RFC 2462 (rfc2462) - Page 2 of 25

IPv6 Stateless Address Autoconfiguration

RFC 2462        IPv6 Stateless Address Autoconfiguration   December 1998


      5.4.  Duplicate Address Detection.........................   13
         5.4.1.  Message Validation.............................   14
         5.4.2.  Sending Neighbor Solicitation Messages.........   14
         5.4.3.  Receiving Neighbor Solicitation Messages.......   15
         5.4.4.  Receiving Neighbor Advertisement Messages......   16
         5.4.5.  When Duplicate Address Detection Fails.........   16
      5.5.  Creation of Global and Site-Local Addresses.........   16
         5.5.1.  Soliciting Router Advertisements...............   16
         5.5.2.  Absence of Router Advertisements...............   17
         5.5.3.  Router Advertisement Processing................   17
         5.5.4.  Address Lifetime Expiry........................   19
      5.6.  Configuration Consistency...........................   19
   6.  SECURITY CONSIDERATIONS..................................   20
   7.  References...............................................   20
   8.  Acknowledgements and Authors' Addresses..................   21
   9.  APPENDIX A: LOOPBACK SUPPRESSION & DUPLICATE ADDRESS
         DETECTION..............................................   22
   10. APPENDIX B: CHANGES SINCE RFC 1971.......................   24
   11. Full Copyright Statement.................................   25

1.  INTRODUCTION

   This document specifies the steps a host takes in deciding how to
   autoconfigure its interfaces in IP version 6. The autoconfiguration
   process includes creating a link-local address and verifying its
   uniqueness on a link, determining what information should be
   autoconfigured (addresses, other information, or both), and in the
   case of addresses, whether they should be obtained through the
   stateless mechanism, the stateful mechanism, or both.  This document
   defines the process for generating a link-local address, the process
   for generating site-local and global addresses via stateless address
   autoconfiguration, and the Duplicate Address Detection procedure. The
   details of autoconfiguration using the stateful protocol are
   specified elsewhere.

   IPv6 defines both a stateful and stateless address autoconfiguration
   mechanism. Stateless autoconfiguration requires no manual
   configuration of hosts, minimal (if any) configuration of routers,
   and no additional servers.  The stateless mechanism allows a host to
   generate its own addresses using a combination of locally available
   information and information advertised by routers. Routers advertise
   prefixes that identify the subnet(s) associated with a link, while
   hosts generate an "interface identifier" that uniquely identifies an
   interface on a subnet. An address is formed by combining the two. In
   the absence of routers, a host can only generate link-local
   addresses. However, link-local addresses are sufficient for allowing
   communication among nodes attached to the same link.




Thomson & Narten            Standards Track