Brocade Virtual ADX Switch and Router Guide (Supporting ADX v03.1.00) - Manual (Page 266)

252 Brocade Virtual ADX Switch and Router Guide
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Filtering
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The name-or-num parameter specifies the name or number of a standard, extended, or named
ACL.
The in | out parameters specify whether the distribute list applies to inbound or outbound routes:
• in – controls the routes the device will accept from the neighbor.
• out – controls the routes sent to the neighbor.
Defining route maps
A route map is a named set of match conditions and parameter settings that the device can use to
modify route attributes and to control redistribution of the routes into other protocols. A route map
consists of a sequence of instances. If you think of a route map as a table, an instance is a row in
that table. The device evaluates a route according to route map instances in ascending numerical
order. The route is first compared against instance 1, then against instance 2, and so on. When a
match is found, the device stops evaluating the route.
Route maps can contain match clauses and set statements. Each route map contains a permit or
deny action for routes that match the match clauses:
• If the route map contains a permit action, a route that matches a match statement is
permitted; 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 is
the default action. To change the default action, configure the last match statement in the last
instance of the route map to permit 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 action
specified by a filter conflicts with the action specified by the route map, the route map action
takes precedence over the filter action.
If the route map contains set clauses, routes that are permitted by the route map match
statements are modified according to the set clauses.
Match statements compare the route against one or more of the following:
• The route BGP4 MED (metric)
• A sequence of AS-path filters
• A sequence of community filters
• A sequence of address filters
• The IP address of the next hop device
• The route tag
• For OSPF routes only, the route type (internal, external type-1, or external type-2)
• An AS-path ACL
• A community ACL
• An IP prefix list
• An IP ACL
For routes that match all of the match statements, the route map set clauses can perform one or
more of the following modifications to the route attributes: