Android (lack of) support for DHCPv6

Wed Jun 10 18:11:38 UTC 2015

I've already written systems to do this kind of thing, but the logging
requirements quickly go through the roof for a non-trivial network;
especially in the case of temporary addressing now default on many
systems.  That isn't so much the issue as operational consistency and
supportability.

The requirement for hosts to be dual stack will exist for some time.

For the sanity of IT workers and users alike (most of which don't really
know the details of IPv6 and barely understand address scopes let alone
multiple addresses) there needs to be some level of consistency between how
hosts are addressed and communicate between the two protocols.  Saying
we'll develop one system for IPv4 and one for IPv6 ultimate results in
"Let's not deploy IPv6 just yet".

This rings especially true when security concerns come up.  Consistency
between IPv4 and IPv6 needs to be possible in this transition period, or
people simply decide to not deploy.  Consistency in addressing and
maintaining a one host one address model has major implications for policy
construction, flow analysis and incident response, denial of service
mitigation, etc.  If the consistency isn't there, you need to "re-invent
the wheel" for every aspect, then maintain different systems for IPv4 and
IPv6 along side one another.

Even worse, if we keep seeing adoption held up by inconsistent client
implementations I fear we'll start seeing commercial products which NAT or
proxy IPv4 to IPv6 to avoid using IPv6 internally.  It's very ugly and
requires some DNS magic to work, but it's not impossible.  We're already
seeing this in terms of cloud computing and virtualization.  Servers have
IPv4 addresses and only a load balancer with an external IPv6 address.

We absolutely need to make it possible for people to adopt IPv6 before we
can reach a point where IPv4 can go away, and for some organizations the
answer of "Just use SLAAC" is simply not acceptable.

They just won't do it.

Preventing IPv6 adoption hurts us all.  And Android not supporting a MAJOR
part of IPv6 like DHCPv6 is preventing adoption.

On Wed, Jun 10, 2015 at 1:42 PM, Sander Steffann <sander at steffann.nl> wrote:

> >
> > It's not the *only* option. There are large networks - O(100k) IPv6
> nodes - that do ND monitoring for accountability, and it does work for
> them. Many devices support this via syslog, even. As you can imagine, my
> Android device gets IPv6 at work, even though it doesn't support DHCPv6.
> Other universities, too. It's obviously  not your chosen or preferred
> mechanism, but it does work.
>
> /me starts to write that whitepaper that educates people on how to do this
>
> Cheers,
> Sander
>
>

-- 
Ray Patrick Soucy
Network Engineer
University of Maine System

T: 207-561-3526
F: 207-561-3531

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