- A
A hub operates at Layer 2, while a switch operates at Layer 1.
Why wrong: This is incorrect; hubs are Layer 1 devices and switches are Layer 2 devices.
- B
A hub sends frames out all ports except the incoming port; a switch sends frames only to the port with the matching MAC address.
This accurately describes the behavior: hubs flood all ports, switches forward based on MAC address table.
- C
A hub uses MAC addresses to make forwarding decisions, while a switch uses IP addresses.
Why wrong: Hubs do not use MAC addresses for forwarding; switches use MAC addresses, not IP addresses.
- D
A hub creates a separate collision domain for each port, while a switch creates a single collision domain.
Why wrong: The opposite is true: hubs create one collision domain for all ports; switches create separate collision domains per port.
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.
A network technician is explaining the difference between a hub and a switch to a junior technician. Which statement correctly describes a key difference between these devices?
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
A hub sends frames out all ports except the incoming port; a switch sends frames only to the port with the matching MAC address.
B is correct because a hub operates at Layer 1 (physical layer) and blindly repeats electrical signals out all ports except the incoming port, creating a single collision domain. In contrast, a switch operates at Layer 2 (data link layer) and uses the MAC address table to forward frames only to the specific port associated with the destination MAC address, reducing unnecessary traffic and creating separate collision domains per port.
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.
- ✗
A hub operates at Layer 2, while a switch operates at Layer 1.
Why it's wrong here
This is incorrect; hubs are Layer 1 devices and switches are Layer 2 devices.
- ✓
A hub sends frames out all ports except the incoming port; a switch sends frames only to the port with the matching MAC address.
Why this is correct
This accurately describes the behavior: hubs flood all ports, switches forward based on MAC address table.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
A hub uses MAC addresses to make forwarding decisions, while a switch uses IP addresses.
Why it's wrong here
Hubs do not use MAC addresses for forwarding; switches use MAC addresses, not IP addresses.
- ✗
A hub creates a separate collision domain for each port, while a switch creates a single collision domain.
Why it's wrong here
The opposite is true: hubs create one collision domain for all ports; switches create separate collision domains per port.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Cisco often tests the confusion between Layer 1 and Layer 2 operations, where candidates mistakenly think a hub operates at Layer 2 or that a switch uses IP addresses, but the key trap is reversing the collision domain behavior—hub creates one collision domain, switch creates many.
Detailed technical explanation
How to think about this question
Under the hood, a switch builds its MAC address table by learning the source MAC addresses of incoming frames and associating them with the ingress port; it then uses this table to make forwarding decisions. A hub, being a simple repeater, has no intelligence and regenerates the signal on all other ports, which can lead to excessive collisions and reduced throughput in half-duplex environments. In real-world scenarios, replacing a hub with a switch in a congested network can dramatically improve performance by isolating collision domains and allowing full-duplex communication.
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.
- →
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: A hub sends frames out all ports except the incoming port; a switch sends frames only to the port with the matching MAC address. — B is correct because a hub operates at Layer 1 (physical layer) and blindly repeats electrical signals out all ports except the incoming port, creating a single collision domain. In contrast, a switch operates at Layer 2 (data link layer) and uses the MAC address table to forward frames only to the specific port associated with the destination MAC address, reducing unnecessary traffic and creating separate collision domains per port.
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.