The Research And Implement Of SNMP-based Network Topology Discovery Algorithm

With the development of the technology of computer networks and the worldwide popularity of Internet, the scal of computer networks is getting bulky and complex, the categories of the devices are multiple, such as hosts, PCs, bridges, routers and switches, which are connected with networks and the information flows on the networks are increasing rapidly. On the other hand, the architectures of networks, corresponding network operating systems and network application softwares are very plentiful, complex, and vary greatly. Therefore, the technique of the computer network management has become a very important issue. The aim of network management is to guarantee its normal running, improve its efficiency and decrease its costs by monitoring and controlling complex computer network. Yet knowledge of the up-to-date topology of a TCP/IP network is the basic of network management and it is also crucial to a number of critical network management tasks.This paper first outlines the concept and classification of network topology discovery and introduces the SNMP in the network topology application. After analyzing the existed logical topology and physical topology algorithm, this paper proposes a binary sort tree data structure based on IP address to improves the original algorithm in logical topology algorithm for inaccurate topology problem caused by multi-port router and it works well, it also uses multi-thread method to discover the devices; This paper describes the key step in the physical topology algorithm based on Spinning Tree Protocol in detail and uses parallel method to visit all the hosts to obtain the information. The algorithm uses SNMP protocol to collect the information from the MIB library of the network devices, then determine the relationship among the routers, switches and hosts, finally construct the topology map according to the information we get..At last, based on the analysis of the logical topology and pshsical topology algorithm this paper realizes a hierarchical network topology structure and display algorithm and displays them in the form of a tree. The entire topological diagram is clear.