- A
Configure an S3 bucket policy that restricts access to the VPC's public IP addresses.
Why wrong: Private subnet instances do not have public IPs, and this would not prevent traffic from going through the NAT gateway.
- B
Create a VPC Gateway Endpoint for S3 and attach a policy allowing access from the private subnets.
Gateway endpoints are free and keep traffic within AWS network.
- C
Route traffic to the NAT gateway and then to the S3 bucket using a VPC peering connection.
Why wrong: NAT gateway adds cost and traffic goes over the internet, not cost-effective.
- D
Create a VPC Interface Endpoint for S3 and associate with the private subnets.
Why wrong: Interface endpoints for S3 incur hourly charges and data processing costs, making them less cost-effective than Gateway endpoints.
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 public and private subnets. The public subnet has a NAT gateway for outbound internet access from private subnets. The private subnets have EC2 instances that need to access an S3 bucket in the same region. The company wants to minimize data transfer costs and avoid traversing the internet. What is the MOST cost-effective solution?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue:
"minimum / minimize"Why it matters: Asks for the least resource use — fewest addresses, smallest subnet, lowest overhead. Eliminate over-provisioned options even if they would technically work.
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
Create a VPC Gateway Endpoint for S3 and attach a policy allowing access from the private subnets.
A VPC Gateway Endpoint for S3 allows private subnet instances to access S3 over the AWS network without traversing the internet or a NAT gateway, eliminating data transfer costs for the NAT gateway and avoiding internet egress charges. This is the most cost-effective solution because gateway endpoints are free and use prefix lists in the route table to direct traffic to S3 via the AWS backbone.
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.
- ✗
Configure an S3 bucket policy that restricts access to the VPC's public IP addresses.
- ✓
Create a VPC Gateway Endpoint for S3 and attach a policy allowing access from the private subnets.
Why this is correct
Gateway endpoints are free and keep traffic within AWS network.
Clue confirmation
The clue word "minimum / minimize" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Route traffic to the NAT gateway and then to the S3 bucket using a VPC peering connection.
- ✗
Create a VPC Interface Endpoint for S3 and associate with the private subnets.
Why it's wrong here
Interface endpoints for S3 incur hourly charges and data processing costs, making them less cost-effective than Gateway endpoints.
Common exam traps
Common exam trap: answer the scenario, not the keyword
AWS often tests the misconception that interface endpoints are always the best choice for AWS service access, but for S3 and DynamoDB, gateway endpoints are the most cost-effective because they are free and avoid the per-GB data processing charges of interface endpoints.
Detailed technical explanation
How to think about this question
A VPC Gateway Endpoint uses a prefix list (e.g., com.amazonaws.us-east-1.s3) in the route table to route traffic to S3 over the AWS private network, leveraging the underlying Border Gateway Protocol (BGP) to direct packets without NAT or internet gateway. Gateway endpoints are horizontally scaled, redundant, and do not require an Elastic Network Interface (ENI), making them inherently more cost-effective than interface endpoints, which use ENIs and incur per-hour and per-GB costs. In practice, this design is critical for high-volume S3 workloads (e.g., log aggregation or data lakes) where NAT gateway data processing costs would otherwise dominate.
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 — study guide chapter
Learn the concepts, then practise the questions
- →
Network Design practice questions
Targeted practice on this topic area only
- →
All ANS-C01 questions
1,705 questions across all exam domains
- →
AWS Certified Advanced Networking Specialty ANS-C01 study guide
Full concept coverage aligned to exam objectives
- →
ANS-C01 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related ANS-C01 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Network Management and Operations practice questions
Practise ANS-C01 questions linked to Network Management and Operations.
Network Security, Compliance and Governance practice questions
Practise ANS-C01 questions linked to Network Security, Compliance and Governance.
Network Design practice questions
Practise ANS-C01 questions linked to Network Design.
Network Implementation practice questions
Practise ANS-C01 questions linked to Network Implementation.
ANS-C01 fundamentals practice questions
Practise ANS-C01 questions linked to ANS-C01 fundamentals.
ANS-C01 scenario practice questions
Practise ANS-C01 questions linked to ANS-C01 scenario.
ANS-C01 troubleshooting practice questions
Practise ANS-C01 questions linked to ANS-C01 troubleshooting.
Practice this exam
Start a free ANS-C01 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 ANS-C01 question test?
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 attach a policy allowing access from the private subnets. — A VPC Gateway Endpoint for S3 allows private subnet instances to access S3 over the AWS network without traversing the internet or a NAT gateway, eliminating data transfer costs for the NAT gateway and avoiding internet egress charges. This is the most cost-effective solution because gateway endpoints are free and use prefix lists in the route table to direct traffic to S3 via the AWS backbone.
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.
Are there clue words in this question I should notice?
Yes — watch for: "minimum / minimize". Asks for the least resource use — fewest addresses, smallest subnet, lowest overhead. Eliminate over-provisioned options even if they would technically work.
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 30, 2026
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.