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 18:08:32
At 4:59 PM -0700 5/8/00, Jonathan Stone wrote:
>..., I didn't intend to distort your words, and I dont think I
>did. Widescale IPv6 deployment is not a sure thing even yet, and
>(as you note) you are often quick to say so.

There you go again.  It's not my uncertainty about IPv6's success that
I am quick to mention, but rather, on those occasions when I do express
my uncertainty, there are qualifications that I am quick to add.

>  I dont think that was misrepresentation.

What I objected to was using my concerns that IPv6 might not succeed as
an argument against doing something that can help it succeed (that being:
including IPv6 in NetBSD).

> >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.  
>That depends on whether you mean IPv6-plus-IPv4 "dual stack" setups,
>or IPv4-only setups.  People have been  breaking the latter, and 
>others have suggested that it become NetBSD policy to not support
>IPv4-only systems.    That makes some of us rather unhappy.

If people were proposing to remove support for IPv4, I could appreciate
your unhappiness, but that doesn't appear to be the case.

If the presence of IPv6 is interfering with the use of IPv4, or causing
the system to crash, then that's a problem that should be fixed.  One would
hope there are less radical ways to fix it than deleting IPv6 entirely
from the system.

Why is an IPv4-only system important to you (i.e., no IPv6, no AppleTalk,
etc.)?  Is there a technical rationale, such as memory shortage?  Or is it
a religious thing?

>But there are still technical issues with IPv6, where doing what IPv4
>does today is (as far as I know) at best an open research problem.

I don't believe that's true, but I'll take that up with you in private
mail, as you suggested.

>And I'm sorry to be the bearer of ill-wind, but yes, as it happens, I
>do seem to be meeting more and more people who see IPv6 acutally
>diplacing of IPv4 as increasingly unlikely.

I don't doubt it.  Interestingly (to me), I have gone through the opposite
evolution, starting off quite pessimistic, and getting more and more
optimistic as the data comes in.  I guess the people you've been talking
to have a different source of data, or draw their conclusions based on
something other than data.