- A
Create a Gateway VPC endpoint for S3 and associate it with the private subnet route tables that contain the instances.
S3 connectivity without NAT typically requires a Gateway VPC endpoint. For a gateway endpoint, you must update the route tables to direct S3 traffic to the endpoint. If DynamoDB works but S3 times out, it often means DynamoDB has the required endpoint while S3 is missing or not routed via the correct route tables.
- B
Replace the security group egress rule to allow all outbound traffic to 0.0.0.0/0 on TCP 443.
Why wrong: Allowing 0.0.0.0/0 does not create a route to the S3 service without NAT. Security groups do not override routing; if traffic is not routed through the S3 VPC endpoint, the connection will still time out.
- C
Add an Internet Gateway to the VPC and route the private subnet’s 0.0.0.0/0 to the IGW.
Why wrong: Adding an Internet Gateway and public routing would defeat the purpose of using private subnets without NAT and increases exposure. The correct solution is service-specific private connectivity using a VPC endpoint for S3.
- D
Switch from network ACLs to security groups by removing the existing NACL allow rules for ephemeral ports.
Why wrong: If DynamoDB works, NACL rules are likely not the blocker for outbound traffic in general. Also, the primary requirement for reaching S3 without NAT is routing via the S3 endpoint. NACL changes would be unnecessary if endpoint routing is already correct.
SAA-C03 Design Secure Architectures Practice Question
This SAA-C03 practice question tests your understanding of design secure architectures. 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.
An application runs on EC2 instances in private subnets in a VPC. There is no NAT gateway. The instances need to download objects from S3 over HTTPS and also call DynamoDB. The security group outbound rules allow TCP 443 to the VPC endpoint addresses. After deployment, the app times out when connecting to S3, but it can reach DynamoDB. Which single change is most likely to restore S3 connectivity?
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.
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 Gateway VPC endpoint for S3 and associate it with the private subnet route tables that contain the instances.
The application is in private subnets without a NAT Gateway, so it cannot reach the internet. A Gateway VPC Endpoint for S3 allows private subnet instances to access S3 over the AWS network without internet connectivity. The security group already allows TCP 443 to the VPC endpoint addresses, so the missing piece is the route table association that directs S3 traffic to the endpoint.
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.
- ✓
Create a Gateway VPC endpoint for S3 and associate it with the private subnet route tables that contain the instances.
Why this is correct
S3 connectivity without NAT typically requires a Gateway VPC endpoint. For a gateway endpoint, you must update the route tables to direct S3 traffic to the endpoint. If DynamoDB works but S3 times out, it often means DynamoDB has the required endpoint while S3 is missing or not routed via the correct route tables.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Replace the security group egress rule to allow all outbound traffic to 0.0.0.0/0 on TCP 443.
Why it's wrong here
Allowing 0.0.0.0/0 does not create a route to the S3 service without NAT. Security groups do not override routing; if traffic is not routed through the S3 VPC endpoint, the connection will still time out.
- ✗
Add an Internet Gateway to the VPC and route the private subnet’s 0.0.0.0/0 to the IGW.
- ✗
Switch from network ACLs to security groups by removing the existing NACL allow rules for ephemeral ports.
Why it's wrong here
If DynamoDB works, NACL rules are likely not the blocker for outbound traffic in general. Also, the primary requirement for reaching S3 without NAT is routing via the S3 endpoint. NACL changes would be unnecessary if endpoint routing is already correct.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often confuse Gateway VPC Endpoints with Interface Endpoints, or assume that allowing outbound HTTPS to 0.0.0.0/0 in a security group is sufficient, forgetting that private subnets have no internet route without a NAT Gateway or Internet Gateway.
Detailed technical explanation
How to think about this question
Gateway VPC Endpoints use prefix lists and route table entries to direct traffic to S3 without leaving the AWS network. The endpoint is horizontally scaled, redundant, and uses the same security group rules as the instances. A common subtlety is that Gateway Endpoints do not support cross-region access or on-premises connectivity via VPN/Direct Connect unless the route tables are explicitly updated.
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.
- →
Design Secure Architectures — study guide chapter
Learn the concepts, then practise the questions
- →
Design Secure Architectures practice questions
Targeted practice on this topic area only
- →
All SAA-C03 questions
1,040 questions across all exam domains
- →
SAA-C03 study guide
Full concept coverage aligned to exam objectives
- →
SAA-C03 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related SAA-C03 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Design Secure Architectures practice questions
Practise SAA-C03 questions linked to Design Secure Architectures.
Design Resilient Architectures practice questions
Practise SAA-C03 questions linked to Design Resilient Architectures.
Design High-Performing Architectures practice questions
Practise SAA-C03 questions linked to Design High-Performing Architectures.
Design Cost-Optimized Architectures practice questions
Practise SAA-C03 questions linked to Design Cost-Optimized Architectures.
SAA-C03 VPC practice questions
Practise SAA-C03 questions linked to SAA-C03 VPC.
SAA-C03 S3 lifecycle policy questions
Practise SAA-C03 questions linked to SAA-C03 S3 lifecycle policy questions.
SAA-C03 RDS Multi-AZ questions
Practise SAA-C03 questions linked to SAA-C03 RDS Multi-AZ questions.
SAA-C03 IAM policy practice questions
Practise SAA-C03 questions linked to SAA-C03 IAM policy.
SAA-C03 Route 53 failover questions
Practise SAA-C03 questions linked to SAA-C03 Route 53 failover questions.
SAA-C03 CloudFront practice questions
Practise SAA-C03 questions linked to SAA-C03 CloudFront.
SAA-C03 NAT gateway questions
Practise SAA-C03 questions linked to SAA-C03 NAT gateway questions.
SAA-C03 VPC endpoint questions
Practise SAA-C03 questions linked to SAA-C03 VPC endpoint questions.
Practice this exam
Start a free SAA-C03 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 SAA-C03 question test?
Design Secure Architectures — This question tests Design Secure Architectures — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Create a Gateway VPC endpoint for S3 and associate it with the private subnet route tables that contain the instances. — The application is in private subnets without a NAT Gateway, so it cannot reach the internet. A Gateway VPC Endpoint for S3 allows private subnet instances to access S3 over the AWS network without internet connectivity. The security group already allows TCP 443 to the VPC endpoint addresses, so the missing piece is the route table association that directs S3 traffic to the endpoint.
What should I do if I get this SAA-C03 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: "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?
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 SAA-C03 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 SAA-C03 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.