AWS Certified Solutions Architect – Associate (SAA-C03) — Question 564

A company has two VPCs that are located in the us-west-2 Region within the same AWS account. The company needs to allow network traffic between these VPCs. Approximately 500 GB of data transfer will occur between the VPCs each month.

What is the MOST cost-effective solution to connect these VPCs?

Answer options

• A. Implement AWS Transit Gateway to connect the VPCs. Update the route tables of each VPC to use the transit gateway for inter-VPC communication.
• B. Implement an AWS Site-to-Site VPN tunnel between the VPCs. Update the route tables of each VPC to use the VPN tunnel for inter-VPC communication.
• C. Set up a VPC peering connection between the VPCs. Update the route tables of each VPC to use the VPC peering connection for inter-VPC communication.
• D. Set up a 1 GB AWS Direct Connect connection between the VPCs. Update the route tables of each VPC to use the Direct Connect connection for inter-VPC communication.

Correct answer: C

Explanation

VPC peering is the most cost-effective option because it does not incur any hourly setup or connection fees, charging only for data transfer. Other solutions like AWS Transit Gateway and AWS Site-to-Site VPN incur ongoing hourly charges per attachment or connection, which would be more expensive for a 500 GB monthly transfer volume. AWS Direct Connect is designed for hybrid cloud connectivity and carries high fixed costs, making it highly uneconomical for simple intra-region VPC-to-VPC routing.