Upgrading to IPv6

Speaking of Comcast, the cable giant is offering an interesting proposal to the standards community concerning the long overdue transition from IPv4 to IPv6, using NATs and tunnels:

Comcast is upgrading its networks from IPv4, the Internet’s main communications protocol, to the standard known as IPv6. IPv4 uses 32-bit addresses and can support 4.3 billion devices connected directly to the Internet. IPv6 uses 128-bit addresses and supports an unlimited number of devices.

At issue is how Comcast will support new customers when IPv4 addresses run out, which is expected in 2011. Comcast can give these customers IPv6 addresses, but their home computers, printers, gaming systems and other Internet-connected devices are likely to support only IPv4.

Comcast engineers have come up with a solution to this problem, dubbed Dual-Stack Lite, which it says is backwards compatible with IPv4 and can be deployed incrementally.

Comcast outlined Dual-Stack Lite in a draft document published by the Internet Engineering Task Force on July 7. Dual-Stack Lite will be discussed at an IETF meeting in Dublin scheduled for later this month.

It’s a reasonable approach, putting the onus of dual stacks on the carrier NATs and home gateways where it belongs. It’s fortunate the IETF has companies like Comcast to give it guidance.

H/T CircleID.

UPDATE: Iljitsch van Beijnum has some further illumination on the Ars Technica blog, without using the “C” word; they don’t go for that sort of thing on Ars.