Discovery of the IPv6 Prefix Used for IPv6 Address Synthesis
RFC 7050

Approval announcement
Draft of message to be sent after approval:

From: The IESG <iesg-secretary@ietf.org>
To: IETF-Announce <ietf-announce@ietf.org>
Cc: RFC Editor <rfc-editor@rfc-editor.org>,
    behave mailing list <behave@ietf.org>,
    behave chair <behave-chairs@tools.ietf.org>
Subject: Protocol Action: 'Discovery of the IPv6 Prefix Used for IPv6 Address Synthesis' to Proposed Standard (draft-ietf-behave-nat64-discovery-heuristic-17.txt)

The IESG has approved the following document:
- 'Discovery of the IPv6 Prefix Used for IPv6 Address Synthesis'
  (draft-ietf-behave-nat64-discovery-heuristic-17.txt) as Proposed
Standard

This document is the product of the Behavior Engineering for Hindrance
Avoidance Working Group.

The IESG contact persons are Martin Stiemerling and Spencer Dawkins.

A URL of this Internet Draft is:
http://datatracker.ietf.org/doc/draft-ietf-behave-nat64-discovery-heuristic/


Technical Summary

    This document describes a method for detecting the presence of DNS64
    and for learning the IPv6 prefix used for protocol translation on an
    access network.  The method depends on the existence of a well-known
    IPv4-only domain name "ipv4only.arpa".  The information learned
    enables nodes to perform local IPv6 address synthesis and to
    potentially avoid NAT64 on dual-stack and multi-interface
    deployments. 

Working Group Summary

    The document specifies a heuristic that is not perfect and so some
    points were rough, but the constraint for this document was to operate
    without changes to code (only configuration) in existing networks.
    Given that constraint, there was strong consensus.  Relaxing the
    constraint would allow one to do better, and that is the focus of a
    draft recently submitted to the PCP WG.


Document Quality

    Jouni Korhonen did a prototype implementation that was presented in the
    WG but not included in commercial product.  Additionally, Cameron Byrne
    (T-Mobile USA) has a 464XLAT implementation that also implements this
    draft, as noted at
    https://sites.google.com/site/tmoipv6/464xlat#TOC-Android-CLAT-on-a-UMTS-IPv6-only-network-with-DNS64-NAT64


Personnel

    Document Shepherd: Dave Thaler (dthaler@microsoft.com)
    Responsible Area Director: Martin Stiemerling