[dhcwg] Re: [v6ops] Re: [IPv6]Re: Android now su pports DHCPv6 PD

Mark Smith <[email protected]> Tue, 16 Sep 2025 21:49:31 +1000
Newsgroups gmane.ietf.dhc,gmane.ietf.v6ops
Message-ID <CAO42Z2zHv=7HgqMj-USZMutJd8HNh9ad_ySZDZODq+zLgtZk0A@mail.gmail.com>
--===============3357840068602636603==
Content-Type: multipart/alternative; boundary="00000000000025f2a5063ee9b8cf"

--00000000000025f2a5063ee9b8cf
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

Hi,

On Tue, 16 Sept 2025 at 19:05, Lorenzo Colitti <lorenzo=3D
[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 pe=
r
> device. A /48 is fine for a small or medium network, but a campus with te=
ns
> 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=E2=80=AFPM Tim Chown <Tim.Chown=3D
> [email protected]> wrote:
>
>> Hi,
>>
>>
>>
>> Good news, thanks.
>>
>>
>>
>> What=E2=80=99s the recommended deployment model for PD to the host in a =
campus
>> WiFi scenario?   I can certainly see advantages for it, as you=E2=80=99v=
e
>> highlighted in your email.  The linked article explains =E2=80=9Cwhat th=
is means
>> for app developers=E2=80=9D but a =E2=80=9Cwhat this means for enterpris=
e/campus network
>> operators=E2=80=9D 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=3D
>> [email protected]> wrote:
>>
>>
>>
>> There was a typo in the original post. It was fixed earlier today; it no=
w
>> says "Android 11 and above"
>>
>>
>>
>> On Tue, Sep 16, 2025 at 3:21=E2=80=AFPM Maciej =C5=BBenczykowski <maze=
=3D
>> [email protected]> wrote:
>>
>> There's a reddit thread:
>>
>>
>> https://www.reddit.com/r/Android/comments/1nhzsst/android_developers_blo=
g_simplifying_advanced/
>>
>> 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=E2=80=AFAM Stan Barber <[email protected]> wro=
te:
>> >
>> > Congrats!
>> >
>> > On Mon, Sep 15, 2025 at 6:32=E2=80=AFPM Lorenzo Colitti <lorenzo=3D
>> [email protected]> wrote:
>> >>
>> >> FYI, we announced DHCPv6 PD support on Android today:
>> >>
>> >>
>> https://android-developers.googleblog.com/2025/09/simplifying-advanced-n=
etworking-with.html
>> >>
>> >> 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 a=
lso
>> 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 sha=
red
>> 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 allo=
ws
>> 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 t=
o
>> unlimited devices, containers, VMs etc. without scaling load on the
>> network. Plus the prefix can be tracked and managed by the operator, whi=
ch
>> 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 t=
o
>> 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]/
>> > --------------------------------------------------------------------
>>
>> --
>> Maciej =C5=BBenczykowski, Kernel Networking Developer @ Google
>>
>> _______________________________________________
> dhcwg mailing list -- [email protected]
> To unsubscribe send an email to [email protected]
>

--00000000000025f2a5063ee9b8cf
Content-Type: text/html; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

<div dir=3D"ltr"><div>Hi,</div><br><div class=3D"gmail_quote gmail_quote_co=
ntainer"><div dir=3D"ltr" class=3D"gmail_attr">On Tue, 16 Sept 2025 at 19:0=
5, Lorenzo Colitti &lt;lorenzo=3D<a href=3D"mailto:[email protected].=
org">[email protected]</a>&gt; wrote:<br></div><blockquote class=
=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid rg=
b(204,204,204);padding-left:1ex"><div dir=3D"ltr">Recommendations for netwo=
rk operators are written in RFC 9663. Some text about expected prefix lengt=
hs is in section 8 of that RFC.=C2=A0RFC 9762 says the prefix must be SLAAC=
-sized, which currently means it must be a /64 per device. A /48 is fine fo=
r a small or medium network, but a campus with tens of thousands of devices=
 on it probably needs more than that.</div></blockquote><div><br></div><div=
>I would assume (and I&#39;m interested to find out otherwise) that once a =
network gets to say 30K hosts, then they&#39;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 thi=
nk a /48 would suit all but the largest networks.</div><div><br></div><div>=
Are there large enterprise or university networks with 10s of 1000s of host=
s that aren&#39;t using BGP (yet?).</div><div><br></div><div>Regards,</div>=
<div>Mark.</div><div>=C2=A0</div><blockquote class=3D"gmail_quote" style=3D=
"margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-le=
ft:1ex"><br><div class=3D"gmail_quote"><div dir=3D"ltr" class=3D"gmail_attr=
">On Tue, Sep 16, 2025 at 5:59=E2=80=AFPM Tim Chown &lt;Tim.Chown=3D<a href=
=3D"mailto:[email protected]" target=3D"_blank">40jisc.ac.uk@dmar=
c.ietf.org</a>&gt; wrote:<br></div><blockquote class=3D"gmail_quote" style=
=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding=
-left:1ex"><div>





<div lang=3D"EN-GB">
<div>
<p class=3D"MsoNormal"><span style=3D"font-size:11pt">Hi,<u></u><u></u></sp=
an></p>
<p class=3D"MsoNormal"><span style=3D"color:rgb(33,33,33)"><u></u>=C2=A0<u>=
</u></span></p>
<p class=3D"MsoNormal"><span style=3D"color:rgb(33,33,33)">Good news, thank=
s.<u></u><u></u></span></p>
<p class=3D"MsoNormal"><span style=3D"color:rgb(33,33,33)"><u></u>=C2=A0<u>=
</u></span></p>
<p class=3D"MsoNormal"><span style=3D"color:rgb(33,33,33)">What=E2=80=99s t=
he recommended deployment model for PD to the host in a campus WiFi scenari=
o?=C2=A0 =C2=A0I can certainly see advantages for it, as you=E2=80=99ve hig=
hlighted in your email.=C2=A0 The linked article explains =E2=80=9Cwhat thi=
s means
 for app developers=E2=80=9D but a =E2=80=9Cwhat this means for enterprise/=
campus network operators=E2=80=9D would be useful.<u></u><u></u></span></p>
<p class=3D"MsoNormal"><span style=3D"color:rgb(33,33,33)"><u></u>=C2=A0<u>=
</u></span></p>
<p class=3D"MsoNormal"><span style=3D"color:rgb(33,33,33)">Is it a given th=
at in a middling or large campus the operator will need to now receive more=
 than a /48 from their NREN?=C2=A0 Or was that always too cautious?=C2=A0 A=
 small but growing number here are obtaining LIR status
 directly.<u></u><u></u></span></p>
<p class=3D"MsoNormal"><span style=3D"color:rgb(33,33,33)"><u></u>=C2=A0<u>=
</u></span></p>
<p class=3D"MsoNormal"><span style=3D"color:rgb(33,33,33)">Tim </span><span=
 style=3D"font-size:11pt"><u></u><u></u></span></p>
<p class=3D"MsoNormal"><span style=3D"font-size:11pt"><u></u>=C2=A0<u></u><=
/span></p>
<div id=3D"m_-8902354524021554512m_7788389079499085868mail-editor-reference=
-message-container">
<div>
<div>
<div>
<p class=3D"MsoNormal" style=3D"margin-left:36pt">On 16/09/2025, 09:49, &qu=
ot;Lorenzo Colitti&quot; &lt;lorenzo=3D<a href=3D"mailto:40google.com@dmarc=
.ietf.org" target=3D"_blank">[email protected]</a>&gt; wrote:<u><=
/u><u></u></p>
</div>
<p class=3D"MsoNormal" style=3D"margin-left:36pt"><u></u>=C2=A0<u></u></p>
<div>
<p class=3D"MsoNormal" style=3D"margin-left:36pt">There was a typo in the o=
riginal post. It was fixed earlier today; it now says &quot;Android 11 and =
above&quot;<u></u><u></u></p>
</div>
<p class=3D"MsoNormal" style=3D"margin-left:36pt"><u></u>=C2=A0<u></u></p>
<div>
<div>
<p class=3D"MsoNormal" style=3D"margin-left:36pt">On Tue, Sep 16, 2025 at 3=
:21<span style=3D"font-family:Arial,sans-serif">=E2=80=AF</span>PM Maciej =
=C5=BBenczykowski &lt;maze=3D<a href=3D"mailto:[email protected]"=
 target=3D"_blank">[email protected]</a>&gt; wrote:<u></u><u></u>=
</p>
</div>
<blockquote style=3D"border-top:none;border-right:none;border-bottom:none;b=
order-left:1pt solid rgb(204,204,204);padding:0cm 0cm 0cm 6pt;margin-left:4=
.8pt;margin-right:0cm">
<p class=3D"MsoNormal" style=3D"margin-left:36pt">There&#39;s a reddit thre=
ad:<br>
<br>
<a href=3D"https://www.reddit.com/r/Android/comments/1nhzsst/android_develo=
pers_blog_simplifying_advanced/" target=3D"_blank">https://www.reddit.com/r=
/Android/comments/1nhzsst/android_developers_blog_simplifying_advanced/</a>=
<br>
<br>
First comment:<br>
<br>
There&#39;s a mistake in the page: running Android and above before the<br>
end of the year via a Google Play System Update.<br>
<br>
Which version?<br>
<br>
<br>
On Tue, Sep 16, 2025 at 3:59<span style=3D"font-family:Arial,sans-serif">=
=E2=80=AF</span>AM Stan Barber &lt;<a href=3D"mailto:[email protected]" target=
=3D"_blank">[email protected]</a>&gt; wrote:<br>
&gt;<br>
&gt; Congrats!<br>
&gt;<br>
&gt; On Mon, Sep 15, 2025 at 6:32<span style=3D"font-family:Arial,sans-seri=
f">=E2=80=AF</span>PM Lorenzo Colitti &lt;lorenzo=3D<a href=3D"mailto:40goo=
[email protected]" target=3D"_blank">[email protected]</a>&g=
t; wrote:<br>
&gt;&gt;<br>
&gt;&gt; FYI, we announced DHCPv6 PD support on Android today:<br>
&gt;&gt;<br>
&gt;&gt; <a href=3D"https://android-developers.googleblog.com/2025/09/simpl=
ifying-advanced-networking-with.html" target=3D"_blank">
https://android-developers.googleblog.com/2025/09/simplifying-advanced-netw=
orking-with.html</a><br>
&gt;&gt;<br>
&gt;&gt; This change should already be live on most Android devices running=
 Android 11 and above. Specifically:<br>
&gt;&gt;<br>
&gt;&gt; RFC 9762: if the P flag is set, the device will ask for a SLAAC-si=
zed 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 suppo=
rt this because it requires a kernel change
 which will be rolling out over the coming months. In future releases, we e=
xpect that the prefix will be shared with downstream devices, wearable devi=
ces, VMs, etc.<br>
&gt;&gt; Heuristic: if the device obtains a default route but not PIO, it w=
ill ask for a prefix, and if it gets it, use it to form addresses. This all=
ows DHCPv6-only networks to support Android devices today without having to=
 upgrade their routers to set the P flag.<br>
&gt;&gt;<br>
&gt;&gt; Over the next few months we also plan to roll out support for DHCP=
v6 address registration (RFC 9686).<br>
&gt;&gt;<br>
&gt;&gt; I would like to thank everyone who contributed to RFC 9663, RFC 97=
62 and RFC 9686. We think that DHCPv6 PD is *better* than either SLAAC or I=
A_NA, because it allows the device to provide end-to-end connectivity to un=
limited devices, containers, VMs etc.
 without scaling load on the network. Plus the prefix can be tracked and ma=
naged 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 ma=
ny addresses. We hope that this
 will allow at least some enterprise operators to deploy IPv6 to Android de=
vices.<br>
&gt;&gt;<br>
&gt;&gt; Cheers,<br>
&gt;&gt; Lorenzo<br>
&gt;&gt; _______________________________________________<br>
&gt;&gt; v6ops mailing list -- <a href=3D"mailto:[email protected]" target=3D"=
_blank">[email protected]</a><br>
&gt;&gt; To unsubscribe send an email to <a href=3D"mailto:v6ops-leave@ietf=
.org" target=3D"_blank">
[email protected]</a><br>
&gt;<br>
&gt; --------------------------------------------------------------------<b=
r>
&gt; IETF IPv6 working group mailing list<br>
&gt; <a href=3D"mailto:[email protected]" target=3D"_blank">[email protected]</a><b=
r>
&gt; List Info: <a href=3D"https://mailman3.ietf.org/mailman3/lists/ipv6@ie=
tf.org/" target=3D"_blank">
https://mailman3.ietf.org/mailman3/lists/[email protected]/</a><br>
&gt; --------------------------------------------------------------------<b=
r>
<br>
--<br>
Maciej =C5=BBenczykowski, Kernel Networking Developer @ Google<u></u><u></u=
></p>
</blockquote>
</div>
</div>
</div>
</div>
</div>
</div>

</div></blockquote></div>
_______________________________________________<br>
dhcwg mailing list -- <a href=3D"mailto:[email protected]" target=3D"_blank">d=
[email protected]</a><br>
To unsubscribe send an email to <a href=3D"mailto:[email protected]" tar=
get=3D"_blank">[email protected]</a><br>
</blockquote></div></div>

--00000000000025f2a5063ee9b8cf--


--===============3357840068602636603==
Content-Type: text/plain; charset="utf-8"
MIME-Version: 1.0
Content-Transfer-Encoding: base64
Content-Disposition: inline

X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KZGhjd2cgbWFp
bGluZyBsaXN0IC0tIGRoY3dnQGlldGYub3JnClRvIHVuc3Vic2NyaWJlIHNlbmQgYW4gZW1haWwg
dG8gZGhjd2ctbGVhdmVAaWV0Zi5vcmcK

--===============3357840068602636603==--