Which option should be left unchecked when using Stateful High Availability (HA)?

In a Stateful High Availability (HA) configuration, enabling Preempt Mode can lead to issues during failover scenarios. When Preempt Mode is active, it allows the primary device to reclaim its role in the active state as soon as it comes back online after a failure. This can cause unnecessary disruptions in the network, particularly if the failover occurs frequently or if the primary device experiences intermittent issues. In high availability setups, it is often preferred to maintain stability and allow the secondary device to handle traffic without abruptly switching back to the primary under certain conditions, which could potentially lead to service interruptions.

When it comes to the other options, they are essential components that support proper functionality of a Stateful HA setup. Enabling Failover ensures that the secondary device can take over when the primary fails. Enable Stateful Sync is crucial for the devices to maintain consistent session data, so sessions can be quickly and seamlessly transferred to the secondary unit during a failover situation. Link Aggregation, which links multiple network connections in parallel, enhances the bandwidth and can also contribute to redundancy, making it a vital part of maintaining connectivity during HA operations.

Overall, leaving the Preempt Mode unchecked helps ensure a more stable HA environment by reducing the chances of disruptions during failover events.