Study On Key Technology Of Firewall

In information sharing time, the network security is extremely important .People did not consider the security problem when constructing the network. With the development of network technology, the fight between network attack and defense is very intense.To guard against network attack, we usually construct firewall. Using firewall technology, and then disposing it carefully, we can implement the security usually. But today network technology is rapidly developing, the present firewall technology is far to support network security. On the one hand, because the majority firewall products can not protect the application level sufficiently, and have not been able to realize content filter technology. On the other hand, because intruder can do everything to seek channels which possibly open behind the firewall .Moreover the firewall result is micro in preventing internal attack. Therefore, the idea that deploying firewall can make our systems safe enough is impractical. The intrusion detection system is a new network security technology which the appeared recently years. It can make up partial insufficiency of firewall. It provides effective intrusion detection to the protected network and adopts corresponding protection method.This paper has an emphasis analysis on firewall technology and intrusion detection technology of the network security technology. According to their respective characteristics, I attempt to design a multi-functions personal firewall software system. This paper is divided three levels to elaborate the design and the realization of this firewall system. First, elaborates this firewall system uses what method to get the package;Second, elaborates how this firewall system filters the package as the foundation, and then strengthens the protection to application level by realizing content filters function;Third, elaborates how this firewall system have the intrusion detection function inside. The intrusion detection function strengthens the firewall system's function, and makes the network defense moreflexible. Finally, the paper tests the personal firewall software system and analyses the result, which proves the rationality and the feasibility of design.