The answer is /26, as it is the smallest subnet prefix that provides the 64 total IP addresses needed to support the 51 required resources after accounting for Azure’s five reserved IPs. Azure reserves the first four and the last IP address in every subnet for protocol operations, so a /27 with only 32 total addresses would leave just 27 usable—far short of the 48 VMs, two load balancer frontend IPs, and one Bastion host. On the AZ-104 exam, this tests your ability to map resource counts to CIDR blocks while remembering that reserved IPs reduce usable space, a common trap where candidates forget to subtract the five fixed addresses. A quick memory tip: always add 5 to your total resource count, then find the next power of two—here, 51 plus 5 equals 56, so the next power of two is 64, which is a /26.
AZ-104 Implement and Manage Virtual Networking Practice Question
This AZ-104 practice question tests your understanding of implement and manage virtual networking. 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 team is creating a subnet for 48 small Linux VMs, two internal load balancer frontend IPs, and one Azure Bastion host. Azure reserves five IP addresses in every subnet. Which subnet prefix is the smallest that will still meet the requirement?
Why wrong: A /27 provides only 27 usable IP addresses after Azure reservations, which is not enough for all required resources.
B
/26
A /26 provides 64 total addresses, and Azure reserves five, leaving 59 usable addresses. That is enough for 48 VMs, two load balancer frontend IPs, and one Bastion host.
C
/25
Why wrong: A /25 would work, but it is larger than necessary and wastes address space that could be used elsewhere.
D
/28
Why wrong: A /28 is far too small for this design and cannot support the number of required private IP addresses.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
/26
The correct answer is /26 because it provides 64 total IP addresses, of which Azure reserves 5, leaving 59 usable IPs. This is the smallest prefix that accommodates the 48 VMs, 2 load balancer frontend IPs, and 1 Bastion host (total 51 required IPs). A /27 would only yield 32 total IPs (27 usable), which is insufficient.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
/27
Why it's wrong here
A /27 provides only 27 usable IP addresses after Azure reservations, which is not enough for all required resources.
✓
/26
Why this is correct
A /26 provides 64 total addresses, and Azure reserves five, leaving 59 usable addresses. That is enough for 48 VMs, two load balancer frontend IPs, and one Bastion host.
Related concept
Read the scenario before looking for a memorised answer.
✗
/25
Why it's wrong here
A /25 would work, but it is larger than necessary and wastes address space that could be used elsewhere.
✗
/28
Why it's wrong here
A /28 is far too small for this design and cannot support the number of required private IP addresses.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often forget Azure reserves 5 IPs per subnet and incorrectly calculate usable IPs as 2^(32-prefix) - 2 (like on-premises), leading them to choose /27 (thinking 30 usable IPs are enough) or /28 (thinking 14 usable IPs are enough).
Detailed technical explanation
How to think about this question
Azure reserves the first four and the last IP address in every subnet (network, gateway, Azure DNS, Azure future use, and broadcast). The subnet size must be calculated using the formula 2^(32-prefix) - 5 for usable IPs. For /26, 2^(32-26) = 64, minus 5 = 59 usable IPs, which comfortably covers the 51 required. In real-world scenarios, always account for Azure reserved IPs and any future scaling needs when choosing subnet sizes.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
TExam Day Tips
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
An e-commerce site experiences heavy traffic on Black Friday and near-zero traffic during off-peak weeks. Rather than provisioning permanent large VMs, the team uses auto-scaling groups that add capacity automatically under load and reduce it overnight. Questions like this test whether you understand elasticity, availability zones, and cloud compute scaling patterns.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this AZ-104 question in full detail.
Implement and Manage Virtual Networking — This question tests Implement and Manage Virtual Networking — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: /26 — The correct answer is /26 because it provides 64 total IP addresses, of which Azure reserves 5, leaving 59 usable IPs. This is the smallest prefix that accommodates the 48 VMs, 2 load balancer frontend IPs, and 1 Bastion host (total 51 required IPs). A /27 would only yield 32 total IPs (27 usable), which is insufficient.
What should I do if I get this AZ-104 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
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 →
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. Based on the exhibit, which subnet prefix should you create for the workload subnet so it has enough usable IP addresses for all listed resources?
medium
A./27
✓ B./26
C./25
D./28
Why B: The workload subnet must support 30 VMs, 5 internal load balancer frontend IPs, and 5 backend pool instances, totaling 40 IP addresses. A /26 subnet provides 64 total IPs, with 62 usable (after reserving network and broadcast addresses), which is sufficient. Smaller prefixes like /27 (30 usable) or /28 (14 usable) lack capacity, while /25 (126 usable) is excessive and wastes IP space.
Last reviewed: Jun 11, 2026
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.
This AZ-104 practice question is part of Courseiva's free Microsoft 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 AZ-104 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.