Which command set is used to force a former primary HA device to shut down all non-heartbeat interfaces during a failover?

The command set used to force a former primary HA (High Availability) device to shut down all non-heartbeat interfaces during a failover includes all the options provided.

The command to configure the HA settings is essential, as it is the starting point for making any modifications to the HA behavior. It sets the context for configuring various parameters, including those related to link failure signaling.

Enabling the link-failed signal is specifically important in an HA environment, as it instructs the device to shut down non-heartbeat interfaces when it detects a failure. This behavior is critical for maintaining network integrity and ensuring that failover processes occur smoothly without unnecessary traffic on interfaces that should be inactive during a failover.

Finally, the command "end" is used to exit the configuration mode. Although it might seem like an ancillary command, it completes the command set necessary to implement any changes made prior to exiting.

Thus, all the commands work together to achieve the goal of properly handling a failover scenario in a High Availability setup, making the selection of all commands as the answer correct.