Sample DNS Zone Record File for iCal in Lion Server
Because DNS for iCal can be tricky if you’re editing by hand, a sample may come in handy. These references are to Lion Server, but you can adopt the procedure to other DNS servers.
In Mac OS X Server (and some Linux/Unix servers), the DNS zone file that you edit is in the /var/named directory. The file has the form db.domainname, such as db.ourserver.macwindowsco.com. To access it in the Finder, choose Go→Go to Folder and then type /var/named. Open the file and type your additions after the line that begins with $INCLUDE /var/zones/db. Do not delete or change this line.
This INCLUDE line inserts your additions into another similarly named file in /var/named/zone. Although you don’t edit this file directly, here’s a sample of the file in /var/named/zone to give you an idea of what the final looks like. This file contains the DNS entities called A records that are referenced in the SRV records. The text after the semicolons represents in-code comments.
;GUID=<GUID here> $TTL 10800 ; default expiration time of a record abc.com. IN SOA ns.abc.com. username.abc.com. ( 2009031903 ;Serial 86400 ;Refresh 3600 ;Retry 604800 ;Expire 345600 ;Negative caching TTL ) abc.com. IN NS ns.abc.com. ;ns.abc.com is the name server for abc.com abc.com. IN A 10.0.0.1 ;this is the IP address of abc.com ns A 10.0.0.2 ; IP address of ns.abc.com name CNAME ns ;"name.abc.com" is another name for "ns.abc.com" calendar IN A 10.0.0.12 ; the IP address for "calendar.abc.com" TXT "The iCal Server that we're using" ical IN CNAME calendar.abc.com. ;"ical.example.com" is another name for "calendar.example.com" _caldav._tcp.abc.com. 86400 IN SRV 0 0 8008 calendar.abc.com.
If you have a backup server to use when the first is down, add another calendar line:
calendar2 IN A 10.0.0.13
Then add another SRV line at the end:
_caldav._tcp.abc.com. 86400 IN SRV 1 0 8008 calendar2.abc.com.
For SSL, the CalDAV line(s) is
_caldavs._tcp.abc.com. 86400 IN SRV 0 0 8443 calendar.abc.com. _caldavs._tcp.abc.com. 86400 IN SRV 1 0 8443 calendar2.abc.com.