WHATEVER HAPPENED TO IPV6?
The implementation of IP in use today is actually the fourth version of the standard, commonly known as IPv4. It was introduced in 1982, and at that time the four-octet address format – representing a total of 4,228,250,625 unique addresses – doubtless seemed quite generous.
As internet usage exploded in the 1990s, however, it became clear that sooner or later IPv4 was going to reach its limit. The architects of the internet foresaw that at some point every possible IPv4 address would be allocated, and it would become impossible to connect any more devices to the internet.
Clearly a new addressing system was needed. Version 5 of IP had already been designated as a system specifically for video streaming (although it never caught on), so in 1998 a new generalpurpose system was drafted under the name IPv6.
IPv6 is similar to IPv4, but instead of four octets it uses a series of eight 16-bit numbers (sometimes called hextets), conventionally written in hexadecimal form with the numbers separated by colons, so a valid address might be 0201:0db8:0000:0006:00ba:1234:5678:0090. To make things slightly more readable, leading zeros can be omitted and zero values can be skipped altogether, so that address could also be written as 201:db8::6:ba:1234:5678:90.
This arrangement might not be snappy, but it allows IPv6 to support 340,282,366,920,938,463, 463,374,607,431,768,211,456 different addresses – enough to allow each person on earth to own 44 octillion connected devices. It’s safe to say that everyone who wants an IPv6 internet address will be able to get one, and it even makes NAT obsolete: on an IPv6 LAN, every device in your home or office can have its own globally unique internet address, with the router simply acting as a gatekeeper.
If you’re wondering why we don’t already have IPv6, the answer is that we do – it’s been built into Windows since Windows XP SP1. The trouble is that IPv6 isn’t directly interoperable with IPv4, and the cost and upheaval of migrating online services, home appliances and so forth has so far ensured that IPv6 remains a niche technology. Various measures have been taken to keep IPv4 up and running for as long as possible. The internet authorities have been reclaiming and reissuing IPv4 address blocks that were previously issued to organisations that are no longer in existence, while some companies have been buying up unused addresses from businesses that no longer need them. In the long run, though, internet providers will inevitably have to start offering IPv6-only connections, and the dominoes will necessarily fall from there. And while this may mean short-term pain, it will also bring benefits. IPv6 is more efficient than IPv4, so it should mean faster and more reliable networks. And at the very least, it will mean that ISPs and IT departments worldwide will no longer need to deal with the uncertainty of not knowing when the addresses will run out.