Research And Implementation Of Distribution Network Sniffer System

Nowadays, Internet has become the integral part of our daily life. Yet the problem of Internet Security has been more and more serious as it brings us convenience. In recent years, many criminals make publicity of the violence, heresy and eroticism through taking the advantage of the Internet. It will lead to disordering of the society. Therefore, we must supervise and control the whole network to purify the environment.This thesis illustrates the concept of sniffer technologies and its current status. Firstly, the model of BPF and File Security Transfer based on OpenSSH are narrated with detail. Then, through Sniffer Pro, there are large numbers of packets that generated while users sending e-mails, QQ or MSN chatting, and browsing. They are analyzed in the following thesis, and then the conclusions come here.Then, the thesis involves the overall design of the Distribution Network Sniffer System, and it is divided into four sections: manager console, capture point, application server and DB server, which are designed and implemented respectively. The first section is for the design of UI, the second section of capture and filtration, the third section of function. Finally, the thesis has involved the discussion of the crucial Problems which have been met in the process of implementation, such as Equilibrium of Distribution, Pattern Match, analysis for XML file, Efficiency especially in process log file, capture & filter packets, the design of multithread and protection for the share resources.