Enabling Quick Ebgp Session Reestablishment - HP 4800G Series Configuration Manual

The current BGP implementation supports the route-refresh capability, with which, a router can
dynamically refresh its BGP routing table when the route selection policy is modified, without tearing
down BGP connections. If a BGP peer does not support route-refresh, you need to save updates from
the peer on the local router. After that, when a route selection policy is modified, the router can refresh
its BGP routing table by using such updates without tearing down BGP connections.
Configure automatic soft-reset
After route refresh is enabled for peers and then a policy is modified, the router advertises a
route-refresh message to the peers, which then resend their routing information to the router. In this way,
the router can perform dynamic route update and apply the new policy without tearing down BGP
connections.
Follow these steps to enable BGP route refresh for a peer/peer group:
Enter system view
Enter BGP view
Enable BGP route refresh for a
peer/peer group
Configure manual soft-reset
If a BGP peer does not support route-refresh, you need to save updates from the peer on the local
router by using the peer keep-all-routes command. When a route selection policy is modified, you can
use the refresh bgp command to refresh the BGP routing table by applying the new policy.
Following these steps to save all route updates from a peer/peer group:
Enter system view
Enter BGP view
Disable BGP route-refresh and
multi-protocol extension capability for a
peer/peer group
Save all routes from a peer/peer group
Return to user view
Perform manual soft reset on BGP
connections

Enabling Quick eBGP Session Reestablishment

If the router receives no keepalive messages from a BGP peer within the holdtime, it tears down the
connection to the peer.
To do...
To do...
Use the command...
system-view
bgp as-number
peer { group-name |
ip-address }
capability-advertise
route-refresh
Use the command...
system-view
bgp as-number
peer { group-name |
ip-address }
capability-advertise
conventional
peer { group-name |
ip-address } keep-all-routes
return
refresh bgp { all | ip-address
| group group-name |
external | internal } { export
| import }
1-33
Remarks
—
—
Optional
Enabled by default
Remarks
—
—
Optional
Enabled by default
Optional
Not saved by default
—
Required