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<div class="moz-cite-prefix">On 2016-04-27 14:12, Andrew Boling
wrote:<br>
</div>
<blockquote
cite="mid:CAPnMbcwAz+F1c_oaaQm8rz2deRUcXXSZf5zR1A_UeC8LazfUbw@mail.gmail.com"
type="cite">
<div dir="ltr">Trying again, with the mailing list included this
time.
<div><br>
</div>
<div><span class="im" style="font-size:12.8000001907349px">On
Wed, Apr 27, 2016 at 4:56 PM, John Levine <span dir="ltr"><<a
moz-do-not-send="true" href="mailto:johnl@taugh.com"
target="_blank">johnl@taugh.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0px 0px 0px
0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><br>
That is, the CNAME at the apex is all by itself, pointing
at another<br>
apex with the right SOA and NS, no glue needed. Is that
valid? Why<br>
or why not?<br>
<br>
</blockquote>
<div><br>
</div>
</span>
<div style="font-size:12.8000001907349px">It's explicitly
invalid per RFC 2181. A zone is required to have SOA and NS
records at the apex, and a CNAME record cannot exist at a
label where those record types exist.</div>
<div style="font-size:12.8000001907349px"><br>
</div>
<div style="font-size:12.8000001907349px"><a
moz-do-not-send="true"
href="https://tools.ietf.org/html/rfc2181#section-6.1"
target="_blank">https://tools.ietf.org/html/rfc2181#section-6.1</a><br>
</div>
<div style="font-size:12.8000001907349px"><a
moz-do-not-send="true"
href="https://tools.ietf.org/html/rfc2181#section-10.1"
target="_blank">https://tools.ietf.org/html/rfc2181#section-10.1</a></div>
</div>
</div>
<div class="gmail_extra"><br>
</div>
</blockquote>
<br>
rfc1035 gets us most of the way too in section 5.2. Use of master
files to define zones<br>
<br>
When a master file is used to load a zone, the operation should be<br>
suppressed if any errors are encountered in the master file.<br>
<...><br>
Several other validity checks that should be performed in addition
to<br>
insuring that the file is syntactically correct:<br>
<...><br>
2. Exactly one SOA RR should be present at the top of the zone.<br>
<br>
Without the SOA, you don't have a zone file, and therefore the zone
should not be loaded. Once a SOA exists, a CNAME cannot coexist.<br>
<br>
<pre class="moz-signature" cols="72">--
Dave Warren
<a class="moz-txt-link-freetext" href="http://www.hireahit.com/">http://www.hireahit.com/</a>
<a class="moz-txt-link-freetext" href="http://ca.linkedin.com/in/davejwarren">http://ca.linkedin.com/in/davejwarren</a>
</pre>
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