Research On Techniques Of Network Topology Discovery

With the rapid development of network technology, all kinds of organization depend on network so much that the operational reliability of network become vital. Therefore, It sets higher demands for network management. Network topology information is the fundament of all other management function in network management. Only by grasping the accurate and complete topology information can we make the suitable and efficient network management. How to discover network topology information rapidly and efficiently is the focus of attention in network management field.In this paper we focus on all kinds of algorithm of network topology discovery, the result show that we can discover comprehensive network topology by two layers: logical network topology discovery and physical network topology discovery.Firstly, this paper analyzes current mainstream algorithm of logical network topology discovery and summarizes the advantages and disadvantages in detail. We propose several improved methods about those disadvantages and solved some problems of classic algorithm.Secondly, this paper investigates the physical network topology algorithm based on address forwarding table and summarizes the restriction of the algorithm. This paper gives some theorems and rules based on Spanning Tree Protocol which are used to infer the connections between network node's ports. A physical network topology discovery algoritlim based on those rules was designed.The algorithm does not depend on address forwarding table completion and do not need extra network traffic.It can discovery the blocked connections and non-SNMP equipments. Accuracy of the algorithm is higher.Finally, a prototype system based on these improved algorithms has been designed and implemented in this paper. The prototype system has been tested in actual network environment. The experimental result is in conformity with actual network topology, verifying that our algorithm can efficiently discover the accurate network topology.With the development of VLAN technology and IPv6 technology, network topology discovery is confronted with new challenges. Physical topology discovery in network with VLAN and topology discovery in IPv6 network are worth further researching.