SV: Samsung phones block WiFi IPv6 when sleeping, delayed notifications

[Benedikt Stockebrand]

Hi Lorenzo and list,

Lorenzo Colitti <lorenzo at google.com> writes:

> On Thu, Jun 11, 2015 at 6:56 PM, Benedikt Stockebrand
> <bs at stepladder-it.com> wrote:
>
>     they should at least send an RS when they wake up and ensure their
>     configuration is still up to date.
>     
>
> That sounds like a bad idea. If devices send an RS every time the user
> turns the screen on, and the router responds with a multicast RA, any
> medium-size network or larger will have multicast RAs flying around
> every 3 seconds and killing everyone's battery.

not quite; as Eric pointed out, RAs may be sent unicast.  While this was
originally intended for underlying NBMA link layers, it does make kind
of sense in this context, too.  The downside with this however is that
it makes monitoring for rogue routers more difficult again (using tools
like ramond) at least in switched networks.

But aside from that, my wording was imprecise.  Make that "send an RS
when they wake up and they determine they have been offline long
enough", for "long enough" being somewhat in the order of "such that the
router lifetime expired" or similar.  Figuring out the exact details is
left as an excercise to the so inclined reader:-)


Cheers,

    Benedikt

-- 
Benedikt Stockebrand,                   Stepladder IT Training+Consulting
Dipl.-Inform.                           http://www.stepladder-it.com/

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