Abstract: The realization of stateful inspection technic and the security requirements of FTP, Web and E-mail services are proposed. On the base of the above analysis, the adoption of application level protocols analysis on stateful inspection firewalls with its implementation on Linux is discussed. It turns out to make stateful inspection firewalls to have more control on application level protocols.

Key words: Stateful inspection, Application level protocols analysis, Firewall, Linux

摘要： 阐述了状态检测技术的实现，分析了FTP、Web和邮件服务的安全需求，在此基础上把应用层协议分析技术应用到状态检测防火墙中，给出了在Linux系统上的实现方案，使状态检测防火墙能更有效地进行应用层的检测和控制。

关键词: 状态检测, 应用层协议分析, 防火墙, Linux