Question 355 of 464
N10-009 Networking Concepts Practice Question
A network administrator wants to segment the network into multiple virtual LANs to reduce broadcast traffic. Which device is required to route traffic between these VLANs?
⚠ Common exam trap
CompTIA often tests the misconception that a Layer 2 switch alone can route between VLANs if it supports VLAN tagging (802.1Q), but the switch must have Layer 3 routing capabilities (either as a Layer 3 switch or with an external router) to actually forward traffic between VLANs.
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
✓
Router or Layer 3 switch
VLANs operate at Layer 2, isolating broadcast domains. To route traffic between different VLANs, a device that can forward packets based on Layer 3 IP addresses is required. A router or a Layer 3 switch (which performs hardware-based routing using ASICs) provides the necessary inter-VLAN routing functionality.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Layer 2 switch
Why it's wrong here
A Layer 2 switch forwards Ethernet frames based on destination MAC addresses and is capable of creating and managing VLANs, effectively segmenting a network into multiple broadcast domains. However, a Layer 2 switch operates solely at the data link layer and does not process IP addresses or routing tables. Therefore, while it can keep traffic within a VLAN separate, it cannot route traffic between different VLANs without the assistance of a Layer 3 device like a router or a Layer 3 switch.
When this WOULD be correct
When the question asks for a device to connect multiple devices within the same VLAN or to segment a network into VLANs without requiring inter-VLAN routing, a Layer 2 switch is the correct answer.
- ✓
Router or Layer 3 switch
Why this is correct
A router or a Layer 3 switch is essential for inter-VLAN routing because these devices operate at Layer 3 of the OSI model, processing IP packets. They maintain routing tables and use IP addresses to forward traffic between different IP subnets, each typically corresponding to a distinct VLAN. This capability allows hosts in separate VLANs to communicate, effectively segmenting the network while maintaining connectivity. Layer 3 switches integrate this routing functionality directly into the switching fabric for higher performance.
- ✗
Bridge
Why it's wrong here
A bridge operates strictly at Layer 2 of the OSI model, forwarding data frames based on MAC addresses to connect two distinct network segments within the same broadcast domain. While it can learn MAC addresses and filter traffic, it lacks the intelligence to understand IP addresses or routing protocols. Consequently, a bridge cannot perform inter-VLAN routing, as it cannot differentiate between or forward traffic across different IP subnets associated with separate VLANs.
When this WOULD be correct
A bridge would be correct in a question about connecting two separate network segments to reduce collision domains while keeping them in the same broadcast domain, such as 'Which device connects two Ethernet segments and forwards frames based on MAC addresses?'
- ✗
Hub
Why it's wrong here
A hub is a rudimentary Layer 1 device that functions purely as a multi-port repeater, simply regenerating and broadcasting incoming electrical signals out to all other connected ports. It operates without any understanding of data frames, MAC addresses, IP addresses, or VLAN tags. Consequently, a hub cannot segment a network, distinguish between different VLANs, or perform any form of routing, making it entirely unsuitable for managing or facilitating inter-VLAN communication.
When this WOULD be correct
In a question asking which device is used to connect multiple devices in a single collision domain or to extend a network segment without any filtering, a hub would be correct. For example: 'Which device operates at Layer 1 and repeats all incoming signals to all ports?'
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.
✓Router or Layer 3 switchCorrect answer▾
Why this is correct
A router or a Layer 3 switch is essential for inter-VLAN routing because these devices operate at Layer 3 of the OSI model, processing IP packets. They maintain routing tables and use IP addresses to forward traffic between different IP subnets, each typically corresponding to a distinct VLAN. This capability allows hosts in separate VLANs to communicate, effectively segmenting the network while maintaining connectivity. Layer 3 switches integrate this routing functionality directly into the switching fabric for higher performance.
✗Layer 2 switchWrong answer — click to see why▾
Why this is wrong here
A Layer 2 switch forwards frames based on MAC addresses and cannot perform routing between VLANs because it lacks Layer 3 IP routing capabilities.
★ When this WOULD be the correct answer
When the question asks for a device to connect multiple devices within the same VLAN or to segment a network into VLANs without requiring inter-VLAN routing, a Layer 2 switch is the correct answer.
Why candidates choose this
Candidates may confuse VLAN segmentation with inter-VLAN routing, assuming that a switch that supports VLANs can also route between them.
✗BridgeWrong answer — click to see why▾
Why this is wrong here
A bridge operates at Layer 2 and cannot perform routing between VLANs; it only forwards frames based on MAC addresses within the same broadcast domain.
★ When this WOULD be the correct answer
A bridge would be correct in a question about connecting two separate network segments to reduce collision domains while keeping them in the same broadcast domain, such as 'Which device connects two Ethernet segments and forwards frames based on MAC addresses?'
Why candidates choose this
Candidates may confuse a bridge with a router or Layer 3 switch, thinking it can handle VLAN routing, or they may recall that bridges can segment networks but forget they lack Layer 3 capabilities.
✗HubWrong answer — click to see why▾
Why this is wrong here
A hub operates at Layer 1 and cannot perform VLAN segmentation or routing; it simply repeats electrical signals to all ports, so it cannot route traffic between VLANs.
★ When this WOULD be the correct answer
In a question asking which device is used to connect multiple devices in a single collision domain or to extend a network segment without any filtering, a hub would be correct. For example: 'Which device operates at Layer 1 and repeats all incoming signals to all ports?'
Why candidates choose this
Candidates may confuse hubs with switches or routers, thinking any networking device can handle VLANs, or they may not understand that hubs lack the intelligence to process VLAN tags or make forwarding decisions.
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?”
Visual reference
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Last reviewed: Jun 30, 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.
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