The Study On Topology Discovery In Network Management System

This paper focuses on the study of various network topology discovery algorithms, which are divided into two parts: network layer topology discovery and link layer topology discovery.On the study of network layer, we introduce the current network layer topology discovery methods: algorithms base on ICMP,ARP,DNS,OSPF,SNMP. In view of the shortage of snmp, we studyed MIB, and bring up the corresponding solution. By merging IP address, and limit the scope of topology discovery, we can accurately and efficiently discover the connections between routers and subnets.On the study of link layer topology discovery, we analyse the current link layer topology discovery algorithm: method base on Address Forwarding Table, then we provide a method based on Spanning Tree Protocol and SNMP to discover the link layer topology. We find out connections between switches by getting the value of MIB variables, which are relative to Spanning Tree, and the connection between switches and terminal devices by Address Forwarding Table. Last, we use asynchronism to find out all switches in the exchange domain, which can get a higher speed in the algorithm.