Issues resolving outlook.office365.com

[Tony Finch]

Thomas Sturm <tst at open.ch> wrote:
>
> We are experiencing strange intermittent issues when resolving
> outlook.office365.com, but also with other domains like e.g.
> amazonaws.com or snort.org.

Based on recent discussions on the mailop list
(https://chilli.nosignal.org/mailman/listinfo/mailop)
the problem seems to be a combination of very short TTLs on the NS records
(which makes any problems occur much more frequently), a weird mapping
from name server names to IP addresses, and lack of EDNS support (which
forces BIND to retry queries).

Tony.
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