Confused about Direct Connect Quotas

Thank you for your question about Direct Connect quotas. Let me clarify some of the information you've mentioned and provide the correct quotas based on the current AWS documentation.

First, let's address the quotas you've mentioned:

1. It's correct that a dedicated Direct Connect connection can have up to 50 private or public virtual interfaces (VIFs).

2. An AWS Direct Connect gateway can indeed be associated with up to 20 virtual private gateways (VPGWs), each connecting to a single VPC.

3. A Direct Connect gateway can have up to 30 virtual interfaces (private or transit) associated with it.

However, there are some misconceptions in the blog information you've read:

1. The statement about connecting 20 VPCs per Private VIF through a Direct Connect Gateway is not accurate. Each private VIF connects to a single VPC through a virtual private gateway. The Direct Connect Gateway allows you to connect multiple VPCs, but not through a single VIF.

2. The claim about Transit Gateway connecting 10 VPCs per Private VIF is also not correct. When using a Transit Gateway with Direct Connect, you use a Transit VIF, not a Private VIF. A Transit VIF can connect to multiple VPCs through the Transit Gateway, but there isn't a specific limit of 10 VPCs.

Regarding your question about the benefit of using a Direct Connect Gateway despite the apparent reduction in available VIFs:

The main advantage of using a Direct Connect Gateway is not about increasing the number of VIFs, but rather about simplifying and centralizing the management of connections to multiple VPCs, potentially across different regions and even AWS accounts. It allows you to connect to up to 20 VPCs through a single gateway, which can be more efficient and easier to manage than setting up individual connections for each VPC.

Additionally, when you use a Transit Gateway with a Direct Connect Gateway, you gain even more flexibility and scalability. This setup allows you to connect to thousands of VPCs across different regions and accounts, providing a hub-and-spoke model for your network architecture.

In summary, while the number of VIFs may seem reduced when using a Direct Connect Gateway, the benefits in terms of simplified management, scalability, and flexibility often outweigh this limitation for complex network setups.
Sources
AWS Direct Connect endpoints and quotas - AWS General Reference
AWS Direct Connect - Amazon Virtual Private Cloud Connectivity Options
Questions regarding VIFs, Direct Connect Gateway, Transit Gateway | AWS re:Post

Hi Manu,

Transit Gateway is the component to make your traffic from any VPC to any VPC if they are all attached it to. Now you can add some granular control using the routing table to segment which VPC can speak to which VPCs. To connect your Direct Connect to your TGW, you will need Transit VIF. Private VIF is used to connect to your site to one or many VPCs, but these VPCs will not able to communicate with each other directly.