- A
Port forwarding to the private IP addresses of the servers.
Correct. Port forwarding translates incoming traffic on specific ports to the appropriate private IP, enabling external access to internal servers.
- B
NAT with overload to translate multiple internal addresses to the single public IP.
Why wrong: Incorrect. NAT overload (PAT) is used for outbound traffic from internal hosts to the internet, not for inbound access to servers.
- C
Static NAT mapping each DMZ server to a unique public IP.
Why wrong: Incorrect. Static NAT requires a one-to-one mapping of private to public IP addresses, but only one public IP is available.
- D
A VPN tunnel between the DMZ and the internal network.
Why wrong: Incorrect. A VPN secures inter-site communication but does not provide internet access to the DMZ servers from external users.
Quick Answer
The answer is port forwarding to the private IP addresses of the servers. This is correct because with only one public IP, the border router must use port forwarding—often implemented as static NAT—to map specific TCP/UDP ports, such as port 80 for web traffic and port 25 for SMTP, to the corresponding private IP addresses of the DMZ servers. On the CompTIA Network+ N10-009 exam, this scenario tests your understanding of how to segregate traffic in a DMZ without multiple public IPs; a common trap is confusing port forwarding with a full one-to-one NAT or assuming a VPN is needed. Remember that port forwarding acts like a switchboard operator: it listens on the single public IP and directs each call (port) to the correct internal extension (server). A useful memory tip is “one IP, many ports—forward each to its own host.”
N10-009 Network Implementation Practice Question
This N10-009 practice question tests your understanding of network implementation. 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 company is implementing a DMZ to host public-facing web and email servers. The DMZ network uses private IP addresses, and the internal network also uses private IP addresses. The company has only one public IP address assigned to the border router's external interface. Which of the following should be configured to allow internet users to access the DMZ servers?
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
Port forwarding to the private IP addresses of the servers.
Port forwarding (often configured as static NAT with a single public IP) allows the border router to forward incoming traffic on specific TCP/UDP ports (e.g., 80 for web, 25 for SMTP) to the private IP addresses of the DMZ servers. Since the company has only one public IP, this is the only way to direct external requests to the correct internal server without requiring multiple public IPs.
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.
- ✓
Port forwarding to the private IP addresses of the servers.
Why this is correct
Correct. Port forwarding translates incoming traffic on specific ports to the appropriate private IP, enabling external access to internal servers.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
NAT with overload to translate multiple internal addresses to the single public IP.
- ✗
Static NAT mapping each DMZ server to a unique public IP.
Why it's wrong here
Incorrect. Static NAT requires a one-to-one mapping of private to public IP addresses, but only one public IP is available.
- ✗
A VPN tunnel between the DMZ and the internal network.
Why it's wrong here
Incorrect. A VPN secures inter-site communication but does not provide internet access to the DMZ servers from external users.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates confuse PAT (overload NAT) with port forwarding, assuming that PAT alone can handle inbound connections, when in fact PAT only supports outbound-initiated sessions unless explicit port forwarding rules are configured.
Detailed technical explanation
How to think about this question
Port forwarding is essentially a form of destination NAT (DNAT) where the router rewrites the destination IP and port of incoming packets to the private IP and port of the target server. The router must also have an ACL allowing the inbound traffic, and the return traffic must be un-NATed (source NAT) to the router's public IP so the external client sees a consistent source address. In real-world deployments, this is often combined with PAT to allow multiple services on the same public IP, but each service must use a unique port number.
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.
- →
Network Implementation — study guide chapter
Learn the concepts, then practise the questions
- →
Network Implementation practice questions
Targeted practice on this topic area only
- →
All N10-009 questions
520 questions across all exam domains
- →
CompTIA Network+ N10-009 study guide
Full concept coverage aligned to exam objectives
- →
N10-009 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related N10-009 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Networking Concepts practice questions
Practise N10-009 questions linked to Networking Concepts.
Network Implementation practice questions
Practise N10-009 questions linked to Network Implementation.
Network Operations practice questions
Practise N10-009 questions linked to Network Operations.
Network Security practice questions
Practise N10-009 questions linked to Network Security.
Network Troubleshooting practice questions
Practise N10-009 questions linked to Network Troubleshooting.
Network+ network fundamentals practice questions
Practise N10-009 questions linked to Network+ network fundamentals.
Practice this exam
Start a free N10-009 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 N10-009 question test?
Network Implementation — This question tests Network Implementation — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Port forwarding to the private IP addresses of the servers. — Port forwarding (often configured as static NAT with a single public IP) allows the border router to forward incoming traffic on specific TCP/UDP ports (e.g., 80 for web, 25 for SMTP) to the private IP addresses of the DMZ servers. Since the company has only one public IP, this is the only way to direct external requests to the correct internal server without requiring multiple public IPs.
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 →
Keep practising
More N10-009 practice questions
- Which layer of the OSI model is responsible for logical addressing and routing of packets between networks?
- Users in VLAN 10 cannot obtain IP addresses from a DHCP server located in VLAN 20. The router has an ip helper-address c…
- Which of the following is a characteristic of a Layer 2 network switch?
- Which of the following network devices operates primarily at Layer 2 of the OSI model and uses MAC addresses to forward…
- Which of the following is a characteristic of UDP when compared to TCP?
- Which of the following IPv6 addresses is a valid link-local address?
Last reviewed: Jun 11, 2026
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.