Research And Development Of Firewall On The Basis Of Linux

With the wide use of computer networks, the problem of their safety is becoming increasingly serious. As an effective means to guarantee the safety of networks, firewalls have been generally accepted and widely used by computer users.On the basis of the studies concerning the technology of firewalls, such as the study of package filter, agent service, status examination, the author, in the present thesis, conducts some researches concerning the basic Linux firewall realization technology and its tools, designs and the realization of the software firewall for Linux, such as the framework of netfilter firewall, its subscriber control program etc.The present firewall software includes the main modules concerning the subscriber verification, package filter, agent service and log management etc., which have such functions as the setting of safety strategies, group filter rules and agent service.The present thesis mainly involves the introduction of the author's research work, a detailed description of the analysis, design, realization process and the major data structure and its calculation of the software firewall based on Linux. For instance, in the discussion of the package filter part, the author analyzes the principles of how the firewall is transferred to IPv6 environment. The last part of the thesis is the discussion of the process of the firewall testing.