During an HA firmware upgrade, what happens to the secondary device after the primary is rebooted?

During an HA firmware upgrade, when the primary device is rebooted, the secondary device is automatically promoted to the primary role. This is an essential function of High Availability (HA) configurations, designed to ensure continuous operation and minimize downtime during maintenance activities.

When the primary unit undergoes a reboot, the HA cluster recognizes that the primary device is no longer operational. The secondary device steps in to take over the responsibilities of the primary device seamlessly. This failover process allows the network to maintain its availability, ensuring that services continue without interruption while the primary device is being upgraded.

The other options suggest that the secondary device either remains idle or undergoes actions that are not relevant to maintaining high availability during firmware upgrades. However, the primary goal of HA is to ensure that there is always an active device ready to handle traffic, which is achieved by promoting the secondary unit to primary during such events.