R3303-HP HSR6800 Routers Layer 3 - IP Routing Configuration Guide

239
Step Command Remarks
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 an active/standby switchover
occurs:
• GR restarter—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.
NOTE:
• Unless otherwise specified, an active/standby switchover collectively refers to an active/standby MPU
switchover in standalone mode and a global active/standby MPU switchover in IRF mode.
• A device can act as a GR restarter and GR helper at the same time.
Following is a GR process:
1. A BGP GR restarter and helper exchange Open messages with GR capability. If both parties have
the GR capability, the session established between them is GR capable.
2. When an active/standby switchover occurs on the GR restarter, the GR restarter does not remove
existing route entries. The GR restarter still uses these routes for packet forwarding. The GR helper
does not delete the routes learned from the GR restarter but mark them as stale and use them for
packet forwarding. During the GR process, packet forwarding is not interrupted.
3. After the active/standby switchover is completed, the GR restarter re-establishes a GR session with
the GR helper. If no BGP session is established within the interval set with the graceful-restart timer
restart command, the GR helper removes the stale routes.
4. If a BGP session is established, routing information is exchanged between them for the GR restarter
to retrieve route entries, and for the GR helper to recover stale routes. You can control the routing