3Com Switch 8800 Family Configuration Guide

Configuring BGP 379
Configuring the route reflection between clients
Perform the following configuration in BGP view.
By default, the route reflection between clients is allowed. If the clients are fully
connected, for the purpose of overhead reduction, it is recommended to use the
undo reflect between-clients command to disable the route reflection between
clients.
Configuring the cluster ID
Generally, there is only one route reflector in a cluster which is identified by the
router ID of the route reflector.
Perform the following configuration in BGP view.
The autonomous system possibly generates routing loop due to the route reflector
in a cluster. After leaving a cluster, a routing update packet possibly tries to go
back to the cluster. Because the routing update packet has not left an AS, the
traditional AS path method cannot detect the loop inside the AS. When
configuring route reflectors, you can use the following two methods to avoid loop
inside the AS. One is to use the cluster ID; the other is to use Originator_ID of a
route reflector.
If you configure Originator_ID improperly, the originator will discard the update
packet when the update packet goes back to the originator. You do not need to
configure Originator_ID. Originator_ID automatically takes effect when BGP is
enabled.
Configuring BGP AS
Confederation Attribute
Confederation provides the method to handle the booming IBGP network
connections inside AS. It divides the AS into multiple sub-AS, in each of which all
IBGP peers are fully connected, and are connected with other sub-AS of the
confederation.
The shortcomings of confederation are that it is required that the route be
re-configured upon switching from non-confederation to confederation solution,
and that the logic topology be basically changed. Furthermore, the path selected
via confederation may not be the best path if there is no manually-set BGP policy.
Configuring confederation_ID
In the eye of the BGP speakers that are not included in the confederation, multiple
sub-ASs that belong to the same confederation are a whole. The external network
Tab le 383 Configure the route reflection between clients
Operation Command
Enable route reflection between clients reflect between-clients
Disable route reflection between clients undo reflect between-clients
Tab le 384 Configure the Cluster_ID of the route reflector
Operation Command
Configure the Cluster_ID of the route reflector reflector cluster-id { cluster-id | address }
Cancel the Cluster_ID of the route reflector undo reflector cluster-id