A, AAAA and CNAME records

For A, AAAA and CNAME records, trace the answer through stub resolver → recursive resolver → delegation → authoritative nameserver. A recursive resolver can answer from cache, so a user response is not necessarily fetched directly from the authoritative server. TTL, record type and response code explain where the result came from and how long it can remain usable.

How to check the DNS result

Check the name and query type first, then the authoritative answer, then the chosen recursive resolver. NXDOMAIN, SERVFAIL, REFUSED and timeout represent different conditions. After a DNS change, compare authoritative data with several resolvers; clearing a local cache helps only when the stale answer is actually local.

The detail that matters

A records map names to IPv4 addresses, AAAA records to IPv6 addresses, while CNAME makes one owner name an alias of another name. Following a CNAME can require additional lookups, and DNS standards place restrictions on mixing CNAME with other data at the same owner name. You can repeat the DNS check with 2ip DNS check.