Guidelines for Using IPv6 Transition Mechanisms during IPv6 Deployment
RFC 6180

Internet Engineering Task Force (IETF)                          J. Arkko
Request for Comments: 6180                                      Ericsson
Category: Informational                                         F. Baker
ISSN: 2070-1721                                            Cisco Systems
                                                                May 2011

 Guidelines for Using IPv6 Transition Mechanisms during IPv6 Deployment

Abstract

   The Internet continues to grow beyond the capabilities of IPv4.  An
   expansion in the address space is clearly required.  With its
   increase in the number of available prefixes and addresses in a
   subnet, and improvements in address management, IPv6 is the only real
   option on the table.  Yet, IPv6 deployment requires some effort,
   resources, and expertise.  The availability of many different
   deployment models is one reason why expertise is required.  This
   document discusses the IPv6 deployment models and migration tools,
   and it recommends ones that have been found to work well in
   operational networks in many common situations.

Status of This Memo

   This document is not an Internet Standards Track specification; it is
   published for informational purposes.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Not all documents
   approved by the IESG are a candidate for any level of Internet
   Standard; see Section 2 of RFC 5741.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc6180.

Arkko & Baker                 Informational                     [Page 1]
RFC 6180               IPv6 Transition Guidelines               May 2011

Copyright Notice

   Copyright (c) 2011 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
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   described in the Simplified BSD License.

Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
   2.  Terminology  . . . . . . . . . . . . . . . . . . . . . . . . .  4
   3.  Principles . . . . . . . . . . . . . . . . . . . . . . . . . .  4
     3.1.  Goals  . . . . . . . . . . . . . . . . . . . . . . . . . .  5
     3.2.  Choosing a Deployment Model  . . . . . . . . . . . . . . .  6
   4.  Guidelines for IPv6 Deployment . . . . . . . . . . . . . . . .  7
     4.1.  Native Dual Stack  . . . . . . . . . . . . . . . . . . . .  8
     4.2.  Crossing IPv4 Islands  . . . . . . . . . . . . . . . . . . 10
     4.3.  IPv6-Only Core Network . . . . . . . . . . . . . . . . . . 11
     4.4.  IPv6-Only Deployment . . . . . . . . . . . . . . . . . . . 11
   5.  Conclusions  . . . . . . . . . . . . . . . . . . . . . . . . . 14
   6.  Further Reading  . . . . . . . . . . . . . . . . . . . . . . . 15
   7.  Security Considerations  . . . . . . . . . . . . . . . . . . . 15
   8.  References . . . . . . . . . . . . . . . . . . . . . . . . . . 16
     8.1.  Normative References . . . . . . . . . . . . . . . . . . . 16
     8.2.  Informative References . . . . . . . . . . . . . . . . . . 16
   Appendix A.  Acknowledgments . . . . . . . . . . . . . . . . . . . 20

Arkko & Baker                 Informational                     [Page 2]
RFC 6180               IPv6 Transition Guidelines               May 2011

1.  Introduction

   The Internet continues to grow beyond the capabilities of IPv4.  The
   tremendous success of the Internet has strained the IPv4 address
   space, which is no longer sufficient to fuel future growth.  At the
   time of this writing, August 2010, the IANA "free pool" contains only
   14 unallocated unicast IPv4 /8 prefixes.  Credible estimates based on
   past behavior suggest that the Regional Internet Registries (RIRs)
   will exhaust their remaining address space by early 2012, apart from
   the development of a market in IPv4 address space.  An expansion in
   the address space is clearly required.  With its increase in the
   number of available prefixes and addresses in a subnet, and