前言目前在网络安全方面,国内的用户对防火墙已经有了很高的认知程度,而对入侵检测系统的作用大多不是非常了解。防火墙看起来好像可以满足系统管理员的一切需求。然而,随着基于雇员的攻击行为和防火墙产品自身问题的增多,使得入侵检测ID(SIntrusionDetectionSystems)正变得越 Preface Currently in the network security, the domestic users have a high degree of awareness of the firewall, and most of the role of intrusion detection system is not very understanding. The firewall seems to satisfy all the needs of the system administrator. However, as employee-based attacks and problems with firewall products themselves have increased, SIntrusion Detection Systems are becoming more