From the horse’s mouth
Comcast is now one of the first major Internet service providers in the USA to set up for full IPv6 operation for its residential and small-business Internet-service products. Here, they are operating this on a dual-stack arrangement with customers able to receive IPv4 and IPv6 addresses and connections.
This is to satisfy realities that are affecting Internet use such as a reduction of publically-available IPv4 addresses and the arrival of the “Internet Of Everything” concept where there will be many devices connected to networks both large and small. IPv6 also opens up newer network-management functionalities like Segment Routing and Service Function Chaining.
Here, they are also optimising the XFinity X1 and XFinity Voice product platforms for IPv6 as well as implementing IPv6 for all of networks associated with the NBC Universal digital-content properties.
If a Comcast subscriber is to benefit from IPv6, they would have to connect the cable modem to a router that supports IPv6 dual-stack functionality. In some cases, you may have to have the existing cable modem swapped out for a newer unit or have Comcast flash the existing unit with newer IPv6-ready firmware. When you set up your router’s IPv6 WAN/Internet options, you may find it best to let the router use the “auto-detect” options.
This could show up as a step in the right direction for IPv6 in the world’s largest and densest Internet-service market.