DeltaV System Time

Hi, 

I'd like to know how to set up the IDDC, Proplus, and other DeltaV workstations in v15 to listen to the time from the Cluster Domain Controller. Do I need to edit the NTP.CONF file or configure the remote network in the Pro Plus?

The Cluster Domain controller is listening time from the Firewall.

The firewall is listening to time from GPS.