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<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif";
color:#1F497D'>Al:<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif";
color:#1F497D'>If you read RFC 2181 section 10.3, RFC 1034 section 3.6, RFC
1912 (page 6), the average person would understand that it’s strongly discouraged.
Perhaps “illegal” is too strong a word, but the weight of the RFCs
and best practices appears to disagree with your assessment that “there
is no such standard nor requirement prohibiting the use of CNAME/alias in an MX
record.”.<o:p></o:p></span></p>
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color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif";
color:#1F497D'>Frank<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
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<p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span
style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>
bind-users-bounces@lists.isc.org [mailto:bind-users-bounces@lists.isc.org] <b>On
Behalf Of </b>Al Stu<br>
<b>Sent:</b> Sunday, January 25, 2009 12:11 AM<br>
<b>To:</b> bind-users@lists.isc.org<br>
<b>Subject:</b> BIND 9.6 Flaw - CNAME vs. A Record in MX Records are NOT
"Illegal"<o:p></o:p></span></p>
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<p class=MsoNormal>BIND 9.6 ‘named’ throws the following
message during startup claiming that it is illegal to use a CNAME/alias in
the MX record. I beg to differ. There is no such standard nor
requirement prohibiting the use of CNAME/alias in an MX record.<o:p></o:p></p>
<p class=MsoNormal> <o:p></o:p></p>
<p class=MsoNormal>Message thrown at startup:<o:p></o:p></p>
<p class=MsoNormal><span style='font-family:"Courier New"'>"named[3307]:
zone <em><span style='font-family:"Courier New"'>MyDomain</span></em>.com/IN: <em><span
style='font-family:"Courier New"'>MyDomain</span></em>.com/MX 'MX1.<em><span
style='font-family:"Courier New"'>MyDomain</span></em>.com' is a CNAME
(illegal)"</span><o:p></o:p></p>
<p class=MsoNormal> <o:p></o:p></p>
<p class=MsoNormal>Additionally in Chapter 6 – BIND Configuration
Reference, Zone File, Discussion of MX Records states the MX records
“must have an associated address record (A or AAAA) – CNAME is not
sufficient.”<o:p></o:p></p>
<p class=MsoNormal> <o:p></o:p></p>
<p class=MsoNormal>Some people seem to think RFC 974 creates a standard which
prohibits the use of CNAME/alias in MX records. But very much to the
contrary RFC 974 demonstrates that CNAME/alias is permitted in MX records.<o:p></o:p></p>
<p class=MsoNormal> <o:p></o:p></p>
<p class=MsoNormal>ISC’s message that a CNAME/alias in an MX record is
illegal is incorrect and just an attempt by ISC to get people to go along with
what is only a perceived rather than actual standard/requirement, and should be
removed so as not to further the fallacy of this perceived perception of a
standard/requirement, as it is neither a standard nor a requirement, and
certainly not illegal.<o:p></o:p></p>
<p class=MsoNormal> <o:p></o:p></p>
<p class=MsoNormal>Al Stu<o:p></o:p></p>
<p class=MsoNormal><span style='font-size:9.0pt;font-family:"Courier New"'><o:p> </o:p></span></p>
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