[dns-operations] about answer status

[Stephane Bortzmeyer]

On Mon, Jun 08, 2015 at 04:12:03PM +0800,
 Kevin C. <kevin at dnsbed.com> wrote 
 a message of 56 lines which said:

> At what case the nameserver returns "NOERROR" or "NXDOMAIN" for a
> non-exist record?

NOERROR is when there was no error :-) NXDOMAIN means "this name does
not exist". They are two completely different cases.

> $ dig defensor.game.yy.com @localhost

This name exists. NOERROR

> $ dig defenser.game.yy.com @localhost

This name does not exist. NXDOMAIN

If you want more technical details:

dig, by default, requests a A record. defensor.game.yy.com has no A
record (ANSWER:0 in dig's answer) but it may have other types of
records (AAAA, for instance, since we are now in the 21st century).

In this specific case, defensor.game.yy.com seems to have no other
types of records ('dig @dwdns1.nsbeta.info ANY defensor.game.yy.com')
But names underneath (something.defensor.game.yy.com) may exist (this
is called an ENT, Empty Non-Terminal).