In version 5.2 of the Cristie Appliance a new feature called Recovery Assurance (RA) has been added that automatically validates backup server clients recoverability.
In this initial release of Recovery Assurance, the backups are validated on the appliance locally using KVM guests - future updates will permit validation to be performed on external hypervisors.
Because of this, specific network configuration changes must be applied to the Appliance’s virtual networking depending on the Hypervisor Virtualization technology the Appliance is deployed to.
For vSphere, the Distributed Virtual Switch (DVS) must have enabled Forged Transmits (to allow guest traffic with a virtual MAC to transit) and Promiscuous Mode (If MAC Learning is not enabled, to allow all switch traffic to be received by the Appliance for correct guest traffic routing)
For Hyper-V, the Appliance virtual machine must have enabled MAC Address Spoofing under Advanced Features
Other hypervisor technologies may have similar options if applicable
Without these options enabled the nested guests will be unable to transmit or receive network traffic.