Shaw's cache blocking me would be an interesting hypothesis. However, wouldn't my first query respond and the others block me? I got no response from any of the queries, suggesting that it is this rd-bit issue Ermine raised.

I should run a DNS cache locally, though.

On 10/10/22 19:23, Guillermo wrote:
El lun, 10 oct 2022 a las 13:28, Laurent Bercot escribió:
   s6dns_engine filters answers that do not seem relevant to in-flight
queries. That includes malformed answers or ones that do not follow
RFC 1035.
   I was made aware (thanks, Ermine) that some caches fail to set the
RD bit in their responses to queries containing the RD bit; these
answers were ignored.
However, the OS would still deliver them to skadnsd in a recv() /
recvfrom() call, right? If my reading of the truss outputs is correct,
the HardenedBSD system isn't getting a response at all, and whatever
error happens with the program running on the OmniOS system, if any,
does not involve the network (I can't tell if skadnsd is delivering
all received answers to the client).

I feel that packet capture tools like tcpdump(1) or OmniOS' snoop(8)
would be better suited for answering the questions that have been
raised so far (malformed packets, ignored responses, lack of
responses, etc.). Also, aren't 18 outstanding queries in a short
amount of time from one single host, like, a lot? Couldn't Shaw's
caches think that they are being DoS'ed :P ?


Ellenor Agnes Bjornsdottir (she)
jabber: ellenor ~on~

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