200-901 Network Fundamentals Practice Question
An administrator is configuring DNS records for a company's domain. Which three DNS record types are most commonly used to map hostnames to IP addresses or aliases? (Choose three.)
⚠ Common exam trap
Cisco often tests the distinction between forward-mapping records (A, AAAA, CNAME) and service-specific or reverse records (MX, PTR), leading candidates to mistakenly include MX or PTR when the question explicitly asks for hostname-to-IP or alias mapping.
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
✓
AAAA
Option A (AAAA) is correct because an AAAA record maps a hostname to an IPv6 address, directly fulfilling the hostname-to-IP mapping purpose. Option B (CNAME) is correct because a Canonical Name record creates an alias from one hostname to another hostname, which is the alias-mapping function described in the question. Option C (A) is correct because an A record maps a hostname to an IPv4 address, the most fundamental hostname-to-IP mapping. Option D (MX) is not correct here because MX records designate mail exchangers for email delivery, not hostname-to-IP or alias mapping. Option E (PTR) is not correct because PTR records provide reverse DNS lookups, mapping IP addresses back to hostnames rather than hostnames to IP addresses.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
AAAA
Why this is correct
AAAA records map a hostname to an IPv6 address, satisfying the requirement to resolve names to IP addresses. Where A records handle IPv4, AAAA provides the 128-bit equivalent, making it one of the standard hostname-to-address mappings alongside A and CNAME.
- ✓
CNAME
Why this is correct
A CNAME record creates an alias pointing one hostname to another canonical name, which then resolves to an A or AAAA record's IP address. This satisfies the stem's requirement for mapping hostnames to aliases, letting services like `www` reference `server1.example.com` without duplicating the underlying IP address.
- ✓
A
Why this is correct
An A record maps a hostname directly to an IPv4 address, satisfying the requirement to resolve names to IP addresses. It is the foundational forward-lookup type, unlike CNAME (alias to another name) or MX (mail routing).
- ✗
MX
Why it's wrong here
MX records direct email delivery to mail exchangers for a domain; they carry no hostname-to-address mapping. It is tempting because MX is a common domain record, and it is genuinely correct when configuring inbound mail routing rather than resolving names to IP addresses or aliases.
- ✗
PTR
Why it's wrong here
PTR records perform reverse resolution, mapping an IP address back to a hostname, which is the opposite direction to the question's requirement. It is tempting because PTR is a genuine DNS mapping record, and it is correct when configuring reverse zones for lookups from addresses to names.
Visual reference
About these practice questions
Courseiva writes every 200-901 question from scratch — 975 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
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.