- A
Attach an Internet Gateway to the VPC and configure route tables for the private subnets.
Why wrong: An Internet Gateway provides internet access, not needed for internal communication.
- B
Place the Fargate tasks in public subnets to allow them to communicate with each other through the internet gateway.
Why wrong: Public subnets and internet gateway expose services to the internet.
- C
Use AWS Cloud Map for service discovery and register a public DNS name for each service.
Why wrong: Public DNS would make services accessible from the internet.
- D
Use an internal Application Load Balancer to distribute traffic between services.
Internal ALB routes traffic within the VPC.
- E
Create a VPC endpoint for Amazon ECS to allow the service to call the ECS API without internet access.
VPC endpoints keep API traffic within the VPC.
Quick Answer
The correct answer involves two steps: deploying an internal Application Load Balancer (ALB) within the VPC and creating a VPC endpoint for Amazon ECS. An internal ALB ensures that traffic between microservices remains private by operating entirely within the VPC, never exposing a public endpoint, while the VPC endpoint allows Fargate tasks to call the ECS API without traversing the internet, preserving a fully private communication path. On the AWS Certified SAP on AWS Specialty PAS-C01 exam, this scenario tests your understanding of how to secure microservices communication within a VPC using ECS Fargate, often appearing as a trap where candidates mistakenly choose a public-facing ALB or an internet gateway. The key is remembering that internal traffic requires both a private load balancer and API endpoints that bypass the public internet. Memory tip: think “Internal ALB + VPC Endpoint = No Internet, No Exposure.”
PAS-C01 Technology Practice Question
This PAS-C01 practice question tests your understanding of technology. 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 is designing a microservices architecture on Amazon ECS with Fargate. The services need to communicate securely and be accessible only within the VPC. Which TWO steps should the solutions architect take to meet these requirements? (Choose TWO.)
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
Use an internal Application Load Balancer to distribute traffic between services.
Option D is correct because an internal Application Load Balancer (ALB) operates within a VPC and does not expose a public endpoint, ensuring that traffic between microservices remains private. It distributes incoming requests to Fargate tasks based on defined rules, enabling secure, internal communication without internet access.
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.
- ✗
Attach an Internet Gateway to the VPC and configure route tables for the private subnets.
Why it's wrong here
An Internet Gateway provides internet access, not needed for internal communication.
- ✗
Place the Fargate tasks in public subnets to allow them to communicate with each other through the internet gateway.
Why it's wrong here
Public subnets and internet gateway expose services to the internet.
- ✗
Use AWS Cloud Map for service discovery and register a public DNS name for each service.
Why it's wrong here
Public DNS would make services accessible from the internet.
- ✓
Use an internal Application Load Balancer to distribute traffic between services.
Why this is correct
Internal ALB routes traffic within the VPC.
Related concept
Read the scenario before looking for a memorised answer.
- ✓
Create a VPC endpoint for Amazon ECS to allow the service to call the ECS API without internet access.
Why this is correct
VPC endpoints keep API traffic within the VPC.
Related concept
Read the scenario before looking for a memorised answer.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often confuse public subnets with the ability to communicate privately, or assume that an internet gateway is required for any inter-service communication, when in fact internal load balancers and VPC endpoints provide fully private connectivity.
Detailed technical explanation
How to think about this question
An internal ALB uses private IP addresses and is only reachable from within the VPC, leveraging VPC routing to direct traffic without traversing the internet. VPC endpoints for Amazon ECS use AWS PrivateLink to provide private connectivity between the VPC and the ECS control plane, eliminating the need for an internet gateway or NAT device for API calls. This setup ensures that all service discovery and traffic remain within the AWS network, enhancing security and reducing latency.
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 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.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
- →
Technology — study guide chapter
Learn the concepts, then practise the questions
- →
Technology practice questions
Targeted practice on this topic area only
- →
All PAS-C01 questions
1,733 questions across all exam domains
- →
AWS Certified SAP on AWS Specialty PAS-C01 study guide
Full concept coverage aligned to exam objectives
- →
PAS-C01 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related PAS-C01 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Design of SAP Workloads on AWS practice questions
Practise PAS-C01 questions linked to Design of SAP Workloads on AWS.
Technology practice questions
Practise PAS-C01 questions linked to Technology.
Migration practice questions
Practise PAS-C01 questions linked to Migration.
Operations and Maintenance practice questions
Practise PAS-C01 questions linked to Operations and Maintenance.
PAS-C01 fundamentals practice questions
Practise PAS-C01 questions linked to PAS-C01 fundamentals.
PAS-C01 scenario practice questions
Practise PAS-C01 questions linked to PAS-C01 scenario.
PAS-C01 troubleshooting practice questions
Practise PAS-C01 questions linked to PAS-C01 troubleshooting.
Practice this exam
Start a free PAS-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 PAS-C01 question test?
Technology — This question tests Technology — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Use an internal Application Load Balancer to distribute traffic between services. — Option D is correct because an internal Application Load Balancer (ALB) operates within a VPC and does not expose a public endpoint, ensuring that traffic between microservices remains private. It distributes incoming requests to Fargate tasks based on defined rules, enabling secure, internal communication without internet access.
What should I do if I get this PAS-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 →
Last reviewed: Jun 11, 2026
This PAS-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 PAS-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.