The correct answer is DMZ, or demilitarized zone, because it creates a separate network segment that isolates public-facing services like a web server from the internal LAN while still allowing controlled internet access. By placing the server in the DMZ, the firewall enforces strict access control policies—permitting inbound traffic from the internet to the DMZ but blocking any direct connections to the internal network, thus containing potential breaches. On the CompTIA Network+ N10-009 exam, this concept tests your understanding of network segmentation for security, often appearing in scenario-based questions where you must choose the technique that balances accessibility with isolation. A common trap is confusing a DMZ with a VPN or a screened subnet; remember that a DMZ is a physically or logically separate network, not just a firewall rule. Memory tip: think of the DMZ as a “buffer zone” between the wild internet and your safe internal network—public servers live there, not inside your house.
N10-009 Network Security Practice Question
This N10-009 practice question tests your understanding of network security. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. 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 is configuring a firewall to allow external users to securely access an internal web server. Which security technique should be used to place the web server in a separate, isolated network segment that is still accessible from the internet?
Why wrong: A VLAN could segment the server logically, but without a firewall controlling access, it does not provide the same level of security isolation as a DMZ.
B
DMZ
A DMZ is specifically designed to host public-facing services while isolating them from the internal network.
C
VPN
Why wrong: A VPN is used to create an encrypted tunnel for remote access, not to isolate a public server.
D
NAT
Why wrong: NAT translates private IPs to public IPs but does not provide the isolated network segment needed.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
DMZ
A DMZ (demilitarized zone) is a separate, isolated network segment that exposes internal services, such as a web server, to external users while keeping the internal LAN secure. By placing the web server in the DMZ, the firewall can allow inbound traffic from the internet to the DMZ while blocking direct access to the internal network, enforcing strict access control policies.
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.
✗
VLAN
Why it's wrong here
A VLAN could segment the server logically, but without a firewall controlling access, it does not provide the same level of security isolation as a DMZ.
✓
DMZ
Why this is correct
A DMZ is specifically designed to host public-facing services while isolating them from the internal network.
Related concept
Read the scenario before looking for a memorised answer.
✗
VPN
Why it's wrong here
A VPN is used to create an encrypted tunnel for remote access, not to isolate a public server.
✗
NAT
Why it's wrong here
NAT translates private IPs to public IPs but does not provide the isolated network segment needed.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often confuse VLANs with security isolation, assuming a VLAN alone provides the same protection as a DMZ, but VLANs lack the firewall-enforced access controls and segmentation from the internet that a DMZ requires.
Detailed technical explanation
How to think about this question
A DMZ typically uses a three-legged firewall architecture with separate interfaces for the internet, DMZ, and internal LAN, or a pair of firewalls (front-end and back-end) to enforce strict traffic flows. In practice, the DMZ subnet is often assigned a public IP range or uses destination NAT (DNAT) to map a public IP to the web server's private IP, while stateful firewall rules permit only specific ports (e.g., TCP 80/443) from the internet to the DMZ and deny all unsolicited traffic from the DMZ to the internal LAN.
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 help-desk technician troubleshoots why a newly connected PC cannot reach shared printers on the same floor. The cable is good, the switch port is active, but the PC is in VLAN 20 and the printers are in VLAN 10. The uplink trunk only allows VLAN 10. A trunk being up does not mean every VLAN crosses it.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this N10-009 question in full detail.
Network Security — This question tests Network Security — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: DMZ — A DMZ (demilitarized zone) is a separate, isolated network segment that exposes internal services, such as a web server, to external users while keeping the internal LAN secure. By placing the web server in the DMZ, the firewall can allow inbound traffic from the internet to the DMZ while blocking direct access to the internal network, enforcing strict access control policies.
What should I do if I get this N10-009 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 →
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 N10-009 practice question is part of Courseiva's free CompTIA 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 N10-009 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.