路由优化（Routing optimization）.doc

路由优化（Routing optimization） The twenty-first chapter is routing optimization In todays high-performance networks, in order to ensure network scalability, stability, security and rapid convergence, we must Network optimization. Routing filtering and policy routing are common methods for routing optimization. 21.1 overview of routing optimization Routing filtering means that some routes are not sent and received in the route update, the passive interface and the distributed control list, Both redistribution and routing strategies can implement routing filtering. Policy routing provides a mechanism for packet forwarding based on standards set by network managers. Policy based Routing is more flexible and more flexible than traditional routing, which allows network managers not only to target addresses but also to root Select the forwarding path based on protocol type, message size, application, or IP source address. The policy routing policy consists of a routing map (route, map) to define. The most important commands in the route map are match and set. Match is used to define matching conditions, and the matching statement detects packets at the input port of the router. Frequently-used Matching criteria include IP addresses, interfaces, metrics, and packet lengths. Set defines the behavior of a statement that conforms to a matching condition. The usual behavior is shown in table 21-1. Table 21-1 behavior of set Set behavior description Set IP next hop sets the next hop address of the packet Set interface sets the packet output interface Set, IP, default, next, hop Sets the default next hop address for routing tables Without routing entries to the destination address of the packet Set default interface sets the default outgoing interface The set IP TOS sets the IP ToS value of the IP packet The set IP precedence sets the priority of the IP packet [attention] 1., the last default of a route map is deny any. The use of this deny depends on the route map How is it used?.