How is VPC attached to TGW from a different account?

Question

If account A does not have TGW, can account A attach VPC to account B's TGW ?

thanks a lot !!

Accepted Answer

Hello.

A TransitGateway created in account B needs to be shared to account A using RAM.  
If you create a TransitGateway attachment in account A after sharing TransitGateway, account A's VPC and account B's VPC will be able to communicate.  
https://repost.aws/knowledge-center/transit-gateway-sharing  
https://docs.aws.amazon.com/vpc/latest/tgw/transit-gateway-share.html

Answer

thanks so much for coaching on this.

Answer

Account A cannot directly attach its VPC to Account B's transit gateway (TGW). However, Account B, which owns the transit gateway, can share it with account A using AWS Resource Access Manager (RAM). This allows account A to attach its VPC to the shared TGW. The key steps are:

1. Account B enables resource sharing in AWS Organizations
2. Account B creates a resource share in Resource Access Manager (RAM) and shares the TGW with account A
3. Account A accepts the resource share invitation
4. Account A accepts the resource share invitation

Hope this clarified your query.

How is VPC attached to TGW from a different account?

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