HSRP Preemption

• Preemption only allows a router to become the active router if it has a higher priority
• A router enabled for preemption, with equal priority but a higher IPv4 address will not preempt an active router. Refer to the topology in the figure

By default, after a router becomes the active router, it will remain the active router even if another router comes online with a higher HSRP priority, it will not be preempted

To force a new HSRP election process to take place when a higher priority router comes online, preemption must be enabled using the standby preempt interface command

With preemption disabled, the router that boots up first will become the active router if there are no other routers online during the election process

With preemption enabled, a router that comes online with a higher HSRP priority will assume the role of the active router