Juniper JUNOSE 11.2.X BGP AND MPLS, Configuration Manual

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Route-Refresh Capability
The route-refresh capability provides a lower-cost alternative to soft reconfiguration as
a means to change policies without major disruptions. The router advertises the
route-refresh capability when it establishes a BGP session with a peer to indicate that it
is capable of exchanging BGP route-refresh messages. If inbound soft reconfiguration is
disabled (the default) and you issue the
clear ip bgp soft in command, the router sends
route-refresh messages to its peers that have advertised this capability. The messages
contain a request for the peer to resend its routes to the router. The new inbound policy
is then applied to the routes as they are received.
Our implementation conforms to RFC 2918—Route Refresh Capability for BGP-4
(September 2000), but it also supports nonstandard implementations.
Cooperative Route Filtering
If a BGP speaker negotiates the cooperative route filtering capability with a peer, then
the speaker can transfer inbound route filters to the peer. The peer then installs the filter
as an outbound route filter (ORF) on the remote end. The ORF is applied by the peer
after application of its configured outbound policies. This cooperative filtering has the
advantage of both reducing the amount of processing required for inbound BGP updates
and reducing the amount of BGP control traffic generated by BGP updates.
clear ip bgp
•
Use to push an ORF to the peer and reapply inbound policy to all received routes without
clearing the BGP session.
•
You can specify the IP address of a BGP neighbor, the name of a BGP peer group, or
an address family to be cleared.
•
Use the asterisk (*) to clear all BGP connections.
•
If the ORF capability is not configured or received on the peer, then the prefix-filter
keyword is ignored and the router performs a normal inbound soft reconfiguration.
•
This command takes effect immediately.
•
There is no no version.
•
See clear ip bgp.
neighbor capability
•
Use to negotiate the exchange of inbound route filters and their installation as ORFs
by specifying the
orf keyword, an ORF type, and the direction of the capability.
•
If you specify a BGP peer group by using the peerGroupName argument, all the members
of the peer group inherit the characteristic configured with this command unless it is
overridden for a specific peer.
•
You cannot configure the receive direction for the orf capability for a peer that is a
member of a peer group or for a peer.
•
When issued with the orf keyword, this command takes effect immediately and
automatically bounces the BGP session.
Copyright © 2010, Juniper Networks, Inc. 98
JunosE 11.2.x BGP and MPLS Configuration Guide