Operational Guidance for IPv6 Deployment in IPv4 Sites Using the Intra-Site Automatic Tunnel Addressing Protocol (ISATAP)
RFC 6964

Independent Submission                                        F. Templin
Request for Comments: 6964                  Boeing Research & Technology
Category: Informational                                         May 2013
ISSN: 2070-1721

    Operational Guidance for IPv6 Deployment in IPv4 Sites Using the
        Intra-Site Automatic Tunnel Addressing Protocol (ISATAP)

Abstract

   Many end-user sites in the Internet today still have predominantly
   IPv4 internal infrastructures.  These sites range in size from small
   home/office networks to large corporate enterprise networks, but
   share the commonality that IPv4 provides satisfactory internal
   routing and addressing services for most applications.  As more and
   more IPv6-only services are deployed, however, end-user devices
   within such sites will increasingly require at least basic IPv6
   functionality.  This document therefore provides operational guidance
   for deployment of IPv6 within predominantly IPv4 sites using the
   Intra-Site Automatic Tunnel Addressing Protocol (ISATAP).

Status of This Memo

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

   This is a contribution to the RFC Series, independently of any other
   RFC stream.  The RFC Editor has chosen to publish this document at
   its discretion and makes no statement about its value for
   implementation or deployment.  Documents approved for publication by
   the RFC Editor are not 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/rfc6964.

Templin                       Informational                     [Page 1]
RFC 6964               ISATAP Operational Guidance              May 2013

Copyright Notice

   Copyright (c) 2013 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
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   (http://trustee.ietf.org/license-info) in effect on the date of
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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Enabling IPv6 Services Using ISATAP . . . . . . . . . . . . .   4
   3.  SLAAC Services  . . . . . . . . . . . . . . . . . . . . . . .   5
     3.1.  Advertising ISATAP Router Behavior  . . . . . . . . . . .   5
     3.2.  ISATAP Host Behavior  . . . . . . . . . . . . . . . . . .   6
     3.3.  Reference Operational Scenario - Shared Prefix Model  . .   6
     3.4.  Reference Operational Scenario - Individual Prefix Model    9
     3.5.  SLAAC Site Administration Guidance  . . . . . . . . . . .  12
     3.6.  Loop Avoidance  . . . . . . . . . . . . . . . . . . . . .  14
     3.7.  Considerations for Compatibility of Interface Identifiers  14
   4.  Manual Configuration  . . . . . . . . . . . . . . . . . . . .  15
   5.  Scaling Considerations  . . . . . . . . . . . . . . . . . . .  15
   6.  Site Renumbering Considerations . . . . . . . . . . . . . . .  16
   7.  Path MTU Considerations . . . . . . . . . . . . . . . . . . .  16
   8.  Alternative Approaches  . . . . . . . . . . . . . . . . . . .  17
   9.  Security Considerations . . . . . . . . . . . . . . . . . . .  17
   10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .  18
   11. References  . . . . . . . . . . . . . . . . . . . . . . . . .  18
     11.1.  Normative References . . . . . . . . . . . . . . . . . .  18
     11.2.  Informative References . . . . . . . . . . . . . . . . .  18

Templin                       Informational                     [Page 2]
RFC 6964               ISATAP Operational Guidance              May 2013

1.  Introduction

   End-user sites in the Internet today internally use IPv4 routing and
   addressing for core operating functions, such as web browsing, file
   sharing, network printing, email, teleconferencing, and numerous
   other site-internal networking services.  Such sites typically have
   an abundance of public and/or private IPv4 addresses for internal
   networking and are separated from the public Internet by firewalls,
   packet filtering gateways, proxies, address translators, and other
   site-border demarcation devices.  To date, such sites have had little
   incentive to enable IPv6 services internally [RFC1687].

   End-user sites that currently use IPv4 services internally come in
   endless sizes and varieties.  For example, a home network behind a