<div dir="ltr">Operators MUST no advertise DNS server IPv6 addresses if they do not work. The fix is simple. I would like to see as much happening over IPv6 as possible, the last thing I really want to see is more happy (happier) eye ball implementations.<br></div><div class="gmail_extra"><br><div class="gmail_quote">On Sun, Apr 24, 2016 at 8:35 PM, 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:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Android does not behave well when configured with IPv6 DNS servers that do not work. This is because it prefers IPv6, does not (yet) ignore unresponsive DNS servers, and has quite high resolver timeouts.<div><div><br></div><div>One infamous example is a German ISP whose CPE announces an IPv6 address in RDNSS but never responds to queries to that address. Perhaps because no other operating system has a problem in this situation, the ISP has not fixed this, and users have been blaming Android. This is by no means the only case, though. Some of you know who you are :)</div></div><div><br></div><div>Future Android releases will likely ignore broken DNS servers. This is unfortunate; we'd hoped that ISPs that provision devices with IPv6 connectivity would be able to ensure that the DNS servers are responsive and that as IPv6 matured this problem would go away. Unfortunately it has not.</div><div><br></div><div>As Erik said, the way to debug this problem would be to have someone running 6.0.1 on voo to run "adb shell dumpsys connectivity --diag" and open a bug as described at <a href="https://source.android.com/source/report-bugs.html" target="_blank">https://source.android.com/source/report-bugs.html</a> .</div></div><div class="HOEnZb"><div class="h5"><div class="gmail_extra"><br><div class="gmail_quote">On Sun, Apr 24, 2016 at 11:21 PM, Brzozowski, John Jason <span dir="ltr"><<a href="mailto:jjmb@jjmb.com" target="_blank">jjmb@jjmb.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Android is properly trying to query DNS over IPv6 unlike other devices/OSes. Most other mobile platforms still prefer the querying of DNS over IPv4 for A/AAAA RR query types.<br></div><div><div><div class="gmail_extra"><br><div class="gmail_quote">On Sun, Apr 24, 2016 at 10:17 AM, Eric Vyncke (evyncke) <span dir="ltr"><<a href="mailto:evyncke@cisco.com" target="_blank">evyncke@cisco.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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<div>Jeroen, Erik and John,</div>
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<div>Thanks for the hint. I will advise the ISP to investigate any DNS issue (such as not returning an error message when requesting a non-existing AAAA) but I wonder why it is linked to that specific Android Marshmallow version.</div>
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<div>-éric</div>
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<span style="font-weight:bold">From: </span><<a href="mailto:ipv6-ops-bounces+evyncke=cisco.com@lists.cluenet.de" target="_blank">ipv6-ops-bounces+evyncke=cisco.com@lists.cluenet.de</a>> on behalf of "Brzozowski, John Jason" <<a href="mailto:jjmb@jjmb.com" target="_blank">jjmb@jjmb.com</a>><br>
<span style="font-weight:bold">Date: </span>Sunday 24 April 2016 at 16:01<br>
<span style="font-weight:bold">To: </span>Erik Kline <<a href="mailto:ek@google.com" target="_blank">ek@google.com</a>><br>
<span style="font-weight:bold">Cc: </span>Jeroen Massar <<a href="mailto:jeroen@massar.ch" target="_blank">jeroen@massar.ch</a>>, IPv6 Ops list <<a href="mailto:ipv6-ops@lists.cluenet.de" target="_blank">ipv6-ops@lists.cluenet.de</a>><br>
<span style="font-weight:bold">Subject: </span>Re: Slow WiFi with Android Marshmallow & IPv6?<br>
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<div>My customers saw this issue at one point. We had issues with DNS over IPv6. Bad DNS and/or network configurations. Once these were fixed, the problems cleared up.<br>
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On Sunday, April 24, 2016, Erik Kline <<a href="mailto:ek@google.com" target="_blank">ek@google.com</a>> wrote:<br>
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On 24 April 2016 at 19:53, Jeroen Massar <<a>jeroen@massar.ch</a>> wrote:<br>
> On 2016-04-24 11:51, Eric Vyncke (evyncke) wrote:<br>
>> One of the first Belgian ISP to deploy IPv6 (VOO) is now recommending to<br>
>> its Android Marshmallow (6.0.1) users to deactivate IPv6 on their<br>
>> residential WiFi CPE... :-(<br>
>><br>
>> It appears that the issue is about IPv6 web sites/apps being really<br>
>> slower when using IPv6.<br>
><br>
> Is it a DNS issue maybe?<br>
><br>
> <a href="https://www.sixxs.net/faq/dns/?faq=ipv6slowconnect" target="_blank">https://www.sixxs.net/faq/dns/?faq=ipv6slowconnect</a><br>
><br>
> As that has been the general cause of "Disable IPv6!!!!!" around the<br>
> world for many years already.<br>
><br>
> Of course, without more details, little one really can say. Bug number<br>
> maybe?<br>
><br>
> Greets,<br>
> Jeroen<br>
><br>
<br>
Yeah, a link to something that eventually leads to a bug report would be good.<br>
<br>
Also if anybody has adb installed they can just try "adb shell dumpsys<br>
connectivity --diag" and see what the over-simplified diagnostic<br>
output shows.<br>
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