| 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. But its research in our country is just at the start, and we have imperfect knowledge. We have to develop the firewall technique quickly to fit the developing speed of our country in the information industry.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, and make a firewall based on the Winsock 2 SPI technology on application layer. The developing direction of my firewall is simple, efficient and less resource occupancy. Users can get basic security in the network without influence in their normal work by using this firewall, and its operation is very simple. Moreover, in view of existing situation that it's difficult to communicate between the users and the code writer, this software provides a feedback function. |
