This chapter presents the progress to date in the deployment of IPv6. There are many sources of information on this. We are now in the rapid adoption phase (finally).

Cisco’s 6lab site ¹

A table depicts the global I P v 6 adoption in the top five countries for deployment. Belgium ranks highest at 66%, and U S A ranks least at 56%.

This widget shows a summary of the deployment percentages in the top five countries (all already above 50%). The “Internet core” shows readiness of the Internet backbones for IPv6. The “Global content” shows how much of the popular content is available over IPv6 (almost always over both IPv4 and IPv6 at this time – there is very little content available over just IPv6). The “Users” indicates what percentage of users can access IPv6 content.

There are many world maps on the 6lab site with frequently updated information about each country.

A world map represents the deployment of all countries. Western countries have a higher deployment percentage than the rest of the world.

The “Prefixes” value is from measurements done by APNIC and Eric Vyncke. It shows the percentage of “allocated” prefixes that are “live” (actually have traffic going to them or at least have entries in the BGP routing tables). Typically, a lot of organizations have made the first step of obtaining a block of addresses from their RIR (Regional Internet Registry), but only some of those have gone live at this time.

The “Transit AS” value has to do with autonomous systems used only for “transit” – information being source and destination ASs. This indicates the readiness of the Internet core.

The “Content” value has to do with how many of the popular (“Alexa 500”) websites are available over IPv6.

The “Users” value is the percentage of users that connect to Google’s search page over IPv6. Note that language and national blocking of google.com (e.g., in China) affect this number.

The overall deployment value is a weighted combination of the above values.

So How Did IPv4 Depletion Go at RIRs?

The following widget on the IPv6 Forum website tells the story.

A table includes the information on the I P v 4 exhaustion counter available on the I P v 6 website.

Apart from ARIN, the RIRs decided to stop allocating IPv4 addresses when they reached their final /8 (16.7 million) addresses. After that they could only be given out in small blocks (e.g., 1024 addresses), for special purposes (such as migration to IPv6). ARIN chose to keep doing allocation until the barrel was completely empty.

Some ISPs, telcos, and cloud providers tried to get as many IPv4 addresses as they could, but many of those have now run out. They can buy a few on the IP address market, but even those will run out at some point, and even now the price of public IPv4 addresses continues to rise.

Google Statistics

A graph depicts the percentage of connections over I P v 6 among google users over the years. The graph shows a considerable increase from 2010 to 2020.

Google tracks the number of connections to its search engine over both IPv4 and IPv6. The preceding chart shows the growth of IPv6 as a percentage of total usage. As of May 1, 2022, connections over IPv6 represent about 40% of all connections, globally. Note that the actual percentage is likely higher, due to distortion caused by Happy Eyeballs.² This is a modification to all recent browsers that will attempt to connect IPv4 or IPv6, depending on which one connected in the shortest time. This can result in a situation where both the user and the website both support IPv6, but they also both support IPv4, and for whatever reason, connection over IPv4 was faster. You can see the current version of this chart at www.google.com/intl/en/ipv6/statistics.html#tab=ipv6-adoption .³

For full details on Happy Eyeballs, see RFC 8305,⁴ “Happy Eyeballs Version 2: Better Connectivity Using Concurrency,” December 2017.

You can see the incredible increase in deployment globally from when The Second Internet book was written. At that time, the Google stats showed .25% adoption. In the intervening years, adoption has increased by over 100 times, even with Happy Eyeballs.

The reason the line is wide vertically is actually quite interesting. It seems that usage is highest on weekends and drops on weekdays. This is because more people have IPv6 at home than they do at work.

Google also breaks down their statistics per country. You can see the current version of this information at www.google.com/intl/en/ipv6/statistics.html#tab=per-country-ipv6-adoption .⁵

Here are a few selected countries from the Google per-country stats as of March 17, 2019:

Country	IPv6 %
Belgium	53.17
Germany	41.72
Greece	35.99
United States	35.24
Malaysia	34.13
Uruguay	34.07
India	32.59
Vietnam	32.19
Japan	29.66
Switzerland	28.94
Brazil	27.68
Taiwan	25.97
France	24.62
Estonia	24.35
Finland	23.80
Mexico	22.92
Canada	22.77
United Kingdom	22.71
Hungary	20.44
Portugal	20.06
Ecuador	19.79
Thailand	18.82
Ireland	18.70
Trinidad and Tobago	17.65
New Zealand	17.11
Netherlands	16.75
Peru	16.62
Australia	15.37
Romania	12.95
Norway	12.27
Puerto Rico	12.26
Bolivia	11.90
Czechia	10.87
Slovenia	10.46
Guatemala	9.51
Saudi Arabia	8.97

Note that these values are based on actual measurements but are heavily influenced by English-speaking ability (the Google site is in English) and per-country restrictions (China blocks Google). Most of the other countries are below 1%.

Another good source of statistics on IPv6 adoption from actual measurements can be found at www.vyncke.org/ipv6status/ .⁶ This site breaks it down by websites, email, and DNS (from Alexa).

Predictions for Future Years

Cisco had a chart to predict future IPv6 deployment based on past data from Google. It predicts that we will reach 100% by 2028. That is just 6 years from now. Perhaps I will do another update to this book in 2028 and see what really happened.

A graph predicts the future I P v 6 deployment on the basis of past data of google users. It shows that 100% deployment can be achieved by 2028.