John Brzozowski has been a long-time IPv6 advocate, and he gave an overview of the advanced state of IPv6 for Comcast’s network. Today, it’s used in the majority of Comcast’s business needs, and it has seen IPv6 usage grow to over 25 percent of its internet-facing traffic. One extremely interesting revelation from John was that IPv6 will effectively become the underlay for all services in Comcast’s network, including IPv4 itself, so effectively it plans to implement IPv4 as a service. This is mainly to support legacy content and endpoints, but natively going with IPv6 has greatly simplified their problems and sidestepped all the complex operations involved in trying to run them as separate offerings.