DP-203 Practice Question: Secure, monitor, and optimize data storage and data processing
This DP-203 practice question tests your understanding of secure, monitor, and optimize data storage and data processing. 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 deploy the ARM template to create a storage account. After deployment, a developer reports that they cannot access the storage account from an Azure Databricks notebook running in the same virtual network as specified in the subnet rule. 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.
The storage account uses customer-managed keys from Key Vault, which requires additional permissions.
Why wrong: Incorrect. Customer-managed keys from Key Vault do not block access; they are used for encryption at rest and require additional permissions but are not the likely reason for the access issue.
B
The firewall default action is Deny, and there are no IP rules allowing the Databricks cluster's public IP.
Why wrong: Incorrect. The firewall default action is Deny, but the subnet rule should allow traffic from the Databricks managed VNet. The Databricks cluster's public IP is not relevant if it is using a managed VNet with private IPs.
C
The Databricks cluster is not using a managed virtual network with a service endpoint to the storage account.
Correct. The most likely reason is that the Databricks cluster is not using a managed virtual network with a service endpoint to the storage account, so traffic from the cluster is not recognized as coming from the allowed subnet.
D
The storage account has hierarchical namespace enabled, which blocks non-ADLS Gen2 tools.
Why wrong: Incorrect. Hierarchical namespace (ADLS Gen2) does not block access; it enables data lake storage features and is compatible with Databricks.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The Databricks cluster is not using a managed virtual network with a service endpoint to the storage account.
The correct answer is C. The storage account firewall is configured with a default deny and a subnet rule allowing traffic from a specific virtual network subnet. For an Azure Databricks notebook to access the storage account, the Databricks workspace must be deployed with a managed virtual network and the cluster must use that same subnet with a service endpoint to the storage account. If the Databricks cluster is not using a managed virtual network or the subnet is not correctly configured, the traffic will be blocked. Option A is incorrect because customer-managed keys from Key Vault do not block access; they are for encryption. Option B is incorrect because the firewall's default deny is expected, but the subnet rule should allow traffic from the Databricks VNet, not the cluster's public IP (Databricks clusters in a managed VNet use private IPs). Option D is incorrect because hierarchical namespace (ADLS Gen2) does not block access; it enables it.
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 storage account uses customer-managed keys from Key Vault, which requires additional permissions.
Why it's wrong here
Incorrect. Customer-managed keys from Key Vault do not block access; they are used for encryption at rest and require additional permissions but are not the likely reason for the access issue.
✗
The firewall default action is Deny, and there are no IP rules allowing the Databricks cluster's public IP.
Why it's wrong here
Incorrect. The firewall default action is Deny, but the subnet rule should allow traffic from the Databricks managed VNet. The Databricks cluster's public IP is not relevant if it is using a managed VNet with private IPs.
✓
The Databricks cluster is not using a managed virtual network with a service endpoint to the storage account.
Why this is correct
Correct. The most likely reason is that the Databricks cluster is not using a managed virtual network with a service endpoint to the storage account, so traffic from the cluster is not recognized as coming from the allowed subnet.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
The storage account has hierarchical namespace enabled, which blocks non-ADLS Gen2 tools.
Why it's wrong here
Incorrect. Hierarchical namespace (ADLS Gen2) does not block access; it enables data lake storage features and is compatible with Databricks.
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.
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 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.
Visual reference
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this DP-203 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 DP-203 subnetting questions on CIDR, address ranges, and subnet selection.
Secure, monitor, and optimize data storage and data processing — This question tests Secure, monitor, and optimize data storage and data processing — CIDR notation defines the prefix length..
What is the correct answer to this question?
The correct answer is: The Databricks cluster is not using a managed virtual network with a service endpoint to the storage account. — The correct answer is C. The storage account firewall is configured with a default deny and a subnet rule allowing traffic from a specific virtual network subnet. For an Azure Databricks notebook to access the storage account, the Databricks workspace must be deployed with a managed virtual network and the cluster must use that same subnet with a service endpoint to the storage account. If the Databricks cluster is not using a managed virtual network or the subnet is not correctly configured, the traffic will be blocked. Option A is incorrect because customer-managed keys from Key Vault do not block access; they are for encryption. Option B is incorrect because the firewall's default deny is expected, but the subnet rule should allow traffic from the Databricks VNet, not the cluster's public IP (Databricks clusters in a managed VNet use private IPs). Option D is incorrect because hierarchical namespace (ADLS Gen2) does not block access; it enables it.
What should I do if I get this DP-203 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 DP-203 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 DP-203 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 DP-203 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.