Question 421 of 1,170
Implement and Manage Virtual NetworkingmediumMultiple ChoiceObjective-mapped

Using Application Security Groups in NSG Rules for Auto-Inclusion

This AZ-104 practice question tests your understanding of implement and manage virtual networking. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. 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 web tier and an app tier run on separate Azure VMs in the same region. Each VM's NIC is added to an application security group named WebASG or AppASG. The administrator must allow only the web tier to connect to the app tier on TCP 8443, and future VM scale-outs must be included automatically. Which NSG rule should be created?

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

An inbound rule with source WebASG, destination AppASG, protocol TCP, and destination port 8443.

Option B is correct because application security groups (ASGs) allow you to configure network security as a natural extension of an application's structure, enabling you to group VMs by their roles (e.g., web tier, app tier) and define rules based on those groups. By creating an inbound NSG rule with source WebASG and destination AppASG on TCP port 8443, any VM added to WebASG can initiate traffic to any VM in AppASG, and future scale-outs are automatically included without manual IP updates. This approach is dynamic, scalable, and aligns with the requirement for automatic inclusion of new VMs.

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.

  • An inbound rule that uses the current web VM's private IP as the source and the current app VM's private IP as the destination.

    Why it's wrong here

    IP-based rules work for one VM, but they do not scale cleanly when the tiers grow or change.

    When this WOULD be correct

    If the question required restricting access to a single, specific VM (e.g., a management VM) and did not require automatic inclusion of new VMs, using static private IPs would be appropriate.

  • An inbound rule with source WebASG, destination AppASG, protocol TCP, and destination port 8443.

    Why this is correct

    Using application security groups is the best fit because the rule follows the role of the VM, not a fixed IP address. When new web or app VMs are added to their respective ASGs, the NSG rule automatically covers them. This provides least-privilege connectivity between tiers while keeping the configuration maintainable during scale-out and redeployment events.

    Related concept

    Read the scenario before looking for a memorised answer.

  • A route table that sends TCP 8443 traffic from the web subnet to the app subnet.

    Why it's wrong here

    Route tables decide where traffic goes, but they do not allow or deny TCP ports between workloads.

    When this WOULD be correct

    A question where the requirement is to force traffic from the web subnet to the app subnet through a specific next hop (e.g., a firewall or NVA) for inspection, and the goal is routing control, not access control based on ASGs.

  • An Azure Firewall application rule collection that permits all traffic between the two subnets.

    Why it's wrong here

    Azure Firewall could filter traffic, but this option is broader than requested and does not describe the most direct NSG-based tier control.

    When this WOULD be correct

    This option would be correct if the question required filtering outbound HTTP/S traffic from the web tier to the internet, or if it required centralized logging and inspection of all traffic between subnets using Azure Firewall, and the question explicitly stated to use Azure Firewall instead of NSGs.

Option-by-option analysis

Why each answer is right or wrong

Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The AZ-104 exam frequently reuses these exact scenarios with slightly different constraints.

An inbound rule with source WebASG, destination AppASG, protocol TCP, and destination port 8443.Correct answer

Why this is correct

Using application security groups is the best fit because the rule follows the role of the VM, not a fixed IP address. When new web or app VMs are added to their respective ASGs, the NSG rule automatically covers them. This provides least-privilege connectivity between tiers while keeping the configuration maintainable during scale-out and redeployment events.

An inbound rule that uses the current web VM's private IP as the source and the current app VM's private IP as the destination.Wrong answer — click to see why

Why this is wrong here

This rule uses static private IPs, so it fails to automatically include future VM scale-outs, violating the requirement for automatic inclusion.

★ When this WOULD be the correct answer

If the question required restricting access to a single, specific VM (e.g., a management VM) and did not require automatic inclusion of new VMs, using static private IPs would be appropriate.

Why candidates choose this

Candidates may think that specifying exact IPs provides precise control, overlooking the need for scalability and dynamic membership provided by application security groups.

A route table that sends TCP 8443 traffic from the web subnet to the app subnet.Wrong answer — click to see why

Why this is wrong here

Route tables control IP routing between subnets, not traffic filtering. They cannot enforce application-layer allow rules like TCP port 8443, and they don't integrate with application security groups for automatic scale-out inclusion.

★ When this WOULD be the correct answer

A question where the requirement is to force traffic from the web subnet to the app subnet through a specific next hop (e.g., a firewall or NVA) for inspection, and the goal is routing control, not access control based on ASGs.

Why candidates choose this

Candidates may confuse routing with network security, thinking that directing traffic via a route table can restrict which ports are allowed, or they may assume route tables can filter traffic like a firewall rule.

An Azure Firewall application rule collection that permits all traffic between the two subnets.Wrong answer — click to see why

Why this is wrong here

Azure Firewall application rules are for outbound HTTP/S traffic from applications, not for inbound network filtering between VMs. This question requires an NSG rule, not a firewall rule, and the requirement is for inbound connectivity from web to app tier.

★ When this WOULD be the correct answer

This option would be correct if the question required filtering outbound HTTP/S traffic from the web tier to the internet, or if it required centralized logging and inspection of all traffic between subnets using Azure Firewall, and the question explicitly stated to use Azure Firewall instead of NSGs.

Why candidates choose this

Candidates may think Azure Firewall is a more comprehensive solution for controlling traffic between tiers, or they may confuse application rules with network rules, assuming it can filter inbound traffic between VMs.

Analysis generated from the official AZ-104blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”

Common exam traps

Common exam trap: answer the scenario, not the keyword

The trap here is that candidates often confuse network security groups (NSGs) with route tables, thinking that routing can enforce access control, or they default to using static IP addresses in NSG rules, missing the dynamic, group-based capability of application security groups that automatically includes new VMs.

Detailed technical explanation

How to think about this question

Application security groups (ASGs) are a feature of Azure Network Security Groups (NSGs) that allow you to reference logical groupings of VM NICs directly in security rules, using the 'ApplicationSecurityGroup' resource ID. Under the hood, the Azure fabric translates these ASG references into the actual IP addresses of the member VMs at the time of rule evaluation, ensuring that any newly added NIC to an ASG is immediately subject to the associated NSG rules without any manual intervention. This is particularly useful in auto-scaling scenarios where VMs are dynamically created and destroyed, as the NSG rules remain valid and effective without requiring updates to IP address lists.

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

A media company stores terabytes of video archives that are accessed once a year for audit purposes. Moving these objects to a cold storage tier (Azure Archive, S3 Glacier, or Google Nearline) costs a fraction of hot storage. Questions like this test whether you understand storage tiers, access frequency tradeoffs, and retrieval latency requirements.

What to study next

Got this wrong? Here's your next step.

Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.

Related practice questions

Related AZ-104 practice-question pages

Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.

Practice this exam

Start a free AZ-104 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-104 question test?

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: An inbound rule with source WebASG, destination AppASG, protocol TCP, and destination port 8443. — Option B is correct because application security groups (ASGs) allow you to configure network security as a natural extension of an application's structure, enabling you to group VMs by their roles (e.g., web tier, app tier) and define rules based on those groups. By creating an inbound NSG rule with source WebASG and destination AppASG on TCP port 8443, any VM added to WebASG can initiate traffic to any VM in AppASG, and future scale-outs are automatically included without manual IP updates. This approach is dynamic, scalable, and aligns with the requirement for automatic inclusion of new VMs.

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 →

How Courseiva writes practice questions · Editorial policy

Same concept, more angles

2 more ways this is tested on AZ-104

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, web servers can reach a backend VM only after it is added to a specific group. What should the administrator change to allow the traffic to match the existing NSG rule?

medium
  • A.Add api01's NIC to ASG-Api.
  • B.Move the deny rule to priority 100.
  • C.Change the source of the allow rule from ASG-Web to VirtualNetwork.
  • D.Place api01 in the same subnet as web01.

Why A: The exhibit shows that the NSG rule allows traffic from ASG-Web to ASG-Api. Since web01 is in ASG-Web, traffic from web01 to api01 is only permitted if api01 is a member of ASG-Api. Adding api01's NIC to ASG-Api ensures the destination matches the NSG rule, allowing the traffic.

Variation 2. A team manages many application VMs and backend VMs. The VM IP addresses change whenever they are rebuilt, but the same traffic rule must always allow the app tier to reach the backend tier on TCP 8443. What should the administrator use in the NSG rule?

easy
  • A.Static private IP addresses for each virtual machine.
  • B.Application Security Groups for the app and backend VMs.
  • C.A user-defined route between the app and backend subnets.
  • D.An availability set for each tier.

Why B: Application Security Groups (ASGs) allow you to group VMs logically and reference them directly in NSG rules without relying on static IP addresses. Since the VM IPs change on rebuild, ASGs ensure the NSG rule for TCP 8443 always applies to the correct app and backend tiers, regardless of IP changes.

Keep practising

More AZ-104 practice questions

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.

Loading comments…

Sign in to join the discussion.

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.