The answer is the cable modem overheating. This is the most likely cause because the router logs show the WAN interface renegotiating its connection, which points to a physical or link-layer issue on the cable modem side rather than a software or configuration problem. When a cable modem overheats, it can intermittently reset or drop its link, typically after hours of operation, matching the pattern of brief outages every few hours. On the CompTIA ITF+ FC0-U61 exam, this scenario tests your ability to distinguish between hardware failure and configuration errors—a common trap is blaming the wireless router or ISP settings when the real culprit is environmental heat buildup. Remember the memory tip: “Heat hits the link first”—if connectivity drops in cycles, check ventilation before touching cables or settings.
FC0-U61 IT Concepts and Terminology Practice Question
This FC0-U61 practice question tests your understanding of it concepts and terminology. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. 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 small business is experiencing intermittent network connectivity issues. Employees report that every few hours, the internet connection drops for about five minutes and then returns. The network uses a cable modem connected to a wireless router. The router logs show that the WAN interface renegotiates its connection around the same times. 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.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The cable modem overheating
The router logs show the WAN interface renegotiating its connection, which indicates a physical or link-layer issue on the cable modem side. Overheating in the cable modem can cause intermittent resets or link drops, typically after hours of operation, matching the pattern of brief outages every few hours. This is a common hardware failure mode for cable modems, especially in poorly ventilated environments.
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.
✗
The router's DHCP lease time is too short
Why it's wrong here
DHCP lease renewal affects internal IP addresses, not the WAN connection.
✗
A computer on the network has a static IP address conflicting with the router
Why it's wrong here
IP conflicts cause issues for that specific computer, not the entire network.
✗
The ISP is performing maintenance
Why it's wrong here
Maintenance is usually scheduled and not at regular short intervals.
✓
The cable modem overheating
Why this is correct
Overheating can cause the modem to reset, dropping the WAN connection periodically.
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.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates see 'WAN interface renegotiates' and immediately think of DHCP lease renewal (Option A), but the WAN interface renegotiation is a link-layer event (e.g., PPPoE or DHCP renewal on the WAN side), not a LAN-side DHCP lease issue, and the pattern of brief, periodic drops points to thermal cycling rather than ISP maintenance.
Detailed technical explanation
How to think about this question
Cable modems use DOCSIS (Data Over Cable Service Interface Specification) to communicate with the ISP's CMTS. Overheating can cause the modem's RF transceiver to fail or trigger a thermal shutdown, forcing a re-initialization of the DOCSIS link, which takes about 3–5 minutes. This is distinct from a simple power cycle; the modem's logs would show 'T3 timeouts' or 'ranging failures' during such events.
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 small business has 20 workstations on the 192.168.1.0/24 network and one public IP from its ISP. The router uses PAT (NAT overload) so all 20 devices share one public address using different source ports. NAT questions test whether you understand the four address terms and which direction each translation applies.
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.
IT Concepts and Terminology — This question tests IT Concepts and Terminology — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The cable modem overheating — The router logs show the WAN interface renegotiating its connection, which indicates a physical or link-layer issue on the cable modem side. Overheating in the cable modem can cause intermittent resets or link drops, typically after hours of operation, matching the pattern of brief outages every few hours. This is a common hardware failure mode for cable modems, especially in poorly ventilated environments.
What should I do if I get this FC0-U61 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Are there clue words in this question I should notice?
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
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 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.
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.