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FC0-U71 Practice Question: A small business is experiencing intermittent…
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?
⚠ Common exam trap
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.
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
✓
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.
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.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This FC0-U71 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-U71 exam.