Take the 2-minute tour ×
Server Fault is a question and answer site for professional system and network administrators. It's 100% free, no registration required.

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.

share|improve this question

1 Answer 1

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?

No. The server that is setup as a resolver is the server that will be used by your server to lookup anything on the whole internet. That's known as a resolver. What you're looking for is an authoritative name server, which is a different thing.

You can think of them like this: the resolver is a phone directory, where you look up a company name and get the number to their phone. The authoritative name server is the company's switch board, that can reply to a question about the extension/IP address to a particular person/server within the company/domain.

[ snip ]

1) Is this the (or 'a') correct way of going about name server assignments?

It's a correct way, even a fairly common one.

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?

It depends. Some registrars, or some software used by your ISP or the registrar, may limit the number of name servers to 2.

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.)?

Yes - but if you register any additional domains, you will need to make sure the 2 alternate name servers will know how to handle them.

Depending on setup, there would be little to no delay in updating. However, DNS replies are cached all over the internet, by any resolving name server that has been asked for them, so a change will usually not be immediately obvious for everybody anyway. A delay of a few minutes in updating the authoritative name servers rarely makes much of a difference.

share|improve this answer
    
Trying to understand your analogy "the resolver is a phone directory, the authoritative name server is the company's switch board, that can reply to question about the extension/IP address to a particular server within the domain." When we look through WHM, we notice that 'abc.example.com' are set as primary and secondary name servers in WHM Setup (not sure if this is correct). When we go to Resolver Config, we see the IP addresses for the 2 main name servers (ns1. & ns2.). When checking our name server IPs, it shows our name server has all DNS zone records. Which is Auth/Resolver? –  Kenny J Mar 22 '13 at 18:57
    
I don't know what WHM setup means. The resolver config tells you the ip addresses of the resolver name servers; the servers listed as your name servers in your SOA records are your authoritative name servers. –  Jenny D Mar 25 '13 at 7:36
    
OK, thanks. If that's the case then the DNS server listed for our machine 'abc.example.com' would be the authoritative and the 2 he wants us to use 'ns1.example.com' and 'ns2.example.com' would be resolvers. That's why I thought it would be preferable to point domains to our DNS address. The domain 'example.com' is under his control at Network Solutions, but he states he cannot register our NS 'abc.' because it is not the authoritative NS for any of his registered TLDs. I asked NetSol and they said it should be no problem adding 3rd name server to domain, even if on separate server. –  Kenny J Mar 25 '13 at 19:05

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.