Disabling Backup Preemption

By default, a Backup device that has a higher priority than another Backup that has become the Master can preempt the new Master, and take over the role of Master. If you want to prevent this behavior, disable preemption.

Preemption applies only to Backup devices and takes effect only when the Master has failed and a Backup has assumed ownership of the VRID. The feature prevents a Backup with a higher priority from taking over as Master from another Backup that has a lower priority but has already become the new Master of the VRID.

Preemption is especially useful for preventing flapping in situations where there are multiple Backup devices and a Backup with a lower priority than another Backup has assumed ownership because the backup with the higher priority was unavailable when ownership changed.

If you enable the non-preempt mode (thus disabling the preemption feature) on all the Backup devices, the Backup that becomes the Master following the disappearance of the Master continues to be the Master. The new Master is not preempted.