Retrospective: How IPv4 Addresses Dwindled

Geoff Huston, chief research engineer for the APNIC Internet registrar, predicted that IPv4 addresses would end in 2020. In the new cycle of materials we will refresh the information on how addresses were depleted, from whom they still remained and why it happened.

/ Unsplash / Loïc Mermilliod

Why do the addresses end

Before moving on to the story of how the IPv4 pool “dried up,” let's talk a bit about the reasons. In 1983, the implementation of TCP / IP used 32-bit addressing. At that time, it seemed that 4.3 billion addresses for 4.5 billion people were enough. But then the developers did not take into account that the planet’s population will almost double, and the Internet will become widespread.

At the same time, in the 80s, many organizations received more addresses than they actually needed. A number of companies still use public addresses for servers that operate exclusively on local networks. The spread of mobile technology, the Internet of things and virtualization added fuel to the fire. Miscalculations in estimating the number of hosts in the global network and inefficient address allocation have led to IPv4 shortages.

How did the addresses end

In the early 2000s, APNIC Director Paul Wilson said IPv4 addresses would end in the next ten years. In general, his forecast turned out to be quite accurate.

2011: As Wilson predicted, the APNIC Internet registrar (in charge of the Asia-Pacific region) had the last block / 8 . The organization introduced a new rule - one 1024-address block in the "one hand". Analysts say that without this restriction, block / 8 would end in a month. APNIC now has only a small number of addresses.

2012: The European Internet Registrar RIPE announced the depletion of the pool. He also began to distribute the last block / 8. The organization followed the example of APNIC and imposed strict restrictions on the distribution of IPv4. In 2015, RIPE had only 16 million free addresses. Today this number has significantly decreased - to 3.5 million . It is worth noting that in 2012, the Worldwide IPv6 launch took place . Global telecom operators have activated a new protocol for some of their customers. Among the first were AT&T, Comcast, Free Telecom, Internode, XS4ALL and others. At the same time, Cisco and D-Link enabled IPv6 by default in the settings of their routers.

A couple of fresh materials from our blog on Habré:

2013: Jeff Huston of APNIC said in a blog post that the IPv4 addresses of the US registrar ARIN will end in the second half of 2014. Around the same time, ARIN representatives announced that they had only two / 8 blocks left.

2015: ARIN became the first registrar to have completely exhausted the pool of free IPv4 addresses. All companies in this region have queued up and are waiting for someone to release their idle IPs.

2017: The stop of the issuance of addresses was announced in the LACNIC registrar, responsible for Latin American countries. Now only those companies that have never received them before can purchase the block. AFRINIC - responsible for the African Region - also imposed restrictions on the issuance of addresses. Their purpose is strictly evaluated, their maximum number in one hand is limited.

2019: Today, all registrars have a relatively small number of addresses. Pools are kept afloat due to the fact that unused addresses are periodically returned to circulation. For example, MIT found 14 million IP addresses. More than half of them decided to resell to needy companies.

What's next

It is believed that IPv4 addresses will end by February 2020. After that, Internet providers, network equipment manufacturers and other companies will have to choose whether to migrate to IPv6 or work with NAT mechanisms .

Network Address Translation (NAT) allows you to translate multiple local addresses into one external. The maximum number of ports is 65 thousand. Theoretically, the same number of local addresses can be mapped to one public address (if you do not take into account some restrictions of individual NAT implementations).

/ Unsplash / Jordan Whitt

Internet service providers can turn to specialized solutions - Carrier Grade NAT. They allow you to centrally manage local and external addresses of subscribers and limit the number of TCP and UDP ports available to clients. Thus, ports between users are distributed more efficiently, plus protection against DDoS attacks appears.

Potential problems with firewalls can be distinguished from the disadvantages of NAT. All user sessions access the network from a single white address. It turns out that only one client at a time can work with sites that open access to services over IP. Moreover, the resource might think that it is undergoing a DoS attack and block access to all clients.

An alternative to NAT is switching to IPv6. These addresses are enough for a long time, plus it has several advantages. For example, the built-in IPSec component that encrypts individual data packets.

So far , only 14.3% of sites worldwide use IPv6. The wide distribution of the protocol is hindered by several factors related to the cost of migration, lack of backward compatibility and technical difficulties in implementation.

We will talk about this next time.

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