Is going IPv6 Alone a realistic option

[rogerivy]

We've been told that from 1st Dec we have only 6 IPv4 addresses, but "unlimited" IPv6 (a big shift in our colocation provider).

I was considering moving entirely to IPv6, until I realised that many people do not have IPv6 (e.g. 3G and 4G users in the UK). As I write this I'm running off the three.co.uk mobile network and http://test-ipv6.com says "You appear to have no IPv6 address".

So my question: is going IPv6 without IPv4 a realistic option?

[kejianshi]

Dual stack or else you may find yourself not getting much traffic.

[Derelict]

Checkout the SixOrNot firefox extension.  It'll tell you at a glance what sites are v6 capable.  There are many popular sites that aren't.  Twitter, for example.

[rogerivy]

I persuaded my colocation service provider to allocate a range of IPv4's to me so my panic is over.
I even considered buying a /24 range of IPs, but that would cost around £2100 which didn't strike me as fun.

I'll test IPv6 slowly - seems to me we're a long way from actually using IPv6 in Europe. Probably decades.