Preemption
A router in a VRRP group operates in either non-preemptive mode or preemptive mode.
Non-preemptive mode—The master router acts as the master as long as it operates correctly, even if a backup router is later assigned a higher priority. Non-preemptive mode helps avoid frequent switchover between the master and backup routers.
Preemptive mode—A backup starts a new master election and takes over as master when it detects that it has a higher priority than the current master. Preemptive mode ensures that the router with the highest priority in a VRRP group always acts as the master.