Question 1easymultiple choice
Full question →easymultiple choiceObjective-mapped
Exhibit
Planned VNet address space: 10.70.0.0/16 Subnet A requirement: about 30 VM NICs Subnet B requirement: about 8 VM NICs and one future jump box Azure reserves 5 IP addresses in each subnet
Based on the exhibit, which subnet prefix should be used for Subnet A so it can support about 30 VM NICs?
Answer choices
Why each option matters
Good practice is not just finding the correct option. The wrong answers often show the exact trap the exam wants you to fall into.
A
Distractor review
/28
A /28 subnet provides too few usable addresses after Azure reservations. It cannot support about 30 VM NICs.
B
Distractor review
/27
A /27 subnet has 32 total addresses, but Azure reserves 5 of them, leaving only 27 usable addresses. That is still short of the requirement for about 30 VM NICs.
C
Best answer
/26
A /26 subnet is the smallest option listed that can support about 30 VM NICs after Azure reserves its five addresses. /26 provides 64 total addresses and enough usable IPs for the requirement, leaving a little room for growth. This is the most efficient choice among the options shown.
D
Distractor review
/25
A /25 subnet would also work, but it uses more address space than necessary. For an easy planning question, the smallest prefix that meets the need is the better answer.
Common exam trap
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.
Technical deep dive
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.
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More questions from this exam
Keep practising from the same exam bank, or move into a focused topic page if this question exposed a weak area.
Question 1
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Question 2
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Question 3
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Question 4
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Question 5
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Question 6
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FAQ
Questions learners often ask
What does this AZ-104 question test?
CIDR notation defines the prefix length.
What is the correct answer to this question?
The correct answer is: /26 — Azure reserves five IP addresses in every subnet, so the usable count matters when planning VM capacity. A /27 leaves only 27 usable addresses, which is not enough for about 30 VM NICs. A /26 provides 64 total addresses and 59 usable, making it the smallest option that comfortably meets the requirement. That is why /26 is the correct subnet prefix here. Why others are wrong: A /28 is far too small, and a /27 still falls short once Azure reserves addresses. A /25 would work, but it consumes more space than needed and is not the most efficient answer. The question is asking for the right size, not the largest safe size.
What should I do if I get this AZ-104 question wrong?
Then try more questions from the same exam bank and focus on understanding why the wrong options are tempting.
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