IPv6 transition architecture discussion

[Pekka Savola <pekkas@netcore.fi>]

Hello,

Triggered by extended discussion at the IETF meeting on NAT-PT, I think we
should try to discuss more about the _core_ matters of the transition, for
example:

1) how to start enabling v6-capable software in the operating systems, and
having operating systems v6-enabled, in such a fashion that it does not
hinder the current usability of v4?

A starter for discussion: v6 connectivity is very poor (see
draft-savola-v6ops-6bone-mess-01 for more).  Vendors are rightfully afraid
(I sure don't want them doing it) to enable v6 by default, as connections
could easily switch to using (badly working) v6.

Do we need to do something about this or just wait N years to operators to
do something.  Note: this is a chicken-and-egg problem, ISP's don't deploy
v6 before it's requested (and paid for, in some way or another), and the
connectivity remains poor because v6 isn't really production yet.

2) are there some cases in the transition which we could ignore, to make 
it simpler?  In particular, this includes v6-only and v4-only 
interoperation.

A starter for discussion: v4-only <-> v6-only in a general case is
complex.  IMO we perhaps shouldn't try to solve the general problem, as it
draws the attention away from more important issues.  Is it ok to require
v6-only nodes will only be deployed when they don't need connectivity to
v4-only nodes (except by proxies -- e.g. TCP/UDP relay or ALG level thing
is IMO just fine)?  

For example, in home networking scenario, enabling v6-only printers etc.
should be trivial _if we require_ TCP/UDP proxy e.g. in one dual-stack
computer in the network.  On the other hand, I would imagine it could be
ok to just say, if you want to use that printer, upgrade your OS, period.

Is it required to be able to communicate between v6-only node in your
network to v4-only nodes in the general internet?  The need for this can
be mitigated by dual-stack ALG's, like web proxies. My suggestion would be
that don't deploy v6-only nodes, requiring v4 internet access, then.  
Such could still be deployed in internal networks -- most v6-only gadgets
today don't really require to be accessible or to access v4 internet
anyway -- and even v4 in the local network is also a bit arguable.

x) there are probably many other "really important" issues we need to have 
some idea of.  It's not all that useful to meddle with scenario details 
until we have some idea how the big picture should work itself out.

I think this is something we need to properly discuss now and possibly at 
the next meeting.

-- 
Pekka Savola                 "Tell me of difficulties surmounted,
Netcore Oy                   not those you stumble over and fall"
Systems. Networks. Security.  -- Robert Jordan: A Crown of Swords