The correct procedure is to upgrade the secondary unit first, then perform a graceful failover, and finally upgrade the original primary. This method prevents an unplanned failover because the active primary remains online to handle traffic while the secondary is being updated; if the secondary upgrade fails, the primary can still take over without service disruption. After the secondary is stable, a graceful failover shifts the active role to it, allowing the original primary to be upgraded without any traffic interruption. On the Fortinet NSE 4 exam, this question tests your understanding of HA cluster upgrade sequencing and the concept of graceful failover, often appearing as a scenario where a candidate must choose between upgrading the primary first (a common trap that would cause a failover) or the correct secondary-first approach. A helpful memory tip is “Upgrade the backup, then flip the stack”—always update the standby unit before the active one to maintain session continuity.
NSE4 System and Network Administration Practice Question
This NSE4 practice question tests your understanding of system and network administration. 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.
An organization has two FortiGate units in an HA cluster. They need to perform a firmware upgrade on the primary unit without causing a failover. Which procedure should be followed?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
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
✓
Upgrade the secondary unit first, then perform a graceful failover, then upgrade the original primary
Option D is correct because in an HA cluster, upgrading the secondary unit first ensures that the primary remains active and can take over if the upgrade fails. After the secondary is upgraded and stable, a graceful failover is performed to make it the new primary, allowing the original primary to be upgraded without causing an unplanned failover or service interruption.
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.
✗
Upgrade the primary unit first, then the secondary will automatically synchronize
Why it's wrong here
Upgrading primary first may cause failover to secondary with old firmware, causing incompatibility.
✗
Upgrade both units simultaneously using the GUI
Why it's wrong here
Simultaneous upgrade may cause both to reboot, causing outage.
✗
Disable HA, upgrade both, then re-enable HA
Why it's wrong here
Disabling HA causes loss of redundancy and potential outage.
✓
Upgrade the secondary unit first, then perform a graceful failover, then upgrade the original primary
Why this is correct
This minimizes downtime as the secondary takes over before the primary is upgraded.
Clue confirmation
The clue word "primary" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates assume upgrading the primary first is safe because the secondary will synchronize, but they overlook that the primary reboot triggers an automatic failover, which is not a 'graceful' upgrade path.
Detailed technical explanation
How to think about this question
FortiGate HA uses FGCP (FortiGate Cluster Protocol) to synchronize configuration and session state. During a graceful failover, the primary sends a 'gratuitous ARP' to update the network, and sessions are maintained because the secondary already has the synchronized session table. This procedure is documented in the FortiOS Administration Guide under 'Upgrading an HA Cluster' and ensures minimal downtime.
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.
TExam Day Tips
→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 exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
System and Network Administration — This question tests System and Network Administration — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Upgrade the secondary unit first, then perform a graceful failover, then upgrade the original primary — Option D is correct because in an HA cluster, upgrading the secondary unit first ensures that the primary remains active and can take over if the upgrade fails. After the secondary is upgraded and stable, a graceful failover is performed to make it the new primary, allowing the original primary to be upgraded without causing an unplanned failover or service interruption.
What should I do if I get this NSE4 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Are there clue words in this question I should notice?
Yes — watch for: "primary". Asks for the main purpose or function, not a secondary benefit. Eliminate answers that describe side-effects or partial functions.
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 →
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
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.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.