DNS servers may become temporarily unavailable due to maintenance, unforeseen issues, etc. An administrator may be concerned if any of the above would effect their Zerto Virtual Replication environment.
VRAs do not rely on external DNS services in order to operate, and do not accept DNS host names.
Zerto best practice recommends configuring VRAs with static IP addresses. Since these appliances are not given specified host names during installation, resolution between VRAs is only done via IP address between sites. If VRAs are installed with DHCP, the IP address given to the VRA on first boot is stored by Zerto Virtual Replication and is the IP addressed used.