- A
The deny-all policy has a higher policy ID than the allow policy
Why wrong: Policy ID does not determine order; the physical order in the policy list does.
- B
The allow policy is configured with the wrong source interface
Why wrong: This would cause a different symptom (traffic not matching), not the deny-all blocking it.
- C
The allow policy uses a schedule that is not active at the current time
Why wrong: A schedule would prevent the policy from being evaluated entirely, but the traffic would hit the next matching policy (the deny-all) and still be denied.
- D
The deny-all policy is placed above the allow policy in the policy list
FortiGate evaluates policies from top to bottom. The first match applies. If the deny-all is above the allow, all traffic is denied.
Quick Answer
The answer is that the deny-all policy is placed above the allow policy in the policy list. This is correct because FortiGate uses first-match logic for firewall policies, meaning the system evaluates policies from top to bottom and applies the first match it finds. Since the deny-all policy sits higher in the sequence, all traffic from the internal network to the DMZ hits that rule first and is dropped, so the more specific allow policy below it is never evaluated. On the Fortinet NSE 4 Network Security Professional exam, this scenario tests your understanding of policy ordering and the critical concept of deny before allow—a common trap where students assume specificity overrides position. Remember that on FortiGate, order always trumps specificity. A simple memory tip: “First match wins, so deny must come after allow to let traffic through.”
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 administrator has configured a firewall policy allowing HTTP traffic from the internal network (10.0.1.0/24) to the DMZ server (192.168.1.10). The policy is placed after a deny-all policy that blocks traffic from internal to DMZ. Even though the allow policy is more specific, traffic is still being denied. 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 deny-all policy is placed above the allow policy in the policy list
FortiGate uses first-match logic for firewall policies. The deny-all policy is placed before the allow policy, so all traffic hits the deny policy first and is dropped. The allow policy never gets evaluated.
Key principle: ACLs process entries top to bottom and stop at the first match. Entry order and interface direction matter as much as the permit or deny statement.
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 deny-all policy has a higher policy ID than the allow policy
Why it's wrong here
Policy ID does not determine order; the physical order in the policy list does.
- ✗
The allow policy is configured with the wrong source interface
Why it's wrong here
This would cause a different symptom (traffic not matching), not the deny-all blocking it.
- ✗
The allow policy uses a schedule that is not active at the current time
Why it's wrong here
A schedule would prevent the policy from being evaluated entirely, but the traffic would hit the next matching policy (the deny-all) and still be denied.
- ✓
The deny-all policy is placed above the allow policy in the policy list
Why this is correct
FortiGate evaluates policies from top to bottom. The first match applies. If the deny-all is above the allow, all traffic is denied.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Standard ACLs match source addresses.
Common exam traps
Common exam trap: ACLs stop at the first match
ACLs are processed top to bottom. The first matching entry wins, and an implicit deny usually exists at the end.
Detailed technical explanation
How to think about this question
ACL questions test precision: source, destination, protocol, port and direction. A generally correct ACL can still fail if it is applied on the wrong interface or in the wrong direction.
KKey Concepts to Remember
- Standard ACLs match source addresses.
- Extended ACLs can match source, destination, protocol and ports.
- The first matching ACL entry is used.
- There is usually an implicit deny at the end.
TExam Day Tips
- Check inbound versus outbound direction.
- Read the ACL from top to bottom.
- Look for a broader permit or deny above the intended line.
Key takeaway
ACLs process entries top to bottom and stop at the first match. Entry order and interface direction matter as much as the permit or deny statement.
Real-world example
How this comes up in practice
A security administrator must allow nursing staff to reach a patient records server while blocking access from the guest Wi-Fi VLAN. After applying an extended ACL, traffic is still blocked from nursing workstations. The ACL was applied outbound instead of inbound on the wrong interface. Questions like this test ACL direction and placement rules.
What to study next
Got this wrong? Here's your next step.
Review ACL processing order, placement rules (standard near destination, extended near source), and inbound vs outbound direction. Study wildcard masks and implicit deny. Then practise related NSE4 ACL questions on filtering logic and placement.
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Firewall Policies and NAT — study guide chapter
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Firewall Policies and NAT practice questions
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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 — Standard ACLs match source addresses..
What is the correct answer to this question?
The correct answer is: The deny-all policy is placed above the allow policy in the policy list — FortiGate uses first-match logic for firewall policies. The deny-all policy is placed before the allow policy, so all traffic hits the deny policy first and is dropped. The allow policy never gets evaluated.
What should I do if I get this NSE4 question wrong?
Review ACL processing order, placement rules (standard near destination, extended near source), and inbound vs outbound direction. Study wildcard masks and implicit deny. Then practise related NSE4 ACL questions on filtering logic and placement.
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?
Standard ACLs match source addresses.
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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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