Mailing List Archive

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

On 24 April 2016 at 19:53, Jeroen Massar <jeroen@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.

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@google.com> wrote:

> On 24 April 2016 at 19:53, Jeroen Massar <jeroen@massar.ch <javascript:;>>
> 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.
>

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

On 2016-04-24 16:17, Eric Vyncke (evyncke) 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.

Something-Something-Happy-Eyeballs... HE also exists because of broken
DNS, not only broken connectivity.

Other versions might thus have better HE, and of course, as it is
Android, newer versions that have that might not be available yet for
the devices that you have...

No idea if Android actually does HE though and if which version, and
even if the "OS" itself does it, it then still depends on the
application if it uses it, which unfortunately as we get a zillion
methods & libraries to actually do connects and every application does
it by-themselves more or less, it is all magic anyway...

Greets,
Jeroen

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

Has someone done testing to very that the same issue doesn't affect,
say, Lollipop?

On 24 April 2016 at 23:17, Eric Vyncke (evyncke) <evyncke@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@lists.cluenet.de> on behalf of
> "Brzozowski, John Jason" <jjmb@jjmb.com>
> Date: Sunday 24 April 2016 at 16:01
> To: Erik Kline <ek@google.com>
> Cc: Jeroen Massar <jeroen@massar.ch>, IPv6 Ops list
> <ipv6-ops@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@google.com> wrote:
>>
>> On 24 April 2016 at 19:53, Jeroen Massar <jeroen@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.

Remember, Android developers refuse to implement DHCPv6 and so can only get DNS server info from RDDNS (rfc6106). Since the number RA devices that support RFC6106 are limited, this provides another problem set for Android devices and IPv6

----
Matthew Huff | 1 Manhattanville Rd
Director of Operations | Purchase, NY 10577
OTA Management LLC | Phone: 914-460-4039
aim: matthewbhuff | Fax: 914-694-5669

From: ipv6-ops-bounces+mhuff=ox.com@lists.cluenet.de [mailto:ipv6-ops-bounces+mhuff=ox.com@lists.cluenet.de] On Behalf Of Brzozowski, John Jason
Sent: Sunday, April 24, 2016 10:21 AM
To: Eric Vyncke (evyncke) <evyncke@cisco.com>
Cc: Erik Kline <ek@google.com>; Jeroen Massar <jeroen@massar.ch>; IPv6 Ops list <ipv6-ops@lists.cluenet.de>
Subject: Re: Slow WiFi with Android Marshmallow & IPv6?

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

On Sun, 24 Apr 2016, Matthew Huff wrote:

> Remember, Android developers refuse to implement DHCPv6 and so can only
> get DNS server info from RDDNS (rfc6106). Since the number RA devices
> that support RFC6106 are limited, this provides another problem set for
> Android devices and IPv6

Well, this actually reduces the risk that Android runs into v6 DNS
resolver related problems, because in non-trivial amount of cases it will
not have a v6 based resolver configured :P

--
Mikael Abrahamsson email: swmike@swm.pp.se

As long as we have either DHCPv6 or RFC6106 we can make this work to enable
IPv6 only for devices like phones, etc. Between DHCPv6 and RFC6106 we have
most devices covered. A co-worker recently introduced me to the Linux
package for RDNSS.

On Sun, Apr 24, 2016 at 11:37 AM, Matthew Huff <mhuff@ox.com> wrote:

> Remember, Android developers refuse to implement DHCPv6 and so can only
> get DNS server info from RDDNS (rfc6106). Since the number RA devices
> that support RFC6106 are limited, this provides another problem set for
> Android devices and IPv6
>
>
>
> ----
>
> Matthew Huff | 1 Manhattanville Rd
>
> Director of Operations | Purchase, NY 10577
>
> OTA Management LLC | Phone: 914-460-4039
>
> aim: matthewbhuff | Fax: 914-694-5669
>
>
>
> *From:* ipv6-ops-bounces+mhuff=ox.com@lists.cluenet.de [mailto:
> ipv6-ops-bounces+mhuff=ox.com@lists.cluenet.de] *On Behalf Of *Brzozowski,
> John Jason
> *Sent:* Sunday, April 24, 2016 10:21 AM
> *To:* Eric Vyncke (evyncke) <evyncke@cisco.com>
> *Cc:* Erik Kline <ek@google.com>; Jeroen Massar <jeroen@massar.ch>; IPv6
> Ops list <ipv6-ops@lists.cluenet.de>
>
> *Subject:* Re: Slow WiFi with Android Marshmallow & IPv6?
>
>
>
> 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@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@lists.cluenet.de> on behalf
> of "Brzozowski, John Jason" <jjmb@jjmb.com>
> *Date: *Sunday 24 April 2016 at 16:01
> *To: *Erik Kline <ek@google.com>
> *Cc: *Jeroen Massar <jeroen@massar.ch>, IPv6 Ops list <
> ipv6-ops@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@google.com> wrote:
>
> On 24 April 2016 at 19:53, Jeroen Massar <jeroen@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.
>
>
>

"Brzozowski, John Jason" <jjmb@jjmb.com> writes:

> As long as we have either DHCPv6 or RFC6106

Shouldn't that be "as long as we have DHCPv6 and RFC6106"? Android does
not support DHCPv6 and (AFAIK) Microsoft does not support RFC6106. So in
a mixed environment you need both.

Jens, who just opened a case at Cisco regarding RFC6106 support on the
Cat 6500 platform
--
----------------------------------------------------------------------------
| Foelderichstr. 40 | 13595 Berlin, Germany | +49-151-18721264 |
| http://blog.quux.de | jabber: jenslink@quux.de | --------------- |
----------------------------------------------------------------------------

Why Android doesn't support DHCPv6 is detailed here:

https://code.google.com/p/android/issues/detail?id=32621#c53

They say to use SLAAC and RFC6106. I happen agree with their reasoning.
It is Microsoft who needs to change, not Google. The IPv6 standard
does not require DHCPv6 and it's a model that is an archaic carryover
from IPv4.

For those who must run DHCPv6 on Android:

https://play.google.com/store/apps/details?id=org.daduke.realmar.dhcpv6client

Now I will also point out something else that affects ISPs - like
Comcast (are you listening?) - and probably affected "this Belgian ISP"
that Erik is reporting.

The issue really isn't what protocol is supported. The issue is
PROPER support of what protocol is selected.

Take Comcast for example. They rolled out IPv6 but the last mile
stinks. If you are a regular Xfinity customer and you use your
own modem, you can put it in bridged mode and use a 3rd party router
behind it. Then, IPv6 support is your problem and you can fight it
out with Dlink or Belkin or Linksys or whoever and if those companies
won't fix their trash you can select a different customer or use
a Linux box as a router or use a real router like a Cisco 2800 or
something.

But if you are a business you are screwed - because you must use
their CPE if you want static IPv4 addresses and they only have 3
CPEs that businesses can use - the Cisco BWG, the Netgear and the
SMC and ALL THREE are broken. The SMC does not support DHCPv6-PD
nor static IPv6 subnetting and if you use it in SLAAC only then
after 6 hours of the IPv6 stack being turned on it reboots. The
Cisco BWG does not support DHCP-PD, and while the Netgear does work
properly on DHCP-PD it has a bad bug with VoIP and it also cannot
support the 100+ speeds due to inadequate CPU. Comcast has known
about these bugs and filed them with their CPE vendors SMC & Cisco who
have basically done nothing. (Comcast DID file bugs with Netgear who
fixed the IPv6 ones and are ignoring the VoIP one go figure)

I am sure other ISPs like the Belgian ISP mentioned by the OP are in
the same boat - their IPv6 deployments are held hostage by firmware
bugs in routers they are deploying to customers. THAT is probably why
the Belgian ISP is telling people to turn off IPv6 - not because
knowledgeable users cannot setup a decent IPv6 environment on their
networks that work with Android - but because that ISP is knowingly
supplying CPE devices with IPv6 bugs to their customers - much like
Comcast continues to do in the United States with the Cisco and SMC
devices.


Ted

On 4/24/2016 11:13 AM, Jens Link wrote:
> "Brzozowski, John Jason"<jjmb@jjmb.com> writes:
>
>> As long as we have either DHCPv6 or RFC6106
>
> Shouldn't that be "as long as we have DHCPv6 and RFC6106"? Android does
> not support DHCPv6 and (AFAIK) Microsoft does not support RFC6106. So in
> a mixed environment you need both.
>
> Jens, who just opened a case at Cisco regarding RFC6106 support on the
> Cat 6500 platform

Ted,
On 25/04/2016 07:55, Ted Mittelstaedt wrote:
> Why Android doesn't support DHCPv6 is detailed here:
>
> https://code.google.com/p/android/issues/detail?id=32621#c53

Yes, we all know Lorenzo's opinion, and the follow-up comments there
give the opposing opinions.

>
> They say to use SLAAC and RFC6106. I happen agree with their reasoning. It is Microsoft who needs to change, not Google. The
> IPv6 standard does not require DHCPv6

Neither does the IPv4 standard, if we're being pedantic.

> and it's a model that is an archaic carryover from IPv4.

It happens to be preferred by a lot of enterprise network operators, so
equipment vendors & o/s really need to support both.

(Also, looking at the history of DHCP and ND/RA, DHCP is not actually
archaic; it's only about 3 years older than IPv6, and was not generally
available until after ND/RA was designed. IPv4 was very annoying to deploy
and prone to fat-finger errors before DHCP was retro-fitted.)

> For those who must run DHCPv6 on Android:
>
> https://play.google.com/store/apps/details?id=org.daduke.realmar.dhcpv6client
>
> Now I will also point out something else that affects ISPs - like
> Comcast (are you listening?) - and probably affected "this Belgian ISP"
> that Erik is reporting.
>
> The issue really isn't what protocol is supported. The issue is
> PROPER support of what protocol is selected.

Absolutely correct, which is why I find the Android choice short-sighted.
Having to install this as an add-on seems very unlikely to produce "PROPER"
support. The first user comment for that add-on is "Doesn't work. There is not
enough space in /system...". Duh.

Brian

Ted,

> On Apr 24, 2016, at 3:55 PM, Ted Mittelstaedt <tedm@ipinc.net> wrote:

> Now I will also point out something else that affects ISPs - like
> Comcast (are you listening?) - and probably affected "this Belgian ISP"
> that Erik is reporting.
>
> The issue really isn't what protocol is supported. The issue is
> PROPER support of what protocol is selected.
>
> Take Comcast for example. They rolled out IPv6 but the last mile
> stinks. …

Documentation, please.

> But if you are a business you are screwed - because you must use
> their CPE if you want static IPv4 addresses …

Interesting point, but not related to DHCP use. Also, many business users are in manufacturing and retail, where web sites and mail services are outsourced, thus mooting most requirements for fix IP addressing of any kind.

All,

Finally, as pointed out in many discussions over the last decade or more on mailing lists such as NANOG, the Android Open Source Project - Issue Tracker, and this list, how a network provider chooses to meet the business requirements for network operations is probably not within the purview of any particular device software developer. Separation of functions is a useful concept in any management regime. For many, it makes sense to let routers concentrate on constructing FIBs and routing packets (with some possible minor DHCP relay activities), let end system managers control end systems using business-appropriate tools, and generally get on with business using whatever tools are both useful and amenable to economical management. DHCP seems to be one of these tools. Deliberately blocking use of such tools seems foolhardy at best.

James R. Cutler
James.cutler@consultant.com
PGP keys at http://pgp.mit.edu

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

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.

On Sun, Apr 24, 2016 at 8:35 PM, Lorenzo Colitti <lorenzo@google.com> wrote:

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

s/MUST no/MUST not/g

On Sun, Apr 24, 2016 at 8:49 PM, Brzozowski, John Jason <jjmb@jjmb.com>
wrote:

> 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.
>
> On Sun, Apr 24, 2016 at 8:35 PM, Lorenzo Colitti <lorenzo@google.com>
> wrote:
>
>> 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@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@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@lists.cluenet.de> on behalf
>>>> of "Brzozowski, John Jason" <jjmb@jjmb.com>
>>>> Date: Sunday 24 April 2016 at 16:01
>>>> To: Erik Kline <ek@google.com>
>>>> Cc: Jeroen Massar <jeroen@massar.ch>, IPv6 Ops list <
>>>> ipv6-ops@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@google.com> wrote:
>>>>
>>>>> On 24 April 2016 at 19:53, Jeroen Massar <jeroen@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.
>>>>>
>>>>
>>>
>>
>

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@lists.cluenet.de [mailto:ipv6-ops-bounces+frnkblk=iname.com@lists.cluenet.de] On Behalf Of Lorenzo Colitti
Sent: Sunday, April 24, 2016 7:36 PM
To: Brzozowski, John Jason <jjmb@jjmb.com>
Cc: Erik Kline <ek@google.com>; Eric Vyncke (evyncke) <evyncke@cisco.com>; Jeroen Massar <jeroen@massar.ch>; IPv6 Ops list <ipv6-ops@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@jjmb.com <mailto:jjmb@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@cisco.com <mailto:evyncke@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@lists.cluenet.de <mailto:ipv6-ops-bounces+evyncke=cisco.com@lists.cluenet.de> > on behalf of "Brzozowski, John Jason" <jjmb@jjmb.com <mailto:jjmb@jjmb.com> >
Date: Sunday 24 April 2016 at 16:01
To: Erik Kline <ek@google.com <mailto:ek@google.com> >
Cc: Jeroen Massar <jeroen@massar.ch <mailto:jeroen@massar.ch> >, IPv6 Ops list <ipv6-ops@lists.cluenet.de <mailto:ipv6-ops@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@google.com <mailto:ek@google.com> > wrote:

On 24 April 2016 at 19:53, Jeroen Massar <jeroen@massar.ch <mailto:jeroen@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.

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@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@lists.cluenet.de [mailto:
> ipv6-ops-bounces+frnkblk=iname.com@lists.cluenet.de] *On Behalf Of *Lorenzo
> Colitti
> *Sent:* Sunday, April 24, 2016 7:36 PM
> *To:* Brzozowski, John Jason <jjmb@jjmb.com>
> *Cc:* Erik Kline <ek@google.com>; Eric Vyncke (evyncke) <evyncke@cisco.com>;
> Jeroen Massar <jeroen@massar.ch>; IPv6 Ops list <ipv6-ops@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@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@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@lists.cluenet.de> on behalf
> of "Brzozowski, John Jason" <jjmb@jjmb.com>
> *Date: *Sunday 24 April 2016 at 16:01
> *To: *Erik Kline <ek@google.com>
> *Cc: *Jeroen Massar <jeroen@massar.ch>, IPv6 Ops list <
> ipv6-ops@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@google.com> wrote:
>
> On 24 April 2016 at 19:53, Jeroen Massar <jeroen@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.
>
>
>
>
>

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@lists.cluenet.de
> [mailto:ipv6-ops-bounces+frnkblk=iname.com@lists.cluenet.de] *On Behalf
> Of *Lorenzo Colitti
> *Sent:* Sunday, April 24, 2016 7:36 PM
> *To:* Brzozowski, John Jason <jjmb@jjmb.com>
> *Cc:* Erik Kline <ek@google.com>; Eric Vyncke (evyncke)
> <evyncke@cisco.com>; Jeroen Massar <jeroen@massar.ch>; IPv6 Ops list
> <ipv6-ops@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@jjmb.com
> <mailto:jjmb@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@cisco.com <mailto:evyncke@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@lists.cluenet.de
> <mailto:ipv6-ops-bounces+evyncke=cisco.com@lists.cluenet.de>> on
> behalf of "Brzozowski, John Jason" <jjmb@jjmb.com
> <mailto:jjmb@jjmb.com>>
> *Date: *Sunday 24 April 2016 at 16:01
> *To: *Erik Kline <ek@google.com <mailto:ek@google.com>>
> *Cc: *Jeroen Massar <jeroen@massar.ch
> <mailto:jeroen@massar.ch>>, IPv6 Ops list
> <ipv6-ops@lists.cluenet.de <mailto:ipv6-ops@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@google.com
> <mailto:ek@google.com>> wrote:
>
> On 24 April 2016 at 19:53, Jeroen Massar
> <jeroen@massar.ch <mailto:jeroen@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.
>

Eric,

Any root cause identified yet? Is it an Android problem, or more in
the category of one that Android merely exposed?

-ek

Agreed 100% - to it's credit Comcast does that on the -working- CPE
devices as far as I can tell...

Ted

On 4/24/2016 5:49 PM, Brzozowski, John Jason wrote:
> 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.
>
> On Sun, Apr 24, 2016 at 8:35 PM, Lorenzo Colitti <lorenzo@google.com
> <mailto:lorenzo@google.com>> wrote:
>
> 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@jjmb.com <mailto:jjmb@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@cisco.com <mailto:evyncke@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@lists.cluenet.de
> <mailto:ipv6-ops-bounces+evyncke=cisco.com@lists.cluenet.de>> on
> behalf of "Brzozowski, John Jason" <jjmb@jjmb.com
> <mailto:jjmb@jjmb.com>>
> Date: Sunday 24 April 2016 at 16:01
> To: Erik Kline <ek@google.com <mailto:ek@google.com>>
> Cc: Jeroen Massar <jeroen@massar.ch
> <mailto:jeroen@massar.ch>>, IPv6 Ops list
> <ipv6-ops@lists.cluenet.de <mailto:ipv6-ops@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@google.com
> <mailto:ek@google.com>> wrote:
>
> On 24 April 2016 at 19:53, Jeroen Massar
> <jeroen@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.
>
>
>
>

Hi,

On Mon, Apr 25, 2016 at 09:35:46AM +0900, Lorenzo Colitti wrote:
> Future Android releases will likely ignore broken DNS servers. This is
> unfortunate;

Actually, it's most fortunate :-) - "a broken DNS server" can always happen,
and client OSes that handle this gracefully lead to happy eyeballs and less
frustration.

Of course it is silly to announce a known-broken v6 address for DNS, but
even with everything done correctly, outages *do* happen - and the whole
point of having more than one recursor available is "make good use of the
list", not "make your users suffer".

Gert Doering
-- NetMaster
--
have you enabled IPv6 on something today...?

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On 4/24/2016 1:42 PM, Brian E Carpenter wrote:
> Ted,
> On 25/04/2016 07:55, Ted Mittelstaedt wrote:
>> Why Android doesn't support DHCPv6 is detailed here:
>>
>> https://code.google.com/p/android/issues/detail?id=32621#c53
>
> Yes, we all know Lorenzo's opinion, and the follow-up comments there
> give the opposing opinions.
>

I've read the follow-ups and am unconvinced. If Microsquash had not
supported DHCPv6 and used RFC6106 then DHCPv6 would have died a quick
death and we wouldn't be having that argument.

Nothing is stopping anyone from pulling down a copy of cyanogenmod,
adding in dhcpv6, rolling their own Android install, and loading it on
a phone manufactured by a company (like HTC) that is not retarded and
allows you to boot your own distro. The commentors are trying to
force their view on the rest of the world and they don't own the
brand, here, Google does.

>>
>> They say to use SLAAC and RFC6106. I happen agree with their reasoning. It is Microsoft who needs to change, not Google. The
>> IPv6 standard does not require DHCPv6
>
> Neither does the IPv4 standard, if we're being pedantic.
>

That is true however I was not being pedantic, I'll be happy to
agree DHCP is a necessity on an IPv4 network.

Just because your Model T required a hand crank in the front
does not mean that my 2000 Ford should come with one. There is
a time for everything.

>
> It happens to be preferred by a lot of enterprise network operators, so
> equipment vendors& o/s really need to support both.
>

If you are talking corporate operators then screw 'em.

I will point out that Microsoft for years forced these "enterprise
network admins" to do networking things (like SMB) that are retarded.
Now, they are a has-been and it's Google's time to pull the same stuff.
If your not going to complain when Microsoft bends you over and
reams you a new one then you can't complain when Google does it.

> (Also, looking at the history of DHCP and ND/RA, DHCP is not actually
> archaic; it's only about 3 years older than IPv6, and was not generally
> available until after ND/RA was designed. IPv4 was very annoying to deploy
> and prone to fat-finger errors before DHCP was retro-fitted.)

Absolutely but that was IPv4 not IPv6.

>
>> For those who must run DHCPv6 on Android:
>>
>> https://play.google.com/store/apps/details?id=org.daduke.realmar.dhcpv6client
>>
>> Now I will also point out something else that affects ISPs - like
>> Comcast (are you listening?) - and probably affected "this Belgian ISP"
>> that Erik is reporting.
>>
>> The issue really isn't what protocol is supported. The issue is
>> PROPER support of what protocol is selected.
>
> Absolutely correct, which is why I find the Android choice short-sighted.
> Having to install this as an add-on seems very unlikely to produce "PROPER"
> support. The first user comment for that add-on is "Doesn't work. There is not
> enough space in /system...". Duh.
>

what protocol is selected by the VENDOR not by the customer. In this
case the customers are used to saying "how high" when Microsoft says
jump and they never complained before. Now they are learning that they
have to say "how high" when Google says jump.

Maybe these customers will realize they should have been telling
Microsoft that they won't buy their stuff until MS properly supported
NFS and many other things they should have supported ages ago.

They made their bed by allowing the OS vendors to have their way,
now they got to lie in it.

Cry me a river.

Ted

> Brian