Windows XP includes the Network Bridge, a feature of the Network Connections folder that allows a computer with multiple network adapters installed to act as a bridge, connecting multiple LAN segments together to form a single network segment. The most common example is a laptop that has a network interface for a wired network and a network interface for a wireless network, although this may apply to any desktop computer as well.
This feature was designed for home networks and is detrimental to the campus network. It unfortunately appears to be the default behavior of the configuration wizard. Bridging by user devices is prohibited. Computers running Windows XP on the University campus network (wired or wireless) must have this feature disabled. If detected, the network switches will automatically disable your port for 5 minutes.
Technical note: The system that disconnects the problem port for 5 minutes is a feature of our Enterasys network equipment called SpanGuard. Cisco has a similar system called Spanning Tree Portfast BPDU Guard.

Disabling Windows XP Network Bridge

...or, for the classic menu layout:
Under the Network Bridge section, right-click on the Network Bridge icon and select Delete.


A pop-up window will appear while the connection is being deleted....


Verify that the Network Bridge section and icon no longer appear in the Network Connections window.