NSE4 High Availability and Diagnostics Practice Question
An administrator is configuring a new FortiGate HA cluster in active-passive mode. The administrator wants to ensure that the primary unit is always the same physical device, even after a reboot or failure, as long as it is operational. Which HA setting should the administrator configure?
⚠ Common exam trap
The trap here is assuming that setting a higher priority alone is sufficient; without override enabled, the unit will not reclaim the primary role after recovering from a failure.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Enable HA override on the preferred primary unit.
To ensure a specific unit always becomes primary when available, the administrator should enable HA override on that unit and set its priority higher than the other unit. Override allows the unit to preempt the current primary after it reboots or recovers from a failure, maintaining a consistent primary device.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Set the HA priority to a higher value on the preferred primary unit.
Why it's wrong here
Setting a higher HA priority designates a preferred primary, but without enabling override, the unit will not automatically reclaim the primary role after a failure and recovery. Priority alone does not guarantee the same unit becomes primary after a reboot; override must be enabled to enforce that behavior.
- ✗
Configure the HA group ID to match the unit's serial number.
Why it's wrong here
The HA group ID is used to identify the cluster and must be the same on all members. It does not influence which unit becomes primary. Setting it to a serial number would not achieve the goal and could cause confusion. Primary election is determined by priority and override, not group ID.
- ✗
Set the HA mode to active-active.
Why it's wrong here
Active-active mode allows both units to process traffic simultaneously, but it does not guarantee a specific unit becomes primary. Primary election still depends on priority and override. Changing to active-active does not ensure the same physical device is always primary after a reboot.
- ✓
Enable HA override on the preferred primary unit.
Why this is correct
Enabling HA override allows a unit with a higher priority to take over as primary when it becomes available, even if another unit is currently primary. This ensures the preferred unit always becomes primary after a reboot or failure, as long as it is operational. Override must be enabled on the unit that should become primary.
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Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Fortinet exam blueprint
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