- A
Place web and app tiers in public subnets, database in private subnet.
Why wrong: App tier does not need internet access.
- B
Place web tier in public subnets, app and database tiers in private subnets.
This isolates app and database from internet.
- C
Place all tiers in private subnets and use a VPN for external access.
Why wrong: Web tier needs internet access.
- D
Place all tiers in public subnets with security groups restricting access.
Why wrong: Public subnets have direct internet access.
Question 500 of 1,748
VPC Subnet Design: Public Web, Private App and Database
This SCS-C02 practice question tests your understanding of infrastructure security. 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. 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 security engineer is designing a network architecture for a three-tier web application. The web tier must be accessible from the internet, but the application and database tiers must not. Which VPC configuration should be used?
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 web tier in public subnets, app and database tiers in private subnets.
Option B is correct because it places the web tier in public subnets with an internet gateway for direct internet access, while the application and database tiers reside in private subnets with no direct internet route. This ensures that only the web tier is exposed, and the app and database tiers can only be reached through the web tier via internal routing, aligning with the principle of least privilege for a three-tier architecture.
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.
- ✗
Place web and app tiers in public subnets, database in private subnet.
Why it's wrong here
App tier does not need internet access.
- ✓
Place web tier in public subnets, app and database tiers in private subnets.
Why this is correct
This isolates app and database from internet.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Place all tiers in private subnets and use a VPN for external access.
Why it's wrong here
Web tier needs internet access.
- ✗
Place all tiers in public subnets with security groups restricting access.
Why it's wrong here
Public subnets have direct internet access.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often confuse security groups with subnet routing, assuming that restrictive security groups alone can prevent internet access even when the subnet is public, but the route table's default route to an internet gateway still allows inbound traffic from the internet.
Detailed technical explanation
How to think about this question
In a VPC, public subnets have a route table entry pointing to an internet gateway (0.0.0.0/0 -> igw-id), while private subnets route traffic through a NAT gateway or virtual private gateway for outbound-only access. The app tier in a private subnet can initiate outbound connections to the internet via a NAT gateway for updates, but inbound connections are blocked unless routed through a load balancer in a public subnet. This design leverages network ACLs and security groups as stateful firewalls, but the subnet's route table is the primary control for internet accessibility.
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.
Visual reference
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.
- →
Infrastructure Security — study guide chapter
Learn the concepts, then practise the questions
- →
Infrastructure Security practice questions
Targeted practice on this topic area only
- →
All SCS-C02 questions
1,748 questions across all exam domains
- →
AWS Certified Security Specialty SCS-C02 study guide
Full concept coverage aligned to exam objectives
- →
SCS-C02 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related SCS-C02 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Threat Detection and Incident Response practice questions
Practise SCS-C02 questions linked to Threat Detection and Incident Response.
Security Logging and Monitoring practice questions
Practise SCS-C02 questions linked to Security Logging and Monitoring.
Identity and Access Management practice questions
Practise SCS-C02 questions linked to Identity and Access Management.
Management and Security Governance practice questions
Practise SCS-C02 questions linked to Management and Security Governance.
Infrastructure Security practice questions
Practise SCS-C02 questions linked to Infrastructure Security.
Data Protection practice questions
Practise SCS-C02 questions linked to Data Protection.
SCS-C02 fundamentals practice questions
Practise SCS-C02 questions linked to SCS-C02 fundamentals.
SCS-C02 scenario practice questions
Practise SCS-C02 questions linked to SCS-C02 scenario.
SCS-C02 troubleshooting practice questions
Practise SCS-C02 questions linked to SCS-C02 troubleshooting.
Practice this exam
Start a free SCS-C02 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 SCS-C02 question test?
Infrastructure Security — This question tests Infrastructure Security — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Place web tier in public subnets, app and database tiers in private subnets. — Option B is correct because it places the web tier in public subnets with an internet gateway for direct internet access, while the application and database tiers reside in private subnets with no direct internet route. This ensures that only the web tier is exposed, and the app and database tiers can only be reached through the web tier via internal routing, aligning with the principle of least privilege for a three-tier architecture.
What should I do if I get this SCS-C02 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 →
Same concept, more angles
1 more ways this is tested on SCS-C02
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A security engineer is designing a network architecture for a web application that must be highly available and secure. The application uses an Application Load Balancer (ALB) in front of EC2 instances. Which architecture meets these requirements?
medium- A.Place both the ALB and EC2 instances in private subnets across two Availability Zones.
- B.Place the ALB in private subnets and EC2 instances in public subnets across two Availability Zones.
- ✓ C.Place the ALB in public subnets and EC2 instances in private subnets across two Availability Zones.
- D.Place both the ALB and EC2 instances in public subnets across two Availability Zones.
Why C: The correct architecture places the ALB in public subnets so it can receive internet traffic, while EC2 instances reside in private subnets for enhanced security. The ALB acts as a reverse proxy, terminating client connections and forwarding requests to the instances over private IPs, which prevents direct internet access to the instances. Deploying across two Availability Zones ensures high availability by surviving an AZ failure.
Keep practising
More SCS-C02 practice questions
- A company uses AWS Organizations with multiple accounts. The security team wants to enforce that all Amazon S3 buckets a…
- A company is designing a multi-tier web application on AWS. The web tier must be accessible from the internet, but the a…
- A company is migrating a legacy application to AWS. The application requires two-way communication between the web serve…
- A security engineer is troubleshooting connectivity issues between an Amazon EC2 instance in a VPC and an on-premises se…
- A security engineer is reviewing the SQS queue policy shown in the exhibit. The queue is subscribed to an SNS topic in t…
- A company uses AWS Organizations with multiple accounts. The security team wants to ensure that all IAM users in the pro…
Last reviewed: Jul 4, 2026
This SCS-C02 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 SCS-C02 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.