The answer is a firewall blocking TCP port 179, an incorrect neighbor IP address, or an ASN mismatch. These three conditions cause the BGP neighbor to remain in the Active state because this state indicates that the router is actively trying to initiate a TCP connection to the neighbor but has not yet succeeded. In BGP operation, the Active state follows the Connect state and persists when the three-way TCP handshake fails, which can happen if the destination IP is unreachable, the autonomous system number in the OPEN message does not match, or a firewall drops the TCP SYN packet on port 179. On the Fortinet NSE 7 Advanced Security NSE7 exam, this question tests your understanding of BGP state machine transitions and common misconfigurations, often appearing as a multi-select scenario where a trap answer is "BGP hold timer expired"—that actually causes the Idle state, not Active. Remember the mnemonic "AIM": Active means IP, ASN, or firewall Misconfiguration.
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.
During a BGP troubleshooting session, an administrator sees that the BGP neighbor state is 'Active'. Which three conditions could cause this state? (Choose THREE.)
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The remote AS number is misconfigured
Active state means BGP is trying to initiate a TCP connection but hasn't succeeded. Common causes include incorrect neighbor IP, ASN mismatch, or TCP port blocking.
Key principle: OSPF neighbour adjacency depends on matching area, hello/dead timers, network type, and authentication — IP reachability alone is not enough.
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 remote AS number is misconfigured
Why this is correct
ASN mismatch causes the remote end to reject the open message, leading to Active state.
Common exam trap: OSPF can fail even when IP connectivity looks correct
OSPF neighbour formation depends on matching areas, timers, network type, authentication and passive-interface behaviour. Do not choose an answer only because the devices can ping.
Detailed technical explanation
How to think about this question
OSPF questions usually test the details that control adjacency and route selection. Read the neighbour state, area, router ID and interface configuration before deciding what is wrong.
KKey Concepts to Remember
OSPF neighbours must agree on key parameters.
Router ID selection can affect neighbour relationships and LSDB output.
OSPF cost influences the preferred path.
A route can appear in OSPF information but not become the installed route.
TExam Day Tips
→Check area mismatch first when OSPF adjacency fails.
→Review passive interfaces when a network is advertised but no neighbour forms.
→Use show ip ospf neighbor and show ip route clues carefully.
Key takeaway
OSPF neighbour adjacency depends on matching area, hello/dead timers, network type, and authentication — IP reachability alone is not enough.
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.
Review OSPF neighbour requirements — matching area type, hello and dead timers, network type, stub flags, and authentication. Study show ip ospf neighbor states (INIT, 2-WAY, FULL). Then practise related NSE7 OSPF questions on adjacency and route selection.
Troubleshooting and Diagnostics — This question tests Troubleshooting and Diagnostics — OSPF neighbours must agree on key parameters..
What is the correct answer to this question?
The correct answer is: The remote AS number is misconfigured — Active state means BGP is trying to initiate a TCP connection but hasn't succeeded. Common causes include incorrect neighbor IP, ASN mismatch, or TCP port blocking.
What should I do if I get this NSE7 question wrong?
Review OSPF neighbour requirements — matching area type, hello and dead timers, network type, stub flags, and authentication. Study show ip ospf neighbor states (INIT, 2-WAY, FULL). Then practise related NSE7 OSPF questions on adjacency and route selection.
What is the key concept behind this question?
OSPF neighbours must agree on key parameters.
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. A FortiGate administrator is troubleshooting a BGP session that fails to establish with a neighbor at 10.0.1.1. Running 'diagnose ip router bgp all' shows the neighbor state as 'Idle'. Which TWO commands should the administrator run NEXT to diagnose the issue?
medium
✓ A.show full-configuration router bgp
✓ B.execute ping 10.0.1.1
C.diagnose ip router bgp all
D.diagnose sys session filter dport 179
E.get router info bgp summary
Why A: To diagnose BGP neighbor establishment issues, the administrator should check both the BGP configuration (including neighbor settings) and the network connectivity (e.g., TCP port 179) between peers.
Last reviewed: Jun 21, 2026
Question Discussion
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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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