Physical topology discovery based on spanning tree protocol

The physical topology discovery is one of the difficulties in network measurements. This paper proposes a novel algorithm for discovering the physical topology of networks based on Spanning Tree Protocol (STP). Our algorithm improves and elevates the accuracy of connection judgments and the effectiveness and efficiency of discoveries greatly; it can also do well in finding backup links, hubs and other dumb devices that do not support SNMP. Besides, we solve the problem that devices´ ports do not correspond to MAC addresses within VLANs.