Hi, I wish there is some guide to proper setup primary and secondary DNS. Scenarios: 1) One single ISPConfig server with 2 IPs: that's easy. 2) Two standalone servers with ISPConfig, so one should be primary, and the other secondary. 3) Two ISPConfig servers, with multiserver setup. The goal is to input DNS records only in the master, and the second one copy from it. There are some posts that you should create an MySQL user to allow servers to connect each other to exchange records, and so on. But, I don't think this is the way a DNS should work. The purpose of second DNS is to keep queries working for a few period until master DNS is in maintenance or restarting, so those hack solutions are like have one server with 2 IPs. To get things simple, we can work in a solution between same services, like bind-to-bind and mydns-to-mydns, although I think this should be "transparent" for DNS replication.