The confederation id command configures confederation ID.
The undo confederation id command removes the BGP confederation.
By default, no confederation ID is configured.
| Parameter | Description | Value |
|---|---|---|
| as-number-plain | Integral AS number | The value is an integer ranging from 1 to 4294967295. |
| as-number-dot | AS number 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
To solve the problem that a large AS may contain too large a full-meshed IBGP, you can use the method of confederation.
Divide the AS into multiple small ASs and group them into a confederation. Some key attributes of routes, such as next hop, MED and the local preference are not dropped when these routes pass the sub-AS. Because seen from the outside, the confederation is still a complete entity. Therefore, the completeness of the original AS is reserved and the excessive connections are reduced.
Precautions
The confederation ID is equal to the number of the entire AS. The other 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 confederation ID. An AS is divided into sub-AS 65001, 65002, 65003, and 65004, and their confederation ID is 9. A peer 1.2.3.4 is a member of the AS confederation with id 9. A peer 3.4.5.6 is a member outside the autonomous system confederation. For the external members, confederation 9 is a complete AS.
<sysname> system-view
[sysname] bgp 65004
[sysname-bgp] confederation id 9
[sysname-bgp] confederation peer-as 65001 65002 65003
[sysname-bgp] peer 1.2.3.4 as-number 65001
[sysname-bgp] peer 3.4.5.6 as-number 65005