As part of a broader organisational restructure, data networking research at Swinburne University of Technology has moved from the Centre for Advanced Internet Architecture (CAIA) to the Internet For Things (I4T) Research Lab.

Although CAIA no longer exists, this website reflects CAIA's activities and outputs between March 2002 and February 2017, and is being maintained as a service to the broader data networking research community.

MAPPING -- Measuring And Practically Predicting INternet Growth

Measuring and predicting growth in Internet addressing, routing complexity and energy usage

IPv6-Capable Subnets Internet Map Time Series

This page shows a time series of IPv4 space maps which indicate IPv6-capable subnets. We plotted observed routed subnets depending on whether a subnet has IPv6-capable hosts. With IPv6-capable we mean hosts that use native IPv6 or 6rd. Hosts that used Teredo, 6to4, or tunnel brokers are not counted as IPv6 capable. The aim is to show subnets that are actually IPv6 capable because the maintaining organisation has enabled IPv6.

IPv6-capable hosts were determined by an IPv6 capability test (see our IMC 2012 paper under papers). Based on the IPv6 addresses of the hosts we filtered out IPv6-capable hosts that used Teredo, 6to4, and well-known tunnelbrokers, as for these we can assume that their subnets are most likely not IPv6 capable. The test data also gives us the IPv4 addresses of all tested hosts including the IPv6 capable hosts. With routing data (e.g. Routeviews) and allocation data (RIRs) we map the IPv4 addresses to routed or allocated subnets.

A subnet is shown in dark orange/brown if no IPv6 capable hosts were detected. A subnet is shown in light blue to dark blue, if IPv6 capable hosts were detected that used 6rd (and no IPv6 capable hosts without 6rd were detected). A subnet is shown in light green to dark green if IPv6 capable hosts were detected. The fraction of tested IPv4 addresses that was IPv6-capable determines the colour of a subnet. If the fraction was very low, the subnet is plotted in light blue/green, if the fraction was very high the subnet is plotted in dark blue/green.

We pre-processed the data in a number of ways:

  • We extrapolate over gaps in the measurement. If there is no measurement result for a subnet in the current time interval, we keep the previous classification. We also keep subnets once classified as IPv6-capable as IPv6-capable in the future, even if their fraction of IPv6-capable addresses drops to zero. In such a case we assume that IPv6 capability has not been switched off, but we simply have not sampled any IPv6-capable address.
  • We only classify a subnet as IPv6 native or 6rd, if there are at least two days in a 3-month period where the subnet was identified as IPv6 native or 6rd.
  • Since the fraction of tested IPv6 capable addresses varies due to noise, in each time interval we compute a weighted average of the current daily fractions and the fractions of the previous interval.
  • Since the fraction of IPv6 capable addresses is very unreliable for a very small number of tests we only compute the fraction if we have tested at least three IPv4 addresses in 24 hours. If fewer than three hosts were tested and there are any IPv6 capable hosts the fraction is set to 0.05 (without any IPv6 capable hosts the fraction is zero).

The first image shows the state at the end of June 2011. Each further image then advances time by 3 months, i.e. the second image show the state at the end of September 2011 and so on.

The buttons of the player are self-explanatory. Note, that moving the mouse cursor inside the image pauses playing. We tested the player with Opera, Firefox, Chrome and IE under Windows and Linux. Note, with Firefox there may be some flickering between image transitions when playing or stepping through the series for the first time. Note, with all browsers there may be some longer delays occasionally between pictures when playing.

IPv6-capable routed subnets


If you would like to contribute to the project (e.g. by giving us access to IPv4 address data), or have any suggestions or comments please contact Sebastian Zander (


The jQuery Image player we use was written by J. Llodra (

APNIC logo

This project has been made possible in part by grants from APNIC for a project titled "Exploring the Utilisation of IPv4 Address Space and Size of the NATed IPv4 Internet" and an ARC linkage grant with APNIC as partner organisation for a project titled "Tools and models for measuring and predicting growth in internet addressing and routing complexity" (project LP110100240). The research has also been supported by Australian Research Council grant FT0991594.

Last Updated: Monday 30-Mar-2015 18:09:07 AEDT | Maintained by: Sebastian Zander ( | Authorised by: Grenville Armitage (