Snmp Protocol Security Analysis And Applied Research

The goal of Network Management is providing a secure and reliable circumstance for computer network. There are three Network Management Model in the world, TMN(Telecommunications Management Network),CMIP(Common Management Information Protocol) and SNMP(Simple Network Management Protocol). SNMP has become the standard for managing networks for its simplity and utility.Recently SNMP are mostly used in management of TCP/IP networks. But in original design the security mechanisms is not so important which compared to its simplity. Considering the menace of SNMP's security, this paper summarizes the SNMP's security requirement and the corresponding security mechanisms. Furthermore, the authors analyses and compare security mechanisms provided by SNMPvl, SNMPv2 and SNMPv3.At the end of this part, the authors provides some measures to protect the network which is managed by using SNMP: using firewall to filtrate the SNMP packet; blocking the exceptional request of the inner network; modify the default public string; using physics insulate in the network.Auto discovering the network topology is the most important contents in network management. In fourth part of this paper we give a methods to automap the topology by using SNMP which be implemented in TCP/IP network environment. Also we give another algorithm by using RIP to discover the network topology. And we discuss the difference between two algorithms. In the different network circumstance the two algorithms have different results. In the small scale network the algorithm using RIP is faster than another, but in large scale network the algorithm using SNMP is more reliable than the algorithm using RIP.