- A
255.255.255.0 (/24)
Why wrong: /24 provides 254 usable hosts, which wastes many addresses.
- B
255.255.255.128 (/25)
Why wrong: /25 provides 126 usable hosts, also wasteful.
- C
255.255.255.224 (/27)
Why wrong: /27 provides only 30 usable hosts, insufficient.
- D
255.255.255.192 (/26)
Correct. /26 gives 62 usable hosts, fitting 50 with minimal waste.
Question 944 of 1,000
200-901 Network Fundamentals Practice Question
This 200-901 practice question tests your understanding of network fundamentals. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A network administrator is configuring a new subnet for a branch office that requires at least 50 usable host addresses. Which subnet mask would meet this requirement while minimizing address waste?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue:
"least"Why it matters: You want the option with minimum overhead, fewest steps, or lowest impact — not the most feature-rich or comprehensive answer.
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 provides 62 usable hosts (2^6 - 2 = 62), which is the smallest subnet meeting the requirement of 50 hosts.
Key principle: Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
255.255.255.0 (/24)
Why it's wrong here
/24 provides 254 usable hosts, which wastes many addresses.
- ✗
255.255.255.128 (/25)
Why it's wrong here
/25 provides 126 usable hosts, also wasteful.
- ✗
255.255.255.224 (/27)
Why it's wrong here
/27 provides only 30 usable hosts, insufficient.
- ✓
255.255.255.192 (/26)
Why this is correct
Correct. /26 gives 62 usable hosts, fitting 50 with minimal waste.
Clue confirmation
The clue word "least" in the question point toward this answer.
Related concept
CIDR notation defines the prefix length.
Common exam traps
Common exam trap: usable hosts are not the same as total addresses
Subnetting questions often tempt you into counting all addresses. In normal IPv4 subnets, the network and broadcast addresses are not usable host addresses.
Detailed technical explanation
How to think about this question
Subnetting questions test whether you can identify the network, broadcast address, usable range, mask and correct subnet. Slow down enough to calculate the block size correctly.
KKey Concepts to Remember
- CIDR notation defines the prefix length.
- Block size helps identify subnet boundaries.
- Network and broadcast addresses are not usable hosts in normal IPv4 subnets.
- The required host count determines the smallest suitable subnet.
TExam Day Tips
- Write the block size before choosing the subnet.
- Check whether the question asks for hosts, subnets or a specific address range.
- Do not confuse /24, /25, /26 and /27 host counts.
Key takeaway
Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.
Real-world example
How this comes up in practice
A network engineer segments a warehouse floor into three subnets: 20 scanners, 5 printers, and 2 management hosts. Picking the wrong mask wastes addresses or leaves too few usable hosts. Exam questions test whether you can apply CIDR notation, calculate block size, and identify the correct usable-host range for a given prefix.
Visual reference
What to study next
Got this wrong? Here's your next step.
Review block sizes, usable host formulas (2^n − 2), and how to find network and broadcast addresses for /24 through /30. Then practise related 200-901 subnetting questions on CIDR, address ranges, and subnet selection.
- →
Network Fundamentals — study guide chapter
Learn the concepts, then practise the questions
- →
Network Fundamentals practice questions
Targeted practice on this topic area only
- →
All 200-901 questions
1,000 questions across all exam domains
- →
Cisco DevNet Associate 200-901 study guide
Full concept coverage aligned to exam objectives
- →
200-901 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related 200-901 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Software Development and Design practice questions
Practise 200-901 questions linked to Software Development and Design.
Understanding and Using APIs practice questions
Practise 200-901 questions linked to Understanding and Using APIs.
Application Deployment and Security practice questions
Practise 200-901 questions linked to Application Deployment and Security.
Cisco Platforms and Development practice questions
Practise 200-901 questions linked to Cisco Platforms and Development.
Network Fundamentals practice questions
Practise 200-901 questions linked to Network Fundamentals.
Infrastructure and Automation practice questions
Practise 200-901 questions linked to Infrastructure and Automation.
200-901 fundamentals practice questions
Practise 200-901 questions linked to 200-901 fundamentals.
200-901 scenario practice questions
Practise 200-901 questions linked to 200-901 scenario.
200-901 troubleshooting practice questions
Practise 200-901 questions linked to 200-901 troubleshooting.
Practice this exam
Start a free 200-901 practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this 200-901 question test?
Network Fundamentals — This question tests Network Fundamentals — CIDR notation defines the prefix length..
What is the correct answer to this question?
The correct answer is: 255.255.255.192 (/26) — A /26 subnet provides 62 usable hosts (2^6 - 2 = 62), which is the smallest subnet meeting the requirement of 50 hosts.
What should I do if I get this 200-901 question wrong?
Review block sizes, usable host formulas (2^n − 2), and how to find network and broadcast addresses for /24 through /30. Then practise related 200-901 subnetting questions on CIDR, address ranges, and subnet selection.
Are there clue words in this question I should notice?
Yes — watch for: "least". You want the option with minimum overhead, fewest steps, or lowest impact — not the most feature-rich or comprehensive answer.
What is the key concept behind this question?
CIDR notation defines the prefix length.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Last reviewed: Jul 4, 2026
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.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.