Date:        Sat, 17 Feb 2007 12:57:59 +0000
    From:        Matthias Scheler <tron@zhadum.org.uk>
    Message-ID:  <20070217125759.GA4531@colwyn.zhadum.org.uk>

  | That can be avoided by rebuilding the userland with "USE_INET6=no"
  | in "/etc/mk.conf". Disabling IPv6 support in "pkgsrc" can be
  | achieved by adding "PKG_OPTIONS= -inet6".

Neither of those should generally be needed, unless you tell an
application that it must use IPv6, they generally won't mind if
IPv6 isn't supported.   Making "telnet -6" go away, rather than
simply not working, probably isn't all that important...

There are just a few places where (by default) NetBSD says "must
use IPv6" (well, not quite that, but close) - one is in the
default sendmail.cf file (sendmail will bitch and moan about
being told to use something that doesn't exist, then work anyway).
Of course, if you don't enable sendmail, that's not an issue,
similarly, you shouldn't be enabling any inet6 entries in inetd.conf.

kre