N10-009 Networking Concepts Practice Question
Which of the following best describes the primary difference between a hub and a switch?
⚠ Common exam trap
Test-takers frequently confuse the OSI layer of a switch (Layer 2) with a router (Layer 3) and incorrectly assume switches are faster because they operate at a higher layer, or they mistakenly think hubs can segment collision domains when in fact they expand them.
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 broadcasts all frames to all ports; a switch forwards frames only to the destination port
A hub operates at Layer 1 (physical layer) and simply repeats electrical signals out all ports, causing all connected devices to receive every frame. A switch operates at Layer 2 (data link layer) and uses the MAC address table to forward frames only to the specific port where the destination device resides, reducing unnecessary traffic and improving network efficiency.
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 switch is faster than a hub because it operates at Layer 3
Why it's wrong here
This statement is incorrect because standard Ethernet switches primarily operate at Layer 2 (the Data Link layer) of the OSI model, not Layer 3. Layer 3 devices, such as routers, handle IP addresses for inter-network routing and routing decisions. While switches are indeed faster than hubs due to their intelligent frame forwarding capabilities, this speed advantage stems from their ability to learn MAC addresses and create dedicated communication paths, not from Layer 3 functionality.
When this WOULD be correct
This option would be correct if the question asked: 'Which of the following best describes the primary difference between a Layer 3 switch and a router?' In that context, a Layer 3 switch can be faster than a router because it uses hardware-based switching at Layer 3.
- ✓
A hub broadcasts all frames to all ports; a switch forwards frames only to the destination port
Why this is correct
Hubs are Layer 1 devices that simply regenerate electrical signals received on one port and send them out all other ports, effectively creating a single collision domain where all connected devices see all traffic. In contrast, a switch operates at Layer 2, building a MAC address table by inspecting source MAC addresses of incoming frames. It then uses this table to intelligently forward frames only to the specific port where the destination MAC address is known to reside, significantly reducing unnecessary traffic on other ports.
- ✗
A hub can segment collision domains; a switch cannot
Why it's wrong here
This statement is incorrect; the opposite is true. A hub operates as a single shared medium, meaning all devices connected to it are part of one large collision domain, where any transmission can collide with another, forcing retransmissions. A switch, however, effectively segments collision domains. Each port on a switch typically represents its own dedicated collision domain, allowing multiple devices to transmit simultaneously without collisions, thereby significantly improving network efficiency and performance.
When this WOULD be correct
If the question were 'Which of the following best describes the primary difference between a hub and a switch regarding collision domains?', then the correct answer would be that a switch segments collision domains while a hub does not.
- ✗
Both hubs and switches operate at the same OSI layer but use different frame types
Why it's wrong here
This statement is false because hubs and switches operate at different OSI layers. Hubs are Layer 1 (Physical layer) devices, functioning as multi-port repeaters that simply regenerate electrical signals without inspecting frame content. Switches, conversely, operate at Layer 2 (Data Link layer), processing MAC addresses for intelligent frame forwarding decisions. Furthermore, both devices handle standard Ethernet frames; they do not utilize different frame types for their respective operations.
When this WOULD be correct
If the question asked about the difference between a router and a switch, then 'operate at the same OSI layer but use different frame types' could be correct if comparing a Layer 3 router (using IP packets) with a Layer 2 switch (using Ethernet frames).
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.
✓A hub broadcasts all frames to all ports; a switch forwards frames only to the destination portCorrect answer▾
Why this is correct
Hubs are Layer 1 devices that simply regenerate electrical signals received on one port and send them out all other ports, effectively creating a single collision domain where all connected devices see all traffic. In contrast, a switch operates at Layer 2, building a MAC address table by inspecting source MAC addresses of incoming frames. It then uses this table to intelligently forward frames only to the specific port where the destination MAC address is known to reside, significantly reducing unnecessary traffic on other ports.
✗A switch is faster than a hub because it operates at Layer 3Wrong answer — click to see why▾
Why this is wrong here
Switches operate at Layer 2 (data link layer), not Layer 3. While some switches can perform Layer 3 routing, the primary difference between a hub and a switch is not speed based on OSI layer; hubs operate at Layer 1 and switches at Layer 2.
★ When this WOULD be the correct answer
This option would be correct if the question asked: 'Which of the following best describes the primary difference between a Layer 3 switch and a router?' In that context, a Layer 3 switch can be faster than a router because it uses hardware-based switching at Layer 3.
Why candidates choose this
Candidates may confuse switches with routers or assume that 'switch' always implies Layer 3 capabilities, and they may think that operating at a higher layer inherently makes a device faster.
✗A hub can segment collision domains; a switch cannotWrong answer — click to see why▾
Why this is wrong here
A hub does not segment collision domains; it actually extends them. A switch segments collision domains by creating a separate collision domain per port.
★ When this WOULD be the correct answer
If the question were 'Which of the following best describes the primary difference between a hub and a switch regarding collision domains?', then the correct answer would be that a switch segments collision domains while a hub does not.
Why candidates choose this
Candidates may confuse the concept of collision domains with broadcast domains, or mistakenly think that hubs provide segmentation because they are older devices that physically separate ports.
✗Both hubs and switches operate at the same OSI layer but use different frame typesWrong answer — click to see why▾
Why this is wrong here
Both hubs and switches operate at Layer 2 (Data Link layer) and use the same Ethernet frame types; the statement is factually incorrect.
★ When this WOULD be the correct answer
If the question asked about the difference between a router and a switch, then 'operate at the same OSI layer but use different frame types' could be correct if comparing a Layer 3 router (using IP packets) with a Layer 2 switch (using Ethernet frames).
Why candidates choose this
Candidates may confuse the OSI layers of hubs and switches, or think that switches use different frame types due to VLAN tagging, but standard Ethernet frames are identical for both devices.
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?”
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 |
Go deeper
Related to this question
Learn chapter
Network Virtualization and VXLAN
Key term
MAC address
A MAC address is a unique hardware identifier assigned to a network interface card that allows devices to communicate on a local network.
Key term
Media Access Control
Media Access Control (MAC) is a sublayer of the Data Link Layer in networking that controls how devices on the same network share access to the physical medium and uniquely identifies each device with a hardware address.
About these practice questions
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
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.