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Use Route Maps and Other Filters to Filter and Alter BGP and OSPF Routes | Page 35
BGP: Applying Distribute, Path, Prefix, and Route Map Filters to a Peer
BGP: Applying Distribute, Path, Prefix, and Route
Map Filters to a Peer
Distribute filters, path filters, prefix filters, and route maps can all be applied to a BGP peer
configuration for both incoming and outgoing updates. However, you cannot combine
distribute filters (ACLs) and prefix filters.
First, enter BGP router mode for the AS. The prompt should look like:
awplus(config-router)#
Then use the following commands to apply:
an ACL to filter incoming route updates:
neighbor <ipadd> distribute-list <acl> in
a path list to filter incoming route updates:
neighbor <ipadd> filter-list <list-name> in
a prefix list to filter incoming route updates:
neighbor <ipadd> prefix-list <list-name> in
a route map to filter incoming route updates or alter their attributes:
neighbor <ipadd> route-map <map-name> in
an ACL to filter outgoing route updates:
neighbor <ipadd> distribute-list <acl> out
a path list to filter outgoing route updates:
neighbor <ipadd> filter-list <list-name> out
a prefix list to filter outgoing route updates:
neighbor <ipadd> prefix-list <list-name> out
a route map to filter outgoing route updates or alter their attributes:
neighbor <ipadd> route-map <map-name> out
You can also use an AS path list, prefix list or ACL in a route map, instead of applying it
directly as a filter.
As mentioned in "Hierarchy of the Different Filters" on page 8, if you configure multiple types
of filter, the switch applies the route maps last. This is true in both the incoming and outgoing
directions.