RE: Android (lack of) support for DHCPv6

["Tony Hain" <alh-ietf () tndh net>]

> -----Original Message-----
> From: NANOG [mailto:nanog-bounces () nanog org] On Behalf Of Mikael
> Abrahamsson
> Sent: Tuesday, June 09, 2015 10:39 PM
> To: Chris Adams
> Cc: nanog () nanog org
> Subject: Re: Android (lack of) support for DHCPv6
>
> On Tue, 9 Jun 2015, Chris Adams wrote:
>
> > Android devices (Samsung and LG) upgraded to Lollipop, I no longer
> > have functioning IPv6 on wifi.  They connect and get an address (with
> > privacy extensions even), but do not install an IPv6 default route.
> > They can talk to local IPv6 devices, but not the Internet.
>
> My Nexus4 with Android 5.1.1 works just fine with IPv6 on wifi.
>
> So talk to your handset manufacturer, they must have broke something.

I filed a platform bug on this back in the ICS timeframe, and it still
persists. As I recall, there are 2 flags provided by the OS related to RA
handling. Rather than using the one that sets a preference between the Cell
vs. Wifi interface, at least Samsung (possibly others) have chosen to use
the other flag that says to completely ignore the WiFi RA if an RA on the
Cell interface has ever occurred. This means devices that have no IPv6 on
their Cell interface will appear to work fine on WiFi. 

I claim that there is a platform bug, because there is never a reason to
ignore the WiFi RA. Use the other flag to set a preference if that is
needed, but ignoring the RA just breaks things in unexpected ways. LC has
did a hand-wave that the "ignore RA" flag is needed for battery life, but
beyond that we appear to be stuck in a world where Clueless OEMs believe in
breaking one network when another might exist.

As a general comment about this thread; people need to treat the handset as
a "ROUTER" and get over it. Just do a PD and treat it like any other router.
Ignore routing protocol announcements from it if when it is run by a
customer, but that is no different than any other CPE router. Most handsets
now days are more capable than most consumer CPE routers, so moving past the
'it is just a voice endpoint' mindset is appropriate.

Tony


> --
> Mikael Abrahamsson    email: swmike () swm pp se