Design And Implement Of The SNMP-based Network Management System

With the development of internet technology, network application is becoming more and more extensive, from information sharing to shopping, making friends, office, teaching and other fields, the network users also show explosive growth and the scale of network coverage is growing. How to construct and expand the network reasonably, how to allocate the network resources reasonably, and how to make the best use of the network performance and so on. To solve these problems is a practical network management system.In this paper, a network management system based on SNMP, PHP, MySQL and so on, the system can show the network connectivity, user information, traffic conditions and so on. This system is based on the actual needs of a unit to achieve, divided into topology discovery, user management and traffic monitoring module, which would make the management,the configuration of network resources and monitoring network state more efficient.User management is mainly in order to improve the security of the management system, and only legal users can be able to manage the network. At the same time, the user password is encrypted by MD5, in the case of database information leakage can also be a good protection of user information security. Due to the special nature of the customer, the security and safety requirements are higher, the network includes a number of special equipments for its safety, and the program has some special codes to enhance the security.Topology discovery mainly start with the specified or default router IP, and breadth first traversal of the three-layer network equipment, taking into account a device generally have multiple interfaces and each interface has its own independent IP address, the system uses the device name to uniquely identify a equipment, this way avoid repeat discovery. After that, use a list and a topology map to present the network structure to managers, list makes it easy for the specific equipment for monitoring, topology for intuitive understanding of the network structure.The condition monitoring is to obtain the data information of the specific equipment through the SNMP operation. The main indicator includes network bandwidth utilization, packet error rate and packet discard rate. The first indicator for load balancing, the last two indicator for the prevention of network failure. In the algorithm, the emphasis is given to the processing of the device restart and counter overflow.