IPv6 Node Information Queries
RFC 4620
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
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