Run CloudFormation template 4.tgw-vpcs.yaml to deploy the VPC in the Same Region as the other accounts Transit Gateway was built in.
note: this should be done in another account. not in the Account with the TGW.
In the AWS Management Console change to the region the VPCs and Transit Gateway were created IN THE OTHER ACCOUNT. This is in the upper right-hand drop-down menu. note: Today, AWS Transit Gateway can only attach to VPCs in the same region as the Transit Gateway. There are architectures that allow for a multi-region design, for example using VPN and a Transit VPC. This is out of scope for this lab.
Click on the CloudFormation Launch link below that corresponds to the AWS Region in which your partner deployed their Transit Gateway.
For the Specify stack details give the stack a name and Select two Availability Zones (AZs) to deploy to. We will be deploying all of the VPCs in the same AZs, but that is not required by AWS Transit Gateway. Click Next.
For Configuration stack options we don’t need to change anything, so just click Next in the bottom right.
Scroll down to the bottom of the Review name_of_your_stack and check the I acknowledge that AWS CloudFormation might create IAM resources with custom names. Click the Create button in the lower right.
Wait for the Stack to show Create_Complete.