On Amazon Web Services (AWS), you can use AWS Resource Access Manager to share AWS Transit Gateway across AWS account boundaries. When you create Transit Gateway attachments across account boundaries, however, the attachments are created without a Name tag. That can make identifying attachments time consuming.
This solution provides an automated mechanism to gather information about each Transit Gateway attachment for accounts within an organization that is managed by AWS Organizations. The process includes looking up the Classless Inter-Domain Routing (CIDR) range from the Transit Gateway route table. The solution then applies a Name tag in the form of <CIDR-range>-<AccountName> to the attachment within the account that holds the transit gateway.
This solution can be used alongside a solution such as the Serverless Transit Network Orchestrator from the AWS Solutions Library. Serverless Transit Network Orchestrator enables the automated creation of Transit Gateway attachments at scale.
