Answer: Use AWS Transit Gateway to manage VPC communication in a single Region and Transit Gateway peering across Regions to manage VPC communications.

## Explanation **Correct Answer: C** - Use AWS Transit Gateway to manage VPC communication in a single Region and Transit Gateway peering across Regions to manage VPC communications. ### Why Option C is Correct: 1. **Transit Gateway** provides a hub-and-spoke model for connecting multiple VPCs within a single region, which simplifies network management compared to VPC peering. 2. **Transit Gateway Peering** allows you to connect Transit Gateways across different AWS regions, enabling inter-region VPC communication. 3. This solution requires the **LEAST administrative effort** because: - You only need to create one Transit Gateway per region - All VPCs in a region attach to their regional Transit Gateway - You create a single peering connection between Transit Gateways in different regions - This scales much better than managing multiple point-to-point connections ### Why Other Options are Incorrect: **Option A (VPC Peering):** - VPC peering is point-to-point and doesn't scale well - You would need to create peering connections between every VPC pair (n*(n-1)/2 connections) - This becomes unmanageable with many VPCs across multiple regions - High administrative overhead **Option B (AWS Direct Connect Gateways):** - Direct Connect is primarily for connecting on-premises networks to AWS - Not designed for VPC-to-VPC communication across regions - More complex and expensive than necessary for this use case - Requires physical connections to AWS Direct Connect locations **Option D (AWS PrivateLink):** - PrivateLink is designed for secure access to services across VPCs - Not designed for full VPC-to-VPC communication - Typically used for exposing services to other VPCs, not for general network connectivity - Would require multiple endpoints and complex routing configurations ### Key AWS Concepts: - **AWS Transit Gateway**: Central network hub that simplifies network architecture - **Transit Gateway Peering**: Connects Transit Gateways across regions - **VPC Peering**: Direct connection between two VPCs (point-to-point) - **AWS Direct Connect**: Dedicated network connection from on-premises to AWS - **AWS PrivateLink**: Private connectivity to services without exposing them to the internet This solution provides the most scalable and manageable approach for connecting multiple VPCs across multiple AWS regions with minimal administrative overhead.

Author: LeetQuiz Editorial Team