- A
Use a VPN connection from the web tier to the application tier, and place both tiers in private subnets.
Why wrong: VPN does not provide internet access to the web tier.
- B
Place both tiers in public subnets and use security groups to restrict traffic from the web tier to the application tier.
Public subnets expose both tiers to the internet, increasing attack surface.
- C
Place web servers in a public subnet with a NAT gateway, and application servers in a private subnet with a default route to the NAT gateway.
Why wrong: NAT gateway only provides outbound internet access, not inbound.
- D
Place web servers in a public subnet with an internet gateway, and application servers in a private subnet with a route to the web subnet via a VPC peering connection.
Why wrong: Correct design for inbound internet access to web tier and internal access to app tier.
VPC Peering for Tier Isolation
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: public subnet. 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 multi-tier web application running on EC2 instances in a VPC. The web tier must be accessible from the internet, but the application tier should only be accessible from the web tier. Which network design configuration meets these requirements?
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 both tiers in public subnets and use security groups to restrict traffic from the web tier to the application tier.
Option B is correct because placing both tiers in public subnets with an internet gateway allows the web tier to be accessible from the internet. Security groups can then be used to restrict inbound traffic to the application tier to only come from the web tier's security group, ensuring that the application tier is not directly accessible from the internet. This design meets the requirement without unnecessary complexity.
Key principle: Public subnet
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Use a VPN connection from the web tier to the application tier, and place both tiers in private subnets.
Why it's wrong here
VPN does not provide internet access to the web tier.
- ✓
Place both tiers in public subnets and use security groups to restrict traffic from the web tier to the application tier.
Why this is correct
Public subnets expose both tiers to the internet, increasing attack surface.
Related concept
Public subnet
- ✗
Place web servers in a public subnet with a NAT gateway, and application servers in a private subnet with a default route to the NAT gateway.
- ✗
Place web servers in a public subnet with an internet gateway, and application servers in a private subnet with a route to the web subnet via a VPC peering connection.
Why it's wrong here
Correct design for inbound internet access to web tier and internal access to app tier.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap is that candidates may think a private subnet is required for the application tier, but security groups can provide sufficient isolation even in public subnets. Alternatively, they may incorrectly choose D because it mentions a private subnet, not realizing that VPC peering is for connecting separate VPCs, not subnets within the same VPC.
Detailed technical explanation
How to think about this question
VPC peering connects two VPCs using the AWS global network, allowing private IP communication without gateways or VPNs. In this design, the web tier's security group must allow inbound HTTP/HTTPS (ports 80/443) from the internet, and the application tier's security group must allow inbound traffic only from the web tier's security group or CIDR. A subtle behavior is that VPC peering does not support transitive routing, so each tier must be in a separate VPC or use explicit routes; if both tiers were in the same VPC, a simpler solution would be to use private subnets with a route to a NAT gateway for outbound access, but the question implies separate VPCs via peering.
KKey Concepts to Remember
- Public subnet
- Security group
- Internet gateway
- Multi-tier architecture
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
Public subnet
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.
Visual reference
What to study next
Got this wrong? Here's your next step.
Review public subnet, 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 — Public subnet.
What is the correct answer to this question?
The correct answer is: Place both tiers in public subnets and use security groups to restrict traffic from the web tier to the application tier. — Option B is correct because placing both tiers in public subnets with an internet gateway allows the web tier to be accessible from the internet. Security groups can then be used to restrict inbound traffic to the application tier to only come from the web tier's security group, ensuring that the application tier is not directly accessible from the internet. This design meets the requirement without unnecessary complexity.
What should I do if I get this ANS-C01 question wrong?
Review public subnet, then practise related ANS-C01 questions on the same topic to reinforce the concept.
What is the key concept behind this question?
Public subnet
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: Jul 4, 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.