Thanks a lot. That's what I kind of figured out from reading the docs on MyDNS. I was trying to zone transfer between 2 MyDNS servers.
I do have a 2 server setup using one ISPConfig3 interface. Isn't replication done by ISPConfig in a setup like that? I was hoping to see the Database on the slave updated as I create zones on the master, but that hasn't happened. I do know that my databases setup are OK since when I create sites on the master, they get updated on the slave.
Could it be that I am missing something?
Thanks as always.