Configuring the keepalive interval and hold time

BGP sends keepalive messages at a specific interval to keep the BGP session between two routers.

If a router receives no keepalive or update message from a peer within the hold time, it tears down the session.

You can configure the keepalive interval and hold time globally or for a specific peer or peer group. The individual settings take precedence over the global settings.

The actual keepalive interval and hold time are determined as follows:

If the hold time settings on the local and peer routers are different, the smaller setting is used. If the hold time is 0, BGP does not send keepalive messages to its peers and never tears down the session.
If the keepalive interval is 0 and the negotiated hold time is not 0, the actual keepalive interval equals 1/3 of the hold time. If the keepalive interval is not 0, the actual keepalive interval is the smaller one between 1/3 of the hold time and the keepalive interval.

To configure the keepalive interval and hold time (IPv4):

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: bgp as-number ip vpn-instance vpn-instance-name	N/A
3. Configure the keepalive interval and hold time.	Configure the global keepalive interval and hold time: timer keepalive keepalive hold holdtime Configure the keepalive interval and hold time for a peer or peer group: peer { group-name \| ip-address [ mask-length ] } timer keepalive keepalive hold holdtime	Use at least one method. By default, the keepalive interval is 60 seconds, and hold time is 180 seconds. The timer command takes effect for new BGP sessions and does not affect existing sessions. If you modify the timers with the peer timer command, BGP immediately closes the existing BGP session and creates a new session to the peer by using the new settings. The holdtime must be at least three times the keepalive interval.

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:
1. bgp as-number
2. ip vpn-instance vpn-instance-name

N/A

3. Configure the keepalive interval and hold time.

Configure the global keepalive interval and hold time: timer keepalive keepalive hold holdtime
Configure the keepalive interval and hold time for a peer or peer group: peer { group-name | ip-address [ mask-length ] } timer keepalive keepalive hold holdtime

Use at least one method.

By default, the keepalive interval is 60 seconds, and hold time is 180 seconds.

The timer command takes effect for new BGP sessions and does not affect existing sessions.

If you modify the timers with the peer timer command, BGP immediately closes the existing BGP session and creates a new session to the peer by using the new settings.

The holdtime must be at least three times the keepalive interval.

To configure the keepalive interval and hold time (IPv6):

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: bgp as-number ip vpn-instance vpn-instance-name	N/A
3. Configure the keepalive interval and hold time.	Configure the global keepalive interval and hold time: timer keepalive keepalive hold holdtime Configure the keepalive interval and hold time for a peer or peer group: peer { group-name \| ipv6-address [ prefix-length ] } timer keepalive keepalive hold holdtime	Use at least one method. By default, the keepalive interval is 60 seconds, and hold time is 180 seconds. The timer command takes effect for new BGP sessions and does not affect existing sessions. If you modify the timers with the peer timer command, BGP immediately closes the existing BGP session and creates a new session to the peer by using the new settings. The holdtime must be at least three times the keepalive interval.