The answer is that the downstream devices are missing the root FortiGate's serial number in the downstream-authorization configuration. Even when the authorization mode is set to 'none', each downstream FortiGate must explicitly list the root FortiGate's serial number to complete the Security Fabric handshake; without it, the root sees the devices as discovered but cannot finalize the adjacency, leaving them in a 'Pending' status. This scenario tests your understanding of the Security Fabric authorization process on the Fortinet NSE 7 Advanced Security NSE7 exam, where a common trap is assuming 'none' mode bypasses all authorization requirements—it only disables password-based approval, not the serial-number trust. Remember the memory tip: "Pending means missing the serial; even 'none' needs the root's ID to be done."
NSE7 Enterprise Firewall and VDOMs Practice Question
This NSE7 practice question tests your understanding of enterprise firewall and vdoms. 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 company has deployed a Security Fabric with a root FortiGate 600E and two downstream FortiGate 200E devices. The network also includes a FortiAnalyzer and a FortiManager. The administrator notices that the Security Fabric topology in FortiGate is not showing the downstream devices. The root FortiGate can ping the management IPs of the downstream devices. Additionally, the administrator has configured the downstream devices with the correct root IP and authorization mode is set to 'none'. However, when running 'diagnose sys fabric list' on the root, it shows the downstream devices with status 'Pending'. The root FortiGate's firewall policy allows all traffic from the downstream subnets. What is the most likely cause of the issue?
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 downstream devices are missing the root FortiGate's serial number in the 'downstream-authorization' configuration.
The 'Pending' status in the output of 'diagnose sys fabric list' indicates that the root FortiGate has discovered the downstream devices but they have not completed the authorization handshake. Even though the authorization mode is set to 'none', each downstream FortiGate must still have the root FortiGate's serial number explicitly listed in its 'downstream-authorization' configuration to be accepted into the Security Fabric. Without this entry, the root will not finalize the adjacency, leaving the downstream devices in a pending state.
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 downstream devices are missing the root FortiGate's serial number in the 'downstream-authorization' configuration.
Why this is correct
When authorization mode is 'none', the root does not automatically authorize; the downstream must have the root's serial in the configuration.
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 FortiAnalyzer is not configured to receive logs from the downstream devices.
Why it's wrong here
FortiAnalyzer is not required for fabric formation.
✗
The downstream devices are using a different management port than the root.
Why it's wrong here
Ping works, so the port is reachable.
✗
The root FortiGate's firewall policy is blocking the downstream devices' Fabric traffic.
Why it's wrong here
The policy allows all traffic from downstream subnets.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates assume setting authorization mode to 'none' removes all authorization requirements, but in reality, the downstream device must still explicitly list the root's serial number to complete the Fabric handshake.
Detailed technical explanation
How to think about this question
The Security Fabric uses a two-phase discovery process: first, the root FortiGate discovers potential downstream devices via LLDP or manual IP configuration; second, the downstream device must authorize the root by including the root's serial number in its 'config system csf' under 'downstream-authorization'. Even with authorization mode set to 'none', the downstream device still requires this explicit serial number entry to complete the Fabric join. The 'Pending' status specifically indicates that the root has received the Fabric join request but the downstream has not yet acknowledged the root's identity in its own configuration.
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 network engineer at a university connects two campus buildings via a fibre link. Both routers run OSPF, but no adjacency forms — even though both routers can ping each other. The engineer finds one router is in area 0 and the other in area 1. OSPF adjacency requires matching area numbers, hello/dead timers, and network type. IP reachability alone is not enough.
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.
Enterprise Firewall and VDOMs — This question tests Enterprise Firewall and VDOMs — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The downstream devices are missing the root FortiGate's serial number in the 'downstream-authorization' configuration. — The 'Pending' status in the output of 'diagnose sys fabric list' indicates that the root FortiGate has discovered the downstream devices but they have not completed the authorization handshake. Even though the authorization mode is set to 'none', each downstream FortiGate must still have the root FortiGate's serial number explicitly listed in its 'downstream-authorization' configuration to be accepted into the Security Fabric. Without this entry, the root will not finalize the adjacency, leaving the downstream devices in a pending state.
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.
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 →
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. Which TWO statements about Security Fabric deployment are correct? (Choose two.)
medium
A.A Security Fabric can contain a maximum of 50 FortiGate devices.
✓ B.The root FortiGate must have a management IP address that is reachable from all downstream devices.
✓ C.Each FortiGate device in the Fabric must have a unique FortiGate serial number.
D.All FortiGate devices in the Fabric must be managed by the same FortiManager.
E.A FortiGate can only belong to one Security Fabric at a time.
Why B: Option B is correct because the root FortiGate acts as the central coordination point for the Security Fabric. All downstream FortiGate devices must be able to reach the root FortiGate's management IP address to establish and maintain the Fabric communication, which uses TCP port 8013 (HTTPS) for the initial handshake and subsequent keepalive messages. Without this reachability, downstream devices cannot join or synchronize with the Fabric.
Variation 2. Which TWO statements about the Security Fabric and FortiManager are correct? (Choose two.)
medium
✓ A.FortiManager can manage multiple Security Fabrics.
B.FortiGate devices must be in transparent mode to join the fabric.
C.FortiAnalyzer must be deployed to use the Security Fabric.
✓ D.The first FortiGate added to the Security Fabric becomes the root FortiGate.
E.A FortiGate can be part of multiple Security Fabrics simultaneously.
Why A: FortiManager can manage multiple Security Fabrics because it is designed as a centralized management platform that can oversee multiple independent FortiGate clusters or fabric topologies. Each Security Fabric is a logical grouping of FortiGate devices that share a common root FortiGate, and FortiManager can be configured to manage several such fabrics simultaneously, each with its own root and member devices, without requiring separate management servers.
Last reviewed: Jun 11, 2026
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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.
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