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FC0-U71 Practice Question: A user is trying to access a website but receives…
A user is trying to access a website but receives a 'DNS server not responding' error. Which of the following is the MOST likely cause?
⚠ Common exam trap
Many exam-takers confuse DNS resolution failures with network connectivity issues or firewall blocks, but the specific error message points directly to the DNS server being unreachable, not to general network or application-layer problems.
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
✓
DNS server is unreachable
The 'DNS server not responding' error indicates that the client cannot reach the DNS server to resolve the domain name into an IP address. This is most commonly caused by the DNS server being unreachable due to network connectivity issues, server downtime, or incorrect DNS server configuration. Without DNS resolution, the browser cannot translate the website's URL into an IP address, even if the network and web server are functional.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
DHCP server is down
Why it's wrong here
DHCP issues would cause IP address problems.
- ✓
DNS server is unreachable
Why this is correct
The error explicitly mentions DNS server.
- ✗
Firewall is blocking the website
Why it's wrong here
Firewall would give a different error.
- ✗
Modem is disconnected
Why it's wrong here
Modem failure would cause no connectivity at all.
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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.