The answer is that the network security group is not associated with the subnet or network interface. Even though the NSG rule has a priority of 100—which is far lower than the default AllowInternetOutbound rule’s priority of 65001, meaning the deny rule should take precedence—an NSG has no effect on traffic until it is explicitly linked to a subnet or a VM’s NIC. Without that association, the rule exists in the template but is never applied, so Azure’s default outbound internet allowance remains in full effect. On the AZ-204 exam, this scenario tests your understanding that defining a rule in an ARM template is only half the work; the NSG resource must be connected via the subnet’s networkSecurityGroup property or the NIC’s networkSecurityGroup property. A common trap is assuming priority alone guarantees enforcement, but association is the prerequisite. Memory tip: “No link, no block—association makes the rule talk.”
AZ-204 Practice Question: Connect to and consume Azure services and third-party services
This AZ-204 practice question tests your understanding of connect to and consume azure services and third-party services. 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.
Refer to the exhibit. You are deploying an ARM template that includes the above network security group rule. The rule is intended to block all outbound internet traffic from a virtual network. However, after deployment, virtual machines in the subnet still have outbound internet access. What is the most likely reason?
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 the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The network security group is not associated with the subnet or network interface.
Option C is correct because the rule has a priority of 100, which is a high priority number (lowest priority). By default, Azure NSGs allow outbound internet traffic with a default rule (AllowInternetOutbound) that has a priority of 65001. Since 100 is lower than 65001, the deny rule should take precedence. However, the issue is that the rule uses 'VirtualNetwork' as the source address prefix, which means it only applies to traffic from the virtual network itself, not to traffic originating from VMs. Actually, the exhibit shows sourceAddressPrefixes as 'VirtualNetwork', which is correct for traffic from the VNet. But the problem is that the rule's priority is 100, which is higher than the default allow rule (65001), so it should work. Wait, let's re-evaluate: priority numbers are lower = higher priority. A priority of 100 means it is evaluated before the default rule (65001). So the rule should block outbound internet. However, the rule might not be applied because the NSG is not associated with the subnet or NIC. But the exhibit only shows the rule definition. The most likely reason from the options is that the NSG is not associated with the subnet or NIC. Option A is wrong because priority 100 is higher than default rules. Option B is wrong because the rule does apply to VMs in the VNet. Option D is wrong because the rule does not need to specify source port ranges. So Option C is correct.
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 destination port range '*' is invalid; you must specify explicit ports.
Why it's wrong here
'*' is a valid wildcard for all ports.
✗
The source address prefix should be '*' instead of 'VirtualNetwork'.
Why it's wrong here
'VirtualNetwork' includes all VMs in the VNet, which is correct for this scenario.
✓
The network security group is not associated with the subnet or network interface.
Why this is correct
Without association, the rule does not take effect.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
The rule priority is too low; it should be lower than the default allow rule.
Why it's wrong here
Priority 100 is higher (lower number) than the default rule (65001), so it should take precedence.
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
Scenario analysis trap
'VirtualNetwork' includes all VMs in the VNet, which is correct for this scenario.
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.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this AZ-204 question in full detail.
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-204 subnetting questions on CIDR, address ranges, and subnet selection.
Connect to and consume Azure services and third-party services — This question tests Connect to and consume Azure services and third-party services — CIDR notation defines the prefix length..
What is the correct answer to this question?
The correct answer is: The network security group is not associated with the subnet or network interface. — Option C is correct because the rule has a priority of 100, which is a high priority number (lowest priority). By default, Azure NSGs allow outbound internet traffic with a default rule (AllowInternetOutbound) that has a priority of 65001. Since 100 is lower than 65001, the deny rule should take precedence. However, the issue is that the rule uses 'VirtualNetwork' as the source address prefix, which means it only applies to traffic from the virtual network itself, not to traffic originating from VMs. Actually, the exhibit shows sourceAddressPrefixes as 'VirtualNetwork', which is correct for traffic from the VNet. But the problem is that the rule's priority is 100, which is higher than the default allow rule (65001), so it should work. Wait, let's re-evaluate: priority numbers are lower = higher priority. A priority of 100 means it is evaluated before the default rule (65001). So the rule should block outbound internet. However, the rule might not be applied because the NSG is not associated with the subnet or NIC. But the exhibit only shows the rule definition. The most likely reason from the options is that the NSG is not associated with the subnet or NIC. Option A is wrong because priority 100 is higher than default rules. Option B is wrong because the rule does apply to VMs in the VNet. Option D is wrong because the rule does not need to specify source port ranges. So Option C is correct.
What should I do if I get this AZ-204 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-204 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 →
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-204 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-204 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.