A Applied Devise Of Subminiature Firewall

Firewall is an effective system to protect local network, reject network security threat and access outside through internet. Firewall is an effective recovery step, can strengthen the security of network, prevent and resist various menace of network. In internet times, firewall has played more and more important rules in network security protecting.The paper is accomplished based on continuously practicing, studying and summarizing in the course of practical working to establish secure enterprise network. In theory , it discusses the principle of how to achieve the firewall system and the realizing frame of the core firewall netfiller under linux operating system in a comparatively comprehensive way, and pays due attentions on the firewall technologies of packet filter and state inspection. Based on these principles, the paper introduces the system framework and internet services of the enterprise network, compartmentalizes the network security areas, stipulates for corresponding security policies aiming at the network hidden security troubles, and writes the firewall programs to arm the enterprise network. Jn the end accomplish the homologous iptables script procedure and make use of the linux bash shell compile the dynamic iptables script procedure, besides, collectivity appraise the firewall system.The characteristics of practicability and low-cost of the firewall system and middle sized enterprises and has a great promoting value. If we change the firewall system it could do inbuilt firewall system, make vast production.