<div dir="ltr"><div dir="ltr"><div dir="ltr">While I happen to agree with you 2002::/16 SHOULD NOT be filtered, and RFC 7526 is quite clear that 2002::/16 is still valid. However, it is perfectly permissible to filter it, if that is the policy a network operator wishes to enforce. </div></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Tue, May 14, 2019 at 10:30 AM JORDI PALET MARTINEZ <<a href="mailto:jordi.palet@consulintel.es">jordi.palet@consulintel.es</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div lang="ES"><div class="gmail-m_-2264573854596257108WordSection1"><p class="MsoNormal"><span lang="EN-US">6to4 is still a valid protocol. IT SHOULD NOT be filtered. 6to4 uses the same protocol as other tunnels such as 6in4 (protocol 41).<u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p><p class="MsoNormal"><a href="https://www.ietf.org/rfc/rfc3056.txt" target="_blank"><span lang="EN-US">https://www.ietf.org/rfc/rfc3056.txt</span></a><span lang="EN-US" style="font-size:11pt"><u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p><p class="MsoNormal"><span lang="EN-US">It works fine for peer to peer applications.<u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p><p class="MsoNormal"><span lang="EN-US">What the IETF deprecated is anycast for 6to4 relays:<u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p><p class="MsoNormal"><a href="https://tools.ietf.org/html/rfc7526" target="_blank"><span lang="EN-US">https://tools.ietf.org/html/rfc7526</span></a><span lang="EN-US" style="font-size:11pt"><u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p><p class="MsoNormal"><span lang="EN-US">I believe Hurricane Electric still hosts 6to4 relays.<u></u><u></u></span></p><div><p class="MsoNormal"><span lang="EN-US" style="font-size:10.5pt;color:black"><br>Regards,<u></u><u></u></span></p><p class="MsoNormal" style="margin-bottom:12pt"><span lang="EN-US" style="font-size:10.5pt;color:black">Jordi<u></u><u></u></span></p><p class="MsoNormal" style="margin-bottom:12pt"><span lang="EN-US" style="font-size:10.5pt;color:black"><u></u> <u></u></span></p></div><p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p><p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p><div><div><p class="MsoNormal" style="margin-left:35.4pt">El 14/5/19 17:25, "Amos Rosenboim" <<a href="mailto:ipv6-ops-bounces+jordi.palet=consulintel.es@lists.cluenet.de" target="_blank">ipv6-ops-bounces+jordi.palet=consulintel.es@lists.cluenet.de</a> en nombre de <a href="mailto:amos@oasis-tech.net" target="_blank">amos@oasis-tech.net</a>> escribió:<span style="font-size:11pt"><u></u><u></u></span></p></div></div><div><p class="MsoNormal" style="margin-left:35.4pt"><u></u> <u></u></p></div><p class="MsoNormal" style="margin-left:35.4pt"><span style="font-size:11pt">Hello,</span><u></u><u></u></p><p class="MsoNormal" style="margin-left:35.4pt"><span style="font-size:11pt"> </span><u></u><u></u></p><p class="MsoNormal" style="margin-left:35.4pt"><span style="font-size:11pt"> </span><u></u><u></u></p><p class="MsoNormal" style="margin-left:35.4pt"><span style="font-size:11pt">As we are trying to tighten the security for IPv6 traffic in our network, I was looking for a reference IPv6 ingress filter.</span><u></u><u></u></p><p class="MsoNormal" style="margin-left:35.4pt"><span style="font-size:11pt">I came up with Job Snijders suggestion (thank you Job) that can be conveniently found at whois -h <a href="http://whois.ripe.net" target="_blank">whois.ripe.net</a> fltr-martian-v6</span><u></u><u></u></p><p class="MsoNormal" style="margin-left:35.4pt"><span style="font-size:11pt"> </span><u></u><u></u></p><p class="MsoNormal" style="margin-left:35.4pt"><span style="font-size:11pt">After applying the filter I noticed some traffic from 6to4 addresses (2002::/16) to our native IPv6 prefixes (residential users in this case).</span><u></u><u></u></p><p class="MsoNormal" style="margin-left:35.4pt"><span style="font-size:11pt">The traffic is a mix of both UDP and TCP but all on high port numbers on both destination and source.</span><u></u><u></u></p><p class="MsoNormal" style="margin-left:35.4pt"><span style="font-size:11pt">It seems to me like some P2P traffic, but I really can’t tell.</span><u></u><u></u></p><p class="MsoNormal" style="margin-left:35.4pt"><span style="font-size:11pt"> </span><u></u><u></u></p><p class="MsoNormal" style="margin-left:35.4pt"><span style="font-size:11pt">This got me thinking, why should we filter these addresses at all ?</span><u></u><u></u></p><p class="MsoNormal" style="margin-left:35.4pt"><span style="font-size:11pt">I know 6to4 is mostly dead, but is it inherently bad ?</span><u></u><u></u></p><p class="MsoNormal" style="margin-left:35.4pt"><span style="font-size:11pt"> </span><u></u><u></u></p><p class="MsoNormal" style="margin-left:35.4pt"><span style="font-size:11pt">And if so, why is the prefix (2002::/16) still being routed ?</span><u></u><u></u></p><p class="MsoNormal" style="margin-left:35.4pt"><span style="font-size:11pt"> </span><u></u><u></u></p><p class="MsoNormal" style="margin-left:35.4pt"><span style="font-size:11pt">Thanks,</span><u></u><u></u></p><p class="MsoNormal" style="margin-left:35.4pt"><span style="font-size:11pt"> </span><u></u><u></u></p><p class="MsoNormal" style="margin-left:35.4pt"><span style="font-size:11pt">Amos Rosenboim</span><u></u><u></u></p><p class="MsoNormal" style="margin-left:35.4pt"><span style="font-size:11pt">-- </span><u></u><u></u></p><p class="MsoNormal" style="margin-left:35.4pt"> <u></u><u></u></p></div><br>**********************************************<br>
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</blockquote></div><br clear="all"><div><br></div>-- <br><div dir="ltr" class="gmail_signature">===============================================<br>David Farmer <a href="mailto:Email%3Afarmer@umn.edu" target="_blank">Email:farmer@umn.edu</a><br>Networking & Telecommunication Services<br>Office of Information Technology<br>University of Minnesota <br>2218 University Ave SE Phone: 612-626-0815<br>Minneapolis, MN 55414-3029 Cell: 612-812-9952<br>=============================================== </div>