Subject: Re: NetBSD FTP Client Question
To: Martti Kuparinen <>
From: Robert Elz <kre@munnari.OZ.AU>
List: tech-net
Date: 03/16/2002 18:06:20
    Date:        Sat, 16 Mar 2002 10:07:52 +0200 (EET)
    From:        Martti Kuparinen <>
    Message-ID:  <>

  | On Fri, 15 Mar 2002, Andrew Gillham wrote:
  | > You can remove IPv6 from your kernel, or you can pass the '-4' option to
  | > ftp.

I wonder if it would be a good idea to add sysctl variables that
do (operationally) the same as #undef INET6 would do - and make it
appear that the kernel has no IPv6 support.

There could even be one to get rid of IPv4 support (should be one).

The "problem" that is caused by utilities attempting to make IPv6 connections
just because the kernel happens to have IPv6 compiled in (where there's no
IPv6 net to use) is largely cosmetic - if ftp (etc) didn't bother telling
you it was attempting to use the IPv6 address, you'd never notice in these
cases (but that would then be annoying when there is an IPv6 net, but the
destination host isn't responding, and you get no indication just what is
taking so long).

Being able to tell people who see the IPv6 connect attempts failing to
	sysctl -w net.inet6.enabled=0
would probably be an advantage - and it should be pretty cheap to support.