Chord does not take into account the mismatching problem between logical network topology and physical network topology, which would cause inefficient routing.

Discovering physical network topology is an important function of network management system because it de-picts links between switches at layer2.

Based on shortage of recent physical topology discovery algorithm,this paper proposes a Width-First Search topology discovery algorithm based on STP and tests it.

Based on the study of heuristic topology probe algorithms and physical topology probe algorithms, an Intra-AS network topology probe named NetworkProbe is designed and implemented, its kernel is an heuristic topology probe algorithm and an physical topology probe algorithm, the SNMP-based algorithm and other topolog.

A root search theorem is proposed, which focuses on the physical network topology discovery in distributed heterogeneous networks environment.

In the paper, three kinds of existing algorithms of physical network topology discovery are analyzed and the limitations of them are pointed out.

Progress and research on physical topology discovery of switched Ethernet;

According to the characteristics of heterogeneous networks and the correlative protocols of network topology discovery,this paper proposes an algorithm for Ethernet physical topology discovery based on heterogeneous multi-subnets,which depends on the SNMP protocol.

This paper proposes an algorithm which accords to and includes the physical topology discovery of heterogeneous IP networks with VLAN which is designed and implemented according to hierarchical design model.