Dell S5148F-ON OS10 Enterprise Edition User Guide Release 10.3.2E-R1 - Page 376

Route-maps Route-maps a series of commands that contain a matching criterion and action. They change the packets meeting the matching criterion. ACLs and prefix-lists can only drop or forward the packet or traffic while route-maps process routes for route redistribution. For example, use a route-map to filter only specific routes and to add a metric. • Route-maps also have an implicit deny. Unlike ACLs and prefix-lists where the packet or traffic is dropped, if a route does not match the route-map conditions, the route is not redistributed. • Route-maps process routes for route redistribution. For example, to add a metric, a route-map can filter only specific routes. If the route does not match the conditions, the route-map decides where the packet or traffic drops. The route is not redistributed if it does not match. • Route-maps use commands to decide what to do with traffic. To remove the match criteria in a route-map, use the no match command. • In a BGP route-map, if you repeat the same match statements; for example, a match metric, with different values in the same sequence number, only the last match and set values are taken into account. Configure match metric OS10(config)# route-map hello OS10(conf-route-map)# match metric 20 View route-map OS10(conf-route-map)# do show route-map route-map hello, permit, sequence 10 Match clauses: metric 20 Change match OS10(conf-route-map)# match metric 30 View updated route-map OS10(conf-route-map)# do show route-map route-map hello, permit, sequence 10 Match clauses: metric 30 To filter the routes for redistribution, combine route-maps and IP prefix lists. If the route or packet matches the configured criteria, the OS10 processes the route based on the permit or deny configuration of the prefix list. When a route-map and a prefix list combine: • For a route map with the permit action: • If a route matches a prefix-list set to deny, the route is denied • If a route matches a prefix-list set to permit, the route is permitted and any set of actions are apply • For a route map with the deny action: • If a route matches a prefix-list set to deny, the route is denied • If a route matches a prefix-list set to permit, the route is denied View both IP prefix-list and route-map configuration OS10(conf-router-bgp-neighbor-af)# do show ip prefix-list ip prefix-list p1: seq 1 deny 10.1.1.0/24 seq 10 permit 0.0.0.0/0 le 32 ip prefix-list p2: seq 1 permit 10.1.1.0/24 seq 10 permit 0.0.0.0/0 le 32 376 Access Control Lists