- A
The static route is disabled by a firewall policy.
Why wrong: Firewall policies do not disable routes; they control traffic flow through the FortiGate.
- B
The static route is configured with a higher priority than the default route.
Why wrong: Priority is not used in static route selection; distance is used.
- C
The static route's destination subnet overlaps with a directly connected subnet.
Why wrong: Overlapping subnets would not cause traffic to use the default route; they would cause ambiguity but typically the more specific route wins.
- D
The static route's gateway is not reachable via any interface.
If the next-hop gateway is unreachable (no ARP entry or interface down), the route will not be installed in the routing table, and traffic will use the default route.
Quick Answer
The answer is that the static route's gateway is not reachable via any interface. Even when a static route has a lower administrative distance than the default route, the FortiGate will not use it if the next-hop gateway is unreachable; the routing table only installs routes whose gateways are directly connected and active. This occurs because the FortiGate performs a recursive lookup on the gateway IP—if that IP is not reachable through a connected interface or another valid route, the static route is considered invalid and is omitted from the forwarding decision, leaving the higher-distance default route as the only viable path. On the Fortinet NSE 4 exam, this scenario tests your understanding of route selection prerequisites beyond distance metrics, often appearing as a trick where candidates assume a lower distance always wins. A common memory tip is “gateway first, distance second”—the route must be reachable before distance even matters.
NSE4 System and Network Administration Practice Question
This NSE4 practice question tests your understanding of system and network administration. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. 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 network administrator notices that after configuring a new static route on a FortiGate, traffic to a remote subnet is still being forwarded via the default route. The administrator confirms the static route is present in the routing table with a lower distance than the default route. 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 choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
The static route's gateway is not reachable via any interface.
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.
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.
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 static route is disabled by a firewall policy.
Why it's wrong here
Firewall policies do not disable routes; they control traffic flow through the FortiGate.
- ✗
The static route is configured with a higher priority than the default route.
Why it's wrong here
Priority is not used in static route selection; distance is used.
- ✗
The static route's destination subnet overlaps with a directly connected subnet.
Why it's wrong here
Overlapping subnets would not cause traffic to use the default route; they would cause ambiguity but typically the more specific route wins.
- ✓
The static route's gateway is not reachable via any interface.
Why this is correct
If the next-hop gateway is unreachable (no ARP entry or interface down), the route will not be installed in the routing table, and traffic will use the default route.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
CIDR notation defines the prefix length.
Common exam traps
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.
- →
System and Network Administration — study guide chapter
Learn the concepts, then practise the questions
- →
System and Network Administration practice questions
Targeted practice on this topic area only
- →
All NSE4 questions
1,000 questions across all exam domains
- →
Fortinet NSE 4 Network Security Professional NSE4 study guide
Full concept coverage aligned to exam objectives
- →
NSE4 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related NSE4 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
System and Network Administration practice questions
Practise NSE4 questions linked to System and Network Administration.
Firewall Policies and NAT practice questions
Practise NSE4 questions linked to Firewall Policies and NAT.
Authentication and VPN practice questions
Practise NSE4 questions linked to Authentication and VPN.
Security Profiles practice questions
Practise NSE4 questions linked to Security Profiles.
High Availability and Diagnostics practice questions
Practise NSE4 questions linked to High Availability and Diagnostics.
NSE4 fundamentals practice questions
Practise NSE4 questions linked to NSE4 fundamentals.
NSE4 scenario practice questions
Practise NSE4 questions linked to NSE4 scenario.
NSE4 troubleshooting practice questions
Practise NSE4 questions linked to NSE4 troubleshooting.
Practice this exam
Start a free NSE4 practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this NSE4 question test?
System and Network Administration — This question tests System and Network Administration — CIDR notation defines the prefix length..
What is the correct answer to this question?
The correct answer is: The static route's gateway is not reachable via any interface.
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 →
Same concept, more angles
1 more ways this is tested on NSE4
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. After upgrading FortiGate firmware from 6.0 to 7.2, an administrator notices that a static route pointing to a next-hop IP 10.0.0.1 is no longer working. The route is present in the configuration but the FortiGate shows it as 'not active'. What is the MOST likely cause?
medium- A.FortiGate now requires a default administrative distance of 10 for static routes
- B.The route was deleted during the upgrade and needs to be re-added
- ✓ C.The next-hop IP is not directly connected to any FortiGate interface
- D.The remote gateway is down
Why C: In FortiOS 7.2, a static route is considered 'active' only if the next-hop IP is reachable via a directly connected interface. If the next-hop IP 10.0.0.1 is not on a directly connected subnet, the route will be present in the configuration but marked as 'not active'. This is a fundamental routing principle: the next hop must be directly reachable (i.e., the router must have an ARP entry for it) for the route to be installed in the routing table.
Last reviewed: Jun 21, 2026
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.