If you dip four links deep from the BBC story about World IPv6 day (that’s today) then you will eventually see a banner headline: “This time it’s for real”.

This is partway down the page at the World IPv6 Launch wesbite, after a surprisingly short list of only 14 participating technology companies, and is about all you’re going to see in the up-front materials that makes any reference to just how long this whole project has been in the works. I think that the simplicity of the statements made is a bit of a breakthrough for the technologists and agencies responsible for IPv6, whose minds are normally preoccupied with the delights of colonic quad notation, rather than easy-to-digest English. Incidentally, on the colonic quads – anyone who has had to explain to uptight clients why their unused, default IPv6 configuration includes FECC:00FF as a valid v6 address will already know just how irritating this whole business really can be.

I won’t recast the kindergarten explanations here, aside from saying that as per usual, Vint Cerf has managed to be technically accurate and commendably short in his blog. What I will say is that I have been spending quite a long time now on another planet entirely (that’ll explain the unanswered phone calls – Ed). I don’t mean by hitching a ride on Virgin Galactic – I mean that I’ve got a pure IPv6 connection, and have had for rather more than a year, and the address allocation I have been given is a /64. This means it has as many bits – and therefore, as many potential unique addresses – as all of Planet Earth, on good old IPv4.

Making a secure network in IPv6 is a whole different mental approach from the old “I’m behind a router so I should be fine” state of mind

I haven’t used more than about four, so far. This is for a couple of reasons. One is that the connection came with an IPv4 address space too; the other is that I’ve found it remarkably difficult to even find bits of hardware or software which implement IPv6 and which might reasonably appear in the average small business network, for me to test on my sparkly new connection. Plus, I really need a means of putting IPv6 traffic into my test device from the far end, and… I haven’t yet come across another truly native IPv6 endpoint I can use for this purpose.

Now, there are workarounds for all these limitations – for one thing, Windows 7 and 8 and the Server releases all support v6 natively. For another, there are many providers who will pretend that you are part of their v6 address space, courtesy of a tunnelling arrangement via v4, so it’s not as if experiments are impossible, just kind of irrelevant for now.

Until the day that your ISP makes a configuration change that includes or imposes v6 on you, you’re highly unlikely to hit any v6 traffic or configuration requirements. However, based on experience I’ve collected in Europe (where v6 adoption has been a lot more rapid, though people I talk to there can’t strictly say why they’ve rushed in), there are grounds for getting to know what the situation will mean for you, because every alteration I’ve had to make so far to IPv4 arrangements kyboshed by v6 have been in a dead panic.

It’s the unexpected that really catches you out; and very often, the ISPs choose to announce their architecture changes in less-travelled parts of their sites, or in newsgroups, or by mailing the contact email address that goes with the affected internet connection. Most of the businesses I deal with have long forgotten those details, and/or never check the ISP’s site or newsgroup (how retro, I hear you say), so it’s always a bit of a shock when stuff starts to move around.

The most worrying scenario is when IPv6 signals a complete overhaul by the ISP, in reality finally imposing a whole load of traffic-shaping and content control which in the old v4 network was loaded into the routers and infrastructure, but which (whisper it quietly) never actually worked. Then what changes isn’t, strictly speaking, anything to do with v4-to-v6 at all; it’s actually everything else about your data and how it reaches you – but they don’t tell you that. Lots of firms who have got away with el-cheapo home-user internet access contracts are, I suspect, about to suffer a very rude awakening indeed from that kind of “upgrade”.

If this kind of root-and-branch reform actually sounds appealing to you (here I am thinking of firms with opinionated, eccentric CEOs and CFOs with strong religious convictions about “computers”), and you are thinking of proposing a wholesale shift to IPv6 as your best way of getting an upgrade done on the back of a bit of FUD for your local Ayatollah, then here is a little word of warning.

One of the major advantages of v6 is global addressing, and the end of network address translation (NAT) as a method of operating your private network, well, privately. Big-time network engineers dislike NAT because it makes their central routers work very hard, while small-time network engineers love it as an easy first step on the road to a secure network. Making a secure network in IPv6 is a whole different mental approach from the old “I’m behind a router so I should be fine” state of mind. Make quite sure you realise what it means to be globally addressable, before you gaily join Vint Cerf and his friends on, as he puts it, the 21st century internet…