King-Shan Lui kinglui@uiuc.edu http://www.students.uiuc.edu/~kinglui/ Title: Spanning Tree Alternate Routing Bridge Protocol Abstract: Bridges are devices for connecting local area networks (LANs) together to form a transparent extended LAN. As home networking technology advances, bridges will be used to connect multiple home network segments at home. In the IEEE 802.1D standard for bridges, a spanning tree is built among bridges for loop-free frame forwarding. Although this approach is simple, it does not support all-pair shortest paths. We present a novel bridge protocol that attempts to find alternate paths that are shorter than their corresponding tree paths on the standard spanning tree. The protocol is backward compatible with the IEEE 802.1D standard and enhances path performance by replacing only a few bridges in an extended LAN. The protocol has a complexity that is comparable to that of the standard and other existing protocols.