ANS-C01 Question 423
Select 2You are designing a VPC architecture for a high-traffic web application hosted on AWS. The application requires public subnets for the web servers and private subnets for the database servers. To optimize the performance and scalability of the architecture, which actions should you take when configuring your subnets?
- A
Assign separate subnets for different Availability Zones to increase fault tolerance.
- B
Use the maximum CIDR block size (e.g., /16) for all subnets to ensure enough IP addresses are available.
- C
Configure NAT Gateways in multiple Availability Zones for private subnets to ensure high availability.
- D
Place all web servers and database servers in the same subnet to simplify routing.
- E
Use smaller CIDR blocks (e.g., /28) for private subnets to minimize wasted IP addresses.
Show answer and explanation
Correct answers: A, C
Explanation
To optimize VPC subnet configuration for performance and scalability, it's essential to distribute subnets across multiple Availability Zones for fault tolerance and high availability. Configuring NAT Gateways in multiple zones ensures private subnets remain operational even during zone failures. These practices follow AWS best practices for designing highly available and resilient network architectures.
- A. Correct.
Assigning separate subnets for different Availability Zones increases fault tolerance by distributing resources across multiple zones, which is a best practice for high availability and resilience.
- B. Incorrect.
Using the maximum CIDR block size for subnets can lead to inefficient IP address utilization, especially in smaller or segmented architectures. Subnets should be sized based on actual requirements.
- C. Correct.
Configuring NAT Gateways in multiple Availability Zones ensures that private subnets can maintain internet connectivity if one NAT Gateway or its associated Availability Zone fails.
- D. Incorrect.
Placing all web servers and database servers in the same subnet violates security best practices. Public and private resources should be kept in separate subnets to control access and secure sensitive data.
- E. Incorrect.
Using very small CIDR blocks (e.g., /28) can result in insufficient IP addresses for scaling resources, especially in private subnets that host multiple services or instances.