I think it has to do with Bonjour (mDNSResponder). Check out this page.
Run the following command in a Terminal:
ps aux | grep mDNS
This should tell you whether or not /usr/sbin/mDNSResponder is running. If it is not, run the following command to launch it:
sudo /usr/sbin/mDNSResponder
Not everything is working smoothly.
We notice that 10.6.8 clients among them have issues with delegated calendars; if user A logs in to the CalDAV server and connects properly, the calendars are downloaded to the client and the own calendar plus the delegated calendars are shown.
When user B creates an account and logs in, chances are that she can successfully connect to the server but by then user A sees his account changed to B and everything in his iCal calendar is wiped. Disabling (taking the calendar offline) the calendar and adding account A again adds the data back in.
At that moment user B sees a blanked calendar and her name changed to A. Disabling this A calendar and re-entering the account for B puts things straight. Sort of.
This has happened multiple times; two users had the problem among them, then another group of four users had the same problem. You just have to keep disabling and re-adding the desired account until all users see only the account they need.
A peculiarity of delegation is that when adding delegates, only three, not more and not less, letters of a delegate should be typed to get a popup that you can actually choose (by pressing Enter). UNLESS the short user name consists of only three or four letters. In that case, the ENTER is rejected, you cannot choose the delegate and you HAVE to ADD a space and one more (fake?) letter. Then the three or four lettered username pops up which you then CAN select. Weird. Now the user is delegated.
Another issue we have is that changes made in a delegated calendar do not always trickle up to the server; consistently from some 10.6.8 clients, but not every client. Neither when you have 'push', nor when you have 'every x minutes'. Annoying.
10.7 clients work flawlessly as far as we can see.
Best Answer
No, the only way to get a FQDN is by using a DNS server, either external to your Xserve or run on the Xserve itself. It's recommended with setting up Mac OS X to set up DNS first before anything else.