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<div>The mapped IPv4 address is probably coming out of a 6PE (or 6VPE) MPLS router where the HopLimit field is copied into the MPLS header and when the poor P router in charge of sending the ICMPv6 has no IPv6 address at all… This is per RFC and perhaps an
explanation why uRPF is not activated?</div>
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<div>No explanation about the :: address though… </div>
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<div>As a security person, I would love to have uRPF enabled where possible but I am afraid that even in IPv4 it is not deployed everywhere :-(</div>
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<div>-éric</div>
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<div>PS: indeed, ask your vendors for features, customers have much more power than you guess :-)</div>
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<span style="font-weight:bold">From: </span>Lorenzo Colitti <<a href="mailto:lorenzo@google.com">lorenzo@google.com</a>><br>
<span style="font-weight:bold">Date: </span>jeudi 28 août 2014 07:46<br>
<span style="font-weight:bold">To: </span>Jeroen Massar <<a href="mailto:jeroen@massar.ch">jeroen@massar.ch</a>><br>
<span style="font-weight:bold">Cc: </span>IPv6 Ops list <<a href="mailto:ipv6-ops@lists.cluenet.de">ipv6-ops@lists.cluenet.de</a>><br>
<span style="font-weight:bold">Subject: </span>Re: Something with filters<br>
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<div class="gmail_quote">On Wed, Aug 27, 2014 at 9:01 AM, Jeroen Massar <span dir="ltr">
<<a href="mailto:jeroen@massar.ch" target="_blank">jeroen@massar.ch</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
9 2001:5a0:a00::2e (2001:5a0:a00::2e) 79.018 ms 79.910 ms 79.960 ms<br>
10 :: (::) 101.893 ms 102.004 ms 103.574 ms<br>
11 <a href="http://rar3.chicago-il.us.xo.net" target="_blank">rar3.chicago-il.us.xo.net</a> (::ffff:65.106.1.155) 104.732 ms<br>
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Yeah baby, we can use the unspecified address in ICMP replies!<br>
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<div>The mapped IPv4 address in there is pretty cool, too... </div>
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