The Preempt command is only needed on the router that is the preferred active HSRP router.
If the active HSRP router A fails, the standby HSRP router B becomes the active. However when router A returns to service(without the preempt command), router B will continue to stay active even though router A has the higher priority.
The preempt command will force Router A to an active state after failure and router B would return to the standby state.
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...