Cloudformation EIP Reverse DNS

I don't believe this is possible via the AWS::EC2::EIP resource type. You could create a custom resource (or a registry resource) to call the ModifyAddressAttribute API (e.g. via boto3) which could update the EIP configuration after it's created.

However, there's a requirement that the reverse DNS entry has a matching forward DNS, so you would also need to create a suitable DNS entry (either in Route53, or in your own DNS system which again would be via a custom resource) before CloudFormation creates/updates the reverse DNS. You can use the DependsOn attribute if necessary for that.

Thanks for the response, I'll look into creating a custom resource. Longer term, is it possible to create a feature request for this functionality within Cloudformation itself?