Research On Techniques Of Automatic Network Topology Discovery And Network Flow Measurement

With the development and application of modern network technology, network scale is increasing continuously, and the structure of network becomes complex. Traditional network security management cannot keep up with the pace of network. Statistics shows that a intrusion on Internet hosts takes place about per 20 seconds. 75 percent to 85 percent of web sites in America could not withstand hacker attacks. As one of the key techniques of ensuring network running, the technique of network administration of security has been one of hot spots for research.The administration of security can not live without the administion of configuration and the adminisration of performance. For example, unreasonable network configuration may leave security holes for hacker. Network topology discovery and network flow measurement guarantee the administration of network security. For these reasons, this paper does research on the techniques of automatic network topology discovery and network flow measurement.1. The technique of Automatic network opology discovery. The present methods of network topology discovery can be divided into two categories: the methods of network layer and the methods of data link layer. Based on thorough studies on the present topology discovery algorithms for network layer and data link layer. This paper designs and implements an algorithm acquiring topology information from multi-data sources and discovering network topology by layer. Acquiring topology from multi data sources ensures the integrity of topology information. Discovery topology by layer not only lessens the algorithm complexity, but also enhances the efficiency of topology discovery.2. Network flow measurement. Accoring to the count of monitor nodes, network flow measurement is divided into single node measurement and muti nodes measurement. The method based on single node measurement has limited capacity and the flow it measures is inadequate. Multi nodes measurement could measure the entire network flow. However, multi nodes measurement may bring much network overload. Based on present algorithms for selecting monitor nodes, this paper implements an algorithm which selects monitor nodes with minimum weak vertex cover.Based on research on the present topology discovery technique and minium weak vertex cover selection algorithms, this paper has designed and implemented a network measure prototype system. A series of tests is carried on, and the results have testified the availability of the algorithms stdied by this paper.