How do you force COPY and UNLOAD traffic to flow through the Amazon VPC and not route it through the internet?

Amazon Redshift enhanced VPC routing: Amazon Redshift forces all the COPY and UNLOAD traffic between your cluster and your data repositories through your Amazon VPC if you use Enhanced VPC routing. If enhanced VPC routing is not enabled, then Amazon Redshift routes the traffic through the internet, including the traffic to other services within the AWS network.