The basic principle and function of sniff technology is briefly introduced in this paper. Various kinds of sniff technology in switching network are analyzed,and ARP protocol is introduced specifically. ARP cheat principle is explained in detail.

• 介绍了嗅探的基本原理和作用,分析了在交换网络环境下的各种嗅探方法,并重点论述了ARP协议,详细阐述了ARP欺骗原理,最后编程实现这一嗅探技术。