This DOP-C02 practice question tests your understanding of sdlc automation. 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 DevOps engineer is setting up an AWS CodeBuild project that needs to access resources in a VPC, such as an Amazon RDS database. The engineer has configured the CodeBuild project to run in the VPC. Which additional configuration is required for CodeBuild to pull the build Docker image?
Attach an internet gateway to the VPC and add a default route to it.
Why wrong: This would make the subnet public, but CodeBuild does not automatically use it; also, security best practices recommend private subnets with NAT.
D
Create a VPC interface endpoint for Amazon ECR and configure the CodeBuild project to use it.
Interface endpoints allow CodeBuild to pull images from ECR without internet access.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Create a VPC interface endpoint for Amazon ECR and configure the CodeBuild project to use it.
Option D is correct because CodeBuild requires a VPC interface endpoint to Amazon ECR or the Docker Hub to pull images when running in a private subnet without internet access. Option A is wrong because internet gateway is not enough; the subnet must be public or have NAT. Option B is wrong because VPC peering does not provide internet access. Option C is wrong because CodeBuild does not have a direct integration with Amazon ECR via a gateway endpoint; ECR requires interface endpoints.
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.
✗
Create a VPC peering connection to another VPC that has internet access.
Why it's wrong here
VPC peering does not provide internet access to the peered VPC.
✗
Configure a VPC gateway endpoint for Amazon ECR.
Why it's wrong here
ECR uses interface endpoints (AWS PrivateLink), not gateway endpoints.
✗
Attach an internet gateway to the VPC and add a default route to it.
Why it's wrong here
This would make the subnet public, but CodeBuild does not automatically use it; also, security best practices recommend private subnets with NAT.
✓
Create a VPC interface endpoint for Amazon ECR and configure the CodeBuild project to use it.
Why this is correct
Interface endpoints allow CodeBuild to pull images from ECR without internet access.
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 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 DOP-C02 subnetting questions on CIDR, address ranges, and subnet selection.
SDLC Automation — This question tests SDLC Automation — CIDR notation defines the prefix length..
What is the correct answer to this question?
The correct answer is: Create a VPC interface endpoint for Amazon ECR and configure the CodeBuild project to use it. — Option D is correct because CodeBuild requires a VPC interface endpoint to Amazon ECR or the Docker Hub to pull images when running in a private subnet without internet access. Option A is wrong because internet gateway is not enough; the subnet must be public or have NAT. Option B is wrong because VPC peering does not provide internet access. Option C is wrong because CodeBuild does not have a direct integration with Amazon ECR via a gateway endpoint; ECR requires interface endpoints.
What should I do if I get this DOP-C02 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 DOP-C02 subnetting questions on CIDR, address ranges, and subnet selection.
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 DOP-C02 practice question is part of Courseiva's free Amazon Web Services 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 DOP-C02 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.