter.

Configuring Internet Connection Sharing

Next, let's configure the PC that will be sharing the Internet connection (the one designated as the "wireless router"). Right-click on My Network Places and select Properties. You should see at least two connections -- one that connects to the Internet (most probably your Ethernet card) and one wireless connection.

Right-click on the Internet connection and select Properties. Click on the advanced tab and check the "Allow other network users to connect through this computer's Internet connection" checkbox under the ICS group (see Figure 7). Select the connection that you want to use for sharing. In my case, I selected the Wireless Network Connection. Click OK to complete the configuration (the Home networking connection is only present when two or more network adapters are installed on the computer).

Figure 7. Enabling ICS

That's it! To confirm that the setup is correct, check the IP address of the two network adapters by issuing the ipconfig command:


C:\Documents and Settings\Administrator>ipconfig

Windows IP Configuration

Ethernet adapter Local Area Connection:

        Connection-specific DNS Suffix  . : dom.mycompany.com
        IP Address. . . . . . . . . . . . : 156.20.217.100
        Subnet Mask . . . . . . . . . . . : 255.255.255.0
        Default Gateway . . . . . . . . . : 156.20.217.31

Ethernet adapter Wireless Network Connection:

        Connection-specific DNS Suffix  . :
        IP Address. . . . . . . . . . . . : 192.168.0.1
        Subnet Mask . . . . . . . . . . . : 255.255.255.0
        Default Gateway . . . . . . . . . :

As you can see, the Internet connection has the IP address of 156.20.217.100, while the wireless network adapter has the IP address of 192.168.0.1. This is important, because the connection that is to be used for sharing must have the IP address of 192.168.0.1; otherwise, the sharing will not work. (You can change it manually in the TCP/IP settings of the wireless adapter, if it is not set correctly.)

One final check before you go on to the next step: launch Internet Explorer to see if you can connect to the Internet.

Your improvised wireless router is now ready to use!

Configuring the Client

On the computer that will share the Internet connection, right-click on your wireless network icon in the Tray and select Properties. You should be able to see the SSID of the ad hoc wireless network (see Figure 8).

Figure 8. Connecting to the ad hoc network

Check the "Allow me to connect to the selected wireless network, even though it is not secure" checkbox, if you did not wish to enable WEP. Click on Connect. You should now be assigned an IP address by the "wireless router" (confirm it using the ipconfig command). In my case, my IP address is 192.168.0.87.

Launch Internet Explorer to check your connection to the Internet.

Summary

Using ICS is a good way to share the single Internet connection that you have with multiple computers. The downside is that at least one computer must always be switched on in order for other computers to share the connection. Another downside is security. Unlike a wireless router, you cannot perform acts like MAC address filtering and 802.1X authentication with ICS. However, using the methods described in this article, you could affordably and quickly set up a "wireless router" without the need for an actual device. This is especially useful in environments like a classroom or a seminar room, where you need to share a single Internet connection among several computers.


O'Reilly & Associates recently released (August 2003) Windows XP Unwired.

Wei-Meng Lee (Microsoft MVP) http://weimenglee.blogspot.com is a technologist and founder of Developer Learning Solutions http://www.developerlearningsolutions.com, a technology company specializing in hands-on training on the latest Microsoft technologies.


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