N10-009 Networking Concepts Practice Question
Which device operates at Layer 1 (Physical) of the OSI model and regenerates electrical signals to extend the distance of a network segment?
⚠ Common exam trap
CompTIA often tests the distinction between a hub (Layer 1, signal regeneration) and a bridge/switch (Layer 2, frame forwarding), trapping candidates who confuse signal regeneration with MAC-based forwarding.
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
✓
Hub
A hub operates at Layer 1 (Physical) of the OSI model. It receives incoming electrical signals on one port and regenerates (repeats) those signals out to all other ports, effectively extending the physical reach of a network segment. Unlike switches or routers, it performs no frame inspection or forwarding decisions.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Switch
Why it's wrong here
A switch operates at Layer 2 (Data Link) of the OSI model, providing significant advancements over hubs by intelligently forwarding data frames. It builds and maintains a MAC address table, learning the source MAC addresses of devices connected to its ports. When a frame arrives, the switch inspects its destination MAC address and forwards the frame only to the specific port where that device is known to reside, effectively segmenting collision domains and reducing unnecessary network traffic.
When this WOULD be correct
A switch would be correct if the question asked: 'Which device connects multiple devices on a LAN, uses MAC addresses to forward frames, and reduces collision domains?'
- ✗
Router
Why it's wrong here
A router functions at Layer 3 (Network) of the OSI model, primarily responsible for connecting different logical networks or subnets and forwarding IP packets between them. It uses routing tables to determine the optimal path for packets based on their destination IP addresses, inspecting the network portion of the address. Routers decrement the Time-To-Live (TTL) field in IP packet headers and are crucial for inter-network communication, including the internet itself.
When this WOULD be correct
A router would be correct for a question asking: 'Which device connects different networks and forwards packets based on logical addressing?'
- ✓
Hub
Why this is correct
A hub is a fundamental Layer 1 device, functioning as a multi-port repeater that operates purely at the physical layer of the OSI model. It receives an incoming electrical signal on one port and regenerates it, broadcasting the signal to all other connected ports without any intelligence regarding data frames or MAC addresses. This action effectively extends the physical range of the network but creates a single, large collision domain for all connected devices.
- ✗
Bridge
Why it's wrong here
A bridge operates at Layer 2 (Data Link) of the OSI model, similar to a switch but typically with fewer ports, often just two. Its primary function is to connect two separate network segments and intelligently filter or forward frames between them based on MAC addresses. By learning the MAC addresses present on each segment, a bridge can reduce traffic by preventing frames destined for a device on the same segment from crossing to the other, thereby segmenting collision domains.
When this WOULD be correct
A bridge would be correct in a question asking: 'Which device connects two network segments and filters traffic based on MAC addresses to reduce collisions?'
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.
✓HubCorrect answer▾
Why this is correct
A hub is a fundamental Layer 1 device, functioning as a multi-port repeater that operates purely at the physical layer of the OSI model. It receives an incoming electrical signal on one port and regenerates it, broadcasting the signal to all other connected ports without any intelligence regarding data frames or MAC addresses. This action effectively extends the physical range of the network but creates a single, large collision domain for all connected devices.
✗SwitchWrong answer — click to see why▾
Why this is wrong here
A switch operates at Layer 2 (Data Link) and uses MAC addresses to forward frames, not at Layer 1. It does not simply regenerate electrical signals; it makes forwarding decisions based on addressing.
★ When this WOULD be the correct answer
A switch would be correct if the question asked: 'Which device connects multiple devices on a LAN, uses MAC addresses to forward frames, and reduces collision domains?'
Why candidates choose this
Candidates may confuse a switch with a hub because both connect multiple devices in a network, but they forget that switches operate at Layer 2 and do not merely regenerate signals.
✗RouterWrong answer — click to see why▾
Why this is wrong here
Routers operate at Layer 3 (Network) and make forwarding decisions based on IP addresses, not by regenerating electrical signals at the physical layer.
★ When this WOULD be the correct answer
A router would be correct for a question asking: 'Which device connects different networks and forwards packets based on logical addressing?'
Why candidates choose this
Candidates may confuse a router's ability to extend network reach (via routing) with the physical signal regeneration function of a hub.
✗BridgeWrong answer — click to see why▾
Why this is wrong here
A bridge operates at Layer 2 (Data Link) and uses MAC addresses to forward frames, not Layer 1 signal regeneration. It does not simply regenerate electrical signals to extend distance.
★ When this WOULD be the correct answer
A bridge would be correct in a question asking: 'Which device connects two network segments and filters traffic based on MAC addresses to reduce collisions?'
Why candidates choose this
Candidates may confuse bridges with repeaters or hubs because both can extend network segments, but bridges operate at a higher layer and provide filtering.
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
Segment
A segment is a division of a larger network, such as a collision domain, broadcast domain, or a portion of a TCP data stream, used to organize traffic and improve performance.
Key term
Frame
A frame is a unit of data at the Data Link layer of networking, containing header, payload, and trailer information for local network delivery.
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.