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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Hi All,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'> RFC 2671 mentions in Section 5.3<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='page-break-before:always'><b><font size=2
face="Courier New"><span lang=EN style='font-size:10.0pt;font-family:"Courier New";
font-weight:bold'>Responders who do not understand these protocol extensions
are</span></font></b><font size=2 face="Courier New"><span lang=EN
style='font-size:10.0pt;font-family:"Courier New"'><o:p></o:p></span></font></p>
<p class=MsoNormal style='page-break-before:always'><font size=2
face="Courier New"><span lang=EN style='font-size:10.0pt;font-family:"Courier New"'>expected
to send a response with RCODE NOTIMPL, FORMERR, or<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span lang=EN
style='font-size:10.0pt'>SERVFAIL.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span lang=EN
style='font-size:10.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span lang=EN
style='font-size:12.0pt'>However the above mentioned error codes are shared [SERVFAIL,
</span></font><font face="Courier New"><span lang=EN style='font-family:"Courier New"'>NOTIMPL</span></font><span
lang=EN>] are shared, so how do we ascertain that the error code returned is an
indication that a particular server is non-EDNS, since the error might be
returned due to some other reason also.<o:p></o:p></span></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span lang=EN
style='font-size:12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span lang=EN
style='font-size:12.0pt'>So essentially my query is how do we decide that a
particular server is EDNS or not? Can it be assumed that each time the above
three error codes are returned , it signifies that the DNS server is not EDNS
capable?<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span lang=EN
style='font-size:12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span lang=EN
style='font-size:12.0pt'>Regards<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span lang=EN
style='font-size:12.0pt'>Ashwin<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span lang=EN
style='font-size:12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=3 face=Arial><span style='font-size:12.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
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