Configuring Bgp As Confederation Attribute - 3Com 8800 Configuration Manual

3Com Switch 8800 Configuration Guide
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.
II. 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.
Table 21-36 Configure the Cluster_ID of the route reflector
Configure the Cluster_ID of the route reflector
Cancel the Cluster_ID of the route reflector
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.

21.2.16 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.
I. 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 does
not need to know the status of internal sub-ASs, and the confederation ID is the AS
number identifying the confederation as a whole.
Perform the following configuration in BGP view.
Operation
21-22
Chapter 21 BGP Configuration
Command
reflector cluster-id { cluster-id |
address }
undo reflector cluster-id