BigIron RX Series Configuration Guide 67153-1002253-01Configuring RIP parameters 24Configuring redistributionYou can configure the device to redistribute routes learned through OSPF or BGP4, connected intoRIP, or static routes. When you redistribute a route from one of these other protocols into RIP, thedevice can use RIP to advertise the route to its RIP neighbors.To configure redistribution, perform the following tasks:• Configure redistribution filters. You can configure filters to permit or deny redistribution for aroute based on its origin (OSPF, BGP4, and so on), the destination network address, and theroute’s metric. You also can configure a filter to set the metric based on these criteria.• Change the default redistribution metric (optional). The device assigns a RIP metric of one toeach redistributed route by default. You can change the default metric to a value up to 16.Configuring redistribution filtersRIP redistribution filters apply to all interfaces. You use route maps to define how you want to denyor permit redistribution.NOTEThe default redistribution action is permit, even after you configure and apply redistribution filtersto the virtual routing interface. If you want to tightly control redistribution, apply a filter to deny allroutes as the last filter (the filter with the highest ID), then apply filters to allow specific routes.A route map is a named set of match conditions and parameter settings that the router can use tomodify route attributes and to control redistribution of the routes into other protocols. A route mapconsists of a sequence of up to 50 instances. If you think of a route map as a table, an instance isa row in that table. The router evaluates a route according to a route map’s instances in ascendingnumerical order. The route is first compared against instance 1, then against instance 2, and soon. As soon as a match is found, the router stops evaluating the route against the route mapinstances.Route maps can contain match statements and set statements. Each route map contains a“permit” or “deny” action for routes that match the match statements.• If the route map contains a permit action, a route that matches a match statement ispermitted; otherwise, the route is denied.• If the route map contains a deny action, a route that matches a match statement is denied.• If a route does not match any match statements in the route map, the route is denied. This isthe default action. To change the default action, configure the last match statement in the lastinstance of the route map to “permit any any”.• If there is no match statement, the software considers the route to be a match.• For route maps that contain address filters, AS-path filters, or community filters, if the actionspecified by a filter conflicts with the action specified by the route map, the route map’s actiontakes precedence over the individual filter’s action.If the route map contains set statements, routes that are permitted by the route map’s matchstatements are modified according to the set statements.In RIP, the match statements are based on prefix lists and access control lists. Set statements arebased on tag values and metric values.To configure redistribution filters, enter a command such as the following.BigIron RX(config-rip-router)#redistribute bgp route-map longroute
