Help us improve your experience.

Let us know what you think.

Do you have time for a two-minute survey?


preempt (Chassis Cluster)


Hierarchy Level


Allow preemption of the primary system based on the priority within a redundancy group.

Configuring preemption for RG0 is not allowed and is blocked when committed.

By configuring the preemptive delay timer and failover limit, you can limit the flapping of the redundancy group state between the secondary and the primary in a preemptive failover.

By default, preemption is disabled.

Example: Consider the following scenario where you have configured a preemptive period as 300 seconds and preemptive limit as 50.

When the preemptive limit is configured as 50, the count starts at 0 and increments with a first preemptive failover; this process continues until the count reaches the configured preemptive limit, that is 50, before the preemptive period expires. When the preemptive limit (50) is exceeded, you must manually reset the preempt count to allow preemptive failovers to occur again.

When you have configured the preemptive period as 300 seconds, and if the time difference between the first preemptive failover and the current failover has already exceeded 300 seconds, and the preemptive limit (50) is not yet reached, then the preemptive period will be reset. After resetting, the last failover is considered as the first preemptive failover of the new preemptive period and the process starts all over again.



Time to wait before the node in secondary state transitions to primary state in a preemptive failover.

  • Range: 1 to 21,600 seconds

  • Default: 1


Maximum number of preemptive failovers allowed in a configured preemptive period.

  • Range: 1 to 50


Time period during which the preemptive limit is applied.

  • Range: 1 to 1400 seconds

Required Privilege Level

interface—To view this statement in the configuration.

interface-control—To add this statement to the configuration.

Release Information

Statement introduced in Junos OS Release 9.0. Support for delay, limit, and period options are added in Junos OS Release 17.4R1.