not a DNS expert so I want to make sure this is being setup properly.
We have someone who has setup a server for us to put sites on. It is a standard LAMP server running cPanel/WHM. They assigned a DNS server on this machine of something like 'abc.example.com'. So we would assume that 'abc.example.com' should be the authoritative primary name server, correct?
But they have told us they cannot register this custom name server address (abc.example.com) so that we can assign it to domains as the primary name server listing. They said that they have 2 primary custom name servers already setup for other their main server - 'ns1.example.com' and 'ns2.example.com', and that this domain 'example.com' and other main TLD domains are registered to this other server. Because of this, they state that they cannot register 'abc.example.com' as a custom name server address.
They have suggested they assign slave records to their 2 primary name servers that point to our 'abc.example.com' name server and records. These would pick up and mirror all entries and changes we make. Then we would point domains to these 2 main name servers that are hosting 'slave' records for our main name server.
1) Is this the (or 'a') correct way of going about name server assignments?
2) Can they not go to the registrar for example.com and add 1 additional name server listing (abc.example.com) pointing to the IP address of our server since the TLD is not registered/existing there?
3) Is it OK for us to point domains to these 2 alternate name servers? Since they are serving slave records that pick up any changes we make, is there a chance these would not be updated as quickly as our main name server when changes are made (i.e., caching, etc.)?
Thanks for any input here. I'm trying to understand DNS and name servers better, but it is a bit confusing right now. Just want to make sure this is setup properly before we start putting sites on their and switching name servers on the domains.