The correct answer is to enable DNS forwarding under Network > DNS and set the system DNS to the desired server. This configuration is correct because FortiGate DNS forwarding allows the device to act as a DNS relay, intercepting all DNS queries from internal clients and forwarding them to a specified server for security filtering, without requiring policy routing or firewall rule changes. On the Fortinet NSE 4 Network Security Professional exam, this concept tests your understanding of how FortiGate can centralize DNS traffic for security inspection, often appearing as a scenario where you must distinguish DNS forwarding from DNS filtering or policy-based forwarding. A common trap is confusing DNS forwarding with configuring DNS server addresses on individual interfaces or assuming a firewall policy is needed to redirect DNS traffic. Remember the memory tip: “Forward at the system level, filter at the policy level”—DNS forwarding is set globally under Network > DNS, not per-interface.
NSE4 System and Network Administration Practice Question
This NSE4 practice question tests your understanding of system and network administration. 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 needs to ensure that all DNS queries from internal clients are forwarded to a specific DNS server for security filtering. Which configuration should be applied?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Enable DNS forwarding under Network > DNS and set the system DNS to the desired server
Option C is correct because DNS forwarding on FortiGate allows the device to act as a DNS relay, intercepting DNS queries from internal clients and forwarding them to a specified DNS server for security filtering. This is configured under Network > DNS by setting the system DNS to the desired server, which ensures all DNS traffic is redirected without requiring policy routing or firewall rule changes.
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.
✗
Use policy routing to redirect DNS traffic to the server
Why it's wrong here
Policy routing can redirect, but DNS forwarding is the appropriate feature.
✗
Create a firewall policy to allow DNS traffic to the external server only
Why it's wrong here
This would block queries to other servers but not force clients to use the FortiGate.
✓
Enable DNS forwarding under Network > DNS and set the system DNS to the desired server
Why this is correct
DNS forwarding makes the FortiGate resolve queries using the specified DNS servers.
Related concept
Read the scenario before looking for a memorised answer.
✗
Configure a DNS database on the FortiGate
Why it's wrong here
DNS database is for hosting zones, not forwarding.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often confuse DNS forwarding with policy routing or firewall policies, assuming traffic redirection requires explicit routing or allow rules, rather than understanding that DNS forwarding is a dedicated application-layer relay feature.
Detailed technical explanation
How to think about this question
DNS forwarding works by the FortiGate listening on UDP/TCP port 53 for client DNS requests and then acting as a DNS client to the configured upstream server, caching responses for performance. This is distinct from DNS proxy or transparent mode, as the FortiGate replaces the original client source IP with its own when forwarding, ensuring the upstream server sees a single source for logging and filtering. In real-world deployments, this is often combined with DNS filter profiles to block malicious domains, leveraging FortiGuard security services.
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: Enable DNS forwarding under Network > DNS and set the system DNS to the desired server — Option C is correct because DNS forwarding on FortiGate allows the device to act as a DNS relay, intercepting DNS queries from internal clients and forwarding them to a specified DNS server for security filtering. This is configured under Network > DNS by setting the system DNS to the desired server, which ensures all DNS traffic is redirected without requiring policy routing or firewall rule changes.
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.
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.