IPv4 Is Not Enough
Last week in Chicago, at the annual SIGCOMM flagship research conference on networking, Arbor collaborators presented some exciting developments in the ongoing story of IPv6 roll out. This joint work (full paper here) between Arbor Networks, the University of Michigan, the International Computer Science Institute, Verisign Labs, and the University of Illinois highlighted how both the pace and nature of IPv6 adoption has made a pretty dramatic shift in just the last couple of years. This study is a thorough, well-researched, effective analysis and discussion of numerous published and previously unpublished measurements focused on the state of IPv6 deployment.
The study examined a decade of data reporting twelve measures drawn from ten global-scale Internet datasets, including several years of Arbor data that represents a third to a half of all interdomain traffic. This constitutes one of the longest and broadest published measurement of IPv6 adoption to date. Using this long and wide perspective, the University of Michigan, Arbor Networks, and their collaborators found that IPv6 adoption, relative to IPv4, varies by two orders of magnitude (100x!) depending on the measure one looks at and, because of this, care must really be taken when looking at individual measurements of IPv6. For example, examining only the fraction of IPv6 to IPv4 traffic, which is still just shy of 1%, is misleading, since virtually all other indicators show that IPv6 is much more ready for use and able to grow very quickly.
In the study, differences in IPv6 deployment across global regions were also apparent. This suggests that both the incentives and obstacles to adopt the new protocol vary in different parts of the world.
Most surprisingly, the team found that over the last three years the nature of IPv6 use, in terms of traffic, content, reliance on transition technology, and performance, has shifted dramatically from prior findings, showing a maturing of the protocol into production mode. For instance, Arbor data shows that the increase in IPv6 traffic relative to IPv4 over each of 2012 and 2013 has been phenomenal, growing more than 400% in each year — a more than quintupling. Arbor data also helped show that *how* people are using IPv6 has likewise evolved immensely, to the point where IPv6 is now largely used natively and mostly for content, neither of which was the case just three years ago.
Interestingly, this study offers a thought-provoking rationale for the high incidence of NNTP and rsync in the IPv6 application mix. Based on the data, the high volumes of NNTP and rsync is likely partially due to synchronization of NNTP and software distribution data between a relatively small number of IPv6-enabled servers that resided within the research and education communities. The significant increase of HTTP and HTTPS traffic in the IPv6 application mix could correlate with a much broader increase of IPv6-connected end-user computers accessing IPv6-enabled web servers.
These changes in adoption rate and the nature of IPv6 use come on the heels of several important IPv4 exhaustion milestones (such as the IANA address depletion event), which began in 2011. Thus, the team believes that this new phase of IPv6 rollout might have been spurred, in part, by a growing shortage of IPv4 addressing.
The study’s conclusions regarding the prevalence of untunneled native IPv6 traffic in today’s Internet are significant in that they imply a level of infrastructure readiness for IPv6. Transition technologies played an important “early adopter” role in the evolution of IPv6 technology and it now appears that IPv6 deployment has entered a stage where Internet infrastructures can support native IPv6 traffic.
In closing, the team noted that, together, IPv6’s very fast recent growth and how its use has shifted signal a true quantum leap. Twenty years after it was standardized, it looks like IPv6 is finally becoming real.
For the full presentation shared at SIGCOMM, click here or on the image below to download.
Many thanks to Jakub Czyz, Scott Iekel-Johnson, Bill Cerveny and Roland Dobbins for assistance with this post!