[sdnog] DNS servfail vs nxdomain

[Daniel Shaw]

Ah, that is true. Thank you for squashing the nits! :-)





-------- Original Message --------
Subject: Re: [sdnog] DNS servfail vs nxdomain
Local Time: January 12, 2017 1:14 PM
UTC Time: January 12, 2017 9:14 AM
From: philip at trouble.is
To: Daniel Shaw <danielshaw at protonmail.com>
Samir S. Omer <samir.saif at sudren.edu.sd>, Sudan NOG <sdnog at sdnog.sd>


> In the case of NXDOMAIN, the authoritative server actually replies,
> but the reply is "this domain or record does not exist".

Nitpicking: it only means "this domain does not exist". If the domain
exists but the record does not, the reply will be NOERROR with zero
answer records.

> And second, in the case of NXDOMAIN for a specific record, it'll also
> cache the answer for the TTL of the parent zone.

It'll cache it for the *negative* TTL of the parent.

Philip
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