Ok, so today is ipv6 day. Again.
But as long as access providers do not offer ipv6 by default, I seriously wonder who I should make my website ipv6-compatible for. Sounds like a catch-22 to me.
However, I may have a useful tip for sysadmins out there. Whenever you rent a VPS you may already have an ipv6 address assigned to it. And if you’re like me, you limit SSH access to it, for instance using iptables. But since your box also has an ipv6 address that it is listening to, do not forget to make changes to ip6tables also.
The huge ipv6 address space makes it almost impossible to find your box using a port scanner, but neighbor VPS-es may be able to guess your address really quickly. So don’t think ipv6 gives you extra security, just more obscurity.
So go fix those ipv6 firewalls! Or disable ipv6 networking until you actually start using it.