提出了一种利用ICMP和SNMP协议特性结合的网络拓扑发现算法 ,采用主动探测与被动监视的技术 ,并对该技术涉及的协议理论进行了分析 .给出了程序功能模块定义、数据结构设计与程序实现步骤 . This paper proposes a network topology discovery algorithm using ICMP and SNMP protocol features, using active probing and passive surveillance techniques, and analyzes the protocol theory involved in this technology.The definition of program functional modules, data structure design and Procedures to achieve the steps.