The answer is an SNMP community string mismatch between the FortiGate and the monitoring server. SNMPv2c relies on plaintext community strings as a rudimentary form of authentication; if the string configured on the FortiGate does not exactly match the one expected by the server, the server will silently discard the incoming trap. Since the monitoring server can ping the FortiGate, basic network connectivity is confirmed, isolating the problem to the application-layer authentication mechanism rather than a routing or firewall issue. On the Fortinet NSE 4 Network Security Professional exam, this scenario tests your understanding of SNMPv2c’s lack of encryption and its dependency on matching community strings—a common pitfall when traps are not received despite successful ICMP reachability. A useful memory tip: “Ping works, traps don’t? Check the string—it’s the password they both must know.”
NSE4 System and Network Administration Practice Question
This NSE4 practice question tests your understanding of system and network administration. 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 FortiGate administrator configures SNMPv2c on the FortiGate to send traps to a monitoring server. However, no traps are received. The monitoring server can ping the FortiGate. 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 the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The SNMP community string does not match between FortiGate and server.
SNMPv2c uses community strings as a form of authentication. If the community string configured on the FortiGate does not match the one configured on the monitoring server, the server will reject the trap. Since the server can ping the FortiGate, network connectivity is fine, and the issue is most likely an authentication mismatch.
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.
✗
SNMPv2c is not supported on FortiGate; only v3 is supported.
Why it's wrong here
SNMPv2c is supported.
✗
The FortiGate's firewall policy blocks SNMP traffic from the monitoring server.
Why it's wrong here
Traps are sent from FortiGate to server; the issue is outbound, not inbound.
✓
The SNMP community string does not match between FortiGate and server.
Why this is correct
SNMPv2c uses community strings; if they differ, the server will reject traps.
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 monitoring server's IP is not in the SNMP trap receiver list on FortiGate.
Why it's wrong here
If the IP were not in the list, no trap would be sent; this is a possible cause but less likely than community mismatch.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates assume SNMP traps are blocked by a firewall policy, but since traps are initiated by the FortiGate (outbound), the server's ability to ping the FortiGate confirms Layer 3 reachability, shifting the focus to authentication or receiver configuration.
Detailed technical explanation
How to think about this question
SNMPv2c relies on plaintext community strings for access control; the FortiGate includes the community string in the trap PDU, and the receiver validates it against its own configuration. A mismatch causes the receiver to silently discard the trap without any error message. In real-world deployments, this is often overlooked when copying configurations between devices, leading to silent failures.
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: The SNMP community string does not match between FortiGate and server. — SNMPv2c uses community strings as a form of authentication. If the community string configured on the FortiGate does not match the one configured on the monitoring server, the server will reject the trap. Since the server can ping the FortiGate, network connectivity is fine, and the issue is most likely an authentication mismatch.
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: "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 →
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.