Safari on IPv6 ?

Daniel G. Kluge dkluge at
Mon Feb 1 14:12:40 CET 2010

Am 01.02.2010 um 11:44 schrieb Bernhard Schmidt:

> On Mon, Feb 01, 2010 at 11:21:53AM +0100, Marco Hogewoning wrote:
> Note: this is only hearsay, some colleagues have this issue.
>> This should be easy, however I can't seem to find the answer online as
>> most articles are about turning off IPv6 instead of one. I noticed
>> Apple's Safari 4.04 defaults to IPv4 instead of IPv6 when both A and
>> AAAA are present. Now you can discuss wether this is a safe default or
>> not, I would really like to know where the little button is to switch
>> this behavior to AAAA first, which I recall used to be the case on
>> earlier editions.
> We have seen a similar behaviour with most applications after upgrading
> to MacOS X 10.6. It seems that the mdns-responder (?) of the system
> which is responsible for all DNS lookups is broken. It sends out both A
> and AAAA queries at the same time, but only seems to accept the first
> (successful?) response it gets.  I've even heard that some people see
> the second UDP response from the cache is rejected with "Port
> unreachable".

That would have been me.

> The effect is not a preference of IPv4, but no preference at all.
> Extremely hard to debug.

And annoying as hell...

> Bugs have been filed with Apple several times, I can ask for the
> bug-ids.

See the Thread on this on

Radar Reports I know of on this are 7333104 & 7416248

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