You are planning a subnet for an application tier in a new spoke virtual network. The subnet must support 34 VM NICs, 5 private endpoints, and 6 extra IP addresses for short-term scale-out during maintenance windows. Azure reserves 5 IP addresses in every subnet. What is the smallest subnet prefix that meets the requirement?

/27

A /27 provides only 27 usable addresses after Azure reservations, which is not enough here.

/25

A /25 would work, but it allocates far more addresses than the scenario requires.

/28

A /28 is much too small for dozens of NICs, private endpoints, and spare capacity.

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 — The subnet needs 34 VM NICs, 5 private endpoints, and 6 additional addresses for temporary growth, which totals 45 usable addresses. Azure also reserves 5 addresses in every subnet, so the prefix must provide at least 50 total addresses. A /26 has 64 total addresses and 59 usable addresses, so it is the smallest prefix that satisfies the requirement without wasting unnecessary space. Why others are wrong: A /27 leaves only 27 usable addresses, which fails the capacity requirement. A /28 is far smaller and cannot host the workload. A /25 would satisfy the need, but it is larger than necessary, so it is not the smallest valid prefix. The question asks for the minimum size that still works, making /26 the only correct choice.

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.