Introducing security group referencing for AWS Transit Gateway

This article introduces a new feature for AWS Transit Gateway: security group referencing. This feature allows you to create inbound security rules that reference security groups defined in other Amazon Virtual Private Clouds (Amazon VPCs) attached to the same transit gateway within the same AWS Region.

Specifically, the article covers:

• Getting started with enabling/disabling security group referencing at the Transit Gateway level and the Transit Gateway VPC attachment level
• Several use cases where security group referencing can enhance security and streamline access control across multiple VPCs:
  • Resource sharing between application tiers across different VPCs
  • Enhancing access to a centralized shared services VPC
  • Resource sharing in a shared VPC model across different AWS accounts
• Considerations and limitations of the security group referencing feature

This new feature provides a convenient way to strengthen security access controls on resources across Transit Gateway and facilitates migration from VPC peering to Transit Gateway.