I have a server on which I host my firstdomain.com. For this I created a name servers: ns.firstdomain.com
Now I would like to host a second domain on that server and to use the same nameserves. I know that is posible (is the solution used in shared-hosting). To do so, I created a Virtual Host:
Allow from all
So you have a DNS server that is hosting firstdomain.com and you associated this domain with ns.firstdomain.com. so on that dns server create another primary zone for seconddomain.com. when you register this domain with godaddy, associate this domain with ns.firstdomain.com as well.
Normally, registrars want for you to specificy at least two NS servers that will be hosting your domain. having more than one NS server will improve the availability and fault tolerance of your DNS infrastructure.
You should have to have atleast two nameservers assigned to single server so if one nameserver fails there would be second one to respond to
Besides each nameserver has to be assigned an dedicated IP
Hope that helps
I agreed too, because as much I knew, one have to specificy at least two DNS servers that will be hosting your domain, having more than one server will improve the availability and fault tolerance of your DNS infrastructure.