The answer is that the spokes lack routes to each other’s networks via the hub. This is the most likely cause of ADVPN shortcut tunnel failure after a FortiOS upgrade because shortcut initiation depends on the spokes having a viable next-hop route through the hub to trigger the dynamic tunnel creation. Even if the ADVPN configuration remains identical, a routing protocol like BGP or OSPF may fail to advertise the remote spoke networks across the hub, leaving each spoke without a path to the other’s subnet. On the Fortinet NSE 7 Advanced Security NSE7 exam, this scenario tests your understanding of how ADVPN shortcuts rely on underlying routing—not just VPN settings—and it’s a common trap to overlook route redistribution after an upgrade. A quick memory tip: “No route, no shortcut”—if the spoke can’t see the destination network in its routing table, the shortcut tunnel will never be built.
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 notices that after upgrading FortiOS, the ADVPN shortcut tunnels are no longer being established. The hub and spokes have the same ADVPN configuration as before. 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.
The spokes do not have routes to each other's networks via the hub
Shortcut tunnels are triggered when a spoke has traffic to another spoke's network but no direct route; if routing is not working (e.g., BGP not advertising), shortcuts won't be negotiated.
B
The IKE version changed to IKEv1
Why wrong: ADVPN works with both IKEv1 and IKEv2; version change wouldn't break shortcuts.
C
Dead Peer Detection (DPD) is disabled on the tunnel
Why wrong: DPD is used for liveness detection, not shortcut establishment.
D
The hub's ADVPN configuration was reset during upgrade
Why wrong: Configurations are preserved across upgrades unless a reset occurs, which is unlikely.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The spokes do not have routes to each other's networks via the hub
ADVPN shortcut tunnel initiation may require proper routing. If dynamic routing (e.g., BGP or OSPF) is not advertising the spoke networks to each other, spokes won't have routes to trigger shortcuts.
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 spokes do not have routes to each other's networks via the hub
Why this is correct
Shortcut tunnels are triggered when a spoke has traffic to another spoke's network but no direct route; if routing is not working (e.g., BGP not advertising), shortcuts won't be negotiated.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
ADVPN works with both IKEv1 and IKEv2; version change wouldn't break shortcuts.
✗
Dead Peer Detection (DPD) is disabled on the tunnel
Why it's wrong here
DPD is used for liveness detection, not shortcut establishment.
✗
The hub's ADVPN configuration was reset during upgrade
Why it's wrong here
Configurations are preserved across upgrades unless a reset occurs, which is unlikely.
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 spokes do not have routes to each other's networks via the hub — ADVPN shortcut tunnel initiation may require proper routing. If dynamic routing (e.g., BGP or OSPF) is not advertising the spoke networks to each other, spokes won't have routes to trigger shortcuts.
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
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 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.
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.