<div dir="ltr">Hi,<div class="gmail_extra"><br><div class="gmail_quote">On 10 October 2013 14:25, Lorenzo Colitti <span dir="ltr"><<a href="mailto:lorenzo@google.com" target="_blank">lorenzo@google.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="ltr"><div>On Thu, Oct 10, 2013 at 12:19 PM, Geoff Huston <span dir="ltr"><<a href="mailto:gih@apnic.net" target="_blank">gih@apnic.net</a>></span> wrote:<br>
</div><div class="gmail_extra"><div class="gmail_quote"><div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
But I've thought about your response, and if I'm allowed to dream (!), and in that dream where the efforts of COmcast, Google etc with IPv6 bear fruit, and I'm allowed to contemplate a world of, say, 33% IPv6 and 66% V4, then wouldn't we then see the remaining Teredo folk having 33% of their peer sessions head into Teredo relays to get to those 33% who are using unicast IPv6? And wouldn't that require these Teredo relays that we all know have been such a performance headache?<br>
</blockquote><div><br></div></div><div>Can't you fix that by telling the app "if all you have is Teredo, prefer Teredo even if the peer has native IPv6 as well"?</div><div><br></div><div>Of course this breaks down when IPv4 goes away, once IPv4 starts going away then there's really way to do peer-to-peer without relays, right? (Also, IPv4 going away is relatively far away at this point.)</div>
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</blockquote></div></div><div class="gmail_extra"><br></div><div class="gmail_extra">These issues are discussed in the document:</div><div class="gmail_extra">---</div><div class="gmail_extra">Even for users that <b>do have native IPv6 –
Teredo will be used to interact with IPv4-only peers</b>, or in cases where IPv6
connectivity between peers is not functioning. In general, Xbox One will
dynamically assess and use the best available connectivity method (Native IPv6,
Teredo, and even IPv4). The implementation is similar in sprit to <a href="http://tools.ietf.org/html/rfc6555">RFC 6555</a>. </div><div class="gmail_extra"><br></div>For that reason, it is important for all interested network operators to understand Teredo operating requirements. Xbox One <b>does not support operating on an IPv6-only</b> network because of the need to reliably interoperate with nodes on IPv4-only networks.<br>
---<div><br><div class="gmail_extra"> John</div></div></div>