Custom DNS server. How they reach each other?

Question

If I have a domain, say example.com at GoDaddy, and a dedicated server, say, 123.123.123.123.

I created 2 records in my named server inside my dedicated machine telling to point ns1.example.com and ns2.example.com to its own IP (123.123.123.123), also the same for example.com.

Now, in GoDaddy I set example.com nameservers to ns1.example.com and ns2.example.com.

The thing is, my dedicated machine knows where to point ns1, ns2 and example.com (to itself), but how the other DNS servers knows that all they point to that IP? Maybe they could ask somewhere where to point example.com and in that server ask for ns1 and ns2, but I don't know how to "spread the word" that example.com, ns1 and ns2 has to point to my IP. Does named do this automatically, spreading it to another DNS servers?

EDIT: A minimal edit. I set up ns1.example.com and ns2.example.com as name servers in GoDaddy, so when a DNS server is asked for example.com, it will look at GoDaddy and know that the name servers are ns1 and ns2, but, how they know that they have to look into GoDaddy? (I think that this is the same question as before...)

Answer 1

Your registrar will modify the master record for that top-level domain.

When a DNS query is made for your domain the DNS servers will forward the query upwards until the request eventually reaches a DNS server with cached information or it reaches the master record. Any cached information may be stale, so you need to wait for the TTL to expire before the new information is requested (this is why it takes up to about 72 hours for your changes to be reflected).

See also - DNS: Recursive and caching name server [wikipedia]