easyMultiple ChoiceObjective-mapped
200-901 Practice Question: A network administrator needs to assign IP…
A network administrator needs to assign IP addresses to 50 hosts in a subnet. Which subnet mask provides the minimum required number of usable addresses while minimizing waste?
⚠ Common exam trap
Cisco often tests the distinction between 'total addresses' and 'usable addresses' — candidates mistakenly count the total 64 addresses as usable, forgetting to subtract the network and broadcast addresses, or they choose a mask that provides exactly 50 total addresses (which is impossible since host bits must be a power of 2).
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
✓
255.255.255.192 (/26)
A /26 subnet mask (255.255.255.192) provides 64 total addresses per subnet, of which 62 are usable (2^6 - 2 = 62). This is the smallest power-of-two block that can accommodate 50 hosts, minimizing waste while meeting the requirement.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
255.255.255.192 (/26)
Why this is correct
62 usable, sufficient and minimal waste.
- ✗
255.255.255.224 (/27)
Why it's wrong here
30 usable, not enough.
- ✗
255.255.255.240 (/28)
Why it's wrong here
14 usable, not enough.
- ✗
255.255.255.128 (/25)
Why it's wrong here
126 usable, wastes 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.