How to integrate primary Plesk DNS server with secondary Slave DNS server?
Note: If the Slave server has Plesk installed, there is no need to install the Slave DNS Manager extension.
Perform the following steps:
Create the same domains in both Master and Slave Plesk servers
Warning: The same domains should exist on both master and slave Plesk servers. It prevents DNS data from getting corrupted.
Change DNS to Slave mode on Slave server side in Domains > example.com > DNS Settings > Switch to Slave
Click Add Record
Specify the IP address of the primary (master) DNS server