The Department of Work and Pensions, UK has an entire /8

[nick at foobar.org (Nick Hilliard)]

On 20/09/2012 20:14, Tony Hain wrote:
> Once the shift starts it will only take 5 years or so
> before people start asking what all the IPv4 fuss was about.

Tony, ipv4 succeeded because it was compelling enough to do so (killer apps
of the time: email / news / ftp, later www instead of limited BBS's,
teletext, etc), because the billing model was right for longhaul access
(unmetered instead of the default expensive models at the time) and because
it worked well over both LANs and WANs (unlike SNA, IPX, decnet, etc).

ipv6 has none of these benefits over ipv4. The only thing in its favour is
a scalable addressing model.  Other than that, it's a world of pain with
application level support required for everything, poor CPE connectivity,
lots of ipv6-incapable hardware out in the world, higher support costs due
to dual-stacking, lots of training required, roll-out costs, licensing
costs (even on service provider equipment - and both vendors C and J are
guilty as accused here), poor application failover mechanisms (ever tried
using outlook when ipv6 connectivity is down?), etc.

The reality is that no-one will seriously move to ipv6 unless the pain of
address starvation substantially outweighs all these issues from a business
/ financial perspective.  It may be happening in places in china - where
there is ipv4 significant address starvation and massive growth, but in
places of effectively full internet penetration and relatively plentiful
ipv4 addresses (e.g. the US + Europe + large parts of asia), its
disadvantages substantially outweigh its sole advantage.

I wish I shared your optimisation that we would soon be living in an ipv6
world, but the sad reality is that its sorry state bears more than a
passing resemblance to the failure of the OSI protocol stack.

Nick