IP stands for Internet Protocol. The v in IPv4 and IPv6 is Version. We use IPv4 and IPv6 for identifying nodes on a network, each node must have an individual address. We have used IPv4 since 1981, and while there are over 4 billion addresses available in its number range that is no longer enough. IPv4 uses 32 bits to provide an address – the computer you are on now probably has an address such as 192.168.1.31 – that’s an IPv4 address. IPv6 uses 128 bits, which provides 340,282,366,920,938,463,463,374,607,431,768,211,456 addresses (you do not need to memorise that number!). We won’t run out anytime soon.
IPv6 provides a number of other benefits compared to IPv4:
- Security (IPSec) is built into IPv6, unlike IPv4 which relies on other protocols using it to secure the data it carries.
- Due to IPv4’s lack of addresses Network Address Translation (NAT) was required for everyone to be online. Now everyone can have their own IPv6 address, which means less processing and tables to identify who is who.
- IPv4 is reliant on a centrally managed addressing system, either manually or through a DHCP server. IPv6 does not need a DHCP server.
The transition from IPv4 to IPv6 is still occurring, that’s why your computer probably still has an IPv4 address (but will likely also have an IPv6 address).
IPv6 addresses are represented as Hexidecimal numbers such as 2001:4860:4860:0000:0000:0000:0000:8888 which is one of Google’s DNS servers. In binary that is 0010000000000001 0100100001100000 0100100001100000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 1000100010001000.