- A
Hub
Why wrong: Hubs operate at Layer 1 and simply repeat electrical signals; they do not make forwarding decisions based on IP addresses.
- B
Switch
Why wrong: Switches operate at Layer 2 and forward frames based on MAC addresses, not IP addresses.
- C
Router
Routers are Layer 3 devices that forward packets based on IP addresses, enabling communication between different networks.
- D
Bridge
Why wrong: Bridges operate at Layer 2 and segment a network based on MAC addresses; they do not route based on IP addresses.
Question 397 of 520
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 technician needs to connect two different networks and forward traffic based on IP addresses. Which of the following devices operates at Layer 3 of the OSI model and should be used?
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
A router operates at Layer 3 (Network layer) of the OSI model and makes forwarding decisions based on IP addresses. It uses routing tables and protocols such as OSPF or BGP to determine the best path for packets between different networks. This makes it the correct device for connecting two distinct networks and forwarding traffic by IP address.
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.
- ✗
Hub
Why it's wrong here
Hubs operate at Layer 1 and simply repeat electrical signals; they do not make forwarding decisions based on IP addresses.
When this WOULD be correct
A hub would be correct if the question asked for a device that connects multiple devices in a single collision domain and operates at Layer 1, with no intelligence for forwarding decisions.
- ✗
Switch
Why it's wrong here
Switches operate at Layer 2 and forward frames based on MAC addresses, not IP addresses.
When this WOULD be correct
A switch would be correct if the question asked for a device to connect devices within the same network and forward traffic based on MAC addresses, or to segment a LAN into VLANs (though that still requires Layer 3 for inter-VLAN routing).
- ✓
Router
Why this is correct
Routers are Layer 3 devices that forward packets based on IP addresses, enabling communication between different networks.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Bridge
Why it's wrong here
Bridges operate at Layer 2 and segment a network based on MAC addresses; they do not route based on IP addresses.
When this WOULD be correct
A technician needs to connect two separate network segments and reduce collision domains by filtering traffic based on MAC addresses. A bridge would be the correct device for this Layer 2 task.
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.
✓RouterCorrect answer▾
Why this is correct
Routers are Layer 3 devices that forward packets based on IP addresses, enabling communication between different networks.
✗HubWrong answer — click to see why▾
Why this is wrong here
A hub operates at Layer 1 (Physical layer) and cannot forward traffic based on IP addresses; it simply repeats electrical signals to all ports.
★ When this WOULD be the correct answer
A hub would be correct if the question asked for a device that connects multiple devices in a single collision domain and operates at Layer 1, with no intelligence for forwarding decisions.
Why candidates choose this
Candidates may confuse hubs with routers because both are used to connect network segments, but they forget that hubs lack IP-based forwarding and operate at a lower layer.
✗SwitchWrong answer — click to see why▾
Why this is wrong here
A switch operates at Layer 2, forwarding frames based on MAC addresses, not IP addresses. The question requires Layer 3 forwarding based on IP addresses, which a switch cannot do.
★ When this WOULD be the correct answer
A switch would be correct if the question asked for a device to connect devices within the same network and forward traffic based on MAC addresses, or to segment a LAN into VLANs (though that still requires Layer 3 for inter-VLAN routing).
Why candidates choose this
Candidates may confuse switches with routers because modern switches often have Layer 3 capabilities, but the question specifies 'operates at Layer 3' and 'forward traffic based on IP addresses,' which is the router's primary function.
✗BridgeWrong answer — click to see why▾
Why this is wrong here
Bridges operate at Layer 2, forwarding frames based on MAC addresses, not IP addresses. They cannot route traffic between different networks at Layer 3.
★ When this WOULD be the correct answer
A technician needs to connect two separate network segments and reduce collision domains by filtering traffic based on MAC addresses. A bridge would be the correct device for this Layer 2 task.
Why candidates choose this
Candidates may confuse bridges with routers because both can connect networks, but bridges work at Layer 2 and do not use IP addresses for 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?”
Common exam traps
Common exam trap: answer the scenario, not the keyword
CompTIA often tests the misconception that a 'multilayer switch' can replace a router for all Layer 3 functions, but the question specifically asks for a device that operates at Layer 3 and forwards based on IP addresses, and a standard switch (even a Layer 3 switch) is still primarily a switch; the correct answer is always the router when the context is connecting different networks.
Detailed technical explanation
How to think about this question
Routers maintain a routing table that contains destination network prefixes, next-hop addresses, and metrics; when a packet arrives, the router performs a longest-prefix match on the destination IP address to select the correct outgoing interface. In real-world scenarios, routers also perform Network Address Translation (NAT) and implement access control lists (ACLs) to filter traffic based on IP addresses. The distinction between routing (Layer 3) and switching (Layer 2) is fundamental to network design, as routers enable communication between different subnets or VLANs.
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 network engineer at a university connects two campus buildings via a fibre link. Both routers run OSPF, but no adjacency forms — even though both routers can ping each other. The engineer finds one router is in area 0 and the other in area 1. OSPF adjacency requires matching area numbers, hello/dead timers, and network type. IP reachability alone is not enough.
Visual reference
Quick reference
Routing Protocol Comparison
| Protocol | Metric | Max Hops | Algorithm | Type |
|---|---|---|---|---|
| RIP v2 | Hop count | 15 | Bellman-Ford | Distance vector |
| OSPF | Cost (bandwidth) | Unlimited | Dijkstra (SPF) | Link state |
| EIGRP | Composite metric | Unlimited | DUAL | Hybrid |
| IS-IS | Cost | Unlimited | Dijkstra | Link state |
| BGP | Policy / attributes | Unlimited | Path vector | Path vector |
RIP's 15-hop limit makes it unsuitable for large networks. OSPF and EIGRP dominate modern enterprise deployments.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
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FAQ
Questions learners often ask
What does this N10-009 question test?
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 — A router operates at Layer 3 (Network layer) of the OSI model and makes forwarding decisions based on IP addresses. It uses routing tables and protocols such as OSPF or BGP to determine the best path for packets between different networks. This makes it the correct device for connecting two distinct networks and forwarding traffic by IP address.
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 →
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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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