NSE4 System and Network Administration Practice Question
A FortiGate is configured as a DHCP server for the internal network. The administrator wants to ensure that clients receive the FortiGate's internal IP address as the default gateway and a specific DNS server. Which configuration step is required?
⚠ Common exam trap
The trap here is thinking that a firewall policy or DNS forwarding is needed to provide DHCP options, when the DHCP server settings already include those parameters.
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
✓
In the DHCP server settings, configure the default gateway and DNS server options, and ensure the internal interface IP is set as the gateway.
When configuring a DHCP server on a FortiGate, you can specify the default gateway and DNS servers that clients receive in the DHCP options. Setting the default gateway to the FortiGate's internal IP ensures clients use it as their gateway. The DNS server option provides the desired DNS server. Other options do not achieve this.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
In the DHCP server settings, configure the default gateway and DNS server options, and ensure the internal interface IP is set as the gateway.
Why this is correct
The DHCP server settings allow you to specify the default gateway and DNS servers that clients receive. Setting the default gateway to the FortiGate's internal IP ensures clients route traffic through it. This is the correct way to provide these parameters to DHCP clients.
- ✗
Configure a DHCP relay on the internal interface pointing to the FortiGate's internal IP address.
Why it's wrong here
A DHCP relay is used when the DHCP server is on a different subnet. Here, the FortiGate is already the DHCP server for the internal network, so a relay is not needed. Configuring a relay would be redundant and could cause conflicts.
- ✗
Enable DNS forwarding on the internal interface and set the DNS server in the system settings.
Why it's wrong here
DNS forwarding enables the FortiGate to answer DNS queries, but it does not configure what DNS server clients receive via DHCP. The DHCP server settings include a DNS server option that directly provides the DNS server to clients. System DNS settings are for the FortiGate's own use.
- ✗
Create a firewall policy that allows DHCP traffic from the internal network to the FortiGate's internal interface.
Why it's wrong here
DHCP is a broadcast protocol that does not require a firewall policy when the FortiGate is the DHCP server on the same subnet. Firewall policies control routed traffic, not DHCP requests to the FortiGate itself. This step is unnecessary and would not affect DHCP options.
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JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Fortinet exam blueprint
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.