Research And Implementation Of Firewall Based On Content Filtering Built On LINUX Kernel

The rapid development of Internet enhance the dependance of network resource .It makes network security become more important than ever. The firewall technique operates on protecting network information very much, and it is an efficient method for guaranteeing the security of information between the protected network and the external network.However, that higher security and good efficiency cannot be acquired simultaneously make the traditional firewall technique embarrassed. The packet filtering firewall which has good efficiency doesn't work well for inspecting, filtering, or mangling the content of network. The popular infection of E-mail virus and the code with hostility are exigent of higher level security to operate on the network content security. Hence, making a study of network content filtering and its product is significant very much. The research and development of content security based on Linux operation system is very important for network national defence as the popularity of Linux.Based on the analysis and research of firewall technique , transport control protocol and its implementation in Linux kernel, and netfilter framework , this paper brings forward a framework including session renewed, protocol analysis and session filtering for network content security solution and implements a content-based firewall prototype according to some designing rules.