DNS Reliability

Thu Sep 12 22:26:43 UTC 2013

On Sep 12, 2013, at 2:35 PM, Randy Bush <randy at psg.com> wrote:

>> Everything else remaining equal...is there a standard or expectation for
>> DNS reliability?
>> ...
>> Measured in queries completed vs. queries lost.
> 
> this is the wrong question.  the protocol is designed assuming query
> failures.
> 
> randy

I think it's part of the right answer.  Capacity and server connectivity issues, what this metric will mostly measure, do matter.

The other part, more likely to get you on CNN and Reddit and the front pages of the NY Times and WSJ, is the area represented by MTBF / MTTR / etc.  how often is DNS for your domain DOWN - or WRONG - and how fast did you recover.

The other subthread about routeability plays into that.  For BIGPLACE environments, you should be considering how many AS numbers independently host DNS instances for you, in how many geographical regions, and do you have a backup registrar available spun up...

-george william herbert

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