Slow WiFi with Android Marshmallow & IPv6?

[Lorenzo Colitti]

All happy eyeballs algorithms have user impact in terms of increased
latency, increased load, or both. We must always ask ourselves whether the
increased latency/load is worth the benefit in response time on broken
networks.

On Mon, Apr 25, 2016 at 12:24 PM, Frank Bulk <frnkblk at iname.com> wrote:

> I thought it was a pretty standard DNS client implementation to move past
> unresponsive DNS servers.
>
>
>
> We hand out several internal DNS servers to our corporate endpoints and I
> really hope they will quickly try the next DNS server if one server happens
> to be down for whatever reason.
>
> Windows: See “Querying the DNS Server, Part 3”
> https://technet.microsoft.com/en-us/library/dd197552(v=ws.10).aspx
>
> OS X: https://support.apple.com/en-us/HT203244
>
>
>
> I would hope that same approach would be used in other operating systems,
> regardless of the transport mechanism (IPv4 or IPv6).  In fact, I would
> like to see a Happy Eyeball implementation in DNS, too.  I don’t want to
> see service provider or corporate helpdesks telling customers to disable
> IPv6 just because there’s some non-optimized IPv6 deployments out there –
> both the helpdesk agents and customers will have hard time unlearning this
> behavior.
>
>
>
> Frank
>
>
>
> *From:* ipv6-ops-bounces+frnkblk=iname.com at lists.cluenet.de [mailto:
> ipv6-ops-bounces+frnkblk=iname.com at lists.cluenet.de] *On Behalf Of *Lorenzo
> Colitti
> *Sent:* Sunday, April 24, 2016 7:36 PM
> *To:* Brzozowski, John Jason <jjmb at jjmb.com>
> *Cc:* Erik Kline <ek at google.com>; Eric Vyncke (evyncke) <evyncke at cisco.com>;
> Jeroen Massar <jeroen at massar.ch>; IPv6 Ops list <ipv6-ops at lists.cluenet.de
> >
>
> *Subject:* Re: Slow WiFi with Android Marshmallow & IPv6?
>
>
>
> 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.
>
>
>
> 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 :)
>
>
>
> 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.
>
>
>
> 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
> https://source.android.com/source/report-bugs.html .
>
>
>
> On Sun, Apr 24, 2016 at 11:21 PM, Brzozowski, John Jason <jjmb at jjmb.com>
> wrote:
>
> 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.
>
>
>
> On Sun, Apr 24, 2016 at 10:17 AM, Eric Vyncke (evyncke) <evyncke at cisco.com>
> wrote:
>
> Jeroen, Erik and John,
>
>
>
> 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.
>
>
>
> -éric
>
>
>
> *From: *<ipv6-ops-bounces+evyncke=cisco.com at lists.cluenet.de> on behalf
> of "Brzozowski, John Jason" <jjmb at jjmb.com>
> *Date: *Sunday 24 April 2016 at 16:01
> *To: *Erik Kline <ek at google.com>
> *Cc: *Jeroen Massar <jeroen at massar.ch>, IPv6 Ops list <
> ipv6-ops at lists.cluenet.de>
> *Subject: *Re: Slow WiFi with Android Marshmallow & IPv6?
>
>
>
> 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.
>
> On Sunday, April 24, 2016, Erik Kline <ek at google.com> wrote:
>
> On 24 April 2016 at 19:53, Jeroen Massar <jeroen at massar.ch> wrote:
> > On 2016-04-24 11:51, Eric Vyncke (evyncke) wrote:
> >> One of the first Belgian ISP to deploy IPv6 (VOO) is now recommending to
> >> its Android Marshmallow (6.0.1) users to deactivate IPv6 on their
> >> residential WiFi CPE... :-(
> >>
> >> It appears that the issue is about IPv6 web sites/apps being really
> >> slower when using IPv6.
> >
> > Is it a DNS issue maybe?
> >
> > https://www.sixxs.net/faq/dns/?faq=ipv6slowconnect
> >
> > As that has been the general cause of "Disable IPv6!!!!!" around the
> > world for many years already.
> >
> > Of course, without more details, little one really can say. Bug number
> > maybe?
> >
> > Greets,
> >  Jeroen
> >
>
> Yeah, a link to something that eventually leads to a bug report would be
> good.
>
> Also if anybody has adb installed they can just try "adb shell dumpsys
> connectivity --diag" and see what the over-simplified diagnostic
> output shows.
>
>
>
>
>
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