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Interesting indeed but I am wondering whether there is a difference
in the semantics of NULL <b>records</b> (rfc1035) and DNS query of
<b>type</b> NULL (rfc8145).<br>
<br>
One refers to a record and the other to a query type, with NULL
overlapping and introducing a confusion, but albeit seeming to refer
to different semantics?<br>
<br>
And it seems unlikely that a Key Tag query could be utilized for any
benefit in malicious DNS tunnelling.<br>
<br>
<div class="moz-cite-prefix">On 22.11.2018 14:38, via Unbound-users
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:20181122143823.Horde.TuNYP8b2ptuIxYSn4xxWXxX@andreasschulze.de"><br>
ѽ҉ᶬḳ℠ via Unbound-users:
<br>
<br>
<blockquote type="cite">NULL records on the other hand should
perhaps not be cached, or even
<br>
permitted for queries, considering
<a class="moz-txt-link-freetext" href="https://tools.ietf.org/html/rfc1035">https://tools.ietf.org/html/rfc1035</a>
<br>
</blockquote>
<br>
interesting, that may break signaling trust anchor knowledge
<br>
<a class="moz-txt-link-freetext" href="https://tools.ietf.org/html/rfc8145#section-5.1">https://tools.ietf.org/html/rfc8145#section-5.1</a>
<br>
<br>
Andreas
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<br>
<br>
<br>
</blockquote>
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