I had a post about this for ISPConfig 2, but I never ended up getting it working so I'm hoping with my new setup of 3, it will be easier. A little summary: I have my domain registered at GoDaddy. In the Domain Manager, I have created 2 hosts: NS1 and NS2: As you can see, the host IP is assumed to be static. Every time my IP changes, I have to come back in here and re-update. It may take 2 days before my sites are up for everyone. Now I set my nameservers as the 2 hosts I set up: My router is setup with DynDNS.org so my host for that is cfcoding.dyndns.org. I also have the DMZ host setup which points to 192.168.1.151 (my server). With that information, I guess it's time to figure out how I need to set this up to work seamlessly between IP changes. I need to change the way the hosts and nameservers in GoDaddy are set up so they are dynamic. Which steps would I need to take to do that? On the ISPConfig end, what do I need to configure in System > System Config > {my server} > Nameservers? What about the DNS Zone section?
Not sure if I understand what you need. But if dyndns dynamically updates your host, why not use a CNAME in your alternative host? And, make sure you read this page http://support.microsoft.com/kb/163971 so that you don't need to wait for two days before DNS gets updated. I decided to quote the Microsoft page because this has the clearest explanation of DNS options regardless of DNS software.