<div dir="auto">QNAME minimization. Their non-compliant load balancers pretending to be authoritative servers give responses that break QNAME minimization.</div><div dir="auto"><br></div><div><br><div class="gmail_quote gmail_quote_container"><div dir="ltr" class="gmail_attr">On Tue, Nov 18, 2025 at 8:06 PM Richard Laager via dns-operations <<a href="mailto:dns-operations@dns-oarc.net">dns-operations@dns-oarc.net</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;padding-left:1ex;border-left-color:rgb(204,204,204)"><br><br><br>---------- Forwarded message ----------<br>From: Richard Laager <<a href="mailto:rlaager@wiktel.com" target="_blank">rlaager@wiktel.com</a>><br>To: <a href="mailto:dns-operations@lists.dns-oarc.net" target="_blank">dns-operations@lists.dns-oarc.net</a><br>Cc: <br>Bcc: <br>Date: Tue, 18 Nov 2025 21:55:06 -0600<br>Subject: geo9/<a href="http://geo10.t-mobile.com" rel="noreferrer" target="_blank">geo10.t-mobile.com</a> Returning NXDOMAIN for WiFi Calling<br><u></u>
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<p>Anyone have a good contact for T-Mobile authoritative DNS? I've
had no response from <a href="mailto:dnsadmin@t-mobile.com" target="_blank">dnsadmin@t-mobile.com</a>.<br>
</p>
<p>My customers are reporting that T-Mobile WiFi calling
(sometimes) does not work on our Internet service. This appears
to be due to DNS resolution failures.</p>
<p>The cause of the failures seems to be that <a href="http://geo9.t-mobile.com" target="_blank">geo9.t-mobile.com</a>
and <a href="http://geo10.t-mobile.com" target="_blank">geo10.t-mobile.com</a> incorrectly return NXDOMAIN when queried
for NS records for
<a href="http://epdg.epc.geo.mnc260.mcc310.pub.3gppnetwork.org" target="_blank">epdg.epc.geo.mnc260.mcc310.pub.3gppnetwork.org</a> and
<a href="http://epc.geo.mnc260.mcc310.pub.3gppnetwork.org" target="_blank">epc.geo.mnc260.mcc310.pub.3gppnetwork.org</a>. Note that they
correctly return an answer when queried for A records. See also:
<a href="https://dnsviz.net/d/epdg.epc.mnc260.mcc310.pub.3gppnetwork.org/dnssec/" target="_blank">https://dnsviz.net/d/epdg.epc.mnc260.mcc310.pub.3gppnetwork.org/dnssec/</a></p>
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<pre cols="72" style="font-family:monospace">--
Richard
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<br><br><br>---------- Forwarded message ----------<br>From: Richard Laager via dns-operations <<a href="mailto:dns-operations@dns-oarc.net" target="_blank">dns-operations@dns-oarc.net</a>><br>To: <a href="mailto:dns-operations@lists.dns-oarc.net" target="_blank">dns-operations@lists.dns-oarc.net</a><br>Cc: <br>Bcc: <br>Date: Tue, 18 Nov 2025 21:55:06 -0600<br>Subject: [dns-operations] geo9/<a href="http://geo10.t-mobile.com" rel="noreferrer" target="_blank">geo10.t-mobile.com</a> Returning NXDOMAIN for WiFi Calling<br>_______________________________________________<br>
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</blockquote></div></div>