Forward: HEADS UP! Default value of ip6_v6only changed

[Bernd Walter]

On Tue, Oct 28, 2003 at 11:51:59PM +0000, Christian Weisgerber wrote:
> Hajimu UMEMOTO <ume at mahoroba.org> wrote:
> 
> > Our default of net.inet6.ip6.v6only was off in 4.X, and was changed to
> > on on 5.X to follow NetBSD's practice.  This behavior on 5.X breaks
> > RFC2553/3493, and the change was intentional from security
> > consideration.  But, NetBSD changed it off by default.
> 
> OpenBSD's behavior is equivalent to v6only on, and OpenBSD doesn't
> even provide a knob.
> 
> Note that the default choice has a major impact on 3rd party software
> (ports).  If we ship with a default of v6only off, then people will
> not fix software to open two sockets.  This in turn means that
> turning v6only on will break this software.  I predict that a good
> many people will then consider the v6only option to be useless.

I can second this.
The first time I noticed this mistake in self written software was when
I tested it on NetBSD, where the default was already to v6only while
FreeBSD still had it off.

-- 
B.Walter                   BWCT                http://www.bwct.de
ticso at bwct.de                                  info at bwct.de