H3C Technologies H3C S12500 Series Switches - Manual (Page 254)

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A confederation contains sub-ASs. In each sub-AS, IBGP peers are fully meshed. Between sub-ASs, EBGP
connections are established.
If routers not compliant with RFC 3065 exist in the confederation, use the confederation nonstandard
command to make the local router compatible with these routers.
Configuring a BGP confederation
After you split an AS into multiple sub-ASs, you can configure a router in a sub-AS in the following way:
1. Enable BGP and specify the AS number of the router. For more information, see " Enabling BGP ."
2. Specify the confederation ID. From an outsider's perspective, the sub-ASs of the confederation is
a single AS, which is identified by the confederation ID.
3. If the router needs to establish EBGP connections to other sub-ASs, you must specify the peering
sub-ASs in the confederation.
A confederation contains a maximum of 32 sub-ASs. The AS number of a sub-AS is effective only in the
confederation.
To configure a BGP confederation:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter BGP view. bgp as-number N/A
3. Configure a confederation ID. confederation id as-number Not configured by default.
4. Specify peering sub-ASs in the
confederation.
confederation peer-as
as-number-list
Not configured by default.
Configuring confederation compatibility
If some other routers in the confederation do not comply with RFC 3065, you must enable confederation
compatibility to allow the router to work with those routers.
To configure confederation compatibility:
Step Command Remarks
1. Enter system view system-view N/A
2. Enter BGP view. bgp as-number N/A
3. Enable compatibility with
routers not compliant with
RFC 3065 in the
confederation.
confederation nonstandard
Optional.
Not enabled by default.
Configuring BGP GR
Graceful Restart (GR) ensures the continuity of packet forwarding when BGP restarts or an
active/standby switchover occurs:
• GR eestarter—Graceful restarting router. It must be GR capable.
• GR helper—A neighbor of the GR restarter. It helps the GR restarter to complete the GR process.