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What is IPv6 and why should you care?

IPv6 addresses

IP addresses are important. Every single device that connects to the internet needs some form of unique address that can be identified and located.

IP stands for Internet Protocol: the communications protocol that allows each machine to have a unique ID and pass packets of data between networks. IPv6 is the most recent version, and includes features that make a big difference to how IP addresses are organised.

IP addresses: the story so far

Before IPv6, there was IPv4. IPv4 was the first standardised, widely implemented version of IP, with development stretching back to the 1970s. But as the internet became rapidly commercialised in the 90s, it became clear that this ageing technology had some serious limitations.

Basically, IP addresses were running out. The core of IPv4 comes from a time when widespread personal computers and mobile devices were still the stuff of science fiction; it was never intended to provide the vast numbers of addresses required in a hyper-connected society.

IPv4’s 32-bit addresses theoretically put the maximum number of IPs somewhere around four billion. That may sound like a lot, but it’s a worryingly low number when you consider that there are already over seven billion people on the planet, let alone individual devices.

IPv6: solving the address shortage

This is where IPv6 comes in. Developed by the Internet Engineering Task Force (IETF – an open standards organisation), IPv6 became a Draft Standard in December 1998, but only achieved full Internet Standard status relatively recently, in July 2017.

Recognising the need for a massive boost in available address space, the IETF worked hard to ensure IPv6 never experiences the same exhaustion problem as IPv4. IPv6 is 128-bit, in theory providing a maximum of around 340, trillion, trillion, trillion addresses.

Needless to say, we won’t be running out of IPv6 addresses any time soon. But the jump to 128-bit isn’t the only change, with IPv6 also offering several upgrades over IPv4.

IPv4 vs IPv6: more improvements

Technical benefits associated with IPv6 include hierarchical address allocation. This helps avoid fragmentation of IP addresses and makes more efficient use of the address space. Multicast addressing is also expanded, simplified and optimised, allowing network packets to be transmitted to multiple destinations simultaneously.

A major difference between IPv4 and IPv6 is packet header structure. You could think of the header like the addressed envelope that contains the letter (the packet). IPv6 does away with the more complex header structure of IPv4, with rarely used fields moved to optional extensions. The result is more efficient packet forwarding via routers and improved overall performance.

But what about all those existing IPv4 addresses? Do they still work alongside IPv6? IPv6 was not originally designed to be interoperable with IPv4, but the reality of the modern internet means a wide variety of technical solutions allow them to cooperate perfectly. The real question is whether IPv6 will ever be the only choice for IP addresses.

The future: will IPv6 replace IPv4?

With its comparatively miniscule address space, you might assume that IPv4 is dead and buried. But in reality IPv4 is in great health, still accounting for about 75% of all internet traffic. IPv6 adoption is creeping up, but it certainly won’t be replacing IPv4 overnight.

So how can this be, if we’re facing a crisis in the number of available IPv4 addresses? After all, 2017 was the year that IPv4 addresses officially “ran out”.

A big part of IPv4’s longevity is down to network address translation (NAT). This is a technology that allows organisations to run thousands of devices behind a handful of public-facing IPs. Similar techniques have also been employed by internet service providers, reducing the number of addresses required by their customers.

Long term though, it’s clear that IPv6 will come to dominate, even if IPv4 sticks around for a long time. The coming decades will likely see an ever-increasing demand for colossal quantities of IPs, with the internet of things (IoT) connecting everything from fridges to thermostats – and every IoT device will need its own unique address.

At Fasthosts, we offer IPv6 addresses on CloudNX, our next-generation cloud hosting platform. Each Virtual Private Server and Bare Metal Server can be assigned with multiple IPv6 addresses at no extra cost. Contact us now for more details on how we can provide your ideal server hosting environment.

Neal Thoms's picture

Neal Thoms

Author As a content creator for Fasthosts, Neal’s main focus is cloud technology and how it’s transforming everything we do online. He’s worked in the web hosting industry for over five years.