[dns-operations] why does that domain resolve?

[Giovane C. M. Moura]

> This is a question of being parent- vs. child- centric.  The parents in
> the DNS tree delegate correctly.  

FWIW, we did a study a couple of years ago [1] analyzing these
inconsistencies. We found 13 million second-level domains (out of 166M)
that were inconsistent [0] (table 1, data from 2019-10-16)


> Indeed.  In our first QNAME minimisation implementation, we used NS
>queries to follow delegations.

We saw this also clearly on .nl and .nz when Google Public DNS  (GDNS)
turned on q-min: fig 3 in [1]. Out of sudden we start to see far more NS
queries from GDNS than the other types of records.

/giovane

[0]
https://www.sidnlabs.nl/downloads/53BNt9EPxZQOCHYjqWhYfR/7295d79a207afc79cab6309d40a15a76/When_parents_and_children_disagree_Diving_into_DNS_delegation_inconsistency.pdf

[1]
https://www.sidnlabs.nl/downloads/4O6kRGL3Un0HrT5TcrBwaG/c69d421eb252da5902f46c1605175649/Clouding_up_the_Internet_how_centralized_is_DNS_traffic_becoming.pdf