rfc2400.txt

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Network Working Group                        Internet Architecture Board
Request for Comments: 2400                                     J. Postel
Obsoletes: 2300, 2200, 2000, 1920, 1880,                     J. Reynolds
1800, 1780, 1720, 1610, 1600, 1540, 1500, 1410,                  Editors
1360, 1280, 1250, 1200, 1140, 1130, 1100, 1083            September 1998
STD: 1
Category: Standards Track


                  INTERNET OFFICIAL PROTOCOL STANDARDS


Status of this Memo

   This memo describes the state of standardization of protocols used in
   the Internet as determined by the Internet Architecture Board (IAB).
   This memo is an Internet Standard.  Distribution of this memo is
   unlimited.

Copyright Notice

   Copyright (C) The Internet Society (1998).  All Rights Reserved.

Table of Contents

   Introduction . . . . . . . . . . . . . . . . . . . . . . . . .   2
   1.  The Standardization Process  . . . . . . . . . . . . . . .   3
   2.  The Request for Comments Documents . . . . . . . . . . . .   5
   3.  Other Reference Documents  . . . . . . . . . . . . . . . .   6
   3.1.  Assigned Numbers . . . . . . . . . . . . . . . . . . . .   6
   3.2.  Gateway Requirements . . . . . . . . . . . . . . . . . .   6
   3.3.  Host Requirements  . . . . . . . . . . . . . . . . . . .   6
   3.4.  The MIL-STD Documents  . . . . . . . . . . . . . . . . .   6
   4.  Explanation of Terms . . . . . . . . . . . . . . . . . . .   7
   4.1.  Definitions of Protocol State (Maturity Level) . . . . .   8
   4.1.1.  Standard Protocol  . . . . . . . . . . . . . . . . . .   8
   4.1.2.  Draft Standard Protocol  . . . . . . . . . . . . . . .   8
   4.1.3.  Proposed Standard Protocol . . . . . . . . . . . . . .   8
   4.1.4.  Experimental Protocol  . . . . . . . . . . . . . . . .   8
   4.1.5.  Informational Protocol . . . . . . . . . . . . . . . .   9
   4.1.6.  Historic Protocol  . . . . . . . . . . . . . . . . . .   9
   4.2.  Definitions of Protocol Status (Requirement Level) . . .   9
   4.2.1.  Required Protocol  . . . . . . . . . . . . . . . . . .   9
   4.2.2.  Recommended Protocol . . . . . . . . . . . . . . . . .   9
   4.2.3.  Elective Protocol  . . . . . . . . . . . . . . . . . .   9
   4.2.4.  Limited Use Protocol . . . . . . . . . . . . . . . . .   9
   4.2.5.  Not Recommended Protocol . . . . . . . . . . . . . . .   9
   5.  The Standards Track  . . . . . . . . . . . . . . . . . . .  10



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   5.1.  The RFC Processing Decision Table  . . . . . . . . . . .  10
   5.2.  The Standards Track Diagram  . . . . . . . . . . . . . .  11
   6.  The Protocols  . . . . . . . . . . . . . . . . . . . . . .  13
   6.1.  Recent Changes . . . . . . . . . . . . . . . . . . . . .  13
   6.1.1.  New RFCs . . . . . . . . . . . . . . . . . . . . . . .  13
   6.1.2.  Other Changes  . . . . . . . . . . . . . . . . . . . .  20
   6.2.  Standard Protocols . . . . . . . . . . . . . . . . . . .  21
   6.3.  Network-Specific Standard Protocols  . . . . . . . . . .  23
   6.4.  Draft Standard Protocols . . . . . . . . . . . . . . . .  24
   6.5.  Proposed Standard Protocols  . . . . . . . . . . . . . .  26
   6.6.  Telnet Options . . . . . . . . . . . . . . . . . . . . .  33
   6.7.  Experimental Protocols . . . . . . . . . . . . . . . . .  35
   6.8.  Informational Protocols  . . . . . . . . . . . . . . . .  38
   6.9.  Historic Protocols . . . . . . . . . . . . . . . . . . .  40
   6.10  Obsolete Protocols . . . . . . . . . . . . . . . . . . .  41
   7.  Contacts . . . . . . . . . . . . . . . . . . . . . . . . .  42
   7.1.  IAB, IETF, and IRTF Contacts . . . . . . . . . . . . . .  42
   7.1.1.  Internet Architecture Board (IAB) Contact  . . . . . .  42
   7.1.2.  Internet Engineering Task Force (IETF) Contact . . . .  42
   7.1.3.  Internet Research Task Force (IRTF) Contact  . . . . .  43
   7.2.  Internet Assigned Numbers Authority (IANA) Contact . . .  44
   7.3.  Request for Comments Editor Contact  . . . . . . . . . .  45
   7.4.  Network Information Center Contact . . . . . . . . . . .  45
   7.5.  Sources for Requests for Comments  . . . . . . . . . . .  46
   8.  Security Considerations  . . . . . . . . . . . . . . . . .  46
   9.  Author's Address . . . . . . . . . . . . . . . . . . . . .  46
   10. Full Copyright Statement . . . . . . . . . . . . . . . . .  47

Introduction

   A discussion of the standardization process and the RFC document
   series is presented first, followed by an explanation of the terms.
   Sections 6.2 - 6.10 contain the lists of protocols in each stage of
   standardization.  Finally, there are pointers to references and
   contacts for further information.

   This memo is intended to be issued every one hundred RFCs; please be
   sure the copy you are reading is current.  Current copies may be
   obtained from the Requests for Comments Editor (RFC-EDITOR) or from
   the Internet Assigned Numbers Authority (IANA) (see the contact
   information at the end of this memo).

   See Section 6.1 for a description of recent changes.  In the official
   lists in sections 6.2 - 6.10, an asterisk (*) next to a protocol
   denotes that it is new to this document or has been moved from one
   protocol level to another, or differs from the previous edition of
   this document.




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1.  The Standardization Process

   The Internet Architecture Board maintains this list of documents that
   define standards for the Internet protocol suite.  See RFC-1601 for
   the charter of the IAB and RFC-1160 for an explanation of the role
   and organization of the IAB and its subsidiary groups, the Internet
   Engineering Task Force (IETF) and the Internet Research Task Force
   (IRTF).  Each of these groups has a steering group called the IESG
   and IRSG, respectively.  The IETF develops these standards with the
   goal of co-ordinating the evolution of the Internet protocols; this
   co-ordination has become quite important as the Internet protocols
   are increasingly in general commercial use.  The definitive
   description of the Internet standards process is found in RFC-2026.

   The majority of Internet protocol development and standardization
   activity takes place in the working groups of the IETF.

   Protocols which are to become standards in the Internet go through a
   series of states or maturity levels (proposed standard, draft
   standard, and standard) involving increasing amounts of scrutiny and
   testing.  When a protocol completes this process it is assigned a STD
   number (see RFC-1311).  At each step, the Internet Engineering
   Steering Group (IESG) of the IETF must make a recommendation for
   advancement of the protocol.

   To allow time for the Internet community to consider and react to
   standardization proposals, a minimum delay of 6 months before a
   proposed standard can be advanced to a draft standard and 4 months
   before a draft standard can be promoted to standard.

   It is general practice that no proposed standard can be promoted to
   draft standard without at least two independent implementations (and
   the recommendation of the IESG).  Promotion from draft standard to
   standard generally requires operational experience and demonstrated
   interoperability of two or more implementations (and the
   recommendation of the IESG).

   In cases where there is uncertainty as to the proper decision
   concerning a protocol a special review committee may be appointed
   consisting of experts from the IETF, IRTF and the IAB with the
   purpose of recommending an explicit action.

   Advancement of a protocol to proposed standard is an important step
   since it marks a protocol as a candidate for eventual standardization
   (it puts the protocol "on the standards track").  Advancement to
   draft standard is a major step which warns the community that, unless
   major objections are raised or flaws are discovered, the protocol is
   likely to be advanced to standard.



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   Some protocols have been superseded by better ones or are otherwise
   unused.  Such protocols are still documented in this memorandum with
   the designation "historic".

   Because it is useful to document the results of early protocol
   research and development work, some of the RFCs document protocols
   which are still in an experimental condition.  The protocols are
   designated "experimental" in this memorandum.  They appear in this
   report as a convenience to the community and not as evidence of their
   standardization.

   Other protocols, such as those developed by other standards
   organizations, or by particular vendors, may be of interest or may be
   recommended for use in the Internet.  The specifications of such
   protocols may be published as RFCs for the convenience of the
   Internet community.  These protocols are labeled "informational" in
   this memorandum.

   In addition to the working groups of the IETF, protocol development
   and experimentation may take place as a result of the work of the
   research groups of the Internet Research Task Force, or the work of
   other individuals interested in Internet protocol development.  The
   the documentation of such experimental work in the RFC series is
   encouraged, but none of this work is considered to be on the track
   for standardization until the IESG has made a recommendation to
   advance the protocol to the proposed standard state.

   A few protocols have achieved widespread implementation without the
   approval of the IESG.  For example, some vendor protocols have become
   very important to the Internet community even though they have not
   been recommended by the IESG.  However, the IAB strongly recommends
   that the standards process be used in the evolution of the protocol
   suite to maximize interoperability (and to prevent incompatible
   protocol requirements from arising).  The use of the terms
   "standard", "draft standard", and "proposed standard" are reserved in
   any RFC or other publication of Internet protocols to only those
   protocols which the IESG has approved.

   In addition to a state (like "Proposed Standard"), a protocol is also
   assigned a status, or requirement level, in this document.  The
   possible requirement levels ("Required", "Recommended", "Elective",
   "Limited Use", and "Not Recommended") are defined in Section 4.2.
   When a protocol is on the standards track, that is in the proposed
   standard, draft standard, or standard state (see Section 5), the
   status shown in Section 6 is the current status.






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   Few protocols are required to be implemented in all systems; this is
   because there is such a variety of possible systems, for example,
   gateways, routers, terminal servers, workstations, and multi-user
   hosts.  The requirement level shown in this document is only a one
   word label, which may not be sufficient to characterize the
   implementation requirements for a protocol in all situations.  For
   some protocols, this document contains an additional status paragraph
   (an applicability statement).  In addition, more detailed status
   information may be contained in separate requirements documents (see
   Section 3).

2.  The Request for Comments Documents

   The documents called Request for Comments (or RFCs) are the working
   notes of the "Network Working Group", that is the Internet research
   and development community.  A document in this series may be on
   essentially any topic related to computer communication, and may be
   anything from a meeting report to the specification of a standard.

   Notice:

      All standards are published as RFCs, but not all RFCs specify
      standards.

   Anyone can submit a document for publication as an RFC.  Submissions
   must be made via electronic mail to the RFC Editor (see the contact
   information at the end of this memo, and see RFC 2223).

   While RFCs are not refereed publications, they do receive technical
   review from the task forces, individual technical experts, or the RFC
   Editor, as appropriate.

   The RFC series comprises a wide range of documents, ranging from
   informational documents of general interests to specifications of
   standard Internet protocols.  In cases where submission is intended
   to document a proposed standard, draft standard, or standard
   protocol, the RFC Editor will publish the document only with the
   approval of the IESG.  For documents describing experimental work,
   the RFC Editor will notify the IESG before publication, allowing for
   the possibility of review by the relevant IETF working group or IRTF
   research group and provide those comments to the author.  See Section
   5.1 for more detail.

   Once a document is assigned an RFC number and published, that RFC is
   never revised or re-issued with the same number.  There is never a
   question of having the most recent version of a particular RFC.
   However, a protocol (such as File Transfer Protocol (FTP)) may be
   improved and re-documented many times in several different RFCs.  It



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   is important to verify that you have the most recent RFC on a
   particular protocol.  This "Internet Official Protocol Standards"
   memo is the reference for determining the correct RFC for the current
   specification of each protocol.

   The RFCs are available from the RFC-EDITOR, and a number of other
   sites.  For more information about obtaining RFCs, see Sections 7.4
   and 7.5.

3.  Other Reference Documents

   There are three other reference documents of interest in checking the
   current status of protocol specifications and standardization.  These
   are the Assigned Numbers, the Gateway Requirements, and the Host
   Requirements.  Note that these documents are revised and updated at
   different times; in case of differences between these documents, the
   most recent must prevail.

   Also, one should be aware of the MIL-STD publications on IP, TCP,
   Telnet, FTP, and SMTP.  These are described in Section 3.4.

3.1.  Assigned Numbers

   The "Assigned Numbers" document lists the assigned values of the
   parameters used in the various protocols.  For example, IP protocol