0引言计算机联网后,人们关注的首要问题是网络安全问题。21世纪以来,网络安全问题愈演愈烈。网络上随处可见垃圾邮件、无处不在的病毒等肆无忌惮的在网上搞破坏。比如“冲击波病毒”就曾经在全球泛滥,无数企业为此经济严重受创,人们可谓是谈病毒就色变。网络安全漏洞无法避免,互联网网民极度缺乏安全感,需要网络安全感的呼声越来越高,于是,发明了入侵检测技术。1入侵检测系统的概念及应用范围 0 Introduction Computer networking, the primary concern is the issue of network security. Since the 21st century, the issue of cybersecurity has intensified. Spam everywhere on the Internet, ubiquitous viruses and other unscrupulous online engage in vandalism. For example, “the shock wave virus” once flooded the world, countless enterprises for this serious economic hardship, people can be said to talk about the virus to change color. Internet security vulnerabilities can not be avoided, Internet users extremely lack of security, the voice of network security needs more and more high, so, invented the intrusion detection technology. 1 intrusion detection system concepts and application areas