Should I be using ipv6_activate_all_interfaces or ip6addrctl_policy="ipv6_prefer"

[John Hay]

On Sat, Aug 30, 2014 at 12:41:56AM +0900, Hiroki Sato wrote:
> John Hay <jhay at meraka.org.za> wrote
>   in <20140829101707.GA83695 at zibbi.meraka.csir.co.za>:
> 
> jh> On Wed, Aug 27, 2014 at 11:59:25AM +0000, Bjoern A. Zeeb wrote:
> jh> >
> jh> > On 27 Aug 2014, at 06:31 , Jonathan Price <freebsd at jonathanprice.org>
> jh> > wrote:
> jh> >
> jh> > > On 2014-08-27 01:40, Peter Wemm wrote:
> jh> > >> On Tuesday 26 August 2014 10:40:27 freebsd at jonathanprice.org wrote:
> jh> > >>> Hello,
> jh> > >>>
> jh> > >>> I am configuring a server with IPv4 and IPv6 addresses and have
> jh> > >>> noticed that
> jh> > >>> FreeBSD seems to be preferring IPv4, such as when establishing SSH
> jh> > >>> connections.
> jh> > >>>
> jh> > >>> After reading through /etc/defaults/rc.conf, and later
> jh> > >>> /etc/rc.d/ip6addrctl
> jh> > >>> I have come to the conclusion that I have two ways to tell FreeBSD to
> jh> > >>> prefer IPv6:
> jh> > >>>
> jh> > >>> 1) Add ipv6_activate_all_interfaces to /etc/rc.conf
> jh> > >>> 2) Add ip6addrctl_policy="ipv6_prefer" to /etc/rc.conf
> jh> > >>>
> jh> ...
> jh> > > However, it does sound like for my purposes it would make more sense
> jh> > > to use ip6addrctl_policy=?ipv6_prefer" as that is more explicitly the
> jh> > > feature I want, rather than getting it inadvertently through the other
> jh> > > knob.
> jh> >
> jh> > Yes. Definitively.  I am not sure if it has happened but if IPv6
> jh> > config is configured through rc.conf that setting should be(come)
> jh> > default.
> jh> >
> jh>
> jh> It does not seem so yet (anymore, it was like that many moons ago). A
> jh> new
> 
> ...
> 
> jh> I think if an IPv6 address is configured on a machine, it should
> jh> prefer ipv6
> jh> addresses. That would match what the rest are doing.
> 
>  True at this moment.  I have a patch to make it set ipv6_prefer when
>  at least one ifconfig_IF_ipv6 is configured.
> 
>  Is there any objection to commit this?  I had hesitated to add this
>  for a technical reason which was eliminated by adding list_vars().

No objection from my side. :-) It would have been great to also have
it in 10 at some stage, but maybe that is rocking the boat too much. :-)

I can maybe just tell about my experience. In our organisation there
are about 300 people. About 2/3 are MS Windows and maybe 1/4 are linux
and a few are FreeBSD. Oh there are a few Macs too. Our network is dual
stacked. On the MS Windows, linux and Mac boxes nothing gets done, they
just pick up IPv6 and work. On every FreeBSD box I have to "switch" on
IPv6. A third of our internet traffic is IPv6 already.

Regards

John
-- 
John Hay -- jhay at meraka.csir.co.za / jhay at meraka.org.za