200-901 Network Fundamentals Practice Question
A network administrator is configuring a DNS server. Which TWO DNS record types are used for IPv6 address resolution?
⚠ Common exam trap
Cisco often tests the distinction between A records (IPv4) and AAAA records (IPv6), and the trap here is that candidates may confuse PTR records as only relevant for IPv4, forgetting that PTR records are equally critical for IPv6 reverse resolution.
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
✓
PTR record
The AAAA record (option D) maps a hostname to a 128-bit IPv6 address, analogous to the A record for IPv4. The PTR record (option C) performs reverse DNS lookup, mapping an IPv6 address to a hostname, which is essential for IPv6 address resolution in scenarios like logging or mail server verification.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
MX record
Why it's wrong here
MX records specify mail servers.
- ✗
CNAME record
Why it's wrong here
CNAME is an alias, not for address resolution.
- ✓
PTR record
Why this is correct
PTR records are used for reverse DNS lookup, which also works with IPv6.
- ✓
AAAA record
Why this is correct
AAAA records map to IPv6 addresses.
- ✗
A record
Why it's wrong here
A records are for IPv4 addresses.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 200-901 practice question is part of Courseiva's free Cisco 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 200-901 exam.