Mac Hostname Configuration
Internal
Procedure
Become root in a terminal.
Then:
1. Change the Primary Hostname
The primary hostname is the fully qualified hostname (example NOMBP2.novaordis.com)
scutil --set HostName NOMBP2.novaordis.com
2. Change the Bonjour Hostname
This is the name usable on the local network (example NOMBP2 or NOMBP2.local, though in some cases the ".local" prefix causes an "Invalid argument" failure, so don't use it):
scutil --set LocalHostName NOMBP2
The local name can also be changed as follows:
System Preferences → Sharing → Computer Name → Edit: NOMBP2 (.local will be added by default).
Query:
scutil --get LocalHostName
3. Change the Computer Name
This is the user-friendly computer name you see in Finder
scutil --set ComputerName NOMBP2
It seems the user-friendly name can also be changed as follows:
System Preferences -> Sharing -> Computer Name -> Edit in place (do not click Edit, that changes the local name, see [MacConfiguration#2.ChangeTheBonjourHostname])
Query:
scutil --get ComputerName
4. Flush the DNS Cache
dnscacheutil -flushcache
Restart the computer.