The answer is firewall policies allowing traffic from each spoke's interface to the other spoke's interface, static routes for spoke networks, and phase2 selectors covering source/destination pairs. In a hub-and-spoke IPsec VPN with policy-based IPsec, the hub acts as a router for spoke-to-spoke traffic, meaning it must have explicit firewall policies to forward packets between the spoke interfaces, static routes to direct traffic to the correct remote spoke networks, and phase2 selectors that include both the source and destination subnets—or a broad 0.0.0.0/0 selector—so the IPsec SA can process the transit traffic. On the Fortinet NSE 4 exam, this tests your understanding that policy-based VPNs require matching selectors and firewall policies for every traffic flow, unlike route-based VPNs where a single tunnel interface simplifies routing. A common trap is forgetting that static routes are needed even when the hub has learned routes dynamically, as policy-based VPNs rely on static entries for phase2 matching. Remember the mnemonic "FSP" for Firewall, Static routes, and Phase2 selectors to recall the three requirements.
NSE4 Authentication and VPN Practice Question
This NSE4 practice question tests your understanding of authentication and vpn. 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.
A company sets up a hub-and-spoke IPsec VPN where all spokes must communicate through the hub. The hub uses policy-based IPsec. Which THREE configurations are required on the hub to allow spoke-to-spoke traffic? (Select three.)
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Separate phase2 selectors defining traffic between each pair of spokes
For spoke-to-spoke traffic via hub, the hub needs firewall policies to forward traffic between spokes, static routes for spoke networks, and phase2 selectors covering source/destination pairs (or use a broad selector).
Key principle: Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
Configure IKEv2 instead of IKEv1
Why it's wrong here
IKE version is not critical for spoke-to-spoke communication; both work.
✓
Separate phase2 selectors defining traffic between each pair of spokes
Why this is correct
Policy-based VPN requires phase2 selectors for each pair or a broad selector covering all subnets.
Common exam trap: usable hosts are not the same as total addresses
Subnetting questions often tempt you into counting all addresses. In normal IPv4 subnets, the network and broadcast addresses are not usable host addresses.
Detailed technical explanation
How to think about this question
Subnetting questions test whether you can identify the network, broadcast address, usable range, mask and correct subnet. Slow down enough to calculate the block size correctly.
KKey Concepts to Remember
CIDR notation defines the prefix length.
Block size helps identify subnet boundaries.
Network and broadcast addresses are not usable hosts in normal IPv4 subnets.
The required host count determines the smallest suitable subnet.
TExam Day Tips
→Write the block size before choosing the subnet.
→Check whether the question asks for hosts, subnets or a specific address range.
→Do not confuse /24, /25, /26 and /27 host counts.
Key takeaway
Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.
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.
Review block sizes, usable host formulas (2^n − 2), and how to find network and broadcast addresses for /24 through /30. Then practise related NSE4 subnetting questions on CIDR, address ranges, and subnet selection.
Authentication and VPN — This question tests Authentication and VPN — CIDR notation defines the prefix length..
What is the correct answer to this question?
The correct answer is: Separate phase2 selectors defining traffic between each pair of spokes — For spoke-to-spoke traffic via hub, the hub needs firewall policies to forward traffic between spokes, static routes for spoke networks, and phase2 selectors covering source/destination pairs (or use a broad selector).
What should I do if I get this NSE4 question wrong?
Review block sizes, usable host formulas (2^n − 2), and how to find network and broadcast addresses for /24 through /30. Then practise related NSE4 subnetting questions on CIDR, address ranges, and subnet selection.
What is the key concept behind this question?
CIDR notation defines the prefix length.
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 NSE4 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 NSE4 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.