Transit Gateway attachment cost to VPC and subnets
As per https://aws.amazon.com/transit-gateway/pricing/ "Price per AWS Transit Gateway attachment" i.e. 5 or 7c /hr
https://docs.aws.amazon.com/vpc/latest/tgw/tgw-vpc-attachments.html "When you attach a VPC to a transit gateway, you must specify one subnet from each Availability Zone to be used by the transit gateway to route traffic. Specifying one subnet from an Availability Zone enables traffic to reach resources in every subnet in that Availability Zone."
Does this mean for a VPC with 3 AZs/Subnets , customers would pay 3 x 7 = 21 c/hr for a VPC ?
The TGW attachment (tgw-attach-xxxxxxxxx) irrespective of the number of AZs for which it is configured is charged on the unique attachment id not the individual AZs. So no difference if you have 1AZ versus when you have 3AZs.
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