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<div class="">Packet size is harder to analyze. ANY often pulls some records that</div>
<div class="">aren't used, and if the site isn't configured carefully then ANY can<br class="">
even end up falling back to TCP, costing bytes _and_ packets. On the<br class="">
other hand, there are a huge number of Internet sites that don't have a<br class="">
noticeable volume of unusual records and don't need TCP, and there's a<br class="">
clear traffic win for every skipped query and skipped no-data response.<br class="">
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<div>My guess is that with DNSSEC, this will be common, as often times the domain apex is where the email would be sent. For my personal domain, that’s @<a href="http://flame.org" class="">flame.org</a>, and weighs in at 1758 bytes to an ANY query right now.</div>
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<div>Once this is done, the MX target then needs to be followed of course (or targets in the case of a failure to connect.)</div>
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<div>In the following, I’m using ESND0. If this isn’t true, we all know anything > 512 bytes as a response was a TCP hit. I’m not as scared of TCP hits as others may be, but I do think they should be avoided when practical.</div>
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<div>ANY comes in as 1769 with or without DNSSEC. Had it asked for the MX directly, it would have gotten 60 bytes without DNSSEC, and 229 with.</div>
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<div>If there was no MX record, I assume then another query would be issued for the AAAA and A records. That’s two more queries, but both of which would be smallish in comparison to the ANY query. The DNSSEC keys nearly always dominate ANY queries at the
apex.</div>
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<div>I’m happy we are discussing issues with ANY queries, and the fairly small number of clients that use them. I would have to see hard numbers collected over a lot of data showing where the ANY query was actually better than following the <MX, AAAA, A> path.
Until data is collected from how people set up zones today, I’m not sure I can say one is better than the other, other than as a feeling that it might help reduce queries but I’m not sure it reduces bandwidth.</div>
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<div>What problem are we specifically trying to solve here again?</div>
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<div>—Michael</div>
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