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On Sun, Jan 22, 2012 at 4:13 PM, Neil Winchurst wrote: > There has been a lot of emails on the list recently about IPv6. I am a > little confused about all this, and I suspect that I am not alone. > > I get the impression that IPv6 is coming in to replace IPv4 but is > taking a long time to happen. > > At the moment for most people there is no point in worrying about it, > IPv4 will carry on working for the foreseeable future . > > Also many ISP's are dragging their heels about this so are not yet ready > for it. > > And, there are not yet many suitable routers on the market. > > These are the 'facts' as I see them at the moment, but I am ready to be > corrected. So can anyone put me right if necessary please? I think > others on the list will be interested too. You put it all quite well. IPv4, the 'current' IP protocol, supports 32-bit IP-addresses like 80.68.88.22, where every 'part' has an 8-bit value which can thus range between 0 and 255. This gives just over 4 billion possible IP addresses (for a number of reasons not all of which can be used). With a world population of around 7 billion, many of whom use (or will use) more than one device, that is nowhere near enough. So we need to move to the next version of the IP protocol: IPv6. It differs from IPv4 in a number of ways, most importantly, it uses 128-bit IP-addresses, which gives a total of around 340 undecillion possible IP addresses, far and far more than we'll ever need. IPv6 can use the same networks as IPv4 and they can run alongside each other quite well. To be able to use IPv6, individual applications, operating systems and routers need to support IPv6 too. All commons operating systems do and quite a few applications too, but most routers don't, including most routers at ISPs. It's a bit of a chicken-and-egg story: it is a good idea to be IPv6 ready, but it continues to be essential to stay IPv4 connected. There are a number of ways to overcome the IPv4-exhaustion, such as buying unused blocks of previously assigned IPv4-addresses and using NAT* at a wider scale and it seems that this is what most businesses are using at the moment. In practise, there isn't much to worry about as a home customer. If you are to choose a new router and/or IPv6, it may be a good idea to make sure they are IPv6-ready, but I'd recommend that as a good practise rather than because without it you wouldn't be able to go online in the future -- that simply isn't the case. For the foreseeable future (which may well be the next few decades), IPv4 and IPv6 will run alongside each other. It's likely that IPv6 usage will start to grow fastest in Africa and Asia, where Internet usage is growing fastest and which have been assigned relatively few IPv4-addresses. In the West (Europe and North America), we'll probably end up seeing what happens there. * NAT means putting a number of devices with a local IP (e.g. 192.168.0.2) behind a shared public IP. Most households with more than one computer use that. It is possible to use this on a wider scale, for instance putting a whole neighbourhood behind one public IP. It is far from ideal, but I believe it happens in places in Russia and Asia. Hope this helps a bit. Martijn. -- The Mailing List for the Devon & Cornwall LUG http://mailman.dclug.org.uk/listinfo/list FAQ: http://www.dcglug.org.uk/listfaq