Quoting RFC2860 [Re: I-D Action:draft-azinger-scalable-addressing-00.txt]

[Brian E Carpenter]

On 2010-09-28 07:05, Fred Baker wrote:
> On Sep 27, 2010, at 9:33 AM, Tony Li wrote:
> 
>> Certainly if someone is running a v6 network that is not Internet connected, then they are welcome to do whatever they like.  ;-)
> 
> I actually disagree. In the Smart Grid world, there have been suggestions that they use IPv4 and simply re-use the IPv4 address space "because the networks will never be connected". You can guess my response to that - "been there, done that, note the road rash". I think that they should operate as though they might eventually become connected, in part to deal with stuxnet-style issues and in part in case they inadvertently or intentionally become connected at some point in the future.

Indeed. One of the ironies of the smart grid debate and how it interacts
with our debate here is that the electrical power industry itself wrote
one of the strongest requirement statements for IPng in RFC 1673.
Please pretend you can't see the OSI references:

   2. Basic Requirements.

      - Scaleability
        The addressing scheme must have essentially an unlimited address
        space to encompass an arbitrarily large number of information
        objects.  Specifically it must solve the fundamental limitations
        of 32 bit formats, a format for 20 octets and above is considered
        suitable.

      - Routing table economy
        Network addressing must achieve significant economy in routing
        database size with very large networks.

      - Support for the existing Internet
        The existing internetworking paradigm and existing OSI and IPS
        applications are to be supported.


   Brian