Comcast6.net

What is this?
Will IPv4 be disabled?
How will you enable support for IPv6 in this first phase?
Can I opt out of IPv6?
Can I disable IPv6?
With IPv6 for standalone computers, what size IPv6 prefix will I receive?
When will Comcast support IPv6 for home networking?
Are you using tunneling or Large Scale NAT (LSN)?
Do your DNS servers support IPv6?
What comes next?


What is this?
We are announcing our plan to begin deploying IPv6 to our XFINITY INTERNET customers. Initially this is in a limited area of California (Pleasanton), but will soon expand to other areas of our network that have been part of our IPv6 technical trials.

Will IPv4 be disabled?
No. We are continuing to provide an IPv4 address to each customer and are now additionally providing IPv6 addresses; this approach is referred to as Native Dual Stack. IPv4 will remain as-is while IPv6 is introduced. Based on our testing and industry best practices, this model will offer the greatest flexibility and seamlessness during the IPv6 transition.

How will you enable support for IPv6 in this first phase?
In our first phase of deployment, we will enable IPv6 on selected standalone computers. This is the case when a customer has just one computer, and where that computer is plugged directly into a cable modem. We will begin with a small number of DOCSIS 3.0 cable modem models (see those modems noted as IPv6-ready at http://mydeviceinfo.comcast.net), which will expand over time. However, Comcast does not directly enable IPv6 functionality on end user systems as this depends upon the capabilities of that computer's operating system. The current major consumer operating systems capable of this are Windows 7, Windows Vista, and Mac OS X 10.7 (Lion).

Can I opt out of IPv6?
No. However, you can disable IPv6 on your system (see the next FAQ).

Can I disable IPv6?
Yes, IPv6 can be disabled on your computer. Please refer to your operating system documentation for instructions on how to do this. Please note that operating system vendors typically do not recommended disabling IPv6.

With IPv6 for standalone computers, what size IPv6 prefix will I receive?
We will allocate a single IPv6 address (/128), since we know that only a single device is connecting, with no additional need to sub-net. We plan to continue to assess address allocation policies as we deploy, particularly given how very new IPv6 is from an operational standpoint globally.

When will Comcast support IPv6 for home networking?
Comcast is planning to begin pilot market deployment of IPv6 home networking support in the near future.

Are you using tunneling or Large Scale NAT (LSN)?
No, not at this time. We are using Native Dual Stack, which means a customer gets both IPv6 and IPv4 addresses simultaneously. As a result no tunneling or Network Address Translation (NAT) is necessary. We believe this approach offers meaningful performance benefits to our customers compared to the alternatives.

Do your DNS servers support IPv6?
Yes. Our DNS servers, both authoritative and caching, support IPv6 today in our network. The servers can send and receive queries for IPv6 records (AAAA) and can communicate over IPv6 to end-users. The IPv6 addresses for our DNS recursive resolvers (which customers use for DNS lookups) are 2001:558:FEED::1 and 2001:558:FEED::2.

What comes next?
This is the first phase of our IPv6 deployment. As with any pilot market deployment of new technology, it is possible that a technical issue may arise which causes us to delay our next steps or even to temporarily disable IPv6 in existing pilot markets. Assuming no issues are encountered, we will expand to additional CMTSs in our network. This will most likely happen first in those areas where we have already been conducting IPv6 trials. At the same time, we will be working to expand the number of eligible cable modem models that can support IPv6. In a subsequent phase we will enable customers with home gateway devices to use IPv6, but we are not yet prepared to commit to a date for doing so since this will, in part, depend upon how the first phase of our pilot market deployment proceeds.