By the end of next year, 2016, the UK should be well down the road of conversion to IPv6 – the newer system of IP addressing which is replacing the current IPv4 system. According to Google’s adoption statistics, several other countries have much higher proportions already using IPv6, compared with the UK’s current figure of 2.6%:

• Belgium 36%
• Switzerland 23%
• USA 21%
• Germany 18%
• Portugal 16%
• Greece 12%
• France 6%.

Open the Network pane, and take a peek at the IP addresses which appear there. The chances are that they will each consist of four numbers, separated by dots, like 192.0.0.10. Look at the external IP address provided by your router – that is the address which the Internet knows your router by – and that will have a similar form. Those are old-style IPv4 addresses, and are on their way out.

The underlying problem is that IPv4 was designed for an Internet of the past, when those four numbers were sufficient to identify every device on the Internet uniquely. There are now so many devices on the Internet that we have all but run out of new IPv4 addresses which can be issued. The Internet is full.

The only way ahead – and there is no choice in this matter – is to switch from IPv4 to IPv6, which uses eight groups of hexadecimal numbers like fe80:0000:0000:0000:0217:f2ff:fe4d:2f70 instead. IPv4 uses four bytes for each address, whilst IPv6 uses 16 (not 6 as you might have guessed). Fuller details about IPv4 and IPv6 are given here.

One of the great advantages with IPv6 is that there are so many addresses available that it will no longer be necessary for computers and other devices on networks to have their own local IP address, sharing a single external address, for example using DHCP. There are schemes for doing this in IPv6, and a replacement for DHCP, but they are not always necessary, as they are in IPv4.

However not all network devices are capable of operating IPv6. Now is the time to start planning and checking what you might need to upgrade or replace so that your computers and network(s) can switch to IPv6 when it happens.

Computers and similar devices

The vast majority of computers, including smart phones, tablets, and PDAs, have hardware which does not worry about network protocols such as IPv4 or IPv6: this is a software matter, although some do rely on firmware. So it is generally down to whether the operating system fully supports IPv6.

Thankfully OS X has enjoyed support for IPv6 since version 10.2 Jaguar (2002), and iOS has always supported it, so only the most ancient of Macs should have problems (and they should no longer be connected to the Internet). Versions of OS X prior to 10.6.7 may only have partial support, or can be tricky under IPv6, but again you should really not let any Mac running such old systems near the Internet.

OS X 10.11 El Capitan and iOS 9 support all the latest bells and whistles in IPv6, and Apple requires all apps running under those to fully embrace IPv6 features.

Windows and Linux/Unix support dates from a similar period.

Routers and network hardware

The most important item for you to check now is your router or modem-router: although most models made in the last few years should have full IPv6 support, some will need firmware upgrades, and some do not have any way of supporting IPv6. This should be made clear in the router’s documentation, or its support site.

One of the largest groups to be affected by this are BT customers who use its Homehub 4, which cannot support IPv6, according to BT. An estimated 6.3 million of BT’s total 7.8 million customers still have the Homehub 4, and BT is looking at how it can replace all those routers by the end of 2016. If you are affected by this, BT should be informing you over the coming months of what it plans to do.

BT’s current intentions are to enable IPv6 on half of its networks by April 2016, and to complete the remaining half by the end of 2016. Sky has apparently converted its first million customers to IPv6 too, and other ISPs have similar programmes in hand.

Other older network hardware such as bridges, WiFi base stations, etc., should also be checked over the coming months, by consulting the manufacturer’s support pages, which should state clearly whether each model does support IPv6. Most of Apple’s network devices, like Airport hardware and Time Capsules, should be fine provided that their firmware is fully up to date.

As IP addressing operates independently of physical connections like Ethernet cabling, cables and similar passive devices are not affected by the change, and will work fine under IPv4 and IPv6.

Testing it out

An increasing number of websites can run helpful tests which may assist your preparations. One worth visiting is Test IPv6, and your ISP may well recommend others in due course.

When to switch

Once you are satisfied that all your networked devices and hardware is compatible with IPv6, you can check your ISP’s support pages to see if you can opt to switch to IPv6 yet. Over the next 6-12 months, most ISPs in the UK should be contacting their customers and advising them when they can transfer. Do not try to change on your own: your ISP needs to move your connection, and they will co-ordinate this with you.

When you are happy that all your gear is ready for IPv6, the earlier that you switch, the better. ISPs are already experienced at transferring accounts, and you should find this less trouble when done sooner, rather than later. If you do think that you have particular problems – an ancient networked scanner or printer, for instance, which cannot support IPv6 – you should raise these with your ISP early, so that they can help you plan a workaround.

May your preparations go smoothly.