IPv6 Node Information Queries
RFC 4620

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Network Working Group                                        M. Crawford
Request for Comments: 4620                                      Fermilab
Category: Experimental                                  B. Haberman, Ed.
                                                                 JHU APL
                                                             August 2006

                     IPv6 Node Information Queries

Status of This Memo

   This memo defines an Experimental Protocol for the Internet
   community.  It does not specify an Internet standard of any kind.
   Discussion and suggestions for improvement are requested.
   Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2006).

Abstract

   This document describes a protocol for asking an IPv6 node to supply
   certain network information, such as its hostname or fully-qualified
   domain name.  IPv6 implementation experience has shown that direct
   queries for a hostname are useful, and a direct query mechanism for
   other information has been found useful in serverless environments
   and for debugging.

Table of Contents

   1. Introduction ....................................................2
   2. Applicability Statement .........................................2
   3. Terminology .....................................................2
   4. Node Information Messages .......................................3
   5. Message Processing ..............................................5
   6. Defined Qtypes ..................................................6
      6.1. NOOP .......................................................7
      6.2. Node Name ..................................................7
      6.3. Node Addresses .............................................8
      6.4. IPv4 Addresses .............................................9
           6.4.1. Discussion ..........................................9
   7. IANA Considerations ............................................10
   8. Security Considerations ........................................10
   9. Acknowledgements ...............................................11
   10. References ....................................................11
      10.1. Normative References .....................................11
      10.2. Informative References ...................................12

Crawford & Haberman           Experimental                      [Page 1]
RFC 4620             IPv6 Node Information Queries           August 2006

1.  Introduction

   This document specifies a mechanism for discovering information about
   names and addresses.  The applicability of these mechanisms is
   currently limited to diagnostic and debugging tools and network
   management (e.g., node discovery).  In the global internet, the
   Domain Name System (DNS) [1][2] is the authoritative source of such
   information and this specification is not intended to supplant or
   supersede it.  In fact, in a well-supported network, the names and
   addresses dealt with by this mechanism will be the same ones, with
   the same relationships, as those listed in the DNS.

   This new Node Information protocol provides facilities that are not
   found in the DNS, for example, discovering relationships between
   addresses without reference to names.  The functions that do overlap
   with the DNS may be useful in serverless environments, for debugging,
   or in regard to link-local and unique-local addresses [3] that often
   will not be listed in the DNS.

2.  Applicability Statement

   IPv6 Node Information Queries include the capability to provide
   forward and reverse name lookups independent of the DNS by sending
   packets directly to IPv6 nodes or groups of nodes.

   The applicability of these mechanisms is currently limited to
   diagnostic and debugging tools and network management (e.g., node
   discovery).  These mechanisms can be used to learn the addresses and
   names for nodes on the other end of a point-to-point link or nodes on
   a shared-medium link such as an Ethernet.  This is very useful when
   debugging problems or when bringing up IPv6 service where there is no
   global routing or DNS name services available.  IPv6's large auto-
   configured addresses make debugging network problems and bringing up
   IPv6 service difficult without these mechanisms.  An example of an
   IPv6 debugging tool using IPv6 Node Information Queries is the ping6
   program in the KAME (http://www.kame.net), USAGI, and other IPv6
   implementations.

   The mechanisms defined in this document may have wider applicability
   in the future, but any use beyond debugging and diagnostic tools is
   left for further study and is beyond the scope of this document.

3.  Terminology

   A "Node Information Query" (or "NI Query") message is sent by a
   "Querier" node to a "Responder" node in an ICMPv6 packet addressed to
   the "Queried Address".  The Query contains a "Subject Address" (which