介绍了计算机网络和网络安全的概念,对于互联网的安全问题提出了解决方案,认为实现网络安全措施的一种重要手段就是防火墙技术,因而重点介绍了防火墙种类和防火墙技术的实现。 Introduced the concept of computer network and network security, and put forward a solution to the security problem of the internet. It is considered that one of the most important means to implement network security measures is firewall technology. Therefore, the types of firewall and the realization of firewall technology are mainly introduced.