Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I'm learning about DNS and have a very basic, generic question about DNS but I can't find an answer anywhere.

I have DNS for a few domains set up as follows: - master records with DNS company A - slave records with DNS company B

Company A's nameservers are:

and company B has three slaves:

Everything works fine transferring the records between the nameservers and keeping them in sync.

But my question is: The registrar of my domain allows me to choose 4 nameservers only. Do I just pick the first 4 for company A, or do I need to include 1 or more of company B's slave nameservers too?

share|improve this question
That's a lot of name servers. Why not just use two from Company A and two from Company B and list all four? That's plenty of redundancy if you ask me. – joeqwerty Nov 3 '12 at 15:28
That limit of four is a stupid idea and I would suggest you explore another DNS hoster. – bortzmeyer Nov 3 '12 at 16:29
Why you have company B at all ? Why company A alone is not enough ? – Sandman4 Nov 3 '12 at 20:41
up vote 3 down vote accepted

The NS records you supply to the registrar should be as network diverse as possible. The reason for that is if one network goes down then some other name server on another network should still be up.

Presumably, all name servers from company A are on one network and all from company B would be on another network. If that's the case choose two from each.

If company A's name servers are on two networks and company B's name servers are on two networks (making 4 in total) then use one from each.

share|improve this answer

Your Answer


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.