Hi, this is Leigh Metcalf again with my colleague Rhiannon Weaver. IPv6, the replacement for IPv4, has been heavily marketed. To consider exactly how popular IPv6 is on the internet, one method is to examine the number of autonomous systems (ASes) that announce IPv6.

Using the data available from Routeviews (http://routeviews.org) and RIPE (https://www.ripe.net/), we counted the number of ASes that announced IPv6 from January 1, 2004 through mid-February of 2013. Figure 1 displays the number of ASes announced as well as important dates in the history of IPv6.

To analyze this curve, the data was split into five groups as shown in Figure 2. The gap in time between Group 1 and Group 2 is due to a data collection issue. The trend for each group was modeled as an exponential growth curve. The growth rates listed in Table 1 show the expected percent growth of the number of announcements in one month's time (31 days), given the general trend at the time for the group.

The fastest growth period was the time between July 2010 and June 2011, when the number of ASes announcing IPv6 space grew by 5.4% on average.

If that growth rate continued through the end of 2011 through 2013, we would expect to see approximately 12,500 ASes announcing IPv6 addresses as of March 1st, 2013. However, after the announcement of World IPv6 day in June 2011, the rate of growth in IPv6 announcements among ASes started to decline.

The numbers are still increasing, but the number of announcements in late February and early March 2013 was closer to 7,000, as opposed to the 12,500 predicted by the group 3 growth rate. If the current growth rate of 2.9% increase per month continues, we could expect the number of Autonomous Systems advertising IPv6 space to double to around 14,000 in approximately 25 months (April 1st, 2015). However, as the graph indicates, the recent growth rates do not appear stable for more than approximately 18 months and may see another shift in that time.