200-201 Network Intrusion Analysis Practice Question
An analyst is investigating a potential DNS tunneling attack. Which characteristic in DNS traffic would most likely indicate DNS tunneling?
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 queries with long, random-looking subdomains to a single domain.
DNS tunneling often encodes data in subdomains, resulting in long, random-looking domain names that differ from legitimate traffic.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
DNS queries with long, random-looking subdomains to a single domain.
Why this is correct
Correct. Tunneling encodes data in subdomains, making them long and random.
- ✗
Frequent DNS queries to the same domain at regular intervals.
Why it's wrong here
Regular intervals suggest beaconing but not necessarily tunneling.
- ✗
DNS queries for domains that are known to be malicious.
Why it's wrong here
Queries to malicious domains indicate C2 but not necessarily tunneling.
- ✗
DNS query responses with unusually large payload sizes.
Why it's wrong here
Large responses can be a sign, but subdomain encoding is more specific.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 200-201 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 200-201 exam.