I've seen enough threads about how to read and set the various names on a Mac so I won't ask about that. However, can someone tell me what difference is between the 3 names and what controls them. I'm assuming that ComputerName comes from "System Preferences>Sharing>Computer Name". How do the others typically get set and what happens if they aren't set or are set incorrectly? Our Hostnames are all blank and we have some LocalHostNames that have a name different from ComputerName.