The answer is that the override setting is not enabled on the active-passive HA cluster. This is because FortiGate’s default HA behavior is non-preemptive, meaning that when the primary unit recovers after a failure, it will not automatically force a failback to regain its active role. The cluster sees the recovered primary as a standby unit and leaves the current secondary as the active device unless the override option is explicitly turned on. On the NSE 4 exam, this concept tests your understanding of HA preemption versus non-preemption, often appearing as a trap where candidates assume a recovered primary will always resume its role. A common memory tip is to think of “override” as the permission slip that tells the cluster to preempt—without it, the primary stays passive. Remember: no override, no automatic failback.
NSE4 High Availability and Diagnostics Practice Question
This NSE4 practice question tests your understanding of high availability and diagnostics. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A FortiGate is configured with an active-passive HA cluster. The admin notices that when the primary unit fails, the secondary takes over, but after the primary recovers, it does not automatically become active again. What is the most likely reason?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "most likely"
Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
Clue: "primary"
Why it matters: Asks for the main purpose or function, not a secondary benefit. Eliminate answers that describe side-effects or partial functions.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Override is not enabled
By default, HA does not preempt. The 'override' setting is disabled. When the primary recovers, it does not force a failback because the cluster is non-preemptive. The admin must enable override if they want automatic failback.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
The primary has a lower priority than the secondary
Why it's wrong here
If priority is lower, it would not become primary, but the scenario implies primary has higher priority.
✓
Override is not enabled
Why this is correct
Override must be enabled to allow a higher-priority unit to preempt the current primary.
Clue confirmation
The clue words "most likely", "primary" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
✗
Session pickup is disabled
Why it's wrong here
Session pickup affects session synchronization, not failback behavior.
✗
The heartbeat interface is down
Why it's wrong here
If heartbeat is down, the cluster would split-brain or fail, not cause this specific behavior.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Many certification questions include familiar terms but test a specific constraint. Read the exact wording before choosing an answer that is generally true but wrong for this case.
Trap categories for this question
Scenario analysis trap
If priority is lower, it would not become primary, but the scenario implies primary has higher priority.
Detailed technical explanation
How to think about this question
This question should be treated as a scenario, not a definition check. Identify the problem, the constraint and the best action. Then compare each option against those facts.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
Use explanations to understand the rule behind the answer.
TExam Day Tips
→Underline the problem statement mentally.
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A practitioner preparing for the NSE4 exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
What to study next
Got this wrong? Here's your next step.
Identify which NSE4 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
High Availability and Diagnostics — This question tests High Availability and Diagnostics — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Override is not enabled — By default, HA does not preempt. The 'override' setting is disabled. When the primary recovers, it does not force a failback because the cluster is non-preemptive. The admin must enable override if they want automatic failback.
What should I do if I get this NSE4 question wrong?
Identify which NSE4 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
Are there clue words in this question I should notice?
Yes — watch for: "most likely", "primary". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A FortiGate administrator has configured an active-passive HA cluster. After a failover event, the former primary unit comes back online and immediately takes over as primary again, causing another failover. The administrator wants the original primary to stay in standby until the current primary fails. Which setting should be configured?
hard
A.Enable HA override on both units
B.Set the HA mode to active-active
✓ C.Disable HA override on both units
D.Increase the HA priority on the primary unit
Why C: HA override (set ha-override enable) causes a device to resume primary role when it becomes available with higher priority. Disabling override prevents this preemptive behavior.
Last reviewed: Jun 21, 2026
Question Discussion
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This NSE4 practice question is part of Courseiva's free Fortinet certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the NSE4 exam.
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