Unable to Add Machine With RAS (Remote Access Service) Enabled

When trying to add a Windows Server that has the Remote Acces role enabled to Veeam Backup & Replication as a Managed Server, the operation fails with:

Failed to check whether remote installer service is available.
The RPC server is unavailable.
RPC function call failed. Function name: [GetSvcVersion]

This occurs because the Remote Access service creates an IP connection that is hard coded to be the first chosen. This prevents Veeam Backup & Replication from being able to connect to the component services it has installed.

In order to add the machine to Veeam, you will need to uninstall Remote Access role/services.

For Hyper-V hosts, it is best practice to keep the host OS as clean as possible. If you would like to use Remote Access (or other roles on the host), it is best to install those roles on a VM inside the host, and not on the host OS itself.