Quick Answer
The answer is interference from neighboring networks. Intermittent slowdowns in a wireless network are most commonly caused by co-channel or adjacent-channel interference, because Wi-Fi operates on shared, unlicensed spectrum in the 2.4 GHz and 5 GHz bands. When nearby access points use overlapping channels or have high utilization, stations must wait for clear channel access, leading to sudden latency spikes and throughput drops rather than consistent poor performance. On the CompTIA ITF+ FC0-U61 exam, this question tests your understanding of wireless fundamentals and troubleshooting—specifically that interference is the prime suspect for intermittent issues, while weak signal or incorrect channel width typically cause steady, not sporadic, problems. A common trap is blaming encryption overhead, but WPA2 has negligible impact on modern hardware. Memory tip: think “neighbors cause noise” for intermittent slowdowns, and remember that consistent issues point to signal or configuration, not interference.
This FC0-U61 practice question tests your understanding of infrastructure. 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 is diagnosing performance issues in a wireless network. Users report intermittent slowdowns. Which of the following is the MOST likely cause?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "most likely"
Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
WPA2 encryption overhead
Why wrong: Encryption overhead is small and constant.
Weak signal from the access point
Why wrong: Weak signal causes constant slow speed, not intermittent.
Interference from neighboring networks
Interference can cause sporadic slowdowns.
Incorrect channel width setting
Why wrong: Channel width affects maximum speed but less likely intermittent.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
Interference from neighboring networks
Intermittent slowdowns in a wireless network are most commonly caused by co-channel or adjacent-channel interference from neighboring networks. Wi-Fi operates on shared, unlicensed spectrum (2.4 GHz and 5 GHz), and overlapping channels or high utilization from nearby access points force stations to wait for clear channel access, causing latency spikes and throughput drops. WPA2 encryption overhead is negligible for modern hardware, and weak signal or incorrect channel width would typically cause consistent, not intermittent, issues.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
WPA2 encryption overhead
Why it's wrong here
Encryption overhead is small and constant.
Weak signal from the access point
Why it's wrong here
Weak signal causes constant slow speed, not intermittent.
Interference from neighboring networks
Why this is correct
Interference can cause sporadic slowdowns.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
Incorrect channel width setting
Why it's wrong here
Channel width affects maximum speed but less likely intermittent.
Common exam traps
The trap here is that candidates confuse 'intermittent slowdowns' with 'weak signal' or 'incorrect channel width,' but CompTIA emphasizes that interference from neighboring networks is the most common cause of sporadic performance issues in dense wireless environments.
Detailed technical explanation
Wi-Fi uses CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance), where stations must sense the medium as idle before transmitting. Interference from neighboring networks causes hidden node problems and increased contention, leading to exponential backoff and retransmissions. Tools like Wireshark or a spectrum analyzer can reveal high channel utilization or non-Wi-Fi interference (e.g., from microwave ovens or Bluetooth) that manifests as intermittent slowdowns.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
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.
What to study next
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FAQ
Infrastructure — This question tests Infrastructure — Read the scenario before looking for a memorised answer..
The correct answer is: Interference from neighboring networks — Intermittent slowdowns in a wireless network are most commonly caused by co-channel or adjacent-channel interference from neighboring networks. Wi-Fi operates on shared, unlicensed spectrum (2.4 GHz and 5 GHz), and overlapping channels or high utilization from nearby access points force stations to wait for clear channel access, causing latency spikes and throughput drops. WPA2 encryption overhead is negligible for modern hardware, and weak signal or incorrect channel width would typically cause consistent, not intermittent, issues.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
Read the scenario before looking for a memorised answer.
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Last reviewed: Jun 25, 2026
This FC0-U61 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 FC0-U61 exam.
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