Quick Answer
The correct action is to assign a network security group (NSG) to the database subnet that denies all inbound traffic from the internet. This works because an NSG acts as a distributed, stateful firewall at the subnet or NIC level, and by default, it includes a rule that allows all inbound traffic from within the virtual network. To isolate the database subnet from direct internet access, you must explicitly add a deny rule with the source set to 'Internet', which overrides the default implicit allow for internet traffic while preserving the default allow for virtual network traffic from the application tier. On the AZ-104 exam, this scenario tests your understanding of NSG rule priority and default rules—a common trap is forgetting that NSGs implicitly allow virtual network traffic, so you only need to block the 'Internet' source, not create complex allow rules for the app tier. Remember the memory tip: "Block the web, keep the VNet"—deny Internet, allow VirtualNetwork.
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.
You are designing an Azure virtual network for a three-tier application. The frontend, application, and database tiers each require their own subnet. You need to ensure that the frontend tier can communicate with the application tier, but the database tier must be isolated from direct inbound traffic from the internet. Which three of the following actions should you include in your design? (Choose three.)
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
Assign a network security group (NSG) to the database subnet that denies all inbound traffic from the internet.
Assigning a network security group (NSG) to the database subnet that denies all inbound traffic from the internet is correct because NSGs act as a distributed, stateful firewall at the subnet or NIC level. By default, NSGs allow all inbound traffic from within the virtual network, so you must explicitly add a deny rule for internet traffic (source 'Internet') to isolate the database tier. This ensures the database subnet is protected from direct inbound internet traffic while still allowing traffic from the application tier via the default allow rule for virtual network traffic.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often think they need to create separate virtual networks or use complex routing/firewall rules for isolation, when in fact a single VNet with subnets and an NSG on the database subnet is sufficient to meet the requirement of isolating the database from the internet while allowing frontend-to-application communication.
Detailed technical explanation
How to think about this question
Network security groups (NSGs) evaluate rules in priority order, with the highest priority (lowest number) applied first; a default deny rule at the end blocks all traffic not explicitly allowed. When you assign an NSG to a subnet, it applies to all resources in that subnet, and the default inbound rule 'AllowVNetInBound' permits traffic from other subnets in the same VNet, so the application tier can still reach the database tier without additional configuration. In a real-world scenario, you might also add a service endpoint or private endpoint for the database to further restrict access, but the core isolation from the internet is achieved with the NSG deny rule.
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.
- →
Implement and Manage Virtual Networking — study guide chapter
Learn the concepts, then practise the questions
- →
Implement and Manage Virtual Networking practice questions
Targeted practice on this topic area only
- →
All AZ-104 questions
1,170 questions across all exam domains
- →
AZ-104 study guide
Full concept coverage aligned to exam objectives
- →
AZ-104 practice test guide
How to use practice tests most effectively before exam day
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.
Manage Azure Identities and Governance practice questions
Practise AZ-104 questions linked to Manage Azure Identities and Governance.
Implement and Manage Storage practice questions
Practise AZ-104 questions linked to Implement and Manage Storage.
Deploy and Manage Azure Compute practice questions
Practise AZ-104 questions linked to Deploy and Manage Azure Compute.
Implement and Manage Virtual Networking practice questions
Practise AZ-104 questions linked to Implement and Manage Virtual Networking.
Monitor and Maintain Azure Resources practice questions
Practise AZ-104 questions linked to Monitor and Maintain Azure Resources.
AZ-104 Azure RBAC practice questions
Practise AZ-104 questions linked to AZ-104 Azure RBAC.
AZ-104 storage account practice questions
Practise AZ-104 questions linked to AZ-104 storage account.
AZ-104 virtual network practice questions
Practise AZ-104 questions linked to AZ-104 virtual network.
AZ-104 NSG practice questions
Practise AZ-104 questions linked to AZ-104 NSG.
AZ-104 Azure Monitor practice questions
Practise AZ-104 questions linked to AZ-104 Azure Monitor.
AZ-104 backup practice questions
Practise AZ-104 questions linked to AZ-104 backup.
AZ-104 managed identity practice questions
Practise AZ-104 questions linked to AZ-104 managed identity.
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: Assign a network security group (NSG) to the database subnet that denies all inbound traffic from the internet. — Assigning a network security group (NSG) to the database subnet that denies all inbound traffic from the internet is correct because NSGs act as a distributed, stateful firewall at the subnet or NIC level. By default, NSGs allow all inbound traffic from within the virtual network, so you must explicitly add a deny rule for internet traffic (source 'Internet') to isolate the database tier. This ensures the database subnet is protected from direct inbound internet traffic while still allowing traffic from the application tier via the default allow rule for virtual network traffic.
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 →
Last reviewed: Jun 11, 2026
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.