校园网安全问题日益受到严重关注,单一的方案无法满足目前的安全需求。该文提出了一个包括物理安全、链路安全、网络级安全、信息安全、应用安全和用户安全的六层网络安全体系,并在此之上给出了一个整体安全解决方案,它的特点是多层次、全方位、分布式,覆盖了从底层到高层,从静态被动防御到动态主动防御,从入侵事前、事中到事后,从系统到桌面,从主机到网络的多方位防护,能够给予网络极高的安全性。该文的安全方案也可以推广到其它类型的局域网。 Campus network security issues are increasingly serious concern, a single solution can not meet the current security needs. This paper presents a six-layer network security system that includes physical security, link security, network-level security, information security, application security and user security and provides an overall security solution on this. Multi-level, omni-directional, distributed, covering from the bottom to the top, from static passive defense to dynamic active defense, from intrusion before and after things, from the system to the desktop, from the host to the network multi-directional protection can be given High security network. This article’s security solution can also be extended to other types of LANs.