N10-009 Network Implementation Practice Question
A company is connecting two buildings that are 300 meters apart. The link must support 10 Gbps. Which combination of cable and transceiver should be used?
⚠ Common exam trap
Many exam-takers assume Cat6a can handle 10 Gbps at any distance, forgetting the 100-meter limitation for twisted-pair copper, or they confuse 10GBASE-LR with 10GBASE-SR, which has a shorter reach on multimode fiber.
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
✓
Single-mode fiber with 10GBASE-LR
Single-mode fiber (SMF) with 10GBASE-LR supports 10 Gbps over distances up to 10 km, easily covering the 300-meter requirement. 10GBASE-LR uses 1310 nm laser optics over single-mode fiber, providing low signal loss and high bandwidth for long-reach links.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Cat6a UTP with 10GBASE-T
Why it's wrong here
While Cat6a UTP cable is capable of supporting 10GBASE-T for 10 Gigabit Ethernet, its maximum specified transmission distance for this speed is strictly limited to 100 meters. Attempting to deploy Cat6a for a 300-meter link would result in significant signal degradation, unreliable connectivity, and failure to meet performance requirements due to excessive attenuation and crosstalk beyond its rated length.
When this WOULD be correct
A question where two buildings are 80 meters apart and require 10 Gbps, with cost as a primary concern, would make Cat6a UTP with 10GBASE-T the correct choice.
- ✗
Cat5e UTP with 1000BASE-T
Why it's wrong here
Cat5e UTP cable, when used with 1000BASE-T, is designed to support Gigabit Ethernet speeds, which is only 1 Gbps, and has a maximum segment length of 100 meters. This option fails on two critical fronts: it does not provide the implied 10 Gbps speed required for modern inter-building links, and its distance limitation makes it entirely unsuitable for a 300-meter connection.
When this WOULD be correct
A question asking for a 1 Gbps link over 100 meters or less, such as connecting two switches within the same building at 1 Gbps, would make Cat5e UTP with 1000BASE-T correct.
- ✓
Single-mode fiber with 10GBASE-LR
Why this is correct
10GBASE-LR is specifically designed for long-reach 10 Gigabit Ethernet over single-mode fiber, supporting distances up to 10 kilometers. This makes it an ideal and robust solution for connecting two buildings 300 meters apart, providing ample bandwidth and significant distance headroom. Single-mode fiber minimizes modal dispersion, ensuring signal integrity over extended runs and offering excellent future-proofing.
- ✗
Multimode fiber with 10GBASE-SR
Why it's wrong here
10GBASE-SR over multimode fiber is a common solution for 10 Gigabit Ethernet over shorter distances, typically up to 300 meters with OM3 fiber or 400 meters with OM4 fiber. While it might technically span 300 meters with higher-grade multimode fiber, single-mode fiber with 10GBASE-LR offers superior performance, greater future scalability, and significantly longer reach capabilities, making it a more robust and reliable choice for a permanent inter-building link.
When this WOULD be correct
A question where the distance is less than 300 meters (e.g., 200 meters) and cost is a primary concern, or where the existing infrastructure already uses multimode fiber. For example: 'A company needs to connect two buildings 200 meters apart at 10 Gbps using existing fiber. Which combination should be used?'
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.
✓Single-mode fiber with 10GBASE-LRCorrect answer▾
Why this is correct
10GBASE-LR is specifically designed for long-reach 10 Gigabit Ethernet over single-mode fiber, supporting distances up to 10 kilometers. This makes it an ideal and robust solution for connecting two buildings 300 meters apart, providing ample bandwidth and significant distance headroom. Single-mode fiber minimizes modal dispersion, ensuring signal integrity over extended runs and offering excellent future-proofing.
✗Cat6a UTP with 10GBASE-TWrong answer — click to see why▾
Why this is wrong here
Cat6a UTP with 10GBASE-T is limited to 100 meters for 10 Gbps, but the distance is 300 meters, exceeding the maximum reach.
★ When this WOULD be the correct answer
A question where two buildings are 80 meters apart and require 10 Gbps, with cost as a primary concern, would make Cat6a UTP with 10GBASE-T the correct choice.
Why candidates choose this
Candidates may mistakenly believe Cat6a supports 10 Gbps over longer distances, or confuse the distance limits of twisted-pair cabling with fiber.
✗Cat5e UTP with 1000BASE-TWrong answer — click to see why▾
Why this is wrong here
Cat5e UTP with 1000BASE-T supports only 1 Gbps, not the required 10 Gbps, and has a maximum distance of 100 meters, insufficient for 300 meters.
★ When this WOULD be the correct answer
A question asking for a 1 Gbps link over 100 meters or less, such as connecting two switches within the same building at 1 Gbps, would make Cat5e UTP with 1000BASE-T correct.
Why candidates choose this
Candidates may confuse Cat5e's capability, thinking it supports 10 Gbps over short distances, or overlook the distance limitation and speed requirement.
✗Multimode fiber with 10GBASE-SRWrong answer — click to see why▾
Why this is wrong here
Multimode fiber with 10GBASE-SR is limited to distances up to 300-400 meters depending on the fiber type (OM3/OM4), but the question specifies a 300-meter link requiring 10 Gbps. While technically possible with OM4, single-mode fiber (10GBASE-LR) is more reliable and standard for this distance, and the correct answer is explicitly single-mode fiber with 10GBASE-LR.
★ When this WOULD be the correct answer
A question where the distance is less than 300 meters (e.g., 200 meters) and cost is a primary concern, or where the existing infrastructure already uses multimode fiber. For example: 'A company needs to connect two buildings 200 meters apart at 10 Gbps using existing fiber. Which combination should be used?'
Why candidates choose this
Candidates may confuse the distance limitations of multimode fiber, thinking 10GBASE-SR can reach 300 meters (it can with OM4), and overlook that single-mode fiber is the standard for longer distances and higher reliability. They might also assume multimode is cheaper and sufficient.
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?”
Go deeper
Related to this question
Learn chapter
Link Aggregation: LACP and PAgP
Key term
Single-mode fiber
Single-mode fiber is a type of optical fiber used in high-speed, long-distance networking that transmits a single light signal along a very thin core, minimizing signal loss and enabling data to travel many kilometers without repeaters.
Key term
Bandwidth
Bandwidth is the maximum amount of data that can travel over a network connection in a given amount of time, usually measured in bits per second.
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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.