What is Non-Authoritative DNS Server?

Non-authoritative name servers do not contain original source files of domain’s zone. They have a cache file for the domains that is constructed from all the DNS lookups done previously. If a DNS server responded for a DNS query which doesn’t have original file is known as a Non-authoritative answer. For example, we query for DNS records of domain tecadmin.net and Google’s open DNS server responded for this query which doesn’t contain domain’s original zone files. This answer is known as a Non-authoritative answer.

What is Authoritative DNS Server?

An authoritative name server is a name server that has the original source files of a domain zone files. The is where the domain administrator has configured the DNS records for a domain. Authoritative DNS server can be master DNS server or its slaves. For example – domain tecadmin.net’s authoritative are alec.ns.cloudflare.com and athena.ns.cloudflare.com. If you directly query to these DNS servers, they will return authoritative answer because they have the original files of domain zone.