World IPv6 Launch has come and gone, and we now have the opportunity to examine its impact on Internet traffic delivery and the migration to IPv6. While our previous blog posts focused on the day itself, this time we are taking a longer view and looking at IPv6 traffic over the past month. This will provide some context for World IPv6 Launch, as well as allow us to see what has been happening since and whether the goal of World IPv6 Launch to permanently enable new IPv6 services was successful.
Below is a graph showing IPv6 traffic levels for the past month as a percentage of all Internet traffic. This data comes from the same providers we have been following, which are all of the providers sharing flow-based data with us as part of our ATLAS Internet monitoring infrastructure and which report carrying both native and tunneled IPv6 services.
As we have noted before, World IPv6 Launch wasn’t like flipping a switch and seeing a sudden spike of IPv6 traffic. Instead, it was a more gradual ramp-up of traffic starting about two weeks before the day itself. This resulted in IPv6 traffic growing from 0.06% to almost 0.15% of all Internet traffic in the weeks leading up to June 6. This is an impressive amount of growth over such a short time. We believe this more than anything else demonstrates the success of World IPv6 Launch as a tool to encourage more providers to adopt IPv6 and make IPv6 services available more broadly. Even more importantly, the increased levels of IPv6 traffic did not diminish after IPv6 Launch Day, but have remained fairly steady since then. This shows that hopefully many of the newly enabled IPv6 services are here to stay – another important milestone on the road to ubiquitous IPv6 adoption.
In addition to looking at the overall levels of IPv6 traffic growth, it is also interesting to take a look at how IPv6 is being used, and how that may have changed as a result of new IPv6 service offerings. Here is the application breakdown for native IPv6 traffic for the same month as the IPv6 traffic level measurement above. Note that it’s not possible to identify applications being used by tunneled IPv6 traffic from flow-based data – that requires direct packet inspection.
We can see that as expected HTTP traffic dominates application usage at up to around 60% of all native IPv6 traffic. It is interesting to note, however, that HTTP’s share of native IPv6 traffic grew in advance of IPv6 day, perhaps indicating increased usage of native IPv6 by “regular” Internet users. Even more interesting, if we take a closer look at certain applications that are very common in IPv4, we can see a noticeable shift in usage over the World IPv6 Launch period:
In this graph we have zoomed in on the non-HTTP applications to take a closer look at three that showed a noticeable shift over IPv6 Launch Day. DNS has historically been a much higher percentage of IPv6 traffic compared to IPv4. This is likely because IPv6 has been used less heavily by users, who consume most of the volumetric content (such as streaming video) on IPv4. Shorter and lower-volume connections (such as HTTP page loads) on IPv6 mean that the DNS lookup that precedes each connection consumes a higher relative percentage of the overall traffic volume. In the lead-up to June 6, however, we saw that change significantly, with DNS dropping from around 3% to less than 1% of IPv6 traffic. This indicates that with World IPv6 Launch more users are consuming larger amounts of content over IPv6, leaving DNS as a much smaller proportion of the traffic volume.
The growth in SSL usage over IPv6 was another interesting trend we observed and may also indicate an increase in traditional Internet activities such as banking or e-commerce taking place over IPv6. Unexpectedly, SSL traffic dropped again after World IPv6 Launch, perhaps indicating that some of those services did not maintain IPv6 access. However, levels of SSL are still significantly higher than they were before World IPv6 Launch so it would seem that at least some of these services have maintained their presence via IPv6 in the ensuing days.
Finally, although not a significant percentage of IPv6 traffic overall, POP email traffic has grown noticeably since June 6. From less than 0.01% of IPv6 traffic, it has grown to almost 1%. While not large compared to other applications, this is an important benchmark for IPv6 adoption since it indicates a core Internet service making the migration to IPv6 and IPv6 starting to look more like IPv4 in terms of usage. It’s one thing for websites to enable IPv6 for HTTP, but it means a lot more if the basic applications that make up the “plumbing” of the Internet also make the leap. This is a hopeful sign for broader IPv6 adoption and for IPv6 meeting its ultimate goal: to become a transparent and ubiquitous way for users to carry out their everyday activities on the Internet.