The answer is that the client’s routing table is set to route all traffic through the VPN. When split tunneling is enabled on the FortiGate, it should only forward traffic destined for specific subnets—such as the corporate network—through the SSL VPN tunnel, while allowing other internet-bound traffic to go directly. However, if the client’s routing table contains a default route (0.0.0.0/0) pointing to the VPN interface, every packet is forced into the tunnel, effectively overriding the split tunneling configuration. On the Fortinet NSE 4 exam, this scenario tests your understanding of how the client-side routing table interacts with server-side split tunneling settings; a common trap is assuming the issue lies solely on the FortiGate policy. Remember that split tunneling is a two-sided configuration: the VPN gateway defines the allowed subnets, but the client must also apply those routes correctly. Memory tip: “Default route defeats split tunnel”—if you see 0.0.0.0/0 on the client, split tunneling is not working.
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.
An administrator has configured an SSL VPN with tunnel mode and split tunneling enabled. However, remote users report that all internet traffic is going through the VPN tunnel. 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 client's routing table is set to route all traffic through the VPN
Split tunneling routes only specific subnets through the tunnel and other traffic directly. If the routing table is set to route all traffic (0.0.0.0/0) via the SSLVPN interface, split tunneling is effectively disabled.
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.
✗
The firewall policy allows traffic to the internet
Why it's wrong here
That would not force traffic through the tunnel.
✗
The SSL VPN portal has 'split tunneling' disabled
Why it's wrong here
The administrator enabled it, so it's likely enabled.
✓
The client's routing table is set to route all traffic through the VPN
Why this is correct
Even with split tunneling enabled on the portal, if the client pushes a route for 0.0.0.0/0, all traffic goes through the tunnel.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
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 network engineer segments a warehouse floor into three subnets: 20 scanners, 5 printers, and 2 management hosts. Picking the wrong mask wastes addresses or leaves too few usable hosts. Exam questions test whether you can apply CIDR notation, calculate block size, and identify the correct usable-host range for a given prefix.
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: The client's routing table is set to route all traffic through the VPN — Split tunneling routes only specific subnets through the tunnel and other traffic directly. If the routing table is set to route all traffic (0.0.0.0/0) via the SSL VPN interface, split tunneling is effectively disabled.
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.
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?
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 →
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 an SSL VPN portal with web mode and split tunneling enabled. Remote users can access internal web applications but cannot reach the internet through the VPN. What needs to be checked?
medium
A.The remote user's browser does not support SSL VPN.
✓ B.The firewall policy allowing internet traffic from the SSL VPN interface is missing or incorrect.
C.The split tunneling setting is disabled.
D.The SSL VPN portal is configured in web mode only; tunnel mode is required for internet access.
Why B: Split tunneling allows internet-bound traffic to bypass the VPN. If users cannot reach the internet, it could be because the split tunneling exclusion list includes internet destinations, or the DNS resolution is not working. However, the most common cause is that the firewall policy for internet traffic is missing or blocking.
Last reviewed: Jun 21, 2026
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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.
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