Should I be using ipv6_activate_all_interfaces or ip6addrctl_policy="ipv6_prefer"

[Peter Wemm]

On Tuesday 26 August 2014 10:40:27 freebsd at jonathanprice.org wrote:
> Hello,
> 
> I am configuring a server with IPv4 and IPv6 addresses and have noticed that
> FreeBSD seems to be preferring IPv4, such as when establishing SSH
> connections.
> 
> After reading through /etc/defaults/rc.conf, and later /etc/rc.d/ip6addrctl
> I have come to the conclusion that I have two ways to tell FreeBSD to
> prefer IPv6:
> 
> 1) Add ipv6_activate_all_interfaces to /etc/rc.conf
> 2) Add ip6addrctl_policy="ipv6_prefer" to /etc/rc.conf
> 
> Could anybody with a little more knowledge on the matter explain to me which
> of the two options is more preferential?

They both do different things.

The activate knob is to enable ipv6 on an interface.  To oversimplify it, if 
you configure an address on an interface, it is "enabled".  However, this 
switch enables this on all the rest of the interfaces, even the ones you 
didn't configure.

ip6addrctl* affects things like hostname lookups to sort the addresses returned 
to the caller.

They are different things entirely.  I think you are expecting the behavior 
that ip6_prefer policy gives you.  That's what we use in the freebsd.org 
cluster to have it use ipv6 where possible.

-- 
Peter Wemm - peter at wemm.org; peter at FreeBSD.org; peter at yahoo-inc.com; KI6FJV
UTF-8: for when a ' or ... just won\342\200\231t do\342\200\246
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