[dns-operations] why does that domain resolve?

Benno Overeinder benno at NLnetLabs.nl
Mon Jun 7 12:43:53 UTC 2021

On 05/06/2021 20:11, Paul Vixie wrote:
> On Sat, Jun 05, 2021 at 05:05:54PM +0200, A. Schulze wrote:
>> ... What are NS records good for, if for $reason no resolver implement step 3.5:
>> 3.5  The resolver ask of the glue-NS for "house.xa." NS to get a authoritative
>> list of "house.xa." NS
> i expect these NS RRs to become visible in any validating full resolver that
> implements QNAME Minimization. that's not a protocol change.

Indeed.  In our first QNAME minimisation implementation, we used NS 
queries to follow delegations.  This worked 99% of the time (well, 
almost all, I can't put a number on it).  We found that there are 
middleboxes that clearly dropped NS queries.  So instead we used QTYPE 
A/AAAA in QNAME minimisation to follow delegations.  With good results.

-- Benno

Benno J. Overeinder
NLnet Labs

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