VRRP preemption is what tells devices in a virtual VRRP router instance that the highest priority device will always take over as VRRP master. This feature is on by default in AW+ when VRRP is enabled. However there may be circumstances when it is undesirable for a VRRP master state to toggle between multiple devices when there is network instability, or when it is preferable to investigate the root cause of a master failover before the original master takes over again. Preemption may, therefore, be disabled. When a master failover takes place, the new VRRP master ownership will not automatically revert back to the original device.
router vrrp 2 vlan3
virtual-ip 192.168.2.254 backup
Preemption cannot be disabled on the device that owns the virtual-ip--meaning it has the virtual-ip configured as an actual IP interface. However, it is possible to configure all devices as VRRP backups with the same VRRP priority (100 is default) as long as the virtual-ip is not set as an actual IP interface. Then, preemption can be set to "false" on all devices.