Connectivity Setup for Transit Gateway and Direct Connect (DX) Gateway with VPC Attachments


We have a Transit Gateway (Tgw) route table that contains associated and propagated routes. The resource type specified in this context is VPC (Virtual Private Cloud).

Next, I have associated the Transit Gateway to the Direct Connect (DX) gateway, using the VPC IP CIDR in the allowed prefix list( advertising to on prem) . This action created the attachment between the Transit Gateway and the DX gateway. However, the association route table ID is not specified, and the association state is currently blank, indicating that there is no active association.

Furthermore, I have created one route table (rtb) for this VPC. In the routes section of this route table, I can observe my VPC CIDR range with the Transit Gateway attachment, where the resource type is marked as VPC.

Now, the question arises: Do I need to associate the DX gateway attachment and create propagation pointing towards my DX gateway attachment in the route table in order to establish connectivity?

Please advise

Ali Md
asked 10 months ago409 views
1 Answer
Accepted Answer

When you associate TGW with a DXGW it would have created the Direct Connect Gateway attachment as you said. You can now 'propagate' the Direct Connect Gateway attachment into the TGW route table, that should install the routes learned via DX from on-premises into that TGW route table.

profile pictureAWS
answered 10 months ago
profile picture
reviewed 2 days ago
profile pictureAWS
reviewed 10 months ago
  • Thanks Tushar! Got it! Do I also need to associate DXGW attachment in the TGW route table ?

  • You dont need to, when you associate TGW to DXGW in Direct Connect console and propagate the DXGW attachment in the route table association happens on its own.

You are not logged in. Log in to post an answer.

A good answer clearly answers the question and provides constructive feedback and encourages professional growth in the question asker.

Guidelines for Answering Questions