N10-009 Networking Concepts Practice Question
A network device receives a frame on one port and forwards it out to all other ports. The device does not examine the destination MAC address. Which type of device is being described?
⚠ Common exam trap
The N10-009 exam often tests the distinction between Layer 1 (hub) and Layer 2 (switch/bridge) devices by describing the 'flooding' behavior of a switch when the MAC address is unknown, which can trick candidates into thinking a switch forwards to all ports without examining the MAC address, but a switch always examines the destination MAC address first.
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 layer) of the OSI model and simply repeats incoming electrical or optical signals out all other ports without any processing of the frame's destination MAC address. This behavior matches the description exactly: the device receives a frame on one port and forwards it out all other ports without examining the MAC address.
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 the Data Link layer (Layer 2) and is an intelligent device that learns MAC addresses of connected devices. Upon receiving a frame, a switch inspects the destination MAC address in the frame header and consults its MAC address table (CAM table). It then forwards the frame only to the specific port associated with that MAC address, significantly reducing unnecessary traffic and creating multiple collision domains, only flooding if the destination is unknown or a broadcast.
When this WOULD be correct
This option would be correct if the question described a device that forwards frames based on destination MAC addresses and maintains a MAC address table to filter traffic, such as 'Which device uses MAC addresses to forward frames only to the intended recipient?'
- ✓
Hub
Why this is correct
A hub operates at the Physical layer (Layer 1) of the OSI model, functioning as a multi-port repeater. When a hub receives an electrical signal (representing a frame) on one port, it simply regenerates that signal and broadcasts it out to all other connected ports, without inspecting any MAC address information. It has no intelligence to make forwarding decisions, effectively creating a single collision domain where all connected devices share the same bandwidth.
- ✗
Bridge
Why it's wrong here
A bridge is a Layer 2 device that connects two or more network segments and makes forwarding decisions based on MAC addresses. Unlike a hub, a bridge learns the MAC addresses of devices on each connected segment and builds a forwarding table to segment traffic. When a frame arrives, the bridge checks the destination MAC address; if the destination is on the same segment as the source, it filters the frame, preventing it from crossing, but forwards it only to the necessary segment if the destination is elsewhere.
When this WOULD be correct
A bridge would be the correct answer if the question described a device that uses MAC addresses to segment collision domains and forwards frames only to the appropriate port based on the destination MAC address, or if the question asked about a device that connects two network segments and filters traffic.
- ✗
Router
Why it's wrong here
A router operates at the Network layer (Layer 3) and is responsible for forwarding packets between different IP networks. When a router receives a packet, it examines the destination IP address in the packet header and consults its routing table to determine the optimal path to the destination network. It then forwards the packet out the appropriate interface, making highly specific, intelligent decisions based on network topology and routing protocols, rather than simply replicating traffic to all ports.
When this WOULD be correct
A router would be the correct answer for a question describing a device that forwards packets based on destination IP address, connects different networks, and uses routing tables to determine the best path.
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 operates at the Physical layer (Layer 1) of the OSI model, functioning as a multi-port repeater. When a hub receives an electrical signal (representing a frame) on one port, it simply regenerates that signal and broadcasts it out to all other connected ports, without inspecting any MAC address information. It has no intelligence to make forwarding decisions, effectively creating a single collision domain where all connected devices share the same bandwidth.
✗SwitchWrong answer — click to see why▾
Why this is wrong here
A switch examines the destination MAC address to forward frames only to the appropriate port, not to all ports, unlike the device described.
★ When this WOULD be the correct answer
This option would be correct if the question described a device that forwards frames based on destination MAC addresses and maintains a MAC address table to filter traffic, such as 'Which device uses MAC addresses to forward frames only to the intended recipient?'
Why candidates choose this
Candidates may confuse hubs with switches because both are used to connect multiple devices in a LAN, but they forget that switches intelligently forward frames based on MAC addresses.
✗BridgeWrong answer — click to see why▾
Why this is wrong here
Bridges examine destination MAC addresses to decide whether to forward or filter frames, and they do not flood frames out all ports unless the address is unknown. This question describes a device that forwards all frames out all ports without examining MAC addresses, which is a hub, not a bridge.
★ When this WOULD be the correct answer
A bridge would be the correct answer if the question described a device that uses MAC addresses to segment collision domains and forwards frames only to the appropriate port based on the destination MAC address, or if the question asked about a device that connects two network segments and filters traffic.
Why candidates choose this
Candidates may confuse bridges with hubs because both are legacy devices used to connect network segments, but they forget that bridges perform MAC address learning and filtering, whereas hubs simply repeat signals.
✗RouterWrong answer — click to see why▾
Why this is wrong here
Routers operate at Layer 3 and examine destination IP addresses to make forwarding decisions, not MAC addresses. They do not forward frames out all ports without inspection.
★ When this WOULD be the correct answer
A router would be the correct answer for a question describing a device that forwards packets based on destination IP address, connects different networks, and uses routing tables to determine the best path.
Why candidates choose this
Candidates may confuse the behavior of a hub with that of a router because both can forward traffic to multiple ports, but they operate at different layers and have distinct forwarding logic.
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
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.
Key term
Hub
A hub is a basic networking device that connects multiple computers or devices together so they can communicate, but it sends all data to every connected port without filtering.
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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.