On Thu Sep 25 04:34:53 2014, jreed@isc.org wrote:
> 
> named manual says about -4:
>        -4
>            Use IPv4 only even if the host machine is capable of IPv6.
> 
> 
> I used named -4 but log output said:
> 
> 22-Sep-2014 14:20:18.922 using default UDP/IPv6 port range: [1024, 
> 65535]
> 22-Sep-2014 14:20:18.923 no IPv6 interfaces found
> ...
> 22-Sep-2014 14:20:24.899 no IPv6 interfaces found
> 
> It said that 81 times within 16 minutes.

Presumable you have interfaces coming and going and named
is re-probing the interface states as a result of those comings
and goings.

> On another named -4 run, I had it configured with:
>   listen-on-v6 { none; };
> and it had the same behaviour.
> I didn't configure all the various other transfer etc tunables for v6 
> to try to turn it off.
> 
> So why is use-v6-udp-ports done if -4 switch sets disable6 to true? 

Because it is simpler and less error prone to always setup the port tables
than to conditionally set them up.

> And why is isc_net_probeipv6() done if disable6 is true?

Because that is the generic mechanism used to see if IPv6 is
supported either by the OS or as the result of a command
line switch.  Doing it one way in named and a different way in
the libraries is more error prone.

> Either let's use disable6 or let's fix documentation.

We don't use IPv6 with 'named -4' to send or receive queries.
That doesn't mean we still don't need to discover stuff.

> Thanks