Setting Up a Bridged Network

Windows XP can serve as a bridge between two or more networks (the Bridging feature is not available in the 64-bit versions of Windows XP.). A bridge forwards all traffic received from any one network to all of the others, and its main purpose is to join networks using disparate media. For example, you can use the bridging feature to join a wired Ethernet network with a phoneline network, a wireless network, or a FireWire network; you can join a slower 10BASE-T network with a 10/100BASE-T network, or you can join all of these types together.

To create a bridged network, install the necessary network adapters in one Windows XP computer, as described previously under "Installing Multiple Network Adapters." Do not bother configuring the adapters yet. When all of the adapters are installed, follow these steps:

1. Log on as a Computer Administrator.
2. View the Network Connections screen.
3. Select all the icons for the network adapters you wish to bridge by clicking with the Shift key held down.
4. Right-click any of the icons and select Bridge Connections.

A new icon will appear that represents the bridge itself. Once established, the bridge will join the network connected to the linked adapters as if they were a single network.

Networking properties like TCP/IP address assignment are now associated with the bridge as a whole, rather than with individual adapters. In effect, the bridge is the "adapter," and the linked network cards are its several physical ports. So, you must now right-click the Bridge icon and configure its TCP/IP properties.

CAUTION Do not bridge a network adapter that is used to connect directly to the Internet, as this will bypass the Internet Connection Firewall.

Later, if needed you can modify the bridge from the Network Connection window:

• To add an additional adapter to the bridge later on, right-click the adapter icon and select Add to Bridge.
• To remove an individual adapter from the bridge, right-click the adapter's icon and select Remove from Bridge. You may need to reconfigure the TCP/IP properties for the newly removed adapter.
• To remove the bridge entirely, right-click the Bridge's icon and select Delete. You may need to reconfigure the TCP/IP properties of the adapters that were part of the bridge.