Technology at Best

IPv6 – How the Internet Finds Things

With the new Internet standard, economy is a thing of the past: thanks to IPv6, there are plenty of addresses, but they are much more complex. This is how the sequence of numbers is structured.

The future of the Internet has dawned with the new IPv6 internet protocol standard. The technical prerequisites were created for the development and operation of new applications for the now ubiquitous areas of the Internet of Things (IoT), interactive online collaboration methods, virtual reality and high-resolution multimedia streaming. Central to this was the expansion of the IP address space : there are now more IP addresses than stars in the universe.

The IPv4 standard uses 32-bit Internet addresses. They are usually represented as four 8-bit blocks separated by dots, each of which is expressed as a three-digit decimal number, for example With IPv6, however, address lengths of 128 bits are used. They are made up of eight 16-bit blocks, which are represented in the hexadecimal system. This means that the bit blocks no longer consist solely of the numbers 0 to 9, but also contain the first six letters of the alphabet (a to f). Each of these blocks is exactly four characters long.

Although the length of the address only quadruples, the address space explodes. It expands itself many times over, because with each additional bit the entire address space doubles, so that with a 128-bit address length, the number of possible IP addresses increases to a tremendous number: 3.4×10 38 . It is difficult to find an equivalent in the real world. Perhaps it suffices to say that the new address space enables each of the seven billion people on earth to connect several quadrillion objects to the Internet of Things.

The 16-bit blocks are separated by a colon. In order to be able to write the addresses as simply as possible, all leading zeros are omitted in the 16-bit blocks. In addition, the longest sequence of 16-bit blocks consisting of all zeros is simply omitted. This is the so-called zero compression.

The following example illustrates this. In its raw format, an address would look like this:

000E: 0C64: 0000: 0000: 0000: 1342: 0E3E: 00FE

First, all leading zeros (marked in bold) are omitted.

From 000 E: 0 C64: 0000: 0000: 0000: 1342: 0 E3E: 00 FE
E: C64: 0000: 0000: 0000: 1342: E3E: FE

The complete address can be easily reconstructed: wherever there are fewer than four characters, zeros must be added at the beginning.

Furthermore, the longest continuous zero successes are compressed, again printed in bold.

E: C64: 0000 : 0000 : 0000 : 1342: E3E: FE
E: C64 :: 1342: E3E: FE

This can drastically reduce the length of an IPv6 address. The omission of the zero blocks can be seen in the IPv6 address as a double colon. Again, it is easy for the computer to reconstruct the omitted blocks, since it is clear that an IPv6 address consists of eight (hexadecimal) blocks. There are five blocks left in the example. The double colon is therefore missing exactly three blocks of zeros. However, this only works if sequences of zeros are only left out in one place in the address. Otherwise one would not know how many blocks of zeros have to be added at the respective places.

As with IPv4, IPv6 addresses are made up of various components. What was in the predecessor prefix and suffix is ​​in the new protocol standard the prefix, the subnet ID and the interface ID.

Structure of the IPv6 addresses

The prefix describes the connection of the IPv6 address to the corresponding internet service provider or the local registry authority. The subnet ID gives an indication of the internal nature of the private network of the corresponding organization, and the interface ID identifies the user. It is basically comparable to the host ID from IPv4.

With the new IPv6 standard, an address space is available that no longer requires detours and workarounds such as subnetting and supernetting . The imperative to be economical when dealing with IPv4 addresses is a thing of the past. Unique IP addresses are now available for every purpose, every expansion and new development in order to make the Internet of the future more performant, more secure and more user-friendly.

by Christoph Meine of Best cutting edge technology Blog DFICLUB.ORG