Router Renumbering for IPv6
RFC 2894

• Status
• IESG evaluation record
• IESG writeups
• Email expansions
• History

• Versions
• 10

Network Working Group                                        M. Crawford
Request for Comments: 2894                                      Fermilab
Category: Standards Track                                    August 2000

                      Router Renumbering for IPv6

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 (2000).  All Rights Reserved.

IESG Note:

   This document defines mechanisms for informing a set of routers of
   renumbering operations they are to perform, including a mode of
   operation in environments in which the exact number of routers is
   unknown. Reliably informing all routers when the actual number of
   routers is unknown is a difficult problem. Implementation and
   operational experience will be needed to fully understand the
   applicabilty and scalability aspects of the mechanisms defined in
   this document when the number of routers is unknown.

Abstract

   IPv6 Neighbor Discovery and Address Autoconfiguration conveniently
   make initial assignments of address prefixes to hosts.  Aside from
   the problem of connection survival across a renumbering event, these
   two mechanisms also simplify the reconfiguration of hosts when the
   set of valid prefixes changes.

   This document defines a mechanism called Router Renumbering ("RR")
   which allows address prefixes on routers to be configured and
   reconfigured almost as easily as the combination of Neighbor
   Discovery and Address Autoconfiguration works for hosts.  It provides
   a means for a network manager to make updates to the prefixes used by
   and advertised by IPv6 routers throughout a site.

Crawford                    Standards Track                     [Page 1]
RFC 2894              Router Renumbering for IPv6            August 2000

Table of Contents

   1.  Functional Overview .......................................    2
   2.  Definitions ...............................................    4
       2.1.  Terminology .........................................    4
       2.2.  Requirements ........................................    5
   3.  Message Format ............................................    5
       3.1.  Router Renumbering Header ...........................    7
       3.2.  Message Body -- Command Message .....................    9
           3.2.1.  Prefix Control Operation ......................    9
               3.2.1.1.  Match-Prefix Part .......................    9
               3.2.1.2.  Use-Prefix Part .........................   11
       3.3.  Message Body -- Result Message ......................   12
   4.  Message Processing ........................................   14
       4.1.  Header Check ........................................   14
       4.2.  Bounds Check ........................................   15
       4.3.  Execution ...........................................   16
       4.4.  Summary of Effects ..................................   17
   5.  Sequence Number Reset .....................................   18
   6.  IANA Considerations .......................................   19
   7.  Security Considerations ...................................   19
       7.1.  Security Policy and Association Database Entries ....   19
   8.  Implementation and Usage Advice for Reliability ...........   20
       8.1.  Outline and Definitions .............................   21
       8.2.  Computations ........................................   23
       8.3.  Additional Assurance Methods ........................   24
   9.  Usage Examples ............................................   25
       9.1.  Maintaining Global-Scope Prefixes ...................   25
       9.2.  Renumbering a Subnet ................................   26
   10.  Acknowledgments ..........................................   27
   11.  References ...............................................   28
   12.  Author's Address .........................................   29
   Appendix -- Derivation of Reliability Estimates ...............   30
   Full Copyright Statement ......................................   32

1.  Functional Overview

   Router Renumbering Command packets contain a sequence of Prefix
   Control Operations (PCOs).  Each PCO specifies an operation, a
   Match-Prefix, and zero or more Use-Prefixes.  A router processes each
   PCO in sequence, checking each of its interfaces for an address or
   prefix which matches the Match-Prefix.  For every interface on which
   a match is found, the operation is applied.  The operation is one of
   ADD, CHANGE, or SET-GLOBAL to instruct the router to respectively add