- A
Makes forwarding decisions based on IP addresses
Why wrong: IP address forwarding is a Layer 3 function performed by routers and Layer 3 switches.
- B
Uses MAC addresses to make forwarding decisions
Layer 2 switches use MAC address tables to forward frames to the correct port based on the destination MAC address.
- C
Can route traffic between different VLANs without a router
Why wrong: Routing between VLANs requires Layer 3 functionality. A pure Layer 2 switch cannot perform inter-VLAN routing.
- D
Provides Network Address Translation (NAT)
Why wrong: NAT is a Layer 3 function typically performed by routers or firewalls.
Question 316 of 520
N10-009 Networking Concepts Practice Question
This N10-009 practice question tests your understanding of networking concepts. 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.
Which of the following is a characteristic of a Layer 2 network switch?
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
✓
Uses MAC addresses to make forwarding decisions
A Layer 2 network switch operates at the Data Link layer of the OSI model and uses MAC addresses to make forwarding decisions. It examines the destination MAC address in an Ethernet frame and consults its MAC address table to determine the appropriate port to forward the frame, enabling efficient local area network communication.
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.
- ✗
Makes forwarding decisions based on IP addresses
Why it's wrong here
IP address forwarding is a Layer 3 function performed by routers and Layer 3 switches.
When this WOULD be correct
This option would be correct for a question asking about a characteristic of a Layer 3 switch or a router, which makes forwarding decisions based on IP addresses.
- ✓
Uses MAC addresses to make forwarding decisions
Why this is correct
Layer 2 switches use MAC address tables to forward frames to the correct port based on the destination MAC address.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Can route traffic between different VLANs without a router
Why it's wrong here
Routing between VLANs requires Layer 3 functionality. A pure Layer 2 switch cannot perform inter-VLAN routing.
When this WOULD be correct
In a question about a multilayer switch that supports both switching and routing, or if the question specifies a Layer 3 switch with routing capabilities enabled, then it can route traffic between VLANs without an external router.
- ✗
Provides Network Address Translation (NAT)
Why it's wrong here
NAT is a Layer 3 function typically performed by routers or firewalls.
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The N10-009 exam frequently reuses these exact scenarios with slightly different constraints.
✓Uses MAC addresses to make forwarding decisionsCorrect answer▾
Why this is correct
Layer 2 switches use MAC address tables to forward frames to the correct port based on the destination MAC address.
✗Makes forwarding decisions based on IP addressesWrong answer — click to see why▾
Why this is wrong here
Layer 2 switches operate at the data link layer and use MAC addresses, not IP addresses, for forwarding decisions. IP addresses are used by Layer 3 devices like routers.
★ When this WOULD be the correct answer
This option would be correct for a question asking about a characteristic of a Layer 3 switch or a router, which makes forwarding decisions based on IP addresses.
Why candidates choose this
Candidates may confuse the functions of Layer 2 and Layer 3 devices, mistakenly thinking switches use IP addresses because they often work with IP networks in practice.
✗Can route traffic between different VLANs without a routerWrong answer — click to see why▾
Why this is wrong here
A Layer 2 switch operates at the data link layer and cannot route traffic between VLANs; inter-VLAN routing requires a Layer 3 device such as a router or a multilayer switch.
★ When this WOULD be the correct answer
In a question about a multilayer switch that supports both switching and routing, or if the question specifies a Layer 3 switch with routing capabilities enabled, then it can route traffic between VLANs without an external router.
Why candidates choose this
Candidates may confuse a Layer 2 switch with a Layer 3 switch or assume that VLANs inherently provide routing, not realizing that separate VLANs require a routing function to communicate.
✗Provides Network Address Translation (NAT)Wrong answer — click to see why▾
Why this is wrong here
Network Address Translation (NAT) is a function typically performed by routers or firewalls, not by Layer 2 switches. Layer 2 switches operate at the data link layer and do not modify IP addresses.
★ When this WOULD be the correct answer
A question asking 'Which device provides Network Address Translation (NAT) to allow multiple devices to share a single public IP address?' would have NAT as the correct answer, typically a router or firewall.
Why candidates choose this
Candidates may confuse the functions of different network devices, especially when studying multiple layers simultaneously, and mistakenly attribute NAT to switches because they are common in home networks where NAT is often performed by a combined router/switch device.
Analysis generated from the official N10-009blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
Common exam traps
Common exam trap: answer the scenario, not the keyword
The N10-009 exam often tests the distinction between Layer 2 and Layer 3 functionality, and the trap here is that candidates may confuse a switch's ability to segment VLANs with the ability to route between them, forgetting that routing requires a Layer 3 device or process.
Detailed technical explanation
How to think about this question
Under the hood, a Layer 2 switch builds its MAC address table by learning the source MAC addresses of incoming frames on each port, associating them with the port number. When a frame arrives with an unknown destination MAC, the switch floods the frame out all ports except the ingress port, a process known as unknown unicast flooding. In a real-world scenario, this behavior can cause issues in large networks with asymmetric routing or when MAC address tables overflow, leading to excessive flooding and potential performance degradation.
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.
Quick reference
OSI Model Reference
| Layer | Name | PDU | Key Protocols / Devices |
|---|---|---|---|
| 7 | Application | Data | HTTP, HTTPS, DNS, SMTP, FTP, SSH |
| 6 | Presentation | Data | TLS / SSL, JPEG, ASCII encoding |
| 5 | Session | Data | NetBIOS, RPC, SIP |
| 4 | Transport | Segment / Datagram | TCP, UDP |
| 3 | Network | Packet | IP, ICMP, OSPF — Routers |
| 2 | Data Link | Frame | Ethernet, Wi-Fi, PPP — Switches, Bridges |
| 1 | Physical | Bits | Cables, NICs, Hubs, Repeaters |
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.
- →
Networking Concepts — study guide chapter
Learn the concepts, then practise the questions
- →
Networking Concepts 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?
Networking Concepts — This question tests Networking Concepts — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Uses MAC addresses to make forwarding decisions — A Layer 2 network switch operates at the Data Link layer of the OSI model and uses MAC addresses to make forwarding decisions. It examines the destination MAC address in an Ethernet frame and consults its MAC address table to determine the appropriate port to forward the frame, enabling efficient local area network communication.
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 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?
- Which of the following security mechanisms requires a user to authenticate before gaining access to the wired network at…
- Which of the following network protocols operates at the Transport layer of the OSI model and provides connection-orient…
- Which of the following is a characteristic of a connectionless protocol at the transport layer?
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.