A company stores test data in multiple on-premises locations and needs to connect those locations to VPCs in an AWS Region. The number of accounts and VPCs will increase over the next year. The network design must simplify administration of new connections and scale. Which solution meets these requirements with the LEAST administrative overhead?

A transit gateway is the most scalable and administratively efficient solution for connecting multiple VPCs and on-premises networks. It acts as a central hub, simplifying network architecture as the number of VPCs and on-premises locations grows. VPC attachments connect the VPCs, and VPN attachments connect the on-premises locations to the transit gateway. Creating peering connections between all VPCs becomes administratively complex and difficult to scale (N(N-1)/2 connections) as the number of VPCs increases. Using an EC2 instance with VPN software introduces a single point of failure and requires managing the instance and software. AWS Direct Connect to a central VPC with peering to others is less flexible and scalable than a transit gateway for a growing number of VPCs and on-premises sites, as the central VPC can become a bottleneck.