What does IPv6 mean?

Thursday, 14 May, 2020

The internet’s origins date back to a 1960s American military project called ARPANET, developed to enable bases to communicate with each other after a nuclear war.

Then in 1991, Sir Tim Berners-Lee pioneered the concept of a worldwide web of interconnected computers, all sharing information over telephone lines.

Put the two together, and the internet as we know it was born.

However, for this fledgling communications network to operate, each connected device required a unique identifier, akin to a postal address or a telephone number.

Without this ID, host servers wouldn’t know which destination device to send information to.

And recipient devices wouldn’t know which address to contact to request more data, from email content and webpage text to multimedia files and program downloads.

To resolve this challenge, a pre-existing Internet Protocol was adopted, based on three experimental 1970s versions.

Debuting in 1981, four years before the first websites went live, the fourth version of the Internet Protocol (IPv4) allocated each connected device a numeric location address.

This comprised four numbers ranging from 0 to 255, separated by full stops. For instance, your home computer might be assigned the address 123.456.78.90.

When you enter a web address or attempt to access online services, the English-language identifier (e. g. https://www.broadbanddeals.co.uk) is translated into an IP address.

However, there can only be 4.3 billion different combinations of IPv4 addresses (256 * 256 * 256 * 256).

With billions of web-enabled Internet of Things devices coming online alongside legions of smartphones, computers and tablets, something had to be done to increase availability.

Step forward the sixth generation of the Internet Protocol address – IPv6.

Six appeal

For a while in the last decade, there were concerns that IPv4 addresses might be completely used up, but IPv6 has eliminated those worries.

Without getting into advanced mathematics, IPv4 can only offer 4,294,967,296 unique addresses – less than the number of adults on the planet.

IPv6 can offer 340,282,366,920,938,463,463,374,607,431,768,211,456 unique addresses.

(That’s 340 billion billion billion billion IP addresses, which ought to be sufficient for a while yet.)

Given the complexity of this new internet protocol, it’s perhaps unsurprising that it took over a decade to progress from a draft standard to an internet standard.

This agonisingly slow process was overseen by the Internet Engineering Task Force, a global open standards organisation run by volunteers on a non-profit basis.

Switching between two incompatible internet protocols proved tricky, but key technical benefits helped to justify the switch, including greater efficiency and superior distribution.

The switch from 32-bit to 128-bit addresses has been incremental. Around 30 per cent of today’s connectivity now takes place over IPv6, up from just 0.26 per cent in January 2010.

You don’t need to understand how IPv6 addresses are divided into quad-nibbles, or why routers no longer have to fragment payload data packets.

All you need to know is that the internet offers limitless potential for connectivity and expansion in the years ahead.

Neil Cumins author picture


Neil is our resident tech expert. He's written guides on loads of broadband head-scratchers and is determined to solve all your technology problems!