Design And Implementation Of The SNMP-Based Network Topology Discovery System

The effect of network topology discovery is exerting a greater and greater influence on the network management with the increase of the size and complexity of network. It is through gathering and maintenance of the exist and the connection of information of network nodes that the network topology discovery eventually produces topological structure. Internet supervision and maintenance personnel can optimize the whole network system, quickly locate and repair the breakdown node if appeared according to the network topology structure. Through the research of SNMP, network topology discovery technology and arithmetic, this paper has designed a network topology discovery system,which can make an automatic discovery accurately and efficiently for network structure.This paper is a detailed illustration of the SNMP management mode and an analysis of the current major network topology discovery algorithm. Specific to some of the existing problems, such as the completeness deficiencies of common topology discovery methods, the imperfection of several VLANS network topology discovery, the accuracy of the integrity of the address forwarding table of switches, this paper makes a detailed analysis and improvement in order to realize a physical topology discovery method,which is based on address forwarding table. This algorithm, which is based on the MKR(Minimum Knowledge Requirement), aims to deduce the forwarding address of each port of the switch so as to, conclude a complete indirect connection relationship between every network equipment. Besides, according to three connected judge rules, the direct connection relationship between every equipment can be judged, the topological structure of each layer from under layer topological tree to upward topological tree in turn can be constructed, and each layer of the structure is finished, excess connections in the database are removed and the repeat cost are reduced, all of the above mentioned methods guaranteed the circulation efficiency of the algorithm. This scheme improved the integrity of several VLAN network topology discovery, and the capability of heterogeneous network topology discovery, which realized the discovery of HUB concentratorIn the process of system research and design, this paper puts forward the general framework of topology discovery system and gives the specific organizational form of data. Based on experiments and measures and after the design works, the paper proved the system's correctness to the heterogeneous network topology discovery and verified the validity of this algorithm. This system can be applied to daily network management as a favorable tools.