What does a Network Bridge do?
The Network Bridge is a new feature of Windows XP. It combines two or more separate networks into one logical network. Adapters that have Internet Connection Sharing (ICS) or Internet Connection Firewall (ICF) enabled cannot be part of the network bridge. For more details, see the following link. XP ICS – Network Bridge http://www.practicallynetworked.com/sharing/xp_ics/networkbridge.
