Setting on domain DNS
 

I register one domain with the registrar and need to change the Nameserver, but I cannot enter with IP address. I can only enter something like NS1.DOMAIN.COM.
I cannot find the nameserver from ISPConfig. Can you show me where..

What I would do, if possible with your isp is set up DNS "A" records to point ns1.yourdomain.com and ns2.yourdomain.com to point to your public ip address and then you can add those two name servers to your dns entries.

Well its the way i would do it.........

Then simply create an A record for ns1.domain.com that points to your ISPConfig server (supposed that it should act as the name server...).

The name server settings are under DNS Manager in ISPConfig.

Great!, appreciated your help :)