一、应用背景 在构建计算机网络系统时,经常会碰到这样一些实例: 一个驻外办事处想与总部联网 不在同一物理空间的小型工作组之间想联网 多台客户机想共享一个Internet接口 不在同一网段上的客户机能相互通信 高等院校的众多教学局域网需要通过逐步形成的校园网经路由器访问 First, the application background In the construction of computer network systems, often encounter such examples: An external office network with headquarters want to be not in the same physical space between the small work groups want to network multiple clients want to share an Internet interface is not Clients on the same network segment can communicate with each other Many teaching LANs in higher education institutions need to be accessed through the gradually formed campus network via routers