[dns-operations] NXDOMAIN and negative caching

[Michael Smitasin]

Thanks, everyone, for the prompt and informative responses. We'll be 
trying to work with the operators of those authoritative servers (/the 
load balancers in front of them) on a fix, though I may reach out if 
we're unable to get in contact with someone at that org via the usual 
channels.

> On 2/1/2016 3:56 PM, Michael Sinatra wrote:
[...]
> (even if it isn't one of our servers that's causing the problem).

It's not =) But it was your building that reported it!

Michael Smitasin
Network Engineer
LBLnet Services Group
Lawrence Berkeley National Laboratory

On 2/2/2016 2:32 AM, Tony Finch wrote:
> Andrew Sullivan <ajs at anvilwalrusden.com> wrote:
>>
>>> - An NXDOMAIN indicates /no/ records exist for that name.
>>
>> Almost.  With DNSSEC, you'll get records for that name, but they prove
>> its non-existence.
>
> Only if you happen to query for an NSEC3 owner name :-)
>
> Tony.
>