- A
The host is accessing Facebook over HTTPS and the policy does not have SSL/TLS deep inspection enabled.
Application control cannot inspect encrypted application signatures without SSL deep inspection to decrypt the traffic.
- B
The firewall policy is using flow-based inspection instead of proxy-based.
Why wrong: The question states proxy-based is used, so this is not the cause.
- C
The application control profile is configured with 'deep inspection' disabled.
Why wrong: Application control can work without deep inspection for many applications; deep inspection is needed only for encrypted traffic.
- D
The application control profile is applied only to outgoing traffic, but the host is using a proxy.
Why wrong: Even with a proxy, application control should still inspect the traffic if the policy is correctly applied.
Quick Answer
The correct answer is that the host is accessing Facebook over HTTPS and the policy does not have SSL/TLS deep inspection enabled. Without SSL decryption, the FortiGate’s proxy-based inspection sees only an encrypted tunnel, not the actual application layer inside it, so application control cannot identify or block Facebook traffic. This question tests your understanding of how application control depends on visibility into encrypted sessions, a common pitfall on the Fortinet NSE 4 Network Security Professional NSE4 exam. The trap is assuming proxy-based inspection alone is enough; remember, without SSL inspection, HTTPS traffic remains opaque to application control. Memory tip: “No decrypt, no detect” — if you don’t break the SSL, you can’t block the app.
NSE4 Security Profiles Practice Question
This NSE4 practice question tests your understanding of security profiles. 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 network administrator notices that traffic from a specific internal host is not being inspected by the application control profile applied to the firewall policy. The policy is configured with proxy-based inspection and the application control profile includes a rule to block 'Facebook'. The administrator confirms the host can still access Facebook. What is the MOST likely cause?
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 host is accessing Facebook over HTTPS and the policy does not have SSL/TLS deep inspection enabled.
Option D is correct because Facebook uses HTTPS. Without SSL deep inspection, FortiGate cannot see the application layer inside the encrypted tunnel, so application control cannot block Facebook.
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 host is accessing Facebook over HTTPS and the policy does not have SSL/TLS deep inspection enabled.
Why this is correct
Application control cannot inspect encrypted application signatures without SSL deep inspection to decrypt the traffic.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
The firewall policy is using flow-based inspection instead of proxy-based.
Why it's wrong here
The question states proxy-based is used, so this is not the cause.
- ✗
The application control profile is configured with 'deep inspection' disabled.
Why it's wrong here
Application control can work without deep inspection for many applications; deep inspection is needed only for encrypted traffic.
- ✗
The application control profile is applied only to outgoing traffic, but the host is using a proxy.
Why it's wrong here
Even with a proxy, application control should still inspect the traffic if the policy is correctly applied.
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.
- →
Security Profiles — study guide chapter
Learn the concepts, then practise the questions
- →
Security Profiles practice questions
Targeted practice on this topic area only
- →
All NSE4 questions
1,000 questions across all exam domains
- →
Fortinet NSE 4 Network Security Professional NSE4 study guide
Full concept coverage aligned to exam objectives
- →
NSE4 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related NSE4 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
System and Network Administration practice questions
Practise NSE4 questions linked to System and Network Administration.
Firewall Policies and NAT practice questions
Practise NSE4 questions linked to Firewall Policies and NAT.
Authentication and VPN practice questions
Practise NSE4 questions linked to Authentication and VPN.
Security Profiles practice questions
Practise NSE4 questions linked to Security Profiles.
High Availability and Diagnostics practice questions
Practise NSE4 questions linked to High Availability and Diagnostics.
NSE4 fundamentals practice questions
Practise NSE4 questions linked to NSE4 fundamentals.
NSE4 scenario practice questions
Practise NSE4 questions linked to NSE4 scenario.
NSE4 troubleshooting practice questions
Practise NSE4 questions linked to NSE4 troubleshooting.
Practice this exam
Start a free NSE4 practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
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 host is accessing Facebook over HTTPS and the policy does not have SSL/TLS deep inspection enabled. — Option D is correct because Facebook uses HTTPS. Without SSL deep inspection, FortiGate cannot see the application layer inside the encrypted tunnel, so application control cannot block Facebook.
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. An organization uses Application Control to allow only business-critical applications and block social media. The administrator has configured the profile to block Facebook and Twitter, but users can still access Facebook. The firewall policy applies the profile correctly. What is the most likely cause?
medium- A.The application control profile is applied to the wrong direction.
- B.Facebook is not included in the default application signatures.
- ✓ C.SSL inspection is not enabled on the firewall policy.
- D.The FortiGate is in flow-based inspection mode.
Why C: Application Control relies on SSL inspection to identify applications like Facebook that use HTTPS. Without SSL inspection enabled on the firewall policy, FortiGate can only see encrypted traffic as generic SSL/TLS flows and cannot match the application signatures for Facebook. Enabling SSL inspection (deep inspection or certificate-based inspection) allows the FortiGate to decrypt the traffic and apply the application control profile correctly.
Keep practising
More NSE4 practice questions
- Drag and drop the steps to capture traffic on a FortiGate interface using the CLI into the correct order.
- Drag and drop the steps to configure HA (High Availability) on a FortiGate pair into the correct order.
- Drag and drop the steps to perform a factory reset on FortiGate via CLI into the correct order.
- Refer to the exhibit. A network administrator configured an IPsec VPN between the main office and a branch office. Remot…
- Given the exhibit, a user in the internal network tries to SSH to a public server (203.0.113.10). What will happen and w…
- An administrator is configuring web filtering on a FortiGate. Which TWO statements about web filtering profiles are corr…
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.
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.