rfc4213.Basic Transition Mechanisms for IPv6 Hosts and Routers.pdfVIP

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. Decaps