<html><head>
<meta content="text/html; charset=ISO-8859-1" http-equiv="Content-Type">
</head><body bgcolor="#FFFFFF" text="#000000"><br>
<br>
<blockquote style="border: 0px none;"
cite="mid:20150316142350.GB26918@xs.powerdns.com" type="cite">
<div style="margin:30px 25px 10px 25px;" class="__pbConvHr"><div
style="display:table;width:100%;border-top:1px solid
#EDEEF0;padding-top:5px"> <div
style="display:table-cell;vertical-align:middle;padding-right:6px;"><img
photoaddress="bert.hubert@netherlabs.nl" photoname="bert hubert"
src="cid:part1.07010201.06020602@redbarn.org" name="postbox-contact.jpg"
height="25px" width="25px"></div> <div
style="display:table-cell;white-space:nowrap;vertical-align:middle;width:100%">
<a moz-do-not-send="true" href="mailto:bert.hubert@netherlabs.nl"
style="color:#737F92
!important;padding-right:6px;font-weight:bold;text-decoration:none
!important;">bert hubert</a></div> <div
style="display:table-cell;white-space:nowrap;vertical-align:middle;">
<font color="#9FA2A5"><span style="padding-left:6px">Monday, March 16,
2015 11:23 PM</span></font></div></div></div>
<div style="color: rgb(136, 136, 136); margin-left: 24px;
margin-right: 24px;" __pbrmquotes="true" class="__pbConvBody"><pre wrap="">On Mon, Mar 09, 2015 at 04:18:12PM +0100, bert hubert wrote:
</pre><blockquote type="cite"><pre wrap="">On Mon, Mar 09, 2015 at 11:08:03AM -0000, D. J. Bernstein wrote:
</pre><blockquote type="cite"><pre wrap="">My "qmail" software is very widely deployed (on roughly 1 million SMTP
server IP addresses) and, by default, relies upon ANY queries in a way
that is guaranteed to work by the mandatory DNS standards.
</pre></blockquote></blockquote><pre wrap=""><!---->(...)
</pre><blockquote type="cite"><pre wrap="">Do you think I read 4.3.2 wrong? Or is there another RFC that updates the
algorithm?
</pre></blockquote><pre wrap=""><!---->
Thanks to some clarification from Dan, I now understand that one can indeed
rely on ANY queries to resolvers to either deliver a CNAME or no CNAME, in
which case there is no CNAME. </pre></div>
</blockquote>
<br>
i'd like to see those clarifications. if any non-CNAME RRset had existed
and been cached, and then replaced by a CNAME, then ANY would not see
the CNAME until the last non-CNAME RRset had expired from that cache.<br>
<br>
which is why, when i want to know if there is a CNAME, i ask if there's a
CNAME.<br>
<br>
i realize that this only matters when the non-CNAME TTL's are one to two
weeks long, and weren't trimmed before replacement with the CNAME.
however, that situation is common enough that i dispute the phrase
quoted above, "guaranteed to work by mandatory DNS standards."<br>
<br>
<blockquote style="border: 0px none;"
cite="mid:20150316142350.GB26918@xs.powerdns.com" type="cite">
<div style="color:#888888;margin-left:24px;margin-right:24px;"
__pbrmquotes="true" class="__pbConvBody">
<pre wrap="">
Separately, I fail to see why we actually need to outlaw ANY queries when we
can happily TC=1 them.
</pre>
</div>
</blockquote>
<br>
TC=1'ing them would be a way to prevent them from being used as an
amplifying reflector. that is not the use case for this. the updated
document makes clear that the iteration complexity in split-authority
systems having a lightweight front end, is the situation where ANY is
painful.<br>
<br>
there never was an ANY-related problem for which TC=1 was the solution.<br>
<br>
<div class="moz-signature">-- <br>Paul Vixie<br>
</div>
</body></html>