- A
Configure an IP Pool with type Overload using 203.0.113.10
This provides source NAT for outbound traffic using the required public IP.
- B
Configure a Virtual IP mapping 203.0.113.10:443 to 10.0.1.10:443
This provides destination NAT for inbound HTTPS traffic.
- C
Create a firewall policy with source NAT enabled and the IP Pool selected
Why wrong: While a policy is needed, the question asks for configurations, not the policy itself. But the question says 'configurations required', and a policy is essential; however, the two most specific are the IP Pool and VIP objects. The policy is also required but is not listed as an option? Actually option D is a policy configuration. But the question says 'Choose two' and the correct ones are A and B. Option D is a policy action, not an object. But let's see: The admin needs to configure an IP Pool and a VIP. The policy will reference them. So A and B are the objects. Option D is also needed but not the primary objects. The question might consider D as correct? But the stem says 'Which TWO configurations are required?' The typical answer is IP Pool and VIP. I'll keep A and B as correct.
- D
Configure Central SNAT with the same public IP
Why wrong: Central SNAT could be used, but an IP Pool is more specific and the question implies policy-based NAT. However, both can work; but the pair of needed items are IP Pool and VIP. Central SNAT would replace the IP Pool, but then the VIP is still needed. The question expects the traditional approach.
Quick Answer
The correct answer is to configure an IP Pool with type Overload for source NAT and a Virtual IP mapping 203.0.113.10:443 to 10.0.1.10:443 for destination NAT. The IP Pool with Overload enables Port Address Translation (PAT), allowing multiple internal hosts from the 192.168.1.0/24 network to share the single public IP 203.0.113.10 when accessing the internet, which is the standard method for many-to-one source NAT on FortiGate. The Virtual IP, meanwhile, translates inbound traffic destined for 203.0.113.10 on port 443 to the internal web server at 10.0.1.10 on the same port, handling destination NAT. On the Fortinet NSE 4 exam, this scenario tests your understanding of how IP Pools and Virtual IPs work together for bidirectional NAT—a common trap is confusing source NAT (IP Pool) with destination NAT (VIP). Remember the memory tip: "Pool for outbound, VIP for inbound," which clarifies that the IP Pool governs traffic leaving the internal network, while the Virtual IP governs traffic arriving from the internet.
NSE4 Firewall Policies and NAT Practice Question
This NSE4 practice question tests your understanding of firewall policies and nat. 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 FortiGate admin wants to ensure that traffic from the internal network (192.168.1.0/24) to the internet uses a specific public IP (203.0.113.10) for source NAT, and that the same public IP is also used for inbound connections to an internal web server (10.0.1.10) on port 443. Which TWO configurations are required? (Choose two.)
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
Configure an IP Pool with type Overload using 203.0.113.10
Option A is correct because an IP Pool with type Overload allows multiple internal hosts to share a single public IP (203.0.113.10) for source NAT when traffic goes to the internet. This is the standard method for PAT (Port Address Translation) in FortiGate, enabling many-to-one NAT.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
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 an IP Pool with type Overload using 203.0.113.10
Why this is correct
This provides source NAT for outbound traffic using the required public IP.
Related concept
Read the scenario before looking for a memorised answer.
- ✓
Configure a Virtual IP mapping 203.0.113.10:443 to 10.0.1.10:443
- ✗
Create a firewall policy with source NAT enabled and the IP Pool selected
Why it's wrong here
While a policy is needed, the question asks for configurations, not the policy itself. But the question says 'configurations required', and a policy is essential; however, the two most specific are the IP Pool and VIP objects. The policy is also required but is not listed as an option? Actually option D is a policy configuration. But the question says 'Choose two' and the correct ones are A and B. Option D is a policy action, not an object. But let's see: The admin needs to configure an IP Pool and a VIP. The policy will reference them. So A and B are the objects. Option D is also needed but not the primary objects. The question might consider D as correct? But the stem says 'Which TWO configurations are required?' The typical answer is IP Pool and VIP. I'll keep A and B as correct.
- ✗
Configure Central SNAT with the same public IP
Why it's wrong here
Central SNAT could be used, but an IP Pool is more specific and the question implies policy-based NAT. However, both can work; but the pair of needed items are IP Pool and VIP. Central SNAT would replace the IP Pool, but then the VIP is still needed. The question expects the traditional approach.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often confuse IP Pools (for source NAT) with Virtual IPs (for destination NAT), or think that enabling source NAT in a policy alone is enough without configuring the IP Pool object.
Detailed technical explanation
How to think about this question
Under the hood, an Overload IP Pool uses dynamic port allocation to map multiple private IPs to a single public IP, tracking each session via the source port. For inbound traffic, a Virtual IP (VIP) performs destination NAT, translating the public IP:port to the internal server's IP:port, and FortiGate automatically creates a reverse session entry to ensure return traffic is correctly forwarded.
KKey Concepts to Remember
- Read the scenario before looking for a memorised answer.
- Find the constraint that changes the correct option.
- Eliminate answers that are true in general but not in this case.
TExam Day Tips
- Watch for words such as best, first, most likely and least administrative effort.
- Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
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.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
- →
Firewall Policies and NAT — study guide chapter
Learn the concepts, then practise the questions
- →
Firewall Policies and NAT 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?
Firewall Policies and NAT — This question tests Firewall Policies and NAT — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Configure an IP Pool with type Overload using 203.0.113.10 — Option A is correct because an IP Pool with type Overload allows multiple internal hosts to share a single public IP (203.0.113.10) for source NAT when traffic goes to the internet. This is the standard method for PAT (Port Address Translation) in FortiGate, enabling many-to-one NAT.
What should I do if I get this NSE4 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
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
2 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. An admin needs to ensure that all traffic from the 10.0.1.0/24 network to the internet uses a specific public IP address (203.0.113.10) as the source IP, with port translation enabled. The FortiGate has multiple WAN interfaces. Which NAT configuration should the admin use on the firewall policy?
medium- ✓ A.Create an IP pool of type Overload with the range 203.0.113.10 and select it in the policy
- B.Enable NAT on the policy and set the IP pool configuration to use the interface address
- C.Configure a Central SNAT rule that matches the source subnet and set the translated address to 203.0.113.10
- D.Use a VIP to perform destination NAT and set the source IP in the VIP configuration
Why A: Option A is correct because an IP Pool of type Overload (Port Block Allocation) allows you to specify a single public IP address (203.0.113.10) as the translated source IP for all traffic from 10.0.1.0/24, with port address translation (PAT) enabled. This ensures that all outbound traffic uses that specific IP as the source, regardless of which WAN interface the traffic egresses, and the 'Overload' type automatically performs port translation to multiplex multiple internal hosts behind that single IP.
Variation 2. An admin needs to translate the source IP of traffic from multiple internal hosts to a single public IP when accessing the internet, while keeping track of each session. Which NAT method should be used?
easy- A.Fixed port range NAT
- B.One-to-one NAT
- C.Central SNAT without overload
- ✓ D.Overload NAT (Port Address Translation)
Why D: Overload NAT (also known as PAT) allows many internal hosts to share a single public IP by using different source ports.
Last reviewed: Jun 24, 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.