API Guide

Route Maps
Although route maps are similar to ACLs and prefix lists in that they consist of a series of commands that contain a matching criterion and
an action, route maps can modify parameters in matching packets.
ACLs and prefix lists can only drop or forward the packet or traffic. Route maps process routes for route redistribution. For example, a
route map can be called to filter only specific routes and to add a metric.
Route maps also have an “implicit deny.” Unlike ACLs and prefix lists; however, where the packet or traffic is dropped, in route maps, if a
route does not match any of the route map conditions, the route is not redistributed.
Implementation Information
The implementation of route maps allows route maps with the no match or no set commands. When there is no match command, all
traffic matches the route map and the
set command applies.
Important Points to Remember
• For route-maps with more than one match clause:
• Two or more match clauses within the same route-map sequence have the same match commands (though the values are
different), matching a packet against these clauses is a logical OR operation.
• Two or more match clauses within the same route-map sequence have different match commands, matching a packet against
these clauses is a logical AND operation.
• If no match is found in a route-map sequence, the process moves to the next route-map sequence until a match is found, or there are
no more sequences.
• When a match is found, the packet is forwarded and no more route-map sequences are processed.
• If a continue clause is included in the route-map sequence, the next or a specified route-map sequence is processed after a match
is found.
Configuration Task List for Route Maps
Configure route maps in ROUTE-MAP mode and apply the maps in various commands in ROUTER RIP and ROUTER OSPF modes.
The following list includes the configuration tasks for route maps, as described in the following sections.
• Create a route map (mandatory)
• Configure route map filters (optional)
• Configure a route map for route redistribution (optional)
• Configure a route map for route tagging (optional)
Creating a Route Map
Route maps, ACLs, and prefix lists are similar in composition because all three contain filters, but route map filters do not contain the
permit and deny actions found in ACLs and prefix lists.
Route map filters match certain routes and set or specify values.
To create a route map, use the following command.
• Create a route map and assign it a unique name. The optional permit and deny keywords are the action of the route map.
CONFIGURATION mode
route-map map-name [permit | deny] [sequence-number]
The default is permit.
The optional seq keyword allows you to assign a sequence number to the route map instance.
The default action is permit and the default sequence number starts at 10. When you use the keyword deny in configuring a route map,
routes that meet the match filters are not redistributed.
To view the configuration, use the show config command in ROUTE-MAP mode.
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Access Control Lists (ACLs)