Slow WiFi with Android Marshmallow & IPv6?

[Jeroen Massar]

On 2016-04-26 10:09, Thomas Schäfer wrote:
> Am 25.04.2016 um 17:40 schrieb Eric Vyncke (evyncke):
>> Thanks to all people pointing me towards a DNS issue.
>>
> 
> I read this thread with great interest. I have a Marshmallow dualstacked
> via Wifi (and via mobile), and I have no issues so far.
> One thing troubles me.
> In my configuration the router gets at least four dns-resolvers two ipv4
> and two ipv6 from the isp. The router itself checks the reliability and
> announces its own ip-address as resolver to the clients. A dead resolver
> would theoretically never reach the client.
> 
> Is this a special feature of avm?

With "avm" you likely mean "AVM Fritz!Box", which btw is not
specifically a 'router' but a CPE (that for IPv4 NATs and for IPv6 sorta
'routes'; on a list like this, please don't call those "routers" though
that is an insult to the real boxes).

Like any other CPE in the world, it will receive DNS servers from the
upstream connection and then offer a local recursive DNS server to the
network behind the device.

And that recursive DNS server will forward DNS queries to the upstream
DNS servers, and indeed, in most implementations (unlike Android which
is a enduser device and does not do what every other platform in the
world does) it will use the fastest responding upstream DNS and keep on
using that till that one fails and then retry the next one till it does
not have any left.

Greets,
 Jeroen