John Curran wrote:
On Nov 22, 2022, at 9:09 AM, John Curran <jcur...@istaff.org> wrote:
...
Interoperability isn’t insurmountable, but does take some investment
of effort. One can imagine any number of techniques (e.g. flag day
after which “production devices” on the Internet must support 240/4,
or DNS resolver hacks that fail to return “A” records with 240/4
addresses unless a flag is set that says “we’re in the 240/4 routable
Internet” [ick], etc., etc.) It doesn’t seem particularly hard to
come up with some approaches to solve the interoperability problem,
but completely ignoring it is not an answer (and makes it rather
difficult to take your proposal seriously…)
Joe -
By the way, you shouldn’t feel particularly bad about skipping out on
the interoperability requirement – anything involving interworking
with the installed Internet is hard, and this is the same lesson that
the IPv6 folks found out the hard way… I will confess that I was a
member of the IETF's IPng Directorate and thus inherently complicit in
that particular fiasco –
John,
Flags days on the internet of today have proven to be of limited value.
Suppose complete interoperability is never actually solved. Why does
240/4 utilitarian value have to be binary? I think we should be trying
to discover these things instead of using them to handwave away any attempt.
The part I feel bad about is that I am actually un-involved in much of
anyway with the 240/4 or other ideas, my sole input has been to attempt
to encourage serious consideration and to rebut naysaying.
Yes, a standards update is only the beginning of a real effort, although
plenty has changed even without that.
Yes, there may and likely will be a large extent of interoperability and
usability challenges for quite some time, perhaps even enough time that
the issue becomes moot.
Yes, it may be insurmountable.
Yes, it may render 240/4 unusable and undesirable to the extent that it
has little contributory effect on IPv4.
However it may not and discouraging serious consideration is actually a
contributing factor preventing any such potential.
And to the extent that you and others have discussed and aired various
points of views and insights, I think I have had some success with my
efforts thus far.
With IPv6, the first answer to interoperability was “let’s do tunnels
between IPng islands”; i.e. helpful for lab environments but useless
otherwise. We then declared that transition was a problem “to be
solved later” but that shouldn’t get in the way of the declaration of
IPng as the new IPv6. Finally, after failing to solve the problem, we
reverted to “ships in the night”; i.e. IPv4 and IPv6 running in
parallel on the same infrastructure – it works, but defeats the entire
idea of IPv6 as a functional substitute for IPv4 for connecting new
customers and infrastructure to the existing IPv4-based Internet
(Luckily, the service provider industry that was growing most rapidly
realized that they really needed IPv6, and they really needed
transition solutions that allowed IPv6 to interoperate for IPv4 for
new connections, and so we eventually saw real solutions such
as 464xlat, ds-lite, etc.)
I feel there is some value for the internet record to contain as much as
possible real debate and consideration instead of group think,
short-sightedness, idealouges and top down approaches which may not look
pretty in hindsight. Such as contained in the much larger details of
your brief recap and that you and others have expanded upon here and
elsewhere in the past.
In other words, a loyal opposition.
Maintaining interoperability with the existing base is hard - far
harder than just “updating the standard” -
Without a standard update, there is a bit of a chicken and egg problem
with pursuing interoperability with any seriousness.
I think 100.64/10 was a missed opportunity to incentivize the industry
to pursue interoperability.
but is absolutely essential if you want viable reuse of 240/4. Of
course, it does raise the question of whether the total effort will be
worth the purported gain, but that really can’t be assessed until
there's some specification of the proposed solution for
interoperability with the existing deployed devices that don’t know
about the 240/4 change.
Thanks,
/John
p.s. Disclaimer(s): my views alone. Warning: may cause dizziness,
headaches, or nausea.
Best,
Joe
