What is AWS Direct Connect Gateway?
Simply put, AWS Direct Connect Gateway allows connectivity to VPCs across multiple Regions. You can create Direct Connect Gateway in any Region, and then access it from any other Region.
It solves couple of key problems (that existed before AWS Direct Connect Gateway was announced):
- You cannot connect a Private VIF to any VPC that is outside the Home Region of the associated Direct Connect.
- You need multiple BGP sessions when you connect Direct Connect (Private VIFs) to multiple VPCs.
How Direct Connect Gateway addresses constraint #1 to extend reach to external Regions (outside Home Region):
(Image courtesy of AWS re:Invent slides)
How Direct Connect Gateway simplifies scenario #2:
(Image courtesy of AWS re:Invent slides)
Additionally, you can connect AWS Direct Connect Gateway directly to a Transit Gateway and thus extend the connectivity reach to all VPCs that are connected to that Transit Gateway.
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