Study And Implementation On Unauthorized Intra-AS Network Topology Probing Algorithm

With the rapid development of computer network technology, network security problems become more and more prominent. Currently, as an important research aspect in network security, Intra-AS network topology probe technology can hardly meet the needs of complex network circumstances, and many problems need to be solved. To solve these problems, the research of Intra-AS network topology probe algorithms is very important. In this paper, the network layer and physical topology probe algorithms are put forward and realized, and the main work concentrates on aspects as follows:1. In order to solve the shortcomings in network topology probe algorithms using ICMP, the heuristic subnet hypothesis technique, heuristic IP address hypothesis technique and heuristic router alias probe technique are studied and put forward, and the Traceroute programme is optimized. Based on these, an ICMP based algorithm of heuristic Intra-AS network topology probe is put forward and realized. Then, the complexity of the algorithm is analyzed. The analysis results show that the heuristic techniques of the algorithm can reduce the cost of network communication effectively, and the algorithm has desirable adaptability in different sized Intra-AS network.2. With the study of three typical theories and algorithms of physical network topology infer, two rules of inferring the direct connection and dump devices based connection are put forward. The rules reduce the requirement of forwarding database's integrality of switches and improve the correctness of physical infer result effectively. Based on the rules, the FDB based algorithm of Intra-AS network physical topology probe is designed and optimized. An important characteristic of the algorithm is that it can infer the network physical topology correctly on the lack of the integrality of forwarding database of switches. The test result shows that the algorithm has satisfied advantage in efficiency which can meet the demand of large-scale Intra-AS network physical topology probe.3. In order to solve the problems in current topology map generation tools, a topology map generation algorithm of large-scale Intra-AS network is designed and implemented. The algorithm can eliminate the overlap, interlace and unreasonable layout among elements in network topology map, and it has ability to rectify the topology map when some topology information is not accurate.4. With the combination of the heuristic topology probe algorithm, physical topology probe algorithm, SNMP based algorithm and other topology probe techniques, an Intra-AS network topology probe prototype named NetworkProbe is designed and implementedwhich can support flexible configuration of probe policies according to the actual network circumstances. The test results show that NetworkProbe has good performance in correctness, completeness and efficiency and has satisfied adaptability in heterogeneous network.Part of productions in this paper has been applied into a National Research Plan and laid the foundation for the successful examination of the project. Additionally, it provides an effective way of probing the aimed network without authorization in aimed network.