464XLAT Explained

IETF recently published RFC 6877 (464XLAT) describing a dual-translation mechanism that allows an IPv6 host (or CPE) in an IPv6-only access network to pretend it still has IPv4 connectivity. Why would one need a kludge ingenious solution like this? In a word: Skype.

For more details, watch the video explaining the need for 464XLAT and two typical use cases: Android handset and a CPE device (example: SOHO router with 3G uplink).


  1. For users it is "whatever", but it's a right/cheap move to provide IPv6 services for millions of users and (I hope) in the near future for everyone with a mobile devices.

    Unfortunately content providers don't need to switch as fast as they should to IPv6 services (our provider translate that for us... we still have 50 years for that).
    1. Enough of the big content providers have already embraced IPv6, so if NAT64 (or whatever other CGN) is broken, the users would blame the content providers, not the ISP (after all, if I can complain on Facebook, and watch backflipping cats, Internet works, right?), so expect to see some panic deployments in the content world in the next few years ... consultant's dream :D
    2. The IPv6 internet is now 2% as big as the IPv4 internet, and that relative size doubles every 10 months. Someone at your provider clearly doesn't understand how exponential growth works...
  2. Lorenzo and myself did a 464XLAT live demo in Paris, Cameron was in the room and Mark Townsley recorded it on his video camera. Thought you might be interested in :)

    http://www.internetsociety.org/deploy360/blog/2013/04/video-464xlat-live-demo-at-world-ipv6-congress-in-paris/ (video embedded at the bottom, after the description of what happened there).

    Cheers, Jan Zorz

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