How do I find the authoritative name-server for a domain name?

Question

How can I find the origins of conflicting DNS records?

Answer 1

I have found that for some domains, the above answers do not work. The quickest way I have found is to first check for an NS record. If that doesn't exist, check for an SOA record. If that doesn't exist, recursively resolve the name using dig and take the last NS record returned. An example that fits this is analyticsdcs.ccs.mcafee.com.

1. Check for an NS record

host -t NS analyticsdcs.ccs.mcafee.com.

2. If no NS found, check for an SOA record

host -t SOA analyticsdcs.ccs.mcafee.com.

3. If neither NS or SOA, do full recursive and take the last NS returned

dig +trace analyticsdcs.ccs.mcafee.com. | grep -w 'IN[[:space:]]*NS' | tail -1

4. Test that the name server returned works

host analyticsdcs.ccs.mcafee.com. gtm2.mcafee.com.