The correct solution is to create a VPC Gateway Endpoint for S3 and add a route from the private subnet to the endpoint. This works because a Gateway Endpoint uses AWS PrivateLink to route traffic directly from your VPC to S3 over the AWS backbone network, completely bypassing the internet and eliminating the need for a NAT Gateway or internet gateway. On the AWS Certified Advanced Networking Specialty ANS-C01 exam, this scenario tests your understanding of when to use Gateway Endpoints versus Interface Endpoints—a common trap is choosing an Interface Endpoint for S3, but Gateway Endpoints are the correct, cost-free choice for same-region S3 access from private subnets. Remember that Gateway Endpoints are only available for S3 and DynamoDB, and they require a route table entry pointing to the endpoint’s prefix list ID. Memory tip: “Gateway for S3, no NAT fee—route the prefix, and you’re free.”
ANS-C01 Network Design Practice Question
This ANS-C01 practice question tests your understanding of network design. 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.
A company has a VPC with CIDR 172.16.0.0/16. They have two subnets: 172.16.1.0/24 (public) and 172.16.2.0/24 (private) in us-west-2a. They have an EC2 instance in the private subnet that needs to access an S3 bucket for log uploads. The company wants to avoid using a NAT Gateway to reduce costs. The S3 bucket is in the same region. Which solution should the network engineer implement?
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 Gateway Endpoint for S3 and add a route from the private subnet to the endpoint.
Option C is correct because a VPC Gateway Endpoint for S3 allows private subnet resources to access S3 without traversing the internet or requiring a NAT Gateway. The endpoint uses AWS PrivateLink to route traffic directly to S3 over the AWS network, and you must add a route in the private subnet's route table pointing to the endpoint (prefix list ID) to enable connectivity.
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.
✗
Assign an IAM instance profile to the EC2 instance that allows S3 access.
Why it's wrong here
IAM controls permissions but does not provide network connectivity to S3.
✗
Set up a VPN connection from the VPC to the S3 bucket.
Why it's wrong here
S3 does not support VPN connections; you need an endpoint or internet access.
✓
Create a VPC Gateway Endpoint for S3 and add a route from the private subnet to the endpoint.
Why this is correct
A gateway endpoint provides private connectivity to S3 without a NAT.
Related concept
Read the scenario before looking for a memorised answer.
✗
Create an S3 access point and configure the VPC to use it.
Why it's wrong here
An S3 access point is a managed endpoint for S3 but still requires network connectivity via a gateway endpoint or NAT.
Common exam traps
Common exam trap: answer the scenario, not the keyword
AWS often tests the misconception that an IAM role alone provides network access, but the trap here is that private subnets require a route to S3, and without a NATGateway or VPC endpoint, traffic cannot leave the subnet even with correct IAM permissions.
Detailed technical explanation
How to think about this question
A VPC Gateway Endpoint for S3 uses a prefix list (e.g., com.amazonaws.us-west-2.s3) in the route table to direct traffic to S3 via the AWS global network, avoiding internet gateways or NAT devices. The endpoint is horizontally scaled, redundant, and highly available within the region, and it supports both IPv4 and IPv6 traffic. In real-world scenarios, this is critical for cost-sensitive workloads like logging or backup where NAT Gateway data processing costs would be prohibitive.
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 startup's cloud architect reviews their monthly bill and notices costs are higher than expected for a long-running batch job. Switching from on-demand instances to Reserved Instances — or using Spot/Preemptible VMs — can reduce compute costs by up to 72 %. Questions like this test whether you understand the tradeoffs between commitment, flexibility, and cost across cloud pricing models.
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.
Network Design — This question tests Network Design — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Create a VPC Gateway Endpoint for S3 and add a route from the private subnet to the endpoint. — Option C is correct because a VPC Gateway Endpoint for S3 allows private subnet resources to access S3 without traversing the internet or requiring a NAT Gateway. The endpoint uses AWS PrivateLink to route traffic directly to S3 over the AWS network, and you must add a route in the private subnet's route table pointing to the endpoint (prefix list ID) to enable connectivity.
What should I do if I get this ANS-C01 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 →
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 ANS-C01 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 ANS-C01 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.