Install guide

Filtering IP Routes 2-29
Software Version 2.7.5
C613-10454-00 REV A
Overview of Filters for each Route Source
The sections above describe each type of filter. This section contains a series of
diagrams that summarise the available filters for each route source:
■ Border Gateway Protocol (BGP-4)
■ Open Shortest Path First (OSPF)
■ Routing Information Protocol (RIP)
■ Interface Routes
■ Statically-Configured Routes
Border Gateway Protocol (BGP-4)
When the router or switch runs BGP, it receives routing information from peer
routers. It may also advertise routing information from BGP and other route
sources to peer routers. You can filter routing information at the processing
points shown in the following figure.
Processing points for route filtering when using BGP
BGP peer
routes in incoming
update message
BGP route table
Routing
Information
Base
(RIB)
inpathlist filter
then
infilter filter
then
inroutemap filter
filtered by
route map
applied using
add bgp import
OSPF, RIP, static
and interface routes
outpathlist filter
then
outfilter filter
then
outroutemap filter
BGP peers
routes for
outgoing
update message
ip-route-filter-bgp
The filtering
router or switch