Firewall Filtering Mechanism

Along with the development of computer technology and the universality of the Internet,the network security becomes an important problem that each network customer must consider. Security Problem of network usually bring the serious consequence. The establishment of firewall system is the important part of the information security.First,this thesis begin from the analyze of the network security.Then,introduce the current firewall technique,include the Packet Filtering firewall,the Application Level Gateway firewall and the Proxy Service firewall.At the end,I put great emphasis on the Packet Filtering firewall. In the recent several years the network attack from inner network increased a lot, in my thesis I make some improvement on the traditional packets filtering firewall, combined with the essence and need of network security, finally I propose one packets filtering firewall system design plan based on the technology and experiment we could use. That is to design a host firewall staying in the inner network terminal. It spreads the firewall to the terminal of inner network so as to protect inner network from invalid visiting and malice damage.