BigIron RX Series Configuration Guide 67153-1001810-01Configuring RIP parameters 24Using prefix lists and route maps as route filtersYou can configure prefix lists to permit or deny specific routes, then apply them globally or toindividual interfaces and specify whether the lists apply to learned routes (in) or advertised routes(out).You can configure route maps to permit or deny specific routes, then apply a route map to aninterface, and specify whether the map applies to learned routes (in) or advertised routes (out).NOTEA route is defined by the destination’s IP address and network mask.NOTEBy default, routes that do not match a prefix list are learned or advertised. To prevent a route frombeing learned or advertised, you must configure a prefix list to deny the route.To configure a prefix list, enter commands such as the following.BigIron RX(config)# ip prefix-list list1 permit 192.53.4.1 255.255.255.0BigIron RX(config)# ip prefix-list list2 permit 192.53.5.1 255.255.255.0BigIron RX(config)# ip prefix-list list3 permit 192.53.6.1 255.255.255.0BigIron RX(config)# ip prefix-list list4 deny 192.53.7.1 255.255.255.0The prefix lists permit routes to three networks, and deny the route to one network.Since the default action is permit, all other routes (routes not explicitly permitted or denied by thefilters) can be learned or advertised.Syntax: ip prefix-list permit | deny | any | anyTo apply a prefix list at the global level of RIP, enter commands such as the following.BigIron RX(config-rip-router)# prefix-list list1 inSyntax: [no] prefix-list in | outTo apply prefix lists to a RIP interface, enter commands such as the following.BigIron RX(config-if-e1000-1/2)# ip rip prefix-list list2 inBigIron RX(config-if-e1000-1/2)# ip rip prefix-list list3 outSyntax: [no] ip rip prefix-list in | outIn applies the prefix list to routes the device learns from its neighbor on the interface.Out applies the prefix list to routes the device advertises to its neighbor on the interface.The commands apply RIP list2 route filters to all routes learned from the RIP neighbor on port 1/2and applies the lists to all routes advertised on port 1/2.To apply a route map to a RIP interface, enter commands such as the following.BigIron RX(config-if-e1000-1/2)# ip rip route-map map1 inSyntax: [no] ip rip route-map in | outThe route-map can be a prefix list or an ACL. Setting this command can change the metric.In applies the route map to routes the device learns from its neighbor on the interface.Out applies the route map to routes the device advertises to its neighbor on the interface.
