Question #1577
A company has two VPCs located in the us-east-1 Region within the same AWS account. The company needs to enable network communication between these VPCs, with approximately 600 GB of data transfer occurring between them monthly.
What is the MOST cost-effective solution to establish connectivity between these VPCs?
Deploy AWS Transit Gateway to interconnect the VPCs. Modify the route tables of each VPC to route inter-VPC traffic through the Transit Gateway.
Configure an AWS Site-to-Site VPN connection between the VPCs. Update the route tables of each VPC to direct traffic via the VPN tunnel for inter-VPC communication.
Establish a VPC peering connection between the VPCs. Adjust the route tables of each VPC to route traffic through the VPC peering connection.
Provision a 1 Gbps AWS Direct Connect link between the VPCs. Update the route tables of each VPC to utilize the Direct Connect connection for inter-VPC traffic.
Explanation
The correct answer is C because VPC peering provides a direct, private connection between two VPCs in the same region without requiring additional infrastructure like VPN gateways, Transit Gateway attachments, or Direct Connect links.
- Option A (Transit Gateway) incurs costs for hourly attachments ($0.05/hour per VPC) and data processing ($0.02/GB), making it more expensive for two VPCs.
- Option B (Site-to-Site VPN) involves VPN hourly costs and data transfer fees over the public internet, which is less efficient and costlier than peering.
- Option D (Direct Connect) is designed for on-premises-to-AWS connectivity, not inter-VPC communication, and requires expensive dedicated links.
VPC peering charges only for data transfer ($0.01/GB in each direction), totaling ~$12/month for 600 GB, making it the most cost-effective choice. Key takeaway: Use VPC peering for simple, low-cost inter-VPC connectivity within the same region.
Answer
The correct answer is: C