For a site I manage, http://archstl.org/, the DNS entry returns an empty (::) IPv6 address when I run $ host archstl.org in the Terminal.
I think the errant IPv6 entry may be the cause of my problem: when a Mac user running Apache Web Server (any flavor) tries to visit archstl.org, they get localhost instead (the Mac seems to pick up archstl.org's IPv6 address rather than the IPv4 address, 174.37.22.142).
Does anyone know how to resolve this issue? I'm not even sure how the IPv6 address is being output for our DNS entry; I don't have any other domain names that return an IPv6 address.
See here for more info on my own troubleshooting: http://archstldev.com/node/74
Best Answer
::is the all-zeroes address, similar to 0.0.0.0 in IPv4. This isn't even localhost (::1) — it's guaranteed to make your site unreachable over IPv6. If your web server has IPv6 connectivity, point the AAAA record for archstl.org at its IPv6 address. If it doesn't remove the AAAA record entirely.