Research And Realization Of Network Topology Discovery

Computer network management plays a vital role in the development of the computer network; Network operation is directly relate to the merits of the performance. Correct network topology information can directly and effectively provide the whole network structure and its states to the network administrator. Moreover, network topology discovery is very significant to network management, network expansion, network performance optimization and network security. It is a common issue for many network institutes to discover and obtain network topology information quickly and accurately.This thesis studies the technology of network topology discovery, and improves the topology discovery algorithm based on SNMP, and achieves accurate and efficient network topology discovery system.Firstly, this thesis outlines the concept and classification of network topology disecovery and introduces the SNMP in the network topology application, and discusses the problem of network topology discovery need to be considered. The thesis also introduces the related knowledge and commonly-used technology about network topology discovery and makes an analysis and general comparison among them from the subject of speed, accuracy, load and applied scope. The algorithm of topology discovery based on SNMP is the most fast and widely used algorithm.Secondly, this thesis analyzes theory and implementation process of the algorithm of network topology discovery based on SNMP in detail, and points out the disadvantages about it. And then, this thesis puts forward of an improved aogorithm of network topology. It resolved the problems of repeat determinant of a more IP address router and anonymous router. The author also implements an accurate and effective topology information discovery system on the real condition.Finally, this thesis describes in detail the implementation of each module. The topology display system uses the improved algorithm. And the information collection module collectes the information of MIB database by using SNMP protocol, and then stores the information in database; Data analysis module calculates and analysises the informaition of network topology extracts from database, and then deliveres to the topology display module. Furthermore, this thesis studies the implementation of information acquisition and display of VLAN. And this thesis also analysises the topology analysis and topology display. The system uses the third-party software development kit SNMP++ to achieve topology discovering system on the development platform of Visual C++. The display module of this system displays the network equipment by structure of top-down. The system has been implemented and tested in the real networks; it is shown that the system is efficient and accurate.