IPv4 was developed back in the Dark Ages of the Internet – 1978. The 32-bit address space allowed for 4 billion addresses, which seemed like a good idea at the time. In 1993, IETF forecasts showed IPv4 addresses running out sometime between 2010 and 2017, so engineers began work on IPv6, which was completed in 1999.
IPv4 v. IPv6
IPv6 uses a 128-bit address space – that is, 2^128 – yielding far more potential addresses than IPv4’s 32-bit scheme, and in fact more addresses than there are grains of sand in the Earth’s crust.
The IANA pool of IPv4 address space was officially depleted on Feb. 3, 2011. This slide shows the steady depletion of that pool over time. Each block or “/8”, equals 16,777,216 addresses.
Network operator measurements
According to numbers provided by the Internet Society, as of Jan. 16, 2014, these are the percentages of IPv6 traffic being carried on these networks.
Verizon Wireless: 40%
Time Warner Cable: 4%
Hughes Network: 36%
T-Mobile USA: 10%
Google Fiber: 72%
China Telecom: 0.23%
NTT Communications: 5%
The view from Akamai
This chart shows IPv6 hits per second on the Akamai content delivery network. The trendline is clearly moving up.
The view from Google
This chart shows the percentage of Google users coming to the site via IPv6. While the trendline is also moving up, total IPv6 traffic is still less than 3%. Drilling down by country, US IPv6 traffic is at 6.29%, Japan is 3.38%, Peru is 5.15% and Romania tops the US at 6.49%.
The view from Alexa
The Internet Society also makes ongoing measurements of IPv6 deployment on its World IPv6 Launch site. It shows that 12.5 percent of the Alexa Top 1,000 websites are currently reachable over IPv6. "That number was 10 percent a year ago," according to Phil Roberts of the Internet Society. In addition, the Internet Society checks the number of network operators who are turning on IPv6. "The first time [we reported on the statistics] we had about 70 networks," Roberts says. "Now we're up to 213."
IPv6 allocations are moving slowly
The trendline of IPv6 assignments is clearly going up, but not at an astronomical pace.
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