Peter Eisentraut <peter_e@gmx.net> writes:
> On 10/25/14 2:52 PM, Tom Lane wrote:
>> And a bit of experimentation later: it seems that on Yosemite (and
>> probably earlier OS X versions), "localhost" maps to all three of these
>> addresses:
>> 127.0.0.1
>> ::1
>> fe80:1::1
>> Binding to 127.0.0.1 does not trigger the firewall popup. Binding
>> to ::1 doesn't, either. But binding to fe80:1::1 does. So the
>> easy fix, for a default installation, is to keep the postmaster
>> from binding to that last address.
>>
>> I'm not sufficiently up on my IPv6 to be sure exactly what that third
>> address does. Perhaps it is a bug in the firewall logic that it
>> considers that address external?
> I think that's exactly it. I have filed a bug with Apple about it.
> For the time begin, I think it's a reasonable workaround to comment out
> the line in /etc/hosts.
Hmm ... I was about to object that that seemed likely to break other
stuff, but on poking around I notice that my non-laptop Yosemite machine
has no such entry at all. (That one was originally Mountain Lion, and was
upgraded to Mavericks and then Yosemite, whereas my laptop was Mavericks
on delivery.) Even more interesting, there's a "/etc/hosts~orig" file on
my laptop that does not have the entry.
A little bit of data gathering later:
wife's laptop (10.9.5): has it
dromedary (10.6.8): has it
prairiedog (10.4.11): doesn't have it
So it looks like Apple has been using this for awhile but it's not really
essential to anything. What worries me a bit is that the evidence on my
laptop suggests there may be code somewhere (like System Preferences) that
will edit the file, so that a manual removal might not "keep".
We shall see.
regards, tom lane