6-7
[Sysname] bgp 100
[Sysname-bgp] ipv4-family vpn-instance vpn1
[Sysname-bgp-vpn1] compare-different-as-med
confederation id
Syntax
confederation id
as-number
undo confederation id
View
BGP view
Default Level
2: System level
Parameters
as-number
: Number of the AS that contains multiple sub-ASs, in the range 1 to 4294967295.
Description
Use the
confederation id
command to configure a confederation ID.
Use the
undo confederation id
command to remove a specified confederation.
By default, no confederation ID is configured.
Configuring a confederation can reduce IBGP connections in a large AS. You can split the AS into
several sub-ASs, and each sub-AS remains fully meshed. These sub-ASs form a confederation. Key
IGP attributes of a route, such as the next hop, MED, local preference, are not discarded when
crossing each sub-AS. The sub-ASs still look like a whole from the perspective of other ASs. This can
ensure the integrity of the former AS, and solve the problem of too many IBGP connections in the AS.
Related commands:
confederation nonstandard
and
confederation peer-as
.
Examples
# Confederation 9 consists of four sub-ASs, namely, 38, 39, 40 and 41. The peer 10.1.1.1 is a member
of the confederation while the peer 200.1.1.1 is outside of the confederation. Take sub AS 41 as an
example.
<Sysname> system-view
[Sysname] bgp 41
[Sysname-bgp] confederation id 9
[Sysname-bgp] confederation peer-as 38 39 40
[Sysname-bgp] group Confed38 external
[Sysname-bgp] peer Confed38 as-number 38
[Sysname-bgp] peer 10.1.1.1 group Confed38
[Sysname-bgp] group Remote98 external
[Sysname-bgp] peer Remote98 as-number 98
[Sysname-bgp] peer 200.1.1.1 group Remote98
confederation nonstandard
Syntax
confederation nonstandard