BIND started replying to queries for .com with .COM

Phil Mayers p.mayers at
Wed Mar 30 11:07:49 UTC 2016

On 30/03/16 01:19, Mark Andrews wrote:
> Your monitoring probe is broken.
> STD 13 says that that the DNS is case preserving.  The problem is
> that lots of servers aren't case preserving instead they echo back
> the query case in the owner names of records returned which named
> then records.

Can I be clear on what you think would be the correct behaviour here?

Presumably the question section should exactly match what the client 
sent always, bit-for-bit, so we're talking about the ans/auth/add 
sections - they should, in your reading of the standards, match the case 
of the on-disk authoritative data, not what the client sent, yes?

Am I correct in assuming that, by case-sensitively compressing labels 
for many years, bind has been doing the opposite (the label compression 
effectively throwing away the carefully case-preserved data)?

I'm curious why this has come to the fore now, if you're able to say?

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