Network management has already become the key of network system. The automatic
topological discovery of network is the precondition of network management, analysis of
performance and localization of fault. With the enlargement of the network size, the
topological structure Of the network layer can't reflect the connecting relation between the
network devices accurately. So, according to the protocol SNMP, ICMP and relevant MIB
information, this text proposes a new and effective automatic topology discovery algorithm
for Ethernet. The algorithm is based on theorem for determining the connection between two
Ethernet devices. Compared with other approaches to Ethernet topology discovery, this
algorithm doesn＇t require all network devices to support SNMP and it is more efficient and
practical. The experimental result demonstrates that the algorithm can construct the
physical topology of IP network fast and exactly.