However, this fact will soon change, not least due to the Internet of Things (IoT): As more and more everyday devices are able to connect to the internet and a large share of them need their own IP address, the availability of IPv4 addresses is gradually becoming scarce. To this end, IPv6 has been launched as the direct successor, enabling around 340 undecillion (a number with 37 zeros) addresses – an almost inexhaustible supply for all future IP requirements.
Addresses of this version have 128 bits and would therefore have to be written as a 128-digit binary number. Since such a number is far too long and impractical, hexadecimal notation is applied to compress the 128 bits into eight blocks of 16 bits, separated by colons. This results in the IPv6 address of 0000:0000:0000:0000:0000:ffff:c0a8:b21f, for example. Here, the letters a to f are also used as hex digits. If we omit the zeros at the start of every block and replace a series of consecutive 0000-blocks with two colons (::), this format can be simplified even further. In our example, this would produce the following shorthand: ::ffff:c0a8:b21f.