Just a hint: This has NOTHING to do with A Records and you wont resolve it in that direction.
I use, and currently hold about 200 domains on 1and1's system, and I'm very familar with their interface. I came upon the exact same problem as you.
The short answer is: you cannot use 1and1 as your domain registar for any domain you intend to use for nameservers. You will need to use another one (by transferring or buying a new domain), GoDaddy works nicely, and I've heard NetworkSolutions does too, etc.
This is a shame in my mind because of the nicely accessable interface 1and1 uses and they are a pretty good value, and how their billing works on monthly invoice intervals.
To explain, for a nameserver to be recognized by the other registrars in "the world" it must be registered as a "domain host". This is a simple matter though usually hidden somewhere obscurely in your registars web interface because of how easily it could be mistaken for a subdomain resolution, and the fact that most people purchasing a domain will never contemplate setting up their own DNS server.
1and1 has decided not to even bother making the "domain host" option available on their customer interface for domains purchased through them! Why they made that decision is for any of us to guess, but fact is they specifically lack that feature.
A suggestion if you want to use your server as configured through your ISPConfig as a DNS server (wich is handy since it keeps you from having to enter all that IP resolution information in some other service, not to mention makes your server a "self-reliant" host with one less point of failure) is to purchase a fun domain you wouldn't mind being used as your DNS name (ns1.whateveryouwant.com) on GoDaddy and use their feature. It works, and thats how I've done it reliably.
The GoDaddy interface has you click on "Domain Hosts" and then click some other link text to the effect of "really edit domain hosts" and then you type in the subdomain to the domain selected ("ns1", etc) and then type in the IP number of the machine (wich would be the IP number of your server with ISPConfig on it).
And again, I only mention GoDaddy because they are pretty affordable and reliable, you could really use any registrar you verified ahead of time to have the "domain host" feature (most all registrars do, 1and1 seems to be a strange exception).
And I still keep the bulk of my domains on 1and1 because, they're cheaper and pretty much fine for domains that dont need to be in some DNS entry.
Last edited by retran; 15th April 2006 at 00:49.