The answer is a router or a Layer 3 switch, as both devices can perform inter-VLAN routing by forwarding packets based on Layer 3 IP addresses. VLANs operate at Layer 2 to isolate broadcast domains, so traffic cannot cross between them without a device that makes routing decisions at the network layer. A standard Layer 2 switch alone cannot route between VLANs, which is a common trap on the CompTIA Network+ N10-009 exam—test-takers often mistakenly choose a multilayer switch without recognizing that a router also satisfies the requirement. This concept tests your understanding of how to segment a network while maintaining connectivity across subnets. Remember the memory tip: “Layer 2 splits, Layer 3 connects”—VLANs split the broadcast domain, but only a Layer 3 device can connect them.
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 administrator wants to segment the network into multiple virtual LANs to reduce broadcast traffic. Which device is required to route traffic between these VLANs?
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.
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.
✗
Layer 2 switch
Why it's wrong here
A Layer 2 switch forwards frames based on MAC addresses and does not perform routing; it cannot route between VLANs without a router.
✓
Router or Layer 3 switch
Why this is correct
Both routers and Layer 3 switches can route traffic between VLANs by processing IP packets.
Related concept
Read the scenario before looking for a memorised answer.
✗
Bridge
Why it's wrong here
A bridge is a Layer 2 device that connects two network segments; it does not route between VLANs.
✗
Hub
Why it's wrong here
A hub is a Layer 1 device that simply repeats signals; it cannot route or distinguish VLANs.
Common exam traps
Common exam trap: answer the scenario, not the keyword
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.
Detailed technical explanation
How to think about this question
Inter-VLAN routing can be implemented using a router-on-a-stick configuration, where a single router interface is configured with subinterfaces (e.g., GigabitEthernet0/0.10, encapsulation dot1Q 10) to handle multiple VLANs. A Layer 3 switch performs this routing in hardware using CEF (Cisco Express Forwarding) and switch virtual interfaces (SVIs), providing much higher throughput than a traditional router. In real-world networks, Layer 3 switches are preferred for high-speed inter-VLAN routing within a campus LAN.
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 help-desk technician troubleshoots why a newly connected PC cannot reach shared printers on the same floor. The cable is good, the switch port is active, but the PC is in VLAN 20 and the printers are in VLAN 10. The uplink trunk only allows VLAN 10. A trunk being up does not mean every VLAN crosses it.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this N10-009 question in full detail.
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: 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.
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 →
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.
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.