Physical Topology Detection Technology Research And Implementation Of Ethernet Network

Nowadays, with the development of the technology of computer network, scale of computer network is getting bulky and complex, the need of reliability of computer network is continually improved, and network management has been the key to normal operation of the network system. It's more and more important to get a complete and correct topology, which can be used in these fields such as network management, network optimization and fault location. And accurate network topology information is crucial for both network management and performance prediction. Given the dynamic nature of today's IP networks, keeping track of topology information manually is a daunting task. In recent years, it has been attracted considerable attention for a mass of researchers on networks in world, and become the hot research area of computer networks. Based on careful analysis on related theory, technique and application of the topology detection in world, this thesis introduces several common protocols which could be used in topology detection, and which are compared to each other according to their suitable application, network load, speed and accuracy. On the base of the physical topology detection algorithm for single or subnets, the author is concerned with summarizing these topology detection algorithms, and comparison of advantages and disadvantages among these algorithms is also presented, and present some difficulties that physical topology detection will confront for multi-subnet networks. Based on studying the methods of physical topology detection and compared them, and gave a novel physical topology detection method for multi-subnet based on SNMP, make use of Ethereal and many protocols such as AFT, STP, which can solve nicely the problem of incomplete AFT, the devices which don't support SNMP and provide a solution for that the AFT can not uniquely define the topology.A complete topology detection system has been designed and implemented, and every modules of the system have also introduced detailed in the end of the thesis. The new method has been tested in the real networks. It is proved that this method is efficient.The innovation of the work in this thesis can be shown as the following four aspects:There protocols SNMP, STP and AFT are combined in this new topology detection method, which can discover multi-subnet and heterogeneous network; Owing to the using of the methods of creating extra traffic and accessing the AFT table in fixed internals, we solve the problem of incomplete AFT; Owing to the using of Ethereal, which can we use to solve the problem of discovering the devices which don't support SNMP; Benefited from STP protocol, we can solve the problem that AFT can not uniquely define the topology.