N10-009 Networking Concepts Practice Question
A network engineer needs to connect two network segments that use different physical media: one segment uses copper Ethernet and the other uses fiber optic. The device must forward frames based on MAC addresses and must not perform any routing. Which device should the engineer choose?
⚠ Common exam trap
CompTIA often tests the distinction between a media converter (Layer 1) and a bridge (Layer 2), leading candidates to choose the media converter because it handles physical media conversion, but they overlook the requirement for MAC address-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
✓
Bridge
A bridge operates at Layer 2, forwarding frames based on MAC addresses while connecting different physical media (e.g., copper to fiber). It does not perform routing, making it the correct choice for this scenario. Unlike a media converter, a bridge also provides segmentation and collision domain isolation.
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 3 switch
Why it's wrong here
A Layer 3 switch combines the functions of a Layer 2 switch with some Layer 3 routing capabilities, allowing it to forward packets between different VLANs or IP subnets. Although it can perform Layer 2 switching, its advanced routing features are not required for simply connecting two network segments with different physical media types. Utilizing a Layer 3 switch for this purpose would introduce unnecessary complexity and cost when a simpler Layer 2 device suffices.
When this WOULD be correct
A Layer 3 switch would be correct when the engineer needs to connect multiple VLANs and perform inter-VLAN routing using IP addresses, while still switching within VLANs at Layer 2.
- ✗
Media converter
Why it's wrong here
A media converter operates solely at Layer 1 (Physical Layer) of the OSI model, translating electrical signals from one cabling type to another, such as copper Ethernet to fiber optic. It does not inspect data frames, learn MAC addresses, or perform any intelligent forwarding decisions. While it addresses physical differences, it cannot segment collision domains or provide the frame forwarding intelligence needed to effectively connect and manage traffic between two distinct network segments.
When this WOULD be correct
A media converter would be correct if the requirement is simply to connect two segments with different physical media (e.g., copper and fiber) without any MAC address-based forwarding or routing, such as extending a single network segment over a fiber link.
- ✓
Bridge
Why this is correct
A bridge operates at Layer 2 (Data Link Layer) of the OSI model, intelligently forwarding data frames based on destination MAC addresses. It learns MAC addresses by inspecting incoming frames and builds a forwarding table. Crucially, a bridge can connect two network segments that utilize different physical media types or signaling methods, effectively extending a single logical network while segmenting collision domains without performing any Layer 3 routing.
- ✗
Router
Why it's wrong here
A router operates at Layer 3 (Network Layer) and is designed to connect different logical IP networks, forwarding packets based on IP addresses. Routers create separate broadcast domains and perform routing decisions to determine the best path between networks. While capable of connecting segments, its primary function involves network layer addressing and routing, which is an unnecessary and overly complex solution for merely connecting two segments with different physical characteristics within the same logical network.
When this WOULD be correct
A router would be correct in a scenario where the network engineer needs to connect two different network segments that use different physical media and also require IP routing, such as connecting two different subnets or VLANs, and the device must forward packets based on IP addresses.
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.
✓BridgeCorrect answer▾
Why this is correct
A bridge operates at Layer 2 (Data Link Layer) of the OSI model, intelligently forwarding data frames based on destination MAC addresses. It learns MAC addresses by inspecting incoming frames and builds a forwarding table. Crucially, a bridge can connect two network segments that utilize different physical media types or signaling methods, effectively extending a single logical network while segmenting collision domains without performing any Layer 3 routing.
✗Layer 3 switchWrong answer — click to see why▾
Why this is wrong here
A Layer 3 switch performs routing based on IP addresses, but the question requires forwarding based on MAC addresses without routing. It also does not inherently connect different physical media like copper and fiber.
★ When this WOULD be the correct answer
A Layer 3 switch would be correct when the engineer needs to connect multiple VLANs and perform inter-VLAN routing using IP addresses, while still switching within VLANs at Layer 2.
Why candidates choose this
Candidates may confuse Layer 3 switches with bridges because both can forward frames, but they overlook that Layer 3 switches route at Layer 3, which is not required here.
✗Media converterWrong answer — click to see why▾
Why this is wrong here
A media converter only changes the physical medium (e.g., copper to fiber) but does not forward frames based on MAC addresses; it operates at Layer 1, not Layer 2.
★ When this WOULD be the correct answer
A media converter would be correct if the requirement is simply to connect two segments with different physical media (e.g., copper and fiber) without any MAC address-based forwarding or routing, such as extending a single network segment over a fiber link.
Why candidates choose this
Candidates see 'different physical media' and assume a media converter is needed, overlooking the explicit requirement to forward frames based on MAC addresses, which requires a Layer 2 device.
✗RouterWrong answer — click to see why▾
Why this is wrong here
A router operates at Layer 3 (network layer) and makes forwarding decisions based on IP addresses, not MAC addresses. The question specifies that the device must forward frames based on MAC addresses and must not perform routing, which is the function of a Layer 2 bridge, not a router.
★ When this WOULD be the correct answer
A router would be correct in a scenario where the network engineer needs to connect two different network segments that use different physical media and also require IP routing, such as connecting two different subnets or VLANs, and the device must forward packets based on IP addresses.
Why candidates choose this
Candidates may mistakenly think a router is needed to connect different physical media (copper and fiber) because routers often have interfaces for both, but they overlook the requirement to forward based on MAC addresses and not perform routing.
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
Access Control Model Comparison
| Model | Acronym | Who Controls Access? | Best For |
|---|---|---|---|
| Discretionary Access Control | DAC | Resource owner | Small teams, file shares |
| Mandatory Access Control | MAC | System / security labels | Classified govt / military |
| Role-Based Access Control | RBAC | Administrator (via roles) | Enterprise environments |
| Attribute-Based Access Control | ABAC | Policy engine (user + resource attributes) | Fine-grained, dynamic policies |
| Rule-Based Access Control | RuBAC | System rules / ACLs | Firewall rules, network ACLs |
Go deeper
Related to this question
Learn chapter
Interior vs Exterior Routing Protocols
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
Bridge
A network device that connects two or more Local Area Networks (LANs) or segments, forwarding traffic based on MAC addresses to reduce collision domains.
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.