A First Look At IPv6 Hypergiant Infrastructure.

Today's Internet is dominated by a small number of companies which are responsible for a large fraction of Internet traffic. These so called "hypergiants" make use of off-nets to deploy parts of their infrastructure in ISP networks. Off-nets ensure that clients from these ISPs get lower latencies and the ISP needs to send less traffic to its upstream providers. They have been relatively well studied in the IPv4 Internet, although their footprint in IPv6 remains unclear. In this paper, we take a first look at the IPv6 hypergiant infrastructure. We perform a first-of-its-kind study of IPv6 off-nets for 14 hypergiants and compare their deployment to IPv4. We find IPv6 off-nets in 2k ASes, compared to the more than 6k off-net ASes for IPv4. Moreover, the majority of IPv6 off-nets deployments are seen in ASes which already deploy IPv4 off-nets. Interestingly, we also see some hypergiants such as Disney and Hulu not making use of any IPv6 off-nets at all. We also uncover the phenomenon of cross-hypergiant deployments, where one hypergiant deploys its infrastructure in another hypergiant's network. Finally, we use latency measurements to compare IPv6 vs. IPv4 latency to off-net prefixes within off-net ASes and find similar results for both protocol versions. We make all our code and data available to encourage replicability.