The answer is that the route's OSPF cost is higher than an existing route with a lower administrative distance. Even when OSPF neighbors reach the FULL state, the FortiGate will not install a learned OSPF route into the routing table if a more preferred route—such as a static route or a route from another protocol with a lower administrative distance—already exists for the same destination, regardless of the OSPF metric. On the Fortinet NSE 7 Advanced Security NSE7 exam, this scenario tests your understanding that neighbor adjacency alone does not guarantee route installation; the routing table decision is based on administrative distance first, then metric. A common trap is assuming a FULL neighbor state means all routes are automatically installed, but the key is that OSPF cost only matters when comparing multiple OSPF paths, not when competing with lower-AD routes. Memory tip: "FULL neighbor, empty table? Check the AD—OSPF loses to a static or connected route."
NSE7 Advanced VPN and Zero Trust Practice Question
This NSE7 practice question tests your understanding of advanced vpn and zero trust. 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.
An administrator has configured an OSPF overlay over an IPsec VPN between two FortiGates. The OSPF neighbors are established, but routes from one side are not being installed in the routing table on the other side. 'get router info ospf neighbor' shows FULL state. 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 route's OSPF cost is higher than an existing route with a lower administrative distance
Even though OSPF neighbors are FULL, routes may not be installed if they are not selected as best paths. One common reason is that the OSPF cost is higher than a static route or another routing protocol's metric. The other options would prevent neighbor from reaching FULL state.
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 IPsec tunnel is using transport mode instead of tunnel mode
Why it's wrong here
Transport mode vs tunnel mode does not affect OSPF route installation.
✓
The route's OSPF cost is higher than an existing route with a lower administrative distance
Why this is correct
OSPF routes have an AD of 110. If a static route (AD 10) or other protocol has a lower AD, the OSPF route may not be installed.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Mismatched authentication would prevent neighbor from reaching FULL state.
✗
The OSPF network type is not set to point-to-point
Why it's wrong here
Network type affects neighbor establishment, but they are FULL, so this is not an issue.
Common exam traps
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.
Advanced VPN and Zero Trust — This question tests Advanced VPN and Zero Trust — OSPF neighbours must agree on key parameters..
What is the correct answer to this question?
The correct answer is: The route's OSPF cost is higher than an existing route with a lower administrative distance — Even though OSPF neighbors are FULL, routes may not be installed if they are not selected as best paths. One common reason is that the OSPF cost is higher than a static route or another routing protocol's metric. The other options would prevent neighbor from reaching FULL state.
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.
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?
OSPF neighbours must agree on key parameters.
About these practice questions
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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. An administrator configures BGP over an IPsec VPN between two FortiGates. The BGP session is established, but routes from the remote site are not being installed in the local routing table. The admin verifies that the BGP neighbor configuration is correct and the remote site is advertising routes. What is the MOST likely cause?
medium
A.The BGP timers are too aggressive causing route flapping
B.The BGP network statement is missing on the local FortiGate
✓ C.A firewall policy is blocking BGP traffic on the VPN interface
D.The next-hop IP address is not reachable
Why C: BGP routes must be allowed by a firewall policy on the loopback or interface used for BGP. Even if the VPN tunnel is up, BGP traffic (TCP port 179) may be blocked by the local-in policy or by the VPN interface's firewall policy if not explicitly allowed.
Last reviewed: Jun 21, 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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