Slow WiFi with Android Marshmallow & IPv6?

[Ted Mittelstaedt]

On 4/24/2016 8:24 PM, Frank Bulk wrote:
> I thought it was a pretty standard DNS client implementation to move
> past unresponsive DNS servers.
>

The big problem are the
morons who setup nameservers, and those nameservers will happily
serve out IPv6 names for maybe 1 or 2 internal domains, then are unable
to resolve anything else - worst of all are when they configure
them to resolve for the world and the nameserver is unable to reach
anything....

Ted

> 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
> <mailto: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 <mailto: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
>         <mailto:ipv6-ops-bounces+evyncke=cisco.com at lists.cluenet.de>> on
>         behalf of "Brzozowski, John Jason" <jjmb at jjmb.com
>         <mailto:jjmb at jjmb.com>>
>         *Date: *Sunday 24 April 2016 at 16:01
>         *To: *Erik Kline <ek at google.com <mailto:ek at google.com>>
>         *Cc: *Jeroen Massar <jeroen at massar.ch
>         <mailto:jeroen at massar.ch>>, IPv6 Ops list
>         <ipv6-ops at lists.cluenet.de <mailto: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
>             <mailto:ek at google.com>> wrote:
>
>                 On 24 April 2016 at 19:53, Jeroen Massar
>                 <jeroen at massar.ch <mailto: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.
>