Research And Implementation Of Distributed Firewall Based On IPSEC In WINODWS System

With rapid development of network information technology,network security problem is more and more prominent,firewall,as a kind of effective safety protection measures are widely used in various types of network,its development is very fast.Windows as the most popular individual operating system,Windows environment research firewall has certain practical significance.Network packet interception is the core of the current development of personal firewall technology.In Windows platform of network packet interception available in user mode and kernel mode on two levels.User mode is the key to HOOK technology used,the Winsock SPI,etc.However,these techniques are a fatal weakness is the packet interception technology team can only on the level,some trojans and viruses easily bypass directly through a call to send and receive data.Kernel mode to intercept network packets is the main technology of the network driver.Packet filtering algorithm of distributed firewall of the host firewall is a linear search,its performance will only get worse and worse with the increase of filtering rules,in order to improve the running speed of the firewall,the illegal packet interception ability,in this paper,a filtering algorithm based on HASH double linked list,and by analyzing and comparing Windows environment network packet interception technology,developed a firewall software,based on NDIS6.0 filtering flooding after test,it’s ability to intercept illegal packet has strong.This article first to the traditional network security and firewall technology are introduced,and points out that the traditional firewall are faced with the problem,then the structure of the distributed firewall,key technology and advantages are studied.This system is mainly composed of strategy actuators,control center,and the client and server communication of three parts,strategy actuators to run in the protected host,enforcing security policy from the policy control center,policy control center to complete the protected host registrations strategy formulation and distribute,work communication to protect internal communication between the host to prevent internal attacks.In this paper,a detailed account of the system framework,and the system was tested and obtained good running effect.