校园网中策略路由技术的实现

策略路由技术是对传统路由技术的扩展和改进，基于策略的路由比传统路由使用更灵活，不仅能够根据目的地址，而且能够根据报文大小、应用或IP源地址来选择转发路径．分析校园网的现状和需求，根据数据包的发起方向(源地址)决定该数据包的路由方向．当内部用户主动发起连接访问外网时，数据到达边界路由器，路由器根据数据包的源地址(也可以同时考虑目的地址)，决定将该数据包发向CERNET还是ChinaNET，实现了校园网、教育科研网和国际互联网之间正确、高效的访问．

Implementation of Policy-Based Routing in Campus Network

Policy-based Routing technology is the extension and improvement of traditional routing technology. In comparison with traditional routing technology, PBR provides more flexibility. With PBR, router can deliver data packet not only based on destination address, but also based on the size, application or source IP address of the datagram to determine the path. This paper analyzed the situation and the requirement of campus network. PBR can use the initiate direction of the data (source address) to determine the routing direction of the data packet. When an internal user takes the initiative in connecting to access the outside network, the data packets will be delivered to the border router, the router will look up the data packets' source address (also can consider the destination address), to determine whether should send the packets to CERNET or ChinaNET. PBR was used to perform the correct and high efficient access among campus network, CERNET and Internet.