IPv6 DNS queries

Hi,


My Mandrake 10 (kernel 2.6.3) box sends IPv6 DNS (AAAA) queries and MDNS
(Multicast DNS) queries before falling back to IPv4. Each query thus takes about
2s to complete.

I guess that it must be simple to disable that (I don't know why it's been turned
on in the first place), but neither adding "NETWORKING_IPV6=off" to
/etc/sysconfig/network nor "adding alias net-pf-10 off" to /etc/modules.conf
helped.

Any idea someone ?


Thanks!
Jean-Marc


Jean-Marc Francois

Jean-Marc Francois wrote:
> Hi,
>
>
> My Mandrake 10 (kernel 2.6.3) box sends IPv6 DNS (AAAA) queries and MDNS
> (Multicast DNS) queries before falling back to IPv4. Each query thus
> takes about
> 2s to complete.
>
> I guess that it must be simple to disable that (I don't know why it's
> been turned
> on in the first place), but neither adding "NETWORKING_IPV6=off" to
> /etc/sysconfig/network nor "adding alias net-pf-10 off" to
> /etc/modules.conf
> helped.
>
> Any idea someone ?
>

The only reliable way to do this, that I am aware of, is turn off ipv6
in your kernel altogether. The thing is that each client uses a
different method to 'detect' that you're 'using' ipv6, and decides to
make an ipv6 dns query. The problem is that those clients are not being
smart enough (or dumb enough), and you're getting ipv6 dns queries when
you'd rather not have them. But the _real_ problem is that you have a
lame dns server. My Actiontec dsl modem is such a beast. My solution was
to run a caching dns server and dhcp locally (off the modem) and have it
forward requests to my ISP's dns servers, thus bypassing the modem. The
problem then went away (in the sense that it doesn't take forever anymore).