H3C Technologies H3C S12500 Series Switches - Manual (Page 245)

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You can configure the keepalive interval and holdtime globally or for a specific peer or peer group. The
intervals configured for the specified peer or peer group takes higher priority. The actual keepalive
interval and holdtime depend on the following cases:
• If the holdtime settings on the local and peer routers are different, the smaller one is used. The
holdtime is no less than three seconds unless it is set to 0.
• If the configured keepalive interval is 0 and the negotiated holdtime is not 0, the actual keepalive
interval equals one-third of the holdtime. The maximum keepalive interval should be one third of the
holdtime and no less than one second.
• If the configured keepalive interval is not 0, the actual keepalive interval is the smaller one between
one third of the holdtime and the keepalive interval.
Follow these guidelines when you configure BGP keepalive interval and holdtime:
• The intervals set with the peer timer command are preferred to those set with the timer command.
• If the router has established a BGP session with a peer, you must reset the BGP session to validate
the new set timers.
• The timer command takes effect for only new BGP sessions.
• After you set new intervals with the peer timer command, the existing BGP session is closed at once,
and a new session to the peer is negotiated by using the configured holdtime.
To configure BGP keepalive interval and holdtime:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter BGP view or BGP-VPN
instance view.
• Enter BGP view:
bgp as-number
• Enter BGP-VPN instance view:
a. bgp as-number
b. ipv4-family vpn-instance
vpn-instance-name
Use either method.
3. Configure BGP keepalive interval
and holdtime.
• Configure the global keepalive
interval and holdtime:
timer keepalive keepalive hold
holdtime
• Configure the keepalive interval
and holdtime for a peer or peer
group:
peer { group-name |
ip-address } timer keepalive
keepalive hold holdtime
Optional.
By default, the keepalive
interval is 60 seconds, and
holdtime is 180 seconds.
Configuring the interval for sending the same update
A BGP router sends an update message to its peers when a route is changed. If the route changes
frequently, the BGP router sends a large number of updates for the route, which can cause route flaps.
This task allows you to configure the interval for sending the same update to a peer or peer group,
avoiding frequent update sending and route flaps.
To configure the interval for sending the same update to a peer or peer group: