- A
Place the ALB in a private subnet and use a Transit Gateway.
Correct. Placing the ALB in a private subnet keeps it internal, and using a Transit Gateway allows the VPN to route traffic to private subnets efficiently.
- B
Place the ALB in a public subnet.
Why wrong: Incorrect. Placing the ALB in a public subnet would expose it to the internet, which is not required and could introduce security risks. The ALB can be accessed via VPN while in a private subnet.
- C
Configure the network ACL on the ALB's subnet to allow inbound traffic from the on-premises CIDR range.
Correct. The network ACL at the subnet level provides a stateless firewall to restrict inbound traffic to the on-premises CIDR.
- D
Configure the ALB security group to allow inbound traffic from the on-premises CIDR range.
Correct. The security group on the ALB provides stateful filtering to allow inbound traffic only from the on-premises CIDR.
- E
Create a NAT gateway in the public subnet for outbound traffic.
Why wrong: Incorrect. A NAT gateway is used for outbound traffic from private subnets to the internet, not for restricting inbound traffic from on-premises.
ANS-C01 Application Load Balancer (ALB) Practice Question
This ANS-C01 practice question tests your understanding of network design. 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. A key principle to apply: application Load Balancer (ALB). 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 deploying a new application in a VPC. The application consists of EC2 instances in an Auto Scaling group behind an Application Load Balancer (ALB). The ALB must only receive traffic from the company's on-premises network via an AWS Site-to-Site VPN. Which THREE steps should the network engineer take to meet this requirement?
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
Place the ALB in a private subnet and use a Transit Gateway.
To restrict ALB traffic exclusively to the on-premises network via Site-to-Site VPN, three steps are needed. First, place the ALB in a private subnet to keep it internal and use a Transit Gateway to route VPN traffic to private subnets. Second, configure the network ACL on the ALB's subnet to allow inbound traffic only from the on-premises CIDR. Third, configure the ALB's security group to allow inbound traffic from the same CIDR. Option B (public subnet) is incorrect because it would make the ALB internet-facing, which is unnecessary and less secure. Option E (NAT gateway) is irrelevant for inbound traffic restriction.
Key principle: Application Load Balancer (ALB)
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Place the ALB in a private subnet and use a Transit Gateway.
Why this is correct
Correct. Placing the ALB in a private subnet keeps it internal, and using a Transit Gateway allows the VPN to route traffic to private subnets efficiently.
Related concept
Application Load Balancer (ALB)
- ✗
Place the ALB in a public subnet.
Why it's wrong here
Incorrect. Placing the ALB in a public subnet would expose it to the internet, which is not required and could introduce security risks. The ALB can be accessed via VPN while in a private subnet.
- ✓
Configure the network ACL on the ALB's subnet to allow inbound traffic from the on-premises CIDR range.
Why this is correct
Correct. The network ACL at the subnet level provides a stateless firewall to restrict inbound traffic to the on-premises CIDR.
Related concept
Application Load Balancer (ALB)
- ✓
Configure the ALB security group to allow inbound traffic from the on-premises CIDR range.
Why this is correct
Correct. The security group on the ALB provides stateful filtering to allow inbound traffic only from the on-premises CIDR.
Related concept
Application Load Balancer (ALB)
- ✗
Create a NAT gateway in the public subnet for outbound traffic.
Common exam traps
Common exam trap: answer the scenario, not the keyword
A common misconception is that an ALB must be placed in a public subnet to be reachable via a Site-to-Site VPN. However, by using a Transit Gateway, the ALB can remain in a private subnet while still receiving traffic from the on-premises network. Security must be enforced at both the network ACL and security group levels.
Detailed technical explanation
How to think about this question
An ALB in a public subnet requires a route table entry pointing to the internet gateway (or virtual private gateway for VPN traffic) for inbound traffic. The ALB's security group and network ACL must explicitly allow the on-premises CIDR range, as the VPN tunnel encapsulates traffic with the on-premises source IP. Under the hood, the ALB's elastic network interface (ENI) in the public subnet uses the VPC's route table to direct return traffic back through the VPN, ensuring symmetric routing.
KKey Concepts to Remember
- Application Load Balancer (ALB)
- Site-to-Site VPN
- Network Access Control List (NACL)
- Security Group
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
Application Load Balancer (ALB)
Real-world example
How this comes up in practice
A healthcare organisation deploys an application with a public-facing web tier and a private database tier. The database subnet has no public IP and only accepts connections from the web tier's security group. Questions like this test whether you can design cloud network isolation using VNets/VPCs, subnets, and security group rules.
Visual reference
What to study next
Got this wrong? Here's your next step.
Review application Load Balancer (ALB), then practise related ANS-C01 questions on the same topic to reinforce the concept.
- →
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 — Application Load Balancer (ALB).
What is the correct answer to this question?
The correct answer is: Place the ALB in a private subnet and use a Transit Gateway. — To restrict ALB traffic exclusively to the on-premises network via Site-to-Site VPN, three steps are needed. First, place the ALB in a private subnet to keep it internal and use a Transit Gateway to route VPN traffic to private subnets. Second, configure the network ACL on the ALB's subnet to allow inbound traffic only from the on-premises CIDR. Third, configure the ALB's security group to allow inbound traffic from the same CIDR. Option B (public subnet) is incorrect because it would make the ALB internet-facing, which is unnecessary and less secure. Option E (NAT gateway) is irrelevant for inbound traffic restriction.
What should I do if I get this ANS-C01 question wrong?
Review application Load Balancer (ALB), then practise related ANS-C01 questions on the same topic to reinforce the concept.
What is the key concept behind this question?
Application Load Balancer (ALB)
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 →
Keep practising
More ANS-C01 practice questions
- A financial services company has a VPC with a public subnet and a private subnet. EC2 instances in the private subnet ne…
- A company is designing a network security architecture for a multi-account environment using AWS Transit Gateway. The se…
- A company is using AWS Direct Connect to connect its on-premises network to AWS. The company wants to encrypt all traffi…
- A company uses AWS Transit Gateway to connect multiple VPCs and on-premises networks via AWS Site-to-Site VPN. The secur…
- A company runs a web application on EC2 instances behind an Application Load Balancer (ALB). The application must be acc…
- A global e-commerce company uses a hub-and-spoke network topology with a transit VPC in us-east-1. Each spoke VPC has an…
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.