On-premises: Both Reprotect and Failback require a site-to-site VPN to replicate data to the on-premises datacenter.

Failback pre-requisites:
- The on-premises Proces Server can be resused when leveraging Azure ExpressRoute.
- Optionally, a Process Server can be deployed in Azure.
- Windows Master Target Server is pre-deployed.
- Linux Master Server is required for VMs.

A physical machine, once failed over to Azure, can only be failed back as a VMware virtual machine (VM).