NS list does not match list from parent zone

Question

I'm attempting to figure out an error message that I got from dnsstuff.com when examining my DNS records. The error reads as follows.

NS list does not match list from parent zone. This should be addressed because queries for this domain may require an extra lookup (and more overhead) because there is no direct relationship between the NS records at the parent and the NS records at the authoritative servers. This can cause delays. The mismatched NS list is:

nameserver ns1.domain.co. | xxx.xx.xxx.xxx is missing NS2.domain.co. | yy.yyy.yy.yyy

There are a couple questions I have regarding this.

1. What is the difference between a parent and authoritative zone? In other forum posts I've seen, the seem to be used interchangeably (although that could be my misperception).
2. What does it mean for the NS list not to match the list from the parent zone? What is "the list from the parent zone" to which they refer?
3. How might you recommend that I resolve this?

In case this affects any answers, I'm running Virtualmin on Ubuntu 12.04.

Any help is appreciated. Many thanks in advance!

Solution

1. For eg example.com the authoritative zone is example.com and the parent zone is com. You manage the delegation information (NS and A/AAAA glue records) in the com zone through your registrar.

2. The delegation information in the parent zone (NS and A/AAAA glue records) should match your NS and A/AAAA records in the authoritative zone.

3. Ensure that the records match. You should know which NS records are desired, ensure that both the delegation information and your authoritative records match the nameservers that you intend to use.

Comments

[neanderslob]

Hi Håkan, thanks for the reply; I think this is clearing a lot up. So, am I understanding you correctly if I interpret your answer as saying that I need to make sure that NS1 and NS2 on GoDaddy's interface must match those defined in my zone records on my VPS? If that's the case, they're both pointing at the same IP numbers. What might I be missing? Thanks again!

[Håkan Lindqvist]

@neanderslob The actual NS records refer to names, not IP addresses. Begin by comparing the set of NS records in your zone with the set of delegatory NS records in the parent zone, then proceed by comparing the referenced A/AAAA records if applicable. dig +trace +add example.com NS may prove helpful.

[neanderslob]

Thanks dude, turned out I was missing a mention of NS2 on the primary server. Your explanation was very helpful.