- A
The packet is denied by implicit deny
Why wrong: Implicit deny only applies if no explicit policy matches.
- B
The packet is allowed by the first policy
The source 10.0.1.5 is within 10.0.0.0/8, so the first policy matches and allows the traffic.
- C
The packet matches both policies and is allowed
Why wrong: Only the first matching policy is used.
- D
The packet is denied by the second policy
Why wrong: The first policy matches first, so the second is not checked.
NSE4 Firewall Policies and NAT Practice Question
This NSE4 practice question tests your understanding of firewall policies and nat. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. 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 multiple policies. The first policy allows traffic from 10.0.0.0/8 to any destination. The second policy denies traffic from 10.0.1.0/24 to any destination. What happens when a packet from 10.0.1.5 to 8.8.8.8 arrives?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue:
"first"Why it matters: Order matters here. You are being tested on which action comes before the others — not which action is generally useful.
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 packet is allowed by the first policy
FortiGate firewall policies are evaluated in sequential order from top to bottom. The first policy matches source 10.0.0.0/8, which includes 10.0.1.5, and allows the traffic to any destination. Since the packet matches this policy first, it is accepted and the second policy is never evaluated. Therefore, the packet is allowed by the first policy.
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 packet is denied by implicit deny
Why it's wrong here
Implicit deny only applies if no explicit policy matches.
- ✓
The packet is allowed by the first policy
Why this is correct
The source 10.0.1.5 is within 10.0.0.0/8, so the first policy matches and allows the traffic.
Clue confirmation
The clue word "first" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
The packet matches both policies and is allowed
Why it's wrong here
Only the first matching policy is used.
- ✗
The packet is denied by the second policy
Why it's wrong here
The first policy matches first, so the second is not checked.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often assume FortiGate uses a longest-prefix match or that a more specific deny policy will override a broader allow policy, but FortiGate strictly follows first-match order, not prefix length.
Detailed technical explanation
How to think about this question
FortiGate firewall policies are processed in a top-down order with a first-match model, unlike routing tables which use longest-prefix match. The source address in the first policy (10.0.0.0/8) is a superset of 10.0.1.0/24, so any host in the 10.0.1.0/24 subnet will match the first policy. This behavior is critical in scenarios where you want to allow broad traffic but deny specific subnets; the deny policy must be placed above the allow policy to take effect.
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 small business has 20 workstations on the 192.168.1.0/24 network and one public IP from its ISP. The router uses PAT (NAT overload) so all 20 devices share one public address using different source ports. NAT questions test whether you understand the four address terms and which direction each translation applies.
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.
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Firewall Policies and NAT — study guide chapter
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FAQ
Questions learners often ask
What does this NSE4 question test?
Firewall Policies and NAT — This question tests Firewall Policies and NAT — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The packet is allowed by the first policy — FortiGate firewall policies are evaluated in sequential order from top to bottom. The first policy matches source 10.0.0.0/8, which includes 10.0.1.5, and allows the traffic to any destination. Since the packet matches this policy first, it is accepted and the second policy is never evaluated. Therefore, the packet is allowed by the first policy.
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: "first". Order matters here. You are being tested on which action comes before the others — not which action is generally useful.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
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Last reviewed: Jun 24, 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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