- A
The user does not have 'Reader' role on the VM.
Why wrong: Bastion requires 'Reader' role to list VMs, but RDP access also needs 'Contributor' or similar roles; however, the scenario says other VMs are accessible, so permissions are likely fine.
- B
The NSG on the VM's subnet does not allow inbound RDP from the AzureBastionSubnet.
Bastion requires the NSG to allow inbound RDP from the Bastion subnet's address prefix.
- C
The VM is located in a different region than the Bastion host.
Why wrong: Bastion can connect to VMs in the same VNet; it doesn't require same region, but the VNet must be in the same region as Bastion.
- D
The VM has a public IP assigned, which interferes with Bastion connectivity.
Why wrong: Bastion can connect to VMs with or without public IPs; the public IP does not interfere.
Quick Answer
The answer is that the Network Security Group (NSG) on the VM’s subnet is not configured to allow inbound RDP traffic from the AzureBastionSubnet. Azure Bastion connects to target VMs using their private IP addresses, so a public IP on the VM is irrelevant for Bastion access. The core requirement is that the NSG associated with the VM’s subnet must explicitly permit inbound RDP on port 3389 from the AzureBastionSubnet’s address prefix; without this rule, the Bastion service cannot establish a session even if the VM is running and has a public IP. On the AZ-500 exam, this scenario tests your understanding of Azure Bastion’s network dependency—specifically that Bastion itself is deployed into its own dedicated subnet and relies on NSG rules to reach VMs, not on public IPs. A common trap is assuming a public IP guarantees RDP connectivity, but Bastion bypasses that entirely. Memory tip: Bastion is a “private bridge”—it needs an NSG door open from its subnet to the VM’s subnet, not a public key.
AZ-500 Secure networking Practice Question
This AZ-500 practice question tests your understanding of secure networking. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. 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.
You configure Azure Bastion to allow secure RDP access to VMs in a VNet. However, users report that they cannot connect to a specific VM, while other VMs in the same VNet are accessible. The VM is running and has a public IP. What is the most likely cause?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue:
"most likely"Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
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
The NSG on the VM's subnet does not allow inbound RDP from the AzureBastionSubnet.
Azure Bastion does not require a public IP on the target VM; it connects to the private IP. However, if the VM has a public IP, Bastion might still work, but the issue could be that the VM's RDP port (3389) is not open in the NSG for the Bastion subnet. Bastion uses a specific set of public IPs to connect, and the NSG on the VM's subnet must allow inbound RDP from the Bastion subnet.
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.
- ✗
The user does not have 'Reader' role on the VM.
Why it's wrong here
Bastion requires 'Reader' role to list VMs, but RDP access also needs 'Contributor' or similar roles; however, the scenario says other VMs are accessible, so permissions are likely fine.
- ✓
The NSG on the VM's subnet does not allow inbound RDP from the AzureBastionSubnet.
Why this is correct
Bastion requires the NSG to allow inbound RDP from the Bastion subnet's address prefix.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
CIDR notation defines the prefix length.
- ✗
The VM is located in a different region than the Bastion host.
Why it's wrong here
Bastion can connect to VMs in the same VNet; it doesn't require same region, but the VNet must be in the same region as Bastion.
- ✗
The VM has a public IP assigned, which interferes with Bastion connectivity.
Why it's wrong here
Bastion can connect to VMs with or without public IPs; the public IP does not interfere.
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.
Trap categories for this question
Similar concept trap
Bastion requires 'Reader' role to list VMs, but RDP access also needs 'Contributor' or similar roles; however, the scenario says other VMs are accessible, so permissions are likely fine.
Scenario analysis trap
Bastion requires 'Reader' role to list VMs, but RDP access also needs 'Contributor' or similar roles; however, the scenario says other VMs are accessible, so permissions are likely fine.
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 company's IT admin needs to give a contractor read-only access to production logs without sharing account credentials. Using role-based access control (RBAC) and temporary scoped permissions — not a permanent shared password — is the correct pattern. Questions like this test whether you can apply least-privilege access across cloud identity services.
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 AZ-500 subnetting questions on CIDR, address ranges, and subnet selection.
- →
Secure networking — study guide chapter
Learn the concepts, then practise the questions
- →
Secure networking practice questions
Targeted practice on this topic area only
- →
All AZ-500 questions
1,000 questions across all exam domains
- →
Microsoft Azure Security Engineer Associate AZ-500 study guide
Full concept coverage aligned to exam objectives
- →
AZ-500 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related AZ-500 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Secure identity and access practice questions
Practise AZ-500 questions linked to Secure identity and access.
Secure compute, storage, and databases practice questions
Practise AZ-500 questions linked to Secure compute, storage, and databases.
Secure Azure using Microsoft Defender for Cloud and Microsoft Sentinel practice questions
Practise AZ-500 questions linked to Secure Azure using Microsoft Defender for Cloud and Microsoft Sentinel.
Manage identity and access practice questions
Practise AZ-500 questions linked to Manage identity and access.
Secure networking practice questions
Practise AZ-500 questions linked to Secure networking.
AZ-500 fundamentals practice questions
Practise AZ-500 questions linked to AZ-500 fundamentals.
AZ-500 scenario practice questions
Practise AZ-500 questions linked to AZ-500 scenario.
AZ-500 troubleshooting practice questions
Practise AZ-500 questions linked to AZ-500 troubleshooting.
Practice this exam
Start a free AZ-500 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 AZ-500 question test?
Secure networking — This question tests Secure networking — CIDR notation defines the prefix length..
What is the correct answer to this question?
The correct answer is: The NSG on the VM's subnet does not allow inbound RDP from the AzureBastionSubnet. — Azure Bastion does not require a public IP on the target VM; it connects to the private IP. However, if the VM has a public IP, Bastion might still work, but the issue could be that the VM's RDP port (3389) is not open in the NSG for the Bastion subnet. Bastion uses a specific set of public IPs to connect, and the NSG on the VM's subnet must allow inbound RDP from the Bastion subnet.
What should I do if I get this AZ-500 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 AZ-500 subnetting questions on CIDR, address ranges, and subnet selection.
Are there clue words in this question I should notice?
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
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: Jun 20, 2026
This AZ-500 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-500 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.