The Application Of Load Balancing Technology In The Firewall

With the computer networks development, and e-commerce greatly in use, Internet security become more and more important. Firewall is one of the main measures to control the invalid access. Firewall is between the Intranet and the Internet networks. It is the only path for the outer computers to enter. Usually, only one computer works as firewall. Therefore, the efficiency of firewall is important. Although we can use a faster computer, such as a supercomputer, work as firewall, one firewall' s reliability is still a big problem.In this paper, we try to use several firewalls work together, like a parallel firewall. We use load balance technology to develop firewall cluster, an advanced minicomputer running as load balance server, distributing loads to firewall 1, firewall 2, …, firewall n, etc.. Windows 2000 Server is selected as the server' s operating system, more network adapters are inserted to the server' s main board. One network adapter is linked to the Internet and the others linked with the firewalls (work as clients).The load balance server is the main work in this research. We have investigated a lot of load balance algorithms used in the DNS server and the Web server, and used a simple load balance algorithm of Round Robin. C++ Windows Socket programming is used, it works in Client/ Server model. The server program is made of four modules: listening module, accepting module, load balance module and sending module. The client program is made of two modules: listening module, accepting module.