Question 18 of 1,000
Troubleshooting and DiagnosticsmediumMultiple SelectObjective-mapped

Quick Answer

The answer is that TCP SYN packets appearing in firewall logs without corresponding SYN-ACK packets is a key symptom of asymmetric routing on a FortiGate. This occurs because asymmetric routing forces packets from the same session to arrive on different FortiGate interfaces, breaking the stateful inspection engine that expects all packets to traverse the same interface; when the SYN-ACK returns via a different path, the firewall sees an incomplete handshake and drops or times out the session, causing high latency. On the Fortinet NSE 7 Advanced Security NSE7 exam, this question tests your understanding of how stateful firewalls handle traffic flow and the specific log signatures that reveal path asymmetry—a common trap is confusing this with simple packet loss or interface congestion. Remember the mnemonic: “SYN without ACK? Check the path back.”

NSE7 Troubleshooting and Diagnostics Practice Question

This NSE7 practice question tests your understanding of troubleshooting and diagnostics. 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 is experiencing high latency on traffic passing through it. The administrator suspects that asymmetric routing is occurring. Which TWO symptoms are indicative of asymmetric routing?

Question 1mediummulti select
Review the full routing breakdown →

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

Traffic from the same source IP arrives on different interfaces for different sessions.

Asymmetric routing occurs when traffic from the same source IP takes different paths through the network, causing packets to arrive on different FortiGate interfaces for different sessions. This breaks stateful inspection because the firewall expects all packets of a session to traverse the same interface; when they don't, it can lead to session timeouts or dropped packets, manifesting as high latency.

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 routing table shows multiple equal-cost paths to the same destination.

    Why it's wrong here

    ECMP can cause load sharing but not necessarily asymmetric routing issues.

  • Traffic from the same source IP arrives on different interfaces for different sessions.

    Why this is correct

    This indicates that the return traffic may be arriving on a different interface than expected.

    Related concept

    Read the scenario before looking for a memorised answer.

  • Traffic matching a policy is logged as allowed but the application does not work.

    Why it's wrong here

    This could be due to many reasons, not specific to asymmetric routing.

  • CPU usage is consistently above 90% during peak hours.

    Why it's wrong here

    High CPU has many causes, not specifically asymmetric routing.

  • The firewall logs show TCP SYN packets but no corresponding SYN-ACK packets for the same session.

    Why this is correct

    Asymmetric routing can cause the SYN-ACK to take a different path, bypassing the firewall.

    Related concept

    Read the scenario before looking for a memorised answer.

Common exam traps

Common exam trap: answer the scenario, not the keyword

The trap here is that candidates often confuse asymmetric routing with general routing issues like ECMP (option A) or performance problems (option D), but the exam specifically tests the stateful firewall behavior where traffic arriving on different interfaces for the same session is the definitive symptom.

Detailed technical explanation

How to think about this question

Asymmetric routing breaks stateful firewalls because the session table is tied to the ingress interface; if the SYN packet arrives on port1 but the SYN-ACK arrives on port2, the firewall may not recognize the SYN-ACK as part of the same session and drops it, leading to TCP retransmissions and high latency. This is often seen in multi-homed networks or when using policy-based routing (PBR) inconsistently. The symptom of TCP SYN packets without corresponding SYN-ACKs (option E) is a classic sign because the return path bypasses the firewall or arrives on a different interface.

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.

Related practice questions

Related NSE7 practice-question pages

Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.

Practice this exam

Start a free NSE7 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 NSE7 question test?

Troubleshooting and Diagnostics — This question tests Troubleshooting and Diagnostics — Read the scenario before looking for a memorised answer..

What is the correct answer to this question?

The correct answer is: Traffic from the same source IP arrives on different interfaces for different sessions. — Asymmetric routing occurs when traffic from the same source IP takes different paths through the network, causing packets to arrive on different FortiGate interfaces for different sessions. This breaks stateful inspection because the firewall expects all packets of a session to traverse the same interface; when they don't, it can lead to session timeouts or dropped packets, manifesting as high latency.

What should I do if I get this NSE7 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 →

How Courseiva writes practice questions · Editorial policy

Last reviewed: Jun 11, 2026

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.

Loading comments…

Sign in to join the discussion.

This NSE7 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 NSE7 exam.