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XK0-006 Practice Question: A newly configured DNS server is unable to…
A newly configured DNS server is unable to resolve any queries from clients. The server is running and network connectivity is verified. What should the administrator check first?
⚠ Common exam trap
The trap here is that candidates often jump to checking client-side resolv.conf or rebooting the server, overlooking the simple verification of whether the DNS service is actually listening on the correct port and protocol (UDP 53) as the first logical troubleshooting step.
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
✓
Check if the DNS service is listening on UDP port 53
The most common reason a DNS server fails to resolve queries despite being running and having network connectivity is that the DNS service is not listening on UDP port 53, which is the default port for DNS queries per RFC 1035. Checking this with a command like `ss -ulpn | grep :53` or `netstat -uan | grep :53` directly verifies whether the service is actually accepting incoming queries. This is the first logical step before investigating client-side configurations or rebooting.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Check /etc/resolv.conf on clients
Why it's wrong here
Client configuration is not the cause if the server is new.
- ✗
Check if DNS service is bound to the loopback address
Why it's wrong here
While possible, checking listening sockets is more fundamental.
- ✓
Check if the DNS service is listening on UDP port 53
Why this is correct
If the service is not listening, queries cannot be answered.
- ✗
Reboot the DNS server
Why it's wrong here
Rebooting is a last resort, not a first diagnostic step.
Visual reference
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Related to this question
Learn chapter
Logical Volume Management (LVM)
Key term
Service
A service is a software component or system that performs a specific function and is available to be used by other programs or users over a network.
Key term
DNS
DNS is the system that translates human-friendly domain names like example.com into machine-readable IP addresses so computers can find each other on a network.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This XK0-006 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 XK0-006 exam.