How to connect your Rancher Hosted Prime network to your AWS transit gateway?

The following steps can be taken to connect your Rancher Hosted Prime network to an AWS transit gateway running in your AWS account.

1. Make sure you have provided the Rancher Hosted Prime team with a CIDR that does not overlap with your existing infrastructure. If not, your Rancher Hosted Prime environment may need to be redeployed with the new CIDR. The CIDR must be a /25 block or larger. Using a /24 is normally preferred.
2. If you haven't already, create a transit gateway in your AWS account. See Create a transit gateway.
3. In the AWS console, go to Resource Access Manager (RAM) service.
4. In RAM, click the orange button in the top right corner labeled "Create a resource share".
5. For the name, use something descriptive that includes both your company name and "Rancher Hosted Prime". For example, "Widget Corp transit gateway for Rancher Hosted Prime". For resource type, select Transit Gateways. Select the transit gateway you want to share. In Principals, check Allow external accounts and enter the AWS account number provided by the Rancher Hosted Prime team. Click the orange "Create resource share" in the bottom right corner.
6. Let the Rancher Hosted Prime team know you have created the share. We will accept the share and make a request to attach the transit gateway to your Rancher Hosted Prime VPC.
7. Accept the request to attach your transit gateway to the Rancher Hosted Prime VPC. To do this, go to the VPC service, click "Transit Gateway Attachments" in the navigation pane, select the transit gateway attachment, choose Actions -> Accept.
8. Provide the Rancher Hosted Prime team with a list of CIDRs you want to be routed through the transit gateway.

See also Transit gateways and Transit gateway sharing considerations for more information.