We're going to run out of IP addresses

IP addressing

All data communication takes place on the Internet via IP addresses. The IP address represents the lowest addressing level on the Internet, on which, for example, the Domain Name System (DNS) or other addressing schemes are based.

Basics of IP addressing

The underlying addressing in the Internet is based on the so-called IP addressing. With this technique, every resource on the Internet is assigned a unique number, the so-called IP address reachable. Every transmission on the Internet takes place between devices with IP addresses. The protocol still used at the moment is the so-called IPv4 ("Internet Protocol Version 4"). This protocol, which was introduced on the Internet in September 1981, is the replacement for the NTP protocol that has been in use on the Internet from the very beginning.

Strictly speaking, IP belongs to the protocol family TCP / IP (see also TCP / IP - house language of the Internet) and represents the lower transmission layer here (see also The DoD layer model). At this point I limit myself to the IP, as this is where the actual transfer takes place between two computers; TCP is an overlying control instance.

In the IPv4 scheme, an IP address consists of exactly 32 bits, which theoretically forms a number range of over four billion IP addresses (exactly 4,294,967,296). However, such columns of numbers are very difficult for us humans to use. Even a purely decimal notation would still be too complicated, which is why the dotted-decimal notation has enforced:

The 32-digit bit sequence is divided into four eight-digit blocks (the so-called Quads) and then converted to the decimal equivalent. Each quad represents (since it is defined as 1 byte) a number between 0 and 255. The individual quads are separated from one another by dots.

Logically speaking, an IP address is split into two parts, the Network- and the Host prefix. These two parts, which can be of different lengths, are used to manage IP addresses in a decentralized hierarchy; Only this split makes it possible to manage the IP address space as we can today.

This complex topic is devoted to a topic of its own: IP subnetting

Decentralized administration

One negative experience that was made with the TCP / IP predecessor was the inflexibility in routing (see on this topic also transmission in the network - routing). NTP addresses could only be assigned from a central point and the routing information of each assigned address had to be entered manually in each connected device in the network. This resulted in a rather cumbersome administration work, since every change in the network meant a huge configuration effort.

For this reason, a hierarchical administration was implemented during the development of the Internet Protocol, which made it possible to allocate entire blocks of IP addresses to an administrative unit, which in turn can allocate smaller blocks from this block to subordinate administrative units.

For this reason, at the beginning of the 1990s, the InterNIC, which until then had solely managed the IP address space, assigned the administration for certain continents to independent institutions and also assigned their own IP address spaces to large companies at the time. In this way, these institutions and large corporations were able to manage their assigned IP address spaces independently from the InterNIC.

In order to be able to manage IP address spaces decentrally, a logical division of the IP address space was necessary in order to be able to determine the area of ​​responsibility for each IP address. This logical division was made with the so-called Network classes realized, with which different sized networks were formed in this way.

IP addresses are assigned hierarchically and in blocks. The highest authority is the IANA, which governs the entire IP address space. On the one hand, it manages the IP address blocks of owners of complete Class A networks, which were assigned to large companies in the early days of IP addresses, and on the other hand, it assigns IP address blocks to regional registration offices for IP addresses, the so-called Regional Internet Registries (RIR)who are responsible for assigning IP addresses in certain continents and regions.

AreaRegional Internet Registry
North America, AntarcticaARIN
Europe, Middle EastRIPE
South America LACNIC
Middle and Far East, PacificAPNIC
Africa AfriNIC

Appropriately qualified Internet providers in the relevant regions can now apply for their own IP address blocks at the Regional Internet Registries, provided they meet the technical and administrative requirements and can provide evidence of a need. These providers are known as Local Internet Registry (LIR). (In some countries there are also their own national registries, which represent an intermediary registry for providers in the country.)

Local Internet Registries are entitled to manage the address range assigned to them largely autonomously, but the assignment of IP addresses by these authorities to other providers and customers is tied to extensive conditions: The application for the necessary IP addresses must be precisely planned and justified the provider must ensure that precise records are kept of the internal transfer of IP addresses. These two conditions in particular create enormous administrative costs for providers, even if the actual assignment of IP addresses by the authorities is traditionally free of charge.

Nevertheless, this documentation of the IP address assignment is important so that it can be determined at any time which provider or user is assigned a certain address block and so that future needs can be estimated. These documented entries can also be researched at the Regional Internet Registries in the local Whois databases at any time.

Is it possible to read out the geographical location of IP addresses?

Basically: no. The allocation of IP addresses and address blocks is regulated quantitatively and is completely independent of geographical location features. The fact that in Europe, for example, a large number of IP addresses with the numbers "80", "192", "193", "194" appear, is simply due to the fact that the RIPE received from the IANA, among other things, precisely these networks for administration Has. In this respect, one could at most assert with greater certainty that IP addresses that begin with "80", for example, are primarily used in Europe.

However, the assignment of a certain number of IP addresses to customers must be documented by the LIR, from whose address inventory the IP addresses originate, to the responsible RIR. For example, if a European provider assigns a network of 8 IP addresses to a customer, he must document this address range with the exact details of the customer and the contact person at RIPE. This documentation is then available to everyone via Whois at RIPE.

Will IP addresses run out anytime soon?

Again and again there are reports in the media that the IP address space on the Internet will soon run out and that the Internet could reach a point where it would be "full". In a sense, this statement is true - when you look at when this statement was made and in what context.

Serious fears that the IP address space could run out in the very short term arose in the early 1990s. The Internet boom was just beginning and in a very short time there was a huge demand worldwide for IP addresses for Internet access and web servers. Extrapolations of the increasing demand resulted in the consumption of all free IP addresses up to the year 1995.

The two main causes of the increasing demand for IP addresses, Internet access and web servers, were defused in a very short time by new technologies: Network Address Translation was introduced for Internet access and a revised version of the HTTP protocol was added to the World Wide Web the version number 1.1 missed, the so-called virtual web server enabled, i.e. the possibility of operating several web servers simultaneously on one IP address.

The need for IP addresses continues to rise, but is nowhere near as drastic as it was in the 1990s. In addition, the assignment of IP addresses by the Regional Internet Registries is now subject to very strict assignment guidelines.

The limited resource "IP address" is therefore still available in sufficient numbers in the existing IPv4 scheme in the medium term.

Related Links

http://www.3com.com/other/pdfs/infra/corpinfo/en_US/501302.pdf (PDF)
Very good introduction to IP addressing from Chuck Semeria

http://zeus.fh-brandenburg.de/~ihno/lehre/internet/
Translation of the document by Ihno Krumreich