I have an OS X 10.6 Server running the iCal service. When users on machines that are bound to Open Directory open their iCal client, it automatically configures their connections to the iCal server at port 8008, even if the user has already manually added their calendar with SSL at port 8443, which results in the user having duplicate calendars.
Is there a way to turn off iCal access for non-SSL connections, or at least the automatic configuration of clients in the Open Directory domain?