200-901 Network Fundamentals Practice Question
Which of the following is a private IPv4 address range as defined by RFC 1918?
⚠ Common exam trap
Cisco often tests the exact prefix length of the 172.16.0.0/12 range, and the trap here is that candidates confuse 172.16.0.0/12 with 172.32.0.0/12, mistakenly thinking any 172.x.x.x address is private.
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
✓
192.168.0.0/16
RFC 1918 defines private IPv4 address ranges that are not routable on the public Internet. The 192.168.0.0/16 range (192.168.0.0 – 192.168.255.255) is explicitly listed in RFC 1918 as a Class C private block, making option A correct.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
192.168.0.0/16
Why this is correct
Correct. 192.168.0.0/16 is private.
- ✗
172.32.0.0/12
Why it's wrong here
This is not private; 172.16.0.0/12 is.
- ✗
172.15.0.0/12
Why it's wrong here
The 172.15.0.0/12 range falls outside the RFC 1918 private block, which reserves 172.16.0.0/12 (i.e., 172.16.0.0 through 172.31.255.255). 172.15.0.0/12 is part of the public internet address space. It tempts because the 172.x.x.x prefix resembles the well-known private 172.16.0.0/12 range, and a candidate might misremember the exact starting boundary as 172.15.0.0 instead of 172.16.0.0. This address would be correct if the question asked for a public range or a different private block.
- ✗
11.0.0.0/8
Why it's wrong here
10.0.0.0/8 is private, not 11.0.0.0/8.
Go deeper
Related to this question
About these practice questions
One of 989 original 200-901 practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. 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.