When to Use Transit VIF vs. Private VIF with AWS Transit Gateway and Direct Connect?

Answer: Great question! The choice between using a Transit Virtual Interface (VIF) and a Private VIF with AWS Transit Gateway and Direct Connect depends on the specific requirements and architecture of your network. Transit VIF: Use Case: Transit VIF is primarily used when you want to connect multiple VPCs across different AWS Regions and on-premises networks through a single Direct Connect connection. Scalability: It simplifies the management of multiple connections by allowing you to use a single connection to the Transit Gateway, which then routes traffic to various VPCs. Example Scenario: If you have a global infrastructure with multiple VPCs spread across different regions and you need to manage these connections centrally, Transit VIF would be the appropriate choice. This is especially useful for organizations with a hub-and-spoke network topology. *Private VIF: Use Case: Private VIF is used for connecting to a specific VPC within a single region. Direct Connection: It provides a direct, dedicated network connection between your on-premises network and a single VPC. Example Scenario: If you have a single VPC or a limited number of VPCs within a single region that require a dedicated and private connection to your on-premises network, using a Private VIF makes sense. This setup is simpler and more cost-effective for fewer connections. *Summary: Transit VIF: Best for large, multi-region setups where centralized management is key. Private VIF: Ideal for single-region, single-VPC connections. For more detailed information, you can refer to this AWS article: AWS Direct Connect User Guide: Types of Virtual Interfaces