Reference Guide
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 prex-lists can only drop or forward the packet or trac while route-maps process routes for route redistribution. For example,
use a route-map to lter only specic routes and to add a metric.
• Route-maps also have an implicit deny. Unlike ACLs and prex-lists where the packet or trac 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 lter only specic routes. If the route
does not match the conditions, the route-map decides where the packet or trac drops. The route is not redistributed if it does not
match.
• Route-maps use commands to decide what to do with trac. 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 dierent values in the same sequence
number, only the last match and set values are taken into account.
Congure 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 lter the routes for redistribution, combine route-maps and IP prex lists. If the route or packet matches the congured criteria, the
OS10 processes the route based on the permit or deny conguration of the prex list.
When a route-map and a prex list combine:
• For a route map with the permit action:
– If a route matches a prex-list set to deny, the route is denied
– If a route matches a prex-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 prex-list set to deny, the route is denied
– If a route matches a prex-list set to permit, the route is denied
View both IP prex-list and route-map conguration
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
Access Control Lists
495