Research and Application on Automatic Network Topology Discovery in ITSM System

Automatic network topology discovery is important for network management and network analysis in ITSM system. Issues like network environment configuration, performance testing and fault detecting all require accurate information of the network topology. According to the requirement of the ITSM system, in this paper we propose an efficient algorithm that is based on SNMP for discovering Layer 3 and Layer 2 topology of the network. The proposed algorithm only requires SNMP to be enabled on routers and managed switches. For Layer 3 topology discovery, this paper proposes a shared subnet based approach to analyze connections between routers. In addition, the algorithm uses a STP based method to discover Layer 2 topology, which does not require the completeness of switchpsilas AFT information. The algorithm has been implemented and tested in several enterprise-level networks, and the results demonstrate that it discovers the network topology accurately and efficiently.