Research And Implementation Of The Firewall Technology Based On Stateful Inspection

Information security problem about the network is paid more attention by everyone living in network information society. The problem also involves all aspects of social life. It is very important and urgent to make research about security technology for building reliable and secure information networks. Firewall is the most popular and technology of network information security.Because traditional firewall such as packet filtering, application gateway can't adapt for the requirement of security of the network gradually, the firewall based on state inspection becomes a research hotspot in network security field. Stateful inspection firewall works in network layer. Stateful Inspection is different from traditional Packet Filter firewall. It doesn't process packet as independent information. It uses the stateful inspection mechanism based on connection tracking. The mechanism enhances the efficiency and the security of system.The theory and function of stateful inspection are analyzed in the paper at first. The technologies used in stateful firewall are researched in the paper such as the connection state among datagram, method to get state, the variance among the connection states and method to record the state in corresponding table.Based on the theory of the stateful inspection, the pivotal stateful inspection model of the firewall is realized with equipment driver program. A stateful inspection firewall on windows platform is implemented in this paper. The confliction between efficiency and security of traditional firewall is resolved. The firewall has both high efficiency like packet filter firewall and high security like application proxy firewall. The graphic user interface based on windows is designed for the stateful inspection firewall in the paper. Users can simply setup and maintenance the system.