Network Dictionary – DNS64 and DNS46

Terms describe the translation of an DNS A record for IPv4 into a AAAA record for IPv6 – DNS46.

And DNS64 is translation of the IPv6 AAAA record into the IPv4 A record.

So, DNS46 will be used for accessing websites on the Internet that are IPv6 only and where your internal systems IPv4 only. Conversely, DNS64 is used for hosts that are IPv6 only to access legacy IPv4 services.

About Greg Ferro

Greg Ferro is a Network Engineer/Architect, mostly focussed on Data Centre, Security Infrastructure, and recently Virtualization. He has over 20 years in IT, in wide range of employers working as a freelance consultant including Finance, Service Providers and Online Companies. He is CCIE#6920 and has a few ideas about the world, but not enough to really count.

He is a host on the Packet Pushers Podcast, blogger at EtherealMind.com and on Twitter @etherealmind and Google Plus

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  • srg

    “Conversely, DNS64 is likely to be used for hosts that are IPv_6_ only to access legacy IPv4 services”? :)

    • http://etherealmind.com Greg Ferro

      Thanks. And Fixed. Nice catch.

  • http://tacacs.org John Payne

    I think you have them the wrong way round in the first half of the post :)
    DNS64 translates A to AAAA so that IPv6 only hosts can reach IPv4 only resources through a NAT64 translator.
    DNS46 would convert AAAA to A.

    • http://www.tuscanynetworks.com Paul Roberts

      I agree with John. Can we get some clarification before confusion sets in, I stumbled across this post when googling for the difference between DNS64 and DNS46.

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