Question 1mediummultiple choice
Full question →Question 178 of 1,000
Quick Answer
The answer is that the forward trust CA certificate is not installed on the users’ devices. This is the most likely reason for the certificate warning because SSL deep inspection works by having the FortiGate generate a new certificate on-the-fly for each HTTPS session, signed by its own forward trust CA. If that CA certificate is not trusted on the client machine, the browser will flag the connection as untrusted, even if the original website’s certificate is perfectly valid. On the Fortinet NSE 4 Network Security Professional NSE4 exam, this concept tests your understanding of the SSL inspection handshake and the critical distinction between the server-side certificate and the locally-issued one. A common trap is assuming the warning indicates a problem with the remote website or the FortiGate’s configuration, when in fact the issue is purely client-side trust. Remember the memory tip: “Trust the CA, or see the warning—the client must install the FortiGate’s CA.”
NSE4 Security Profiles Practice Question
This NSE4 practice question tests your understanding of security profiles. Examine the command output carefully: the correct answer depends on what the output actually shows, not on general recall alone. 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 administrator has configured a firewall policy with SSL deep inspection using a forward trust CA certificate. When users access an HTTPS website with a valid certificate, they still receive a certificate warning. 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.
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
✓
The forward trust CA certificate is not installed on the users' devices
For deep inspection, the FortiGate's CA certificate must be installed and trusted on client devices. Otherwise, browsers will show a warning that the connection is not private because the certificate is issued by an untrusted authority.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
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.
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.
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Security Profiles — study guide chapter
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Security Profiles practice questions
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FAQ
Questions learners often ask
What does this NSE4 question test?
Security Profiles — This question tests Security Profiles — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The forward trust CA certificate is not installed on the users' devices — For deep inspection, the FortiGate's CA certificate must be installed and trusted on client devices. Otherwise, browsers will show a warning that the connection is not private because the certificate is issued by an untrusted authority.
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". 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 →
Same concept, more angles
1 more ways this is tested on NSE4
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 configures SSL deep inspection on a policy using a self-signed CA certificate. Users report that they see a certificate warning in their browsers when accessing HTTPS sites. What is the most effective solution to eliminate these warnings?
hard- A.Use a publicly trusted CA certificate for the FortiGate
- B.Disable deep inspection and use certificate inspection only
- C.Add the websites to the exemption list in the SSL/SSH profile
- ✓ D.Install the FortiGate's CA certificate on all client machines in the trusted root store
Why D: To avoid certificate warnings, the FortiGate's CA certificate must be trusted by all clients. Deploying the CA certificate via Group Policy ensures that all domain-joined machines trust certificates signed by the FortiGate.
Last reviewed: Jun 21, 2026
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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