The version of nginx in Squeeze [0.7.67-3], without any reconfiguration,
[in particular, without adding any explicit "listen" configuration],
happily creates both a 0.0.0.0:80 IPv4-only and a [::]:80 IPv6-only
However, BOTH the nginx wheezy [1.1.12-1] and squeeze-backports
[1.1.8-2~bpo60+1] versions, have the default behaviour (with
similar default-config, no "listen" lines) of listening ONLY
for Legacy IPv4 connections!!
This is bad when you have a dual-stacked host with both A and AAAA
For example, squid3 on the same host, connecting to the host itself
by its' own name, gets 'connection refused' over IPv6 and doesn't
seem to fall back to IPv4 at all.
This can currenty be worked around by manually overriding the 'listen'
entries in the config, to have either an IPv4 socket AND an
IPv6-only-IPv6-listen-socket, or a single IPv6-with-IPv4-
compatibility listen socket.
We could, change the, default config file included, which creates
complexity in updating, though this may be needed to make
the comments in the file clear as to what is expected by default.
I would think, a neater thing to do would be to patch the code to
default to IPv4+IPv6 sockets, unless the user overrides it
in the config-file...