Research On The Capture Method Of LAN Network Traffic

With the rapid development of Internet technology, the requirement for network has been increasing unprecedentedly. The increase of network users and applications leads to the decrease of network performance. So more and more people focus on optimizing network performance and rationally using network resources. This makes it vital to research into the technology of capturing network packets fast and effectively, which is the basis of estimating network performance.At first, the fundamentals of capturing network data was presented in this paper, and the method of capturing data packet based on WinPcap was introduced by describing the BPF (Berkeley Packet Filter) filtration mechanism and Libpcap database. In this section, the WinPcap database, which includes the internal construction, main functions and the process of capturing, was expatiated detailedly, and TCP/IP protocols and the encapsulation and decomposition of data packet were introduced. secondly, the solution on the problem of high loss rate of data packet existing in the high speed network now was brought forward. In this section, the full process from design to implement of capturing packets system was elaborated. Dynamical multithreading technology was accomplished by using multithreading technology provided by Visual C++6.0. The network traffic captured using the method mentioned above was statistically analyzed and modeled by dominate host computer and the graph of network traffic of each host computer was presented. Finally, the whole work in this paper was summarized.The technology of capture data packets not only is the basis of optimizing network performance and increasing the efficiency of utilizing network but also had been used in wide fields such as Network Planning, Behavioral Analysis of Network, Network Monitoring and Network Security. Therefore, the research on capturing data packets has a great significance.