Subject: Re: -current sendmail cancer in IPv4-only kernel
To: Jonathan Stone <jonathan@DSG.Stanford.EDU>
From: Steve Deering <>
List: current-users
Date: 05/08/2000 16:14:29
At 2:34 PM -0700 5/7/00, Jonathan Stone wrote:
>Even Steve Deering has always said that IPv6 may never be deployed.


I don't follow this mailing list (someone forwarded your message to me),
but it looks like you are seriously distorting my words.  I have indeed
often publicly expressed my worry that IPv6 won't succeed in taking over
from IPv4, due to the inertia of the installed base and the apparent
preference by many for short-term hacks and loss of IP functionality,
rather than doing what needs to be done to really fix the problems.  But
whenever I say that, I am also quick to point out that I am pessimistic
by nature (that way, I am never disappointed, and often pleasantly
surprised) and that, nonetheless, the chances of success are high enough,
and the alternative of just letting the Internet decay is irresponsible
enough, that I continue to put my own time and effort into making IPv6

Using those concerns of mine to support your argument for an "IPv6-free
system" is disingenuous.  If no one had implemented IPv6 for NetBSD,
that might have supported your "IPv6 is undeployable" argument.  But
the fact is, it has been implemented, and the only reason I can imagine
for keeping IPv6 out of NetBSD is to make sure you don't do anything that
might help IPv6 deployment (which I suspect is your real goal, given that
you have an agenda that depends on IPv6 being "undeployable").

>As more and more people are acutally seeing IPv6, more and more of them
>are saying it is unlikely to ever be widely deployed.

At least, that's what you wish were true, but there's certainly no public
evidence of it.  Sure, there are lots of doubters, critics, and people
with their own paper designs or fantasies of what they believe to be
superior solutions, as there are with any piece of technology.  As far as
I can see, they are outnumbered by the people who see IPv6 as good enough
and tested enough, and the problems it solves as serious and urgent enough,
to just get on with deploying it.

>Indeed, people more clueful than Frank or I are even as far as to say
>that IPv6 is _undeployable_.

Since no one has proven the "undeployability" of IPv6 (on the contrary,
some have successfully deployed it, albeit on a small scale so far),
that's a pretty clueless thing to say with any certainty.

>  NetBSD may disagree with that position, but it's certainly not an
>untenable or obviously-wrong position.

It's untenable on any technical grounds, and though nothing is obvious
about the future, the chances of deployment look pretty damn good right
now, given the status of the numerous implementations and the pull from
major new markets like China and new classes of devices like cell phones.

>So. Given the very real technical questions over the future of IPv6,...

You mean political/academic/religious questions...

> We need to continue to support IPv6-free systems for the foreseeable

I don't know exactly what's being proposed, but I can't imagine anyone
is proposing to do anything to prevent the continued use of IPv4 on
NetBSD systems.  So what technical problem are you trying avoid by having
an "IPv6-free system"?