<html><head><meta http-equiv="Content-Type" content="text/html; charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div class="">Hi Brian</div><div class=""><br class=""></div><div class="">yep, reverse of DNS64 is more or less what I am trying to achieve. And I found a way - a minimal DNS lookup library for LUA that has no dependencies and runs very quickly:</div><div class=""><br class=""></div><div class=""><a href="https://github.com/spc476/SPCDNS" class="">https://github.com/spc476/SPCDNS</a></div><div class=""><br class=""></div><div class="">It works really nicely with powerdns lua scripts. Beware though of circular queries when having query triggering a query.</div><div class=""><br class=""></div><div class=""><br class=""></div><div class="">Cheers,</div><div class=""><br class=""></div><div class="">R.</div><div class=""><br class=""></div><div class=""><div class="">
<span class="Apple-style-span" style="border-collapse: separate; font-variant-ligatures: normal; font-variant-east-asian: normal; font-variant-position: normal; line-height: normal; border-spacing: 0px;"><div class="">-- <br class="">Radoslaw Kamil Ejsmont, Ph.D.<br class=""><a href="http://radoslaw.ejsmont.net/" class="">http://radoslaw.ejsmont.net</a></div></span>
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<div><br class=""><blockquote type="cite" class=""><div class="">On 12 Feb 2018, at 18:34, Brian Candler <<a href="mailto:b.candler@pobox.com" class="">b.candler@pobox.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div class="">On 12/02/2018 17:23, Pieter Lexis wrote:<br class=""><blockquote type="cite" class="">If you known the (sub) domains that need this special processing, you<br class="">could simplify your life by adding them to a DNSSuffixMatchGroup[1] and<br class="">if the domain name in the AAAA query is not matched in this group, send<br class="">a NODATA response to let the client retry with A.<br class=""></blockquote><br class="">Another way to do it would be if you know the IPv6 *prefixes* of the cloud site(s) you need to reach via the tunnel. You could then filter out any AAAA responses which are not within those prefixes.<br class=""><br class="">It also occurs to me that what you're asking for sounds quite similar to what DNS64 does, but backwards:<br class=""><br class="">* DNS64: if AAAA query has no data then check for A record, and if it exists, embed it into AAAA response<br class=""><br class="">* What you want: if AAAA query has data then check for A record, and if it exists, change AAAA response to NODATA<br class=""><br class="">But it may not be straightforward to hack the powerdns DNS64 code to work that way.<br class=""><br class=""><a href="https://doc.powerdns.com/md/recursor/dns64/" class="">https://doc.powerdns.com/md/recursor/dns64/</a><br class=""><br class="">Cheers,<br class=""><br class="">Brian.<br class=""><br class="">_______________________________________________<br class="">Pdns-users mailing list<br class="">Pdns-users@mailman.powerdns.com<br class="">https://mailman.powerdns.com/mailman/listinfo/pdns-users<br class=""></div></div></blockquote></div><br class=""></div></body></html>