200-901 Network Fundamentals Practice Question
Which TWO of the following are valid private IPv4 address ranges? (Select two.)
⚠ Common exam trap
Many exam-takers confuse the 172.16.0.0/12 private range with adjacent public ranges like 172.15.0.0/12 or 172.32.0.0/12, or mistaking the link-local 169.254.0.0/16 for a private range.
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
✓
10.0.0.0/8
Option B, 10.0.0.0/8, is correct because RFC 1918 designates the entire 10.0.0.0/8 block as a private IPv4 range, giving roughly 16.7 million addresses for internal use. Option E, 192.168.0.0/16, is also correct because RFC 1918 reserves 192.168.0.0/16 for private networks, commonly used in home and small-office LANs. The third RFC 1918 range, 172.16.0.0/12, covers 172.16.0.0 through 172.31.255.255, which is why option A (172.15.0.0/12) and option C (172.32.0.0/12) fall outside the private block and are invalid. Option D, 169.254.0.0/16, is not a private range but the APIPA/link-local block (RFC 3927), automatically self-assigned when DHCP fails, so it does not qualify.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
172.15.0.0/12
Why it's wrong here
Private range starts at 172.16.0.0.
- ✓
10.0.0.0/8
Why this is correct
10.0.0.0/8 sits within the RFC 1918 private addressing space, spanning 10.0.0.0 to 10.255.255.255. It satisfies the stem's requirement for a valid private IPv4 range, unlike public or reserved blocks. Organisations use it for internal networks, with NAT handling external traffic.
- ✗
172.32.0.0/12
Why it's wrong here
The range `172.32.0.0/12` is incorrect because it falls outside the IANA-reserved private Class B IPv4 address space. The designated private range for Class B is `172.16.0.0` through `172.31.255.255`, which is represented by `172.16.0.0/12`. This option is tempting as it uses the `172.` prefix and the `/12` CIDR mask, correctly associated with the Class B private range, but the starting address `172.32.0.0` is a public IP address, making the entire specified range public.
- ✗
169.254.0.0/16
Why it's wrong here
169.254.0.0/16 is the link-local range, self-assigned when DHCP fails, not RFC 1918 private space. It is tempting because it is non-routable on the public internet, which resembles private addressing, but it would be correct only for automatic address configuration on a local segment.
- ✓
192.168.0.0/16
Why this is correct
192.168.0.0/16 falls within RFC 1918 private addressing, satisfying the stem's requirement for a valid private IPv4 range. It provides 65,536 addresses for internal networks, and Microsoft Entra ID-integrated environments commonly use it for on-premises subnets that must not route across the public internet.
Visual reference
About these practice questions
One of 975 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 and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Cisco exam blueprint
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.