For our testing purposes we need DNS clustering between two dns-only-servers and one hosting server.
Dns-only-servers have currently installed dns-only-cPanel.
Hosting server have installed real cPanel.
Hosting server will be standalone, dns1 will sync with hosting server(s) and with dns2, dns2 will sync with dns1.
Pretty simple and clear, but we don't have time to do this. We hope you have a good cPanel knowledge.