[dhcwg] Re: [v6ops] Re: Re: Re: [IPv6]Re: An droid now supports DHCPv6 PD

Lorenzo

>From the perspective of a network operator, how do I verify the Android
devices are actually making use of the PD they leased from the network? And
how they sub-lease it, if they are doing that in some cases.

For instance, in my personal home lab, I do /64 PD in addition to SLAAC,
and some Android devices from other users indeed pulls a /64 lease, which I
can see on my router/DHCPv6 server.

But no traffic ever flows in/out of the delegated PD, the devices appear to
pull the lease and then proceed to do nothing. These are non-AOSP Android
devices, so it probably varies by many of the various Android OEM
implementations. For example, Xiaomi devices floods my VLAN with Router
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*--*
Best Regards
Daryll Swer
Website: daryllswer.com
<https://l.shortlink.es/l/d23649aed4c2ecb19e878bc80984f94257888400?u=2153471>


On Tue, 16 Sept 2025 at 18:08, Daryll Swer <[email protected]> wrote:

> I'm working on an IPv6 deployment right now where I accounted for RFC9663
> or simply in other words: ia_pd on endpoints.
>
> I'm doing /38 per campus, /51 per VLAN, /60 per endpoint, 512 devices per
> VLAN, 8192 VLANs/VNIs.
>
> The reason for /60s is an edge case involving users with compute nodes and
> their own hypervisors. If I exclude this factor, then /64 per endpoint is
> sufficient in other more common scenarios.
>
> --
> Sent from my iPhone
>
>
> On Tue, 16 Sep 2025 at 5:19 PM, Mark Smith <[email protected]> wrote:
>
>> Hi,
>>
>> On Tue, 16 Sept 2025 at 19:05, Lorenzo Colitti <lorenzo=
>> [email protected]> wrote:
>>
>>> Recommendations for network operators are written in RFC 9663. Some text
>>> about expected prefix lengths is in section 8 of that RFC. RFC 9762 says
>>> the prefix must be SLAAC-sized, which currently means it must be a /64 per
>>> device. A /48 is fine for a small or medium network, but a campus with tens
>>> of thousands of devices on it probably needs more than that.
>>>
>>
>> I would assume (and I'm interested to find out otherwise) that once a
>> network gets to say 30K hosts, then they've moved to BGP as their main
>> routing protocol. 65 536 /64 routes in BGP is a walk in the park, so a /48
>> for a network of say 50K hosts each with is own /64 and 15K /64s left over
>> for everything else would seem to be a large network. In other words, I
>> think a /48 would suit all but the largest networks.
>>
>> Are there large enterprise or university networks with 10s of 1000s of
>> hosts that aren't using BGP (yet?).
>>
>> Regards,
>> Mark.
>>
>>
>>>
>>> On Tue, Sep 16, 2025 at 5:59 PM Tim Chown <Tim.Chown=
>>> [email protected]> wrote:
>>>
>>>> Hi,
>>>>
>>>>
>>>>
>>>> Good news, thanks.
>>>>
>>>>
>>>>
>>>> What’s the recommended deployment model for PD to the host in a campus
>>>> WiFi scenario?   I can certainly see advantages for it, as you’ve
>>>> highlighted in your email.  The linked article explains “what this means
>>>> for app developers” but a “what this means for enterprise/campus network
>>>> operators” would be useful.
>>>>
>>>>
>>>>
>>>> Is it a given that in a middling or large campus the operator will need
>>>> to now receive more than a /48 from their NREN?  Or was that always too
>>>> cautious?  A small but growing number here are obtaining LIR status
>>>> directly.
>>>>
>>>>
>>>>
>>>> Tim
>>>>
>>>>
>>>>
>>>> On 16/09/2025, 09:49, "Lorenzo Colitti" <lorenzo=
>>>> [email protected]> wrote:
>>>>
>>>>
>>>>
>>>> There was a typo in the original post. It was fixed earlier today; it
>>>> now says "Android 11 and above"
>>>>
>>>>
>>>>
>>>> On Tue, Sep 16, 2025 at 3:21 PM Maciej Żenczykowski <maze=
>>>> [email protected]> wrote:
>>>>
>>>> There's a reddit thread:
>>>>
>>>>
>>>> https://www.reddit.com/r/Android/comments/1nhzsst/android_developers_blog_simplifying_advanced/
>>>> <https://l.shortlink.es/l/94320df07ba30152b776a3bb291de9de682ecb31?u=2153471>
>>>>
>>>> First comment:
>>>>
>>>> There's a mistake in the page: running Android and above before the
>>>> end of the year via a Google Play System Update.
>>>>
>>>> Which version?
>>>>
>>>>
>>>> On Tue, Sep 16, 2025 at 3:59 AM Stan Barber <[email protected]> wrote:
>>>> >
>>>> > Congrats!
>>>> >
>>>> > On Mon, Sep 15, 2025 at 6:32 PM Lorenzo Colitti <lorenzo=
>>>> [email protected]> wrote:
>>>> >>
>>>> >> FYI, we announced DHCPv6 PD support on Android today:
>>>> >>
>>>> >>
>>>> https://android-developers.googleblog.com/2025/09/simplifying-advanced-networking-with.html
>>>> <https://l.shortlink.es/l/e1fede7071e6cf4b46d6593b2ad9cd6dd3156bfa?u=2153471>
>>>> >>
>>>> >> This change should already be live on most Android devices running
>>>> Android 11 and above. Specifically:
>>>> >>
>>>> >> RFC 9762: if the P flag is set, the device will ask for a
>>>> SLAAC-sized prefix, and if it gets it, use it to form addresses. Some
>>>> devices will also disable SLAAC as per the SHOULD in the RFC. Not all
>>>> devices will support this because it requires a kernel change which will be
>>>> rolling out over the coming months. In future releases, we expect that the
>>>> prefix will be shared with downstream devices, wearable devices, VMs, etc.
>>>> >> Heuristic: if the device obtains a default route but not PIO, it
>>>> will ask for a prefix, and if it gets it, use it to form addresses. This
>>>> allows DHCPv6-only networks to support Android devices today without having
>>>> to upgrade their routers to set the P flag.
>>>> >>
>>>> >> Over the next few months we also plan to roll out support for DHCPv6
>>>> address registration (RFC 9686).
>>>> >>
>>>> >> I would like to thank everyone who contributed to RFC 9663, RFC 9762
>>>> and RFC 9686. We think that DHCPv6 PD is *better* than either SLAAC or
>>>> IA_NA, because it allows the device to provide end-to-end connectivity to
>>>> unlimited devices, containers, VMs etc. without scaling load on the
>>>> network. Plus the prefix can be tracked and managed by the operator, which
>>>> means that it should be possible to deploy it in networks that require
>>>> DHCPv6 or that have scaling issues dealing with many addresses. We hope
>>>> that this will allow at least some enterprise operators to deploy IPv6 to
>>>> Android devices.
>>>> >>
>>>> >> Cheers,
>>>> >> Lorenzo
>>>> >> _______________________________________________
>>>> >> v6ops mailing list -- [email protected]
>>>> >> To unsubscribe send an email to [email protected]
>>>> >
>>>> > --------------------------------------------------------------------
>>>> > IETF IPv6 working group mailing list
>>>> > [email protected]
>>>> > List Info: https://mailman3.ietf.org/mailman3/lists/[email protected]/
>>>> <https://l.shortlink.es/l/8c35987be16c96d285bacf1db33a24154967198a?u=2153471>
>>>> > --------------------------------------------------------------------
>>>>
>>>> --
>>>> Maciej Żenczykowski, Kernel Networking Developer @ Google
>>>>
>>>> _______________________________________________
>>>
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