Juniper JUNOSE 11.2.X BGP AND MPLS, Configuration Manual

Page: 452 / 742

When the route-refresh capability has been negotiated for the route-target address
family. BGP handles route-refresh messages for the RT-MEM-AFI-SAFI by resending all
RT-MEM-NLRI routes to the remote peer
You can use the neighbor maximum-prefix command to specify the maximum number
of prefixes that the speaker can receive from a BGP peer.
Route-target filtering generally follows the standard BGP rules for route advertisement
to determine when to advertise RT-MEM-NLRI prefixes that have been received from
BGP peers. Table 88 on page 416 lists the destinations that the prefixes are advertised to
based on their source. In this table, client-to-client reflection is enabled and the source
and destination peers are not the same.
Table 88: Route-Target Filtering Advertisement Rules for Routes Received
from Peers
Advertise to EBGP
Confederation
Peer? Advertise
to EBGP
Peer?
Advertise to
IBGP Route
Reflector
Nonclient? Advertise to
IBGP Route
Reflector
Client?
Routes Received From
Yes Yes Yes Yes IBGP route reflector client
Yes Yes No Yes IBGP route reflector
nonclient
Yes Yes Yes Yes EBGP peer
Yes Yes Yes Yes EBGP confederation peer
Advertising to IBGP clients varies from the standard advertisement rules in terms of path
attribute modifications. When locally originated RT-MEM-NLRI routes are advertised to
IBGP route reflector clients, BGP does the following:
•
Sets the originator ID as the router ID of the advertising router.
•
Sets the next hop as the local address of the session.
This behavior is useful when the route reflector does not advertise the
Default-RT-MEM-NLRI route.
When locally originated RT-MEM-NLRI routes are advertised to IBGP route reflector
nonclients, the route from the client is advertised to the nonclient peer when the best
path route is advertised by a nonclient but an alternative route from a client exists. This
behavior signals the client’s interest in the route target routes that were not selected as
the best path.
You cannot filter RT-MEM-NLRI routes with inbound policies or outbound policies, because
policy items cannot currently match a RT-MEM-NLRI prefix (origin AS number:route
target). However, you can filter route-target filtering routes with policies that include
items that match on other BGP attributes, such as the extended community attached
to the route-target filtering route.
Copyright © 2010, Juniper Networks, Inc. 416
JunosE 11.2.x BGP and MPLS Configuration Guide