What is IPv6?
The IP (the Internet Protocol) is one of the most important protocols for modern computing networks, including the Internet. It is responsible for identifying each machine on the network by a unique address (the IP address) and routing packets of data from their source to the correct destination machine through this addressing. The current version of the IP protocol being used is IPv4 (IP version 4).
So why do we need IPv6?
The current structure of an IP (IPv4) address is 4 numbers ranging between 0 and 255, each separated by a dot. You will have seen something like this 192.168.0.1 when setting up your DSL, an IPv4 address is made up of 32 binary digits (bits). The maximum number you can make with 32 bits is 4.3 billion (2 raised to power 32).
Every device connected to the Internet should have a unique IP address – no two machines can have the same address. So this means that the Internet can theoretically hold only 4.3 billion connected devices, that’s a lot of devices, but when you think of the modern world with multiple computers in homes, smart phones, pda’s and even internet connected fridges, it’s not going to last long. The remaining IPv4 addresses are dwindling and considering the amount of user computers, hosts and other devices that are connected on the Internet, we will run out of IP addresses in the not too distant future.
The limitations of IPv4 and the explosion of Internet connected devices has led to the development of a new version of IP called IPv6 (IP version 6). There was an IPv5 but that was purely for research and was never deployed. IPv6 is the version that is ready to be deployed over the whole Internet and be adopted by all devices, connected Internet and networks. IPv6 brings many improvements, mainly in the number of machines that can be accommodated on the Internet
IPv6 addresses consists of 128 bits, allowing an astronomical number of devices. This is equivalent to the value of 2 raised to the power of 128, that’s very nearly 40 trailing zero’s.
Ok, I know what you’re thinking, that’s a massive number! However, this has been solved – IPv6 addresses have rules to compress them. First, the numbers are represented in hexadecimal instead of decimal numbers. Decimal numbers are numbers from 0 to 9. Hexadecimal numbers result from the grouping of bits in 4, giving the following characters:
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F. An IPv6 address is made up of these characters. Since the bits are grouped in 4, and IPv6 address will consist of 32 characters.
An example of an IPv6 address is
This one has only 19 characters – there has been some compression, we will cover that in a later blog post. Note that the separator has changed from the dot to the colon.
IPv6 brings more improvements over the current IPv4 system such as better security and auto configuration on routers, as well as solving the problem of dwindling IP addresses.
Switching from IPv4 to IPv6
The day when IPv4 will no longer be viable is coming and now that IPv6 is around, the biggest challenge is to make the transition from IPv4 to IPv6. This is a massive task. If you think of a motorway, let’s say the M25, this is effectively resurfacing the entire motorway. To keep the traffic moving, it has to be done a part at a time.