A retail company has an on-premises datacenter in Europe and an AWS footprint in eu-west-1 and us-east-1. They need to route on-premises traffic into VPCs in either Region, and support routed traffic directly between VPCs in those Regions. No single network point of failure is allowed. They already have two 1 Gbps Direct Connect links from on-premises to two separate Direct Connect locations in Europe (DX-A and DX-B). Each Region has a single AWS Transit Gateway for intra-Region inter-VPC routing. Which design meets these requirements?

The correct design uses transit VIFs from both Direct Connect links (DX-A and DX-B) into a single Direct Connect gateway. This provides high availability for on-premises connectivity. Associating both the eu-west-1 and us-east-1 Transit Gateways with this Direct Connect gateway allows on-premises traffic to reach VPCs in either region. Finally, peering the two Transit Gateways enables direct, intra-AWS cross-Region routing between VPCs. Incorrect options: Using private VIFs is incorrect because they only support a single VPC per VIF, not multiple VPCs via a Transit Gateway. Creating separate Direct Connect gateways for each Transit Gateway and then peering the Direct Connect gateways is not the standard or most efficient way to achieve cross-region Transit Gateway routing. Transit Gateway peering is designed for this. Configuring the Direct Connect gateway to route traffic between Transit Gateways is not a supported feature; Direct Connect gateways connect to Transit Gateways, but Transit Gateway peering handles inter-region routing between them.