Research Of Firewall Technology

The security of computer network consists of pretending the invasion of net virus and hackers. We can keep back the net virus using software of anti-virus,such as KV3000 and Rising. Meanwhile we can prevent the hackers using the firewall technology. The key idea of firewall technology is to build a kind of relative safe sub-environments among the nets. Based on debating the essential conception and system structure of the firewall technology,this paper sums up three important method about firewall technology:Packet Filter,Application Gateway and Proxy. Furthermore,this paper discusses the security of the firewall,including the ability of anti-attack and invasion check-up through the firewall Log. Finally,this paper,through debugging,give a model firewall that can prevent various attacks from Internet based on Linux sever. At the same time,according to firewall's rules,some users can only visit http/https/ftp outside. Some can get more rights,such as email,realplay,ICQ and soon.