Which solution will meet these requirements MOST cost-effectively?
Create one transit gateway in eu-west-1. Attach the VPCs in us-east-2 and the VPC in eu-west-1 to the transit gateway. Create the necessary route entries in each VPC so that the traffic is routed through the transit gateway.
Create one transit gateway in each Region. Attach the involved subnets to the regional transit gateway. Create the necessary route entries in the associated route tables for each subnet so that the traffic is routed through the regional transit gateway. Peer the two transit gateways.
Create a full mesh VPC peering connection configuration between all the VPCs. Create the necessary route entries in each VPC so that the traffic is routed through the VPC peering connection.
Create one VPC peering connection for each VPC in us-east-2 to the VPC in eu-west-1. Create the necessary route entries in each VPC so that the traffic is routed through the VPC peering connection.
Explanations:
This option suggests a single transit gateway in eu-west-1 that connects both regions. However, it does not provide a direct solution to restrict access only to one specific VPC from the US region, as it could inadvertently allow traffic to all VPCs attached to the transit gateway.
While this option creates a separate transit gateway in each region, it complicates the setup unnecessarily and still does not ensure that only one specific VPC is accessible from the US region without allowing access to others. The peering aspect adds complexity without achieving the requirement.
A full mesh VPC peering setup would create multiple peering connections between all VPCs, leading to potential access to all VPCs instead of isolating the connection to just one. This does not meet the requirement of restricting access.
This option sets up individual VPC peering connections from each VPC in us-east-2 to the specific VPC in eu-west-1. This configuration ensures that only the desired VPC is accessible, maintaining the required isolation while being a cost-effective solution with a straightforward routing setup.
I weigh that the answer is:
Create one VPC peering connection for each VPC in us-east-2 to the VPC in eu-west-1. Create the necessary route entries in each VPC so that the traffic is routed through the VPC peering connection.