Hi,

I realize this is not a Linux specific question, but I figure Linux admins have a better understanding of networking in general.

I assume this is a very basic/beginner question, but it has been puzzling me for a little while. Here goes:

If I register a new domain (let's mydomain123.com) and I want to use my own DNS server. After registering the domain name, at the registrar, I want to set my DNS servers to be:
ns1.mydomain123.com
ns2.mydomain123.com

My question is, how does the registrar (or root name servers) know what the ip address of ns1.mydomain123.com is? I will obviously set the IP address on my dns servers. At first glance, I would think this is impossible, since ns1 is just a record inside the specific domain that it is authoritative for. However, I have seen several examples companies who have a setup exactly like this.

Can someone clarify this for me?

Thanks.

For the primary domain you tell the Registrar of the primary domain the IP address of the DNS servers. They typically have a place to configure your own DNS server IPs. This gets confused often with the place where you tell it the DNS servers to use for your domain which isn't exactly the same thing.

It becomes clearer when you setup other domains but use the same primary domain's DNS servers. In those you simply enter the name server names and not the IPs. Only the primary needs to know the IPs as all others would refer to the primary to get the records.

Also don't forget the Registrars only deal with the forward lookups. You also have to have your ISP delegate the IP range you're using to you and you'll need to provide them with your DNS server names and IPs for reverse lookups.

Thank you for the reply. That makes total sense. I just dug around deeper in my registrar and I found a spot to register my name servers (it was buried a little deeper than I would have expected).

Thanks again for the clarification.