Create a central egress VPC that has private NAT gateways. Connect all the VPCs to the central egress VPC by using AWS Transit Gateway. Use the private NAT gateways to connect to Amazon S3 and Systems Manager by using private IP addresses.

Create a central shared services VPC. In the central shared services VPC, create interface VPC endpoints for Amazon S3 and Systems Manager to access. Ensure that private DNS is turned off. Connect all the VPCs to the central shared services VPC by using AWS Transit Gateway. Create an Amazon Route 53 forwarding rule for each interface VPC endpoint. Associate the forwarding rules with all the VPCs. Forward DNS queries to the interface VPC endpoints in the shared services VPC.

Create a central shared services VPIn the central shared services VPC, create interface VPC endpoints for Amazon S3 and Systems Manager to access. Ensure that private DNS is turned off. Connect all the VPCs to the central shared services VPC by using AWS Transit Gateway. Create an Amazon Route 53 private hosted zone with a full service endpoint name for Amazon S3 and Systems Manager. Associate the private hosted zones with all the VPCs. Create an alias record in each private hosted zone with the full AWS service endpoint pointing to the interface VPC endpoint in the shared services VPC.

Create a central shared services VPC. In the central shared services VPC, create interface VPC endpoints for Amazon S3 and Systems Manager to access. Connect all the VPCs to the central shared services VPC by using AWS Transit Gateway. Ensure that private DNS is turned on for the interface VPC endpoints and that the transit gateway is created with DNS support turned on.