Why was the IPA introduced?

Reason 1: Simplified networking thanks to IPv6

IPv6 brings many new features for easier networking of computer systems. With IPv6, host systems are able to automatically and independently select a unique IP address for a network interface ("autoconfiguration").

Reason 2: Shortage of the IPv4 address space

The most pressing reason for IPv6 is the drastic shortage of the IPv4 address space. On February 1, 2011, the IANA, which is responsible for assigning IP addresses, reported that the IPv4 address pool was exhausted. Separate terms and conditions apply to the remaining "reserve blocks".

The predecessor - IPv4

Internet Protocol Version 4 was specified in RFC 791 in 1981. In the following year, the then new protocol was adapted by ARPANET - i.e. the forerunner of today's Internet - and was thus used worldwide. This protocol for addressing servers and computers on the Internet consists of four blocks, each block in turn from a range of numbers from 0 to 255 (256 numbers). So each block can have 28 take different numbers. The entire IP address space thus offers 28 x 28 x 28 x 28 = 4 294 967 296 possibilities.

What looks like a lot of addresses at first glance, however, has proven to be insufficient in practice. In addition to the small number of addresses - in relation to the total population of the world and the steadily increasing number of mobile devices - the current distribution of the networks is also a major problem. Particularly in the early days of the Internet, excessively large IP blocks were given to companies and institutions that can no longer be easily reclaimed today. The situation is made more difficult by the fact that, due to the scarcity of resources, many companies now have an economic interest in renting or selling IP address ranges.

The addresses are also geographically very unevenly distributed, while statistically in many parts of America and Europe far less than 10 people share an IP address, in large parts of Africa and Asia there are hundreds. This picture can be seen very well in the distribution of the address spaces to the so-called Regional Internet Registries (RIR) see which your IP addresses are from the Internet Assigned Numbers Authority (IANA).
It is easy to see that the ARIN responsible for North America has a significantly larger IP pool than the other registries.

The successor - IPv6

For this reason, IPv6 was published as the official successor in December 1998 (RFC 2460), which is not only intended to greatly expand the address space, but also brings improved and newly introduced features with it. IPv6 is made up of 8 blocks, each block being able to represent 65,536 different numbers. For more information see notation. With the new version of the Internet Protocol, there are around 340 sextillion (3.4 x 1038 ) Addresses available. This is by far sufficient to provide every home computer, every server and even every mobile phone in the world with a unique IP address.