Basic Transition Mechanisms for IPv6 Hosts and Routers
RFC 4213
Document | Type |
RFC - Proposed Standard
(October 2005; Errata)
Obsoletes RFC 2893
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Last updated | 2018-12-20 | ||
Stream | IETF | ||
Formats | plain text pdf html bibtex | ||
Stream | WG state | (None) | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 4213 (Proposed Standard) | |
Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | David Kessens | ||
Send notices to | kurtis@kurtis.pp.se |
Network Working Group E. Nordmark Request for Comments: 4213 Sun Microsystems, Inc. Obsoletes: 2893 R. Gilligan Category: Standards Track Intransa, Inc. October 2005 Basic Transition Mechanisms for IPv6 Hosts and Routers Status of This Memo This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited. Copyright Notice Copyright (C) The Internet Society (2005). Abstract This document specifies IPv4 compatibility mechanisms that can be implemented by IPv6 hosts and routers. Two mechanisms are specified, dual stack and configured tunneling. Dual stack implies providing complete implementations of both versions of the Internet Protocol (IPv4 and IPv6), and configured tunneling provides a means to carry IPv6 packets over unmodified IPv4 routing infrastructures. This document obsoletes RFC 2893. Nordmark & Gilligan Standards Track [Page 1] RFC 4213 Basic IPv6 Transition Mechanisms October 2005 Table of Contents 1. Introduction ....................................................2 1.1. Terminology ................................................3 2. Dual IP Layer Operation .........................................4 2.1. Address Configuration ......................................5 2.2. DNS ........................................................5 3. Configured Tunneling Mechanisms .................................6 3.1. Encapsulation ..............................................7 3.2. Tunnel MTU and Fragmentation ...............................8 3.2.1. Static Tunnel MTU ...................................9 3.2.2. Dynamic Tunnel MTU ..................................9 3.3. Hop Limit .................................................11 3.4. Handling ICMPv4 Errors ....................................11 3.5. IPv4 Header Construction ..................................13 3.6. Decapsulation .............................................14 3.7. Link-Local Addresses ......................................17 3.8. Neighbor Discovery over Tunnels ...........................18 4. Threat Related to Source Address Spoofing ......................18 5. Security Considerations ........................................19 6. Acknowledgements ...............................................21 7. References .....................................................21 7.1. Normative References ......................................21 7.2. Informative References ....................................21 8. Changes from RFC 2893 ..........................................23 1. Introduction The key to a successful IPv6 transition is compatibility with the large installed base of IPv4 hosts and routers. Maintaining compatibility with IPv4 while deploying IPv6 will streamline the task of transitioning the Internet to IPv6. This specification defines two mechanisms that IPv6 hosts and routers may implement in order to be compatible with IPv4 hosts and routers. The mechanisms in this document are designed to be employed by IPv6 hosts and routers that need to interoperate with IPv4 hosts and utilize IPv4 routing infrastructures. We expect that most nodes in the Internet will need such compatibility for a long time to come, and perhaps even indefinitely. The mechanisms specified here are: - Dual IP layer (also known as dual stack): A technique for providing complete support for both Internet protocols -- IPv4 and IPv6 -- in hosts and routers. Nordmark & Gilligan Standards Track [Page 2] RFC 4213 Basic IPv6 Transition Mechanisms October 2005 - Configured tunneling of IPv6 over IPv4: A technique for establishing point-to-point tunnels by encapsulating IPv6 packets within IPv4 headers to carry them over IPv4 routing infrastructures. The mechanisms defined here are intended to be the core of a "transition toolbox" -- a growing collection of techniques that implementations and users may employ to ease the transition. The tools may be used as needed. Implementations and sites decide which techniques are appropriate to their specific needs. This document defines the basic set of transition mechanisms, but these are not the only tools available. Additional transition and compatibility mechanisms are specified in other documents.Show full document text