IPv4 history ends, IPv6 era officially arrives

1. What’s coming has finally come—IPv4 address exhaustion

The long-standing prediction that the world will soon run out of IPv4 addresses has finally arrived - all 4.3 billion IPv4 addresses have been allocated, which means there are no more IPv4 addresses to be allocated to ISPs and other large network infrastructure providers.

IPv4 was introduced in the early 1980s. IPv4 addresses are 32-bit numbers used to identify devices on the Internet, so only a limited number of Internet addresses are provided (2^32 is about 4.3 billion). With the rapid development of the Internet, the surge in the number of connected devices, from PCs to smartphones and IoT sensors, has led to the rapid consumption of IPv4 reserves.

In fact, researchers had foreseen such a future as early as the 1980s.

The global management body of IP addresses is the Internet Assigned Numbers Authority (IANA), which assigns IP addresses to five regional Internet registries (RIRs) around the world.

As of February 3, 2011, IANA has allocated all IPv4 addresses to five regional Internet registries:

• The African Network Information Centre (AFRINIC) is responsible for Africa;
• The North American Network Information Center (ARIN) covers Antarctica, Canada, parts of the Caribbean, and the United States;
• Asia Pacific Network Information Centre (APNIC) is responsible for East Asia, Oceania, South Asia and Southeast Asia;
• The Latin American Network Information Center (LACNIC) covers much of the Caribbean and all of Latin America;
• The RIPE NCC is responsible for Europe, Central Asia, Russia and West Asia.

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2. The demise of IPv4

The continuous Internet registration has caused IPv4 to be consumed at a rate visible to the naked eye:

• April 15, 2011: Asia Pacific APNIC announced the exhaustion of IPv4 /8 addresses;
• September 14, 2012: European RIPE NCC announces exhaustion of IPv4 /8 addresses;
• June 10, 2014: Latin America LACNIC announces exhaustion of IPv4 /10 addresses;
• September 24, 2015: North American ARIN announced that all IPv4 addresses were exhausted;
• April 21, 2017: AFRINIC announced the exhaustion of IPv4 /8 addresses;
• November 25, 2019: European RIPE NCC announced that all IPv4 addresses are exhausted!

To be continued…

Editor's note: Many media outlets used the headline "Global IPv4 Address Exhaustion" to report this news. According to multiple investigations by Ansu Networks, in fact, the five regions all have their own IPv4 address allocation processes, including phased consumption, reservation strategy and limited strategy, in order to delay the decay time and smoothly migrate to IPv6. Strictly speaking, the only regions that have officially announced that all IPv4 addresses have been exhausted are ARIN in North America and RIPE NCC in Europe.

The news of the exhaustion of European RIPE NCC IPv4 addresses was announced by Nikolas Pediaditis in an email that reads as follows:

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(Translation):

In theory, the exhaustion of IPv4 addresses means that no new IPv4 devices can be added to the Internet. But in practice, we have some ways to buffer the impact of IPv4 address exhaustion.

First, the ISP can reuse or recycle unused IPv4 addresses. Second, we can use the same IP address privately behind the ISP router through Network Address Translation (NAT) technology.

Of course, the final step is the transition to IPv6. In order to ensure a smooth transition, the entire industry has already prepared for the rainy day and formulated a response strategy to achieve direct point-to-point connections across the entire Internet with 3.4×10^38 address space.

According to the 44th "Statistical Report on Internet Development in China", as of June 2019, the number of IPv6 addresses in China was 50,286 blocks/32, ranking first in the world.

3. What are the advantages of IPv6 over IPv4?

IPv4 address exhaustion is one of the driving forces behind the emergence of IPv6. IPv6 is a network layer protocol similar to IPv4. IPv4 uses 32-bit addresses and can only provide 2^32 IPv4 addresses, while IPv6 uses 128-bit addresses and can provide 2^128 unique IPv6 addresses.

One of the original purposes of developing IPv6 was to solve the problem of shortage of IPv4 addresses. However, after considering the various problems encountered in the development, deployment and operation of IPv4, the designers of IPv6 have added a number of new functions to IPv6, giving it more technical advantages over IPv4.

• Huge IP address space - there is no need to worry about the problem of URL exhaustion in the future like IPv4. IPv6 has reserved a broad space for innovation in the protocol, providing a new basic platform for the long-term upgrade and evolution of the Internet.
• Enhanced multicast support and streaming support - this allows multimedia applications on the network to have a great development opportunity, provides a good network platform for service quality control, and adds support for automatic configuration. This is an improvement and expansion of DHCP, making network management more convenient and faster.
• Faster content acquisition speed - IPv6 address allocation follows the clustering principle, which allows the router to use one record in the routing table to represent a subnet, greatly reducing the length of the routing table in the router and increasing the speed at which the router forwards data packets, making it faster to connect and obtain content through IPv6.
• Higher security - Traditional network security mechanisms are only established at the application layer, such as E-mail encryption, access security (HTTP and SSL), etc. There is no way to ensure the security of the Internet and the Internet of Things from the IP layer. IPv6 can achieve security at the IP layer. Users can encrypt data at the network layer and verify IP messages, ensuring the integrity and confidentiality of the packets.
• Internet real-name system is feasible - Another important application of IPv6 popularization is Internet identity authentication under the Internet real-name system. One of the important reasons why it is difficult to implement Internet real-name system on IPv4 networks is that IP resources are insufficient, so different people share an IP at different times, and IP addresses and Internet users cannot be matched one-to-one. The emergence of IPv6 will solve this problem once and for all from a technical perspective. Since IP resources will no longer be tight, when operators apply for network access for users, they can directly assign a fixed IP to each user, realizing a one-to-one correspondence between real users and IP addresses.
• Multi-host feature supports 5G applications - a typical IPv6 device can have multiple addresses, and a terminal can establish multiple hosts at the same time, providing source address-based traffic diversion applications for mobile edge computing. Due to the multi-host feature, it can be established first and then disconnected during switching, so that mobile devices can maintain connection with the Internet when moving between different networks, reducing data packet loss and improving user experience. In the upcoming 5G era, IPv6 will have a wider range of applications.

Currently, the large-scale deployment of IPv6 still faces a series of problems. For example, the network quality and service performance need to be improved, the proportion of IPv6 traffic is still relatively low, the breadth and depth of IPv6 transformation of Internet applications are insufficient, the stock of household fixed broadband gateways needs to be transformed, and the IPv6 network security defense protection capabilities need to be improved.

It is expected that IPv4 and IPv6 will coexist on the Internet for a long time, and it is difficult to predict when IPv6 will completely replace IPv4. However, transitioning to IPv6 is the only long-term solution to the exhaustion of IPv4 addresses.

The Action Plan for Promoting Large-Scale Deployment of Internet Protocol Version 6 (IPv6) issued by the General Office of the CPC Central Committee and the General Office of the State Council clearly puts forward the overall goals, roadmap, timetable and key tasks for the development of my country's next generation Internet based on IPv6 in the next five to ten years. According to the plan, the following goals for large-scale deployment of IPv6 in my country are as follows:

• By the end of 2020, the number of active IPv6 users will exceed 500 million, accounting for more than 50% of Internet users;
• By the end of 2025, my country's IPv6 network scale, user scale, and traffic scale will rank first in the world. The network, applications, and terminals will fully support IPv6, and the balanced evolution and upgrade to the next-generation Internet will be fully completed.