The confederation id command configures a BGP confederation and specifies a confederation ID for the BGP confederation.
The undo confederation id command removes the specified BGP confederation.
By default, no BGP confederation is configured.
| Parameter | Description | Value |
|---|---|---|
| as-number-plain | Specifies the number of the AS, in integer format. | The value is an integer that ranges from 1 to 4294967295. |
| as-number-dot | Specifies the number of the AS, in dotted notation. | The value is in the format of x.y, where x and y are integers that range from 1 to 65535 and from 0 to 65535, respectively. |
Usage Scenario
A large AS may contain a huge number of fully meshed IBGP peer relationships. In this situation, configure a confederation.
Divide the AS into multiple small sub-ASs and group them into a confederation. Then establish EBGP connections between sub-ASs and establish fully meshed IBGP connections within the same sub-AS. Some key attributes of routes, such as the next hop, MED, and local preference are not discarded when these routes pass through sub-ASs. This can reduce the number of fully meshed IBGP peer relationships in an AS and keep the integrity of the original AS.
Precautions
The confederation ID is equal to the AS number. An external AS must specify the confederation ID when specifying the AS number of the peer. All the sub-ASs in the same confederation must be configured with the same confederation ID that must be different from the number of any sub-AS.
# Configure a confederation ID. An AS is divided into sub-ASs 65001, 65002, 65003, and 65004, and their confederation ID is 9. Peer 10.2.3.4 is a member of the AS confederation. Peer 10.4.5.6 is a member outside the AS confederation. For the external members, confederation 9 is a complete AS.
<HUAWEI> system-view
[HUAWEI] bgp 65001
[HUAWEI-bgp] confederation id 9
[HUAWEI-bgp] confederation peer-as 65002 65003 65004
[HUAWEI-bgp] peer 10.2.3.4 as-number 65002
[HUAWEI-bgp] peer 10.4.5.6 as-number 65005