Request for Comments
Encyclopedia
In computer network
engineering, a Request for Comments (RFC) is a memorandum
published by the Internet Engineering Task Force
(IETF) describing methods, behaviors, research, or innovations applicable to the working of the Internet
and Internet-connected systems.
Through the Internet Society
, engineers and computer scientist
s may publish discourse
in the form of an RFC, either for peer review
or simply to convey new concepts, information, or (occasionally) engineering humor. The IETF adopts some of the proposals published as RFCs as Internet standard
s.
project. Today, it is the official publication channel for the Internet Engineering Task Force (IETF), the Internet Architecture Board
(IAB), and—to some extent—the global community of computer network researchers in general.
The authors of the first RFCs typewrote
their work and circulated hard copies
among the ARPA
researchers. Unlike the modern RFCs, many of the early RFCs were requests for comments. The RFC leaves questions open and is written in a less formal style. This less formal style is now typical of Internet Draft
documents, the precursor step before being approved as an RFC.
In December 1969, researchers began distributing new RFCs via the newly operational ARPANET. RFC 1, entitled "Host Software", was written by Steve Crocker
of the University of California, Los Angeles
(UCLA), and published on April 7, 1969. Although written by Steve Crocker, the RFC emerged from an early working group
discussion between Steve Crocker, Steve Carr and Jeff Rulifson
.
In RFC 3, which first defined the RFC series, Crocker started attributing the RFC series to the "Network Working Group". This wasn't so much a formal committee as a loose association of researchers interested in the ARPANET project. In effect, it was anyone who wanted to join in on meetings and discussions about the project.
Many of the subsequent RFCs of the 1970s also came from UCLA, because UCLA was one of the first Interface Message Processor
s (IMPs) on ARPANET.
The Augmentation Research Center
(ARC) at Stanford Research Institute
, directed by Douglas Engelbart
, was another of the four first ARPANET nodes
and the source of early RFCs.
The ARC became the first Network Information Center
, which was managed by Elizabeth J. Feinler
to distribute them along with other network information.
From 1969 until 1998, Jon Postel
served as the RFC editor
. (On his death in 1998, his obituary was published as RFC 2468.)
Following the expiration of the original ARPANET contract with the U.S. federal government, the Internet Society (acting on behalf of the IETF) contracted with the Networking Division of the University of Southern California
(USC) Information Sciences Institute
(ISI) to assume the editorship and publishing responsibilities (under the direction of the IAB).
Sandy Ginoza joined USC/ISI in 1999 to work on RFC editing, and Alice Hagens in 2005.
Bob Braden
took over the role of RFC project lead, while Joyce K. Reynolds
continued to be part of the team until October 13, 2006.
In July 2007, "streams" of RFCs were defined, so the editing duties could be divided. IETF documents came from IETF working groups or submissions sponsored by an IETF area director from the Internet Engineering Steering Group
. The IAB can publish its own documents. A research stream of documents comes from the Internet Research Task Force
(IRTF), and and independent stream includes documents from other outside sources.
A new model was proposed in 2008, refined, and published in August 2009, splitting the task into several roles.
The streams were also refined in December 2009, with standards defined for their style.
In January 2010 the RFC editor function was moved to a contractor, Association Management Solutions with Glenn Kowack serving as interim series editor.
. Once assigned a number and published, an RFC is never rescinded or modified; if the document requires amendments, the authors publish a revised document. Therefore, some RFCs supersede others; the superseded RFCs are said to be deprecated, obsolete, or even obsoleted (sic). Together, the serialized RFCs compose a continuous historical record of the evolution of Internet standards and practices. For more details about RFCs and the RFC process, see RFC 2026, "The Internet Standards Process, Revision 3".
The RFC production process differs from the standardization
process of formal standards organizations such as ISO
. Internet technology experts may submit an Internet Draft
without support from an external institution. Standards-track RFCs are published with approval from the IETF, and are usually produced by experts participating in working groups, which first publish an Internet Draft. This approach facilitates initial rounds of peer review before documents mature into RFCs.
The RFC tradition of pragmatic, experience-driven, after-the-fact standards authorship accomplished by individuals or small working groups can have important advantages over the more formal, committee-driven process typical of ISO and national standards bodies.
Most RFCs use a common set of terms such as "MUST" and "NOT RECOMMENDED" (as defined by RFC 2119), Augmented Backus–Naur Form
(ABNF) (as defined by RFC 5234) as a metalanguage, and simple text-based formatting, in order to keep the RFCs consistent and easy to understand.
RFCs:
BCP: Best Current Practice; mandatory IETF RFCs not on standards track, see below.
FYI: For Your Information; informational RFCs promoted by the IETF as specified in RFC 1150 (FYI 1). In 2011 RFC 6360 obsoleted FYI 1 and concluded this sub-series.
STD: Standard
; this used to be the third and highest maturity level of the IETF standards track specified in RFC 2026 (BCP 9). In 2011 RFC 6410 (a new part of BCP 9) reduced the standards track to two maturity levels.
, (2) IRTF
, (3) IAB
, and (4) independent submission. Only the IETF creates BCPs and RFCs on standards track. An independent submission is checked by the IESG
for conflicts with IETF work; the quality is assessed by an independent submission editorial board. In other words, IRTF and independent RFCs are supposed to contain relevant info or experiments for the Internet at large not in conflict with IETF work, compare RFC 4846, RFC 5742, and RFC 5744.
is the RFC Editor. Almost any individual published RFC, for example RFC 5000, can be retrieved via the URL
:
http://www.rfc-editor.org/rfc/rfc5000.txt
Every RFC is submitted as plain ASCII
text and is published in that form, but may also be available in other formats
. However, the definitive
version of any standards-track
specification is the ASCII version.
For easy access to the metadata of an RFC, including abstract, keywords, author(s), publication date, errata, status,
and especially later updates, the RFC Editor site offers a search form with many
features. A redirection sets some efficient parameters, example:
The official International Standard Serial Number
(ISSN) of the RFC series is 2070-1721.
(IESG), can approve standards-track
RFCs.
Each RFC is static; if the document is changed, it is submitted again and assigned a new RFC number. If an RFC becomes an Internet Standard (STD), it is assigned an STD number but retains its RFC number; however, when an Internet Standard is updated, its number stays the same and it simply refers to a different RFC or set of RFCs. A given Internet Standard, STD n, may be RFCs x and y at a given time, but later the same standard may be updated to be RFC z instead. For example, in 2007 RFC 3700 was an Internet Standard—STD 1—and in May 2008 it was replaced with RFC 5000, so RFC 3700 changed to Historic, RFC 5000 became an Internet Standard, and STD 1 is RFC 5000. When STD 1 is updated again, it will simply refer to a newer RFC that will have completed the standards track, but it will still be STD 1. Best Current Practices work in a similar fashion; BCP n refers to a certain RFC or set of RFCs, but which RFC or RFCs may change over time.
The definitive list of Internet Standards is itself an Internet Standard, STD 1: Internet Official Protocol Standards.
Structure and Delegation (RFC 1591). Some informational RFCs formed the FYI sub-series. Some old FYIs are still interesting, e.g., the Internet User's Glossary RFC 1983 (FYI 18), and The Tao of IETF RFC 4677 (FYI 17).
(IANA) registries it is less clear; most of these documents are BCPs, but some are on the standards track.
The BCP series also covers technical recommendations for how to practice Internet standards; for instance the recommendation to use source filtering to make DoS attacks more difficult (RFC 2827: "Network Ingress Filtering: Defeating Denial of Service Attacks which employ IP Source Address Spoofing") is BCP 38.
Computer network
A computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information....
engineering, a Request for Comments (RFC) is a memorandum
Memorandum
A memorandum is from the Latin verbal phrase memorandum est, the gerundive form of the verb memoro, "to mention, call to mind, recount, relate", which means "It must be remembered ..."...
published by the Internet Engineering Task Force
Internet Engineering Task Force
The Internet Engineering Task Force develops and promotes Internet standards, cooperating closely with the W3C and ISO/IEC standards bodies and dealing in particular with standards of the TCP/IP and Internet protocol suite...
(IETF) describing methods, behaviors, research, or innovations applicable to the working of the Internet
Internet
The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...
and Internet-connected systems.
Through the Internet Society
Internet Society
The Internet Society or ISOC is an international, nonprofit organization founded during 1992 to provide direction in Internet related standards, education, and policy...
, engineers and computer scientist
Computer scientist
A computer scientist is a scientist who has acquired knowledge of computer science, the study of the theoretical foundations of information and computation and their application in computer systems....
s may publish discourse
Discourse
Discourse generally refers to "written or spoken communication". The following are three more specific definitions:...
in the form of an RFC, either for peer review
Peer review
Peer review is a process of self-regulation by a profession or a process of evaluation involving qualified individuals within the relevant field. Peer review methods are employed to maintain standards, improve performance and provide credibility...
or simply to convey new concepts, information, or (occasionally) engineering humor. The IETF adopts some of the proposals published as RFCs as Internet standard
Internet standard
In computer network engineering, an Internet Standard is a normative specification of a technology or methodology applicable to the Internet. Internet Standards are created and published by the Internet Engineering Task Force .-Overview:...
s.
History
The inception of the RFC format occurred in 1969 as part of the seminal ARPANETARPANET
The Advanced Research Projects Agency Network , was the world's first operational packet switching network and the core network of a set that came to compose the global Internet...
project. Today, it is the official publication channel for the Internet Engineering Task Force (IETF), the Internet Architecture Board
Internet Architecture Board
The Internet Architecture Board is the committee charged with oversight of the technical and engineering development of the Internet by the Internet Society ....
(IAB), and—to some extent—the global community of computer network researchers in general.
The authors of the first RFCs typewrote
Typewriter
A typewriter is a mechanical or electromechanical device with keys that, when pressed, cause characters to be printed on a medium, usually paper. Typically one character is printed per keypress, and the machine prints the characters by making ink impressions of type elements similar to the pieces...
their work and circulated hard copies
Hard copy
In information handling, a hard copy is a permanent reproduction, or copy, in the form of a physical object, of any media suitable for direct use by a person , of displayed or transmitted data...
among the ARPA
Defense Advanced Research Projects Agency
The Defense Advanced Research Projects Agency is an agency of the United States Department of Defense responsible for the development of new technology for use by the military...
researchers. Unlike the modern RFCs, many of the early RFCs were requests for comments. The RFC leaves questions open and is written in a less formal style. This less formal style is now typical of Internet Draft
Internet Draft
Internet Drafts is a series of working documents published by the IETF. Typically, they are drafts for RFCs, but may be other works in progress not intended for publication as RFCs. It is considered inappropriate to rely on Internet Drafts for reference purposes...
documents, the precursor step before being approved as an RFC.
In December 1969, researchers began distributing new RFCs via the newly operational ARPANET. RFC 1, entitled "Host Software", was written by Steve Crocker
Steve Crocker
Stephen D. Crocker is the inventor of the Request for Comments series, authoring the very first RFC and many more. He received his bachelor's degree and PhD from the University of California, Los Angeles. Crocker is chair of the board of the Internet Corporation for Assigned Names and Numbers,...
of the University of California, Los Angeles
University of California, Los Angeles
The University of California, Los Angeles is a public research university located in the Westwood neighborhood of Los Angeles, California, USA. It was founded in 1919 as the "Southern Branch" of the University of California and is the second oldest of the ten campuses...
(UCLA), and published on April 7, 1969. Although written by Steve Crocker, the RFC emerged from an early working group
Working group
A working group is an interdisciplinary collaboration of researchers working on new research activities that would be difficult to develop under traditional funding mechanisms . The lifespan of the WG can last anywhere between a few months and several years...
discussion between Steve Crocker, Steve Carr and Jeff Rulifson
Jeff Rulifson
Johns Frederick Rulifson is an American computer scientist.-Biography:Johns Frederick Rulifson was born August 20, 1941 in Bellefontaine, Ohio. His father was Erwin Charles Rulifson and mother was Virginia Helen Johns...
.
In RFC 3, which first defined the RFC series, Crocker started attributing the RFC series to the "Network Working Group". This wasn't so much a formal committee as a loose association of researchers interested in the ARPANET project. In effect, it was anyone who wanted to join in on meetings and discussions about the project.
Many of the subsequent RFCs of the 1970s also came from UCLA, because UCLA was one of the first Interface Message Processor
Interface Message Processor
The Interface Message Processor was the packet-switching node used to interconnect participant networks to the ARPANET from the late 1960s to 1989. It was the first generation of gateways, which are known today as routers. An IMP was a ruggedized Honeywell DDP-516 minicomputer with...
s (IMPs) on ARPANET.
The Augmentation Research Center
Augmentation Research Center
Stanford Research Institute's Augmentation Research Center was founded in the 1960s by electrical engineer Douglas Engelbart to develop and experiment with new tools and techniques for collaboration and information processing. The main product to come out of ARC was the revolutionary oN-Line...
(ARC) at Stanford Research Institute
SRI International
SRI International , founded as Stanford Research Institute, is one of the world's largest contract research institutes. Based in Menlo Park, California, the trustees of Stanford University established it in 1946 as a center of innovation to support economic development in the region. It was later...
, directed by Douglas Engelbart
Douglas Engelbart
Douglas Carl Engelbart is an American inventor, and an early computer and internet pioneer. He is best known for his work on the challenges of human-computer interaction, resulting in the invention of the computer mouse, and the development of hypertext, networked computers, and precursors to GUIs...
, was another of the four first ARPANET nodes
Node (networking)
In communication networks, a node is a connection point, either a redistribution point or a communication endpoint . The definition of a node depends on the network and protocol layer referred to...
and the source of early RFCs.
The ARC became the first Network Information Center
InterNIC
The Internet Network Information Center, known as InterNIC, was the Internet governing body primarily responsible for domain name and IP address allocations from 1972 until September 18, 1998 when this role was assumed by the Internet Corporation for Assigned Names and Numbers...
, which was managed by Elizabeth J. Feinler
Elizabeth J. Feinler
Elizabeth Jocelyn "Jake" Feinler is an American information scientist.From 1972 until 1989 she was director of the Network Information Systems Center at the Stanford Research Institute...
to distribute them along with other network information.
From 1969 until 1998, Jon Postel
Jon Postel
Jonathan Bruce Postel was an American computer scientist who made many significant contributions to the development of the Internet, particularly with respect to standards...
served as the RFC editor
Editing
Editing is the process of selecting and preparing written, visual, audible, and film media used to convey information through the processes of correction, condensation, organization, and other modifications performed with an intention of producing a correct, consistent, accurate, and complete...
. (On his death in 1998, his obituary was published as RFC 2468.)
Following the expiration of the original ARPANET contract with the U.S. federal government, the Internet Society (acting on behalf of the IETF) contracted with the Networking Division of the University of Southern California
University of Southern California
The University of Southern California is a private, not-for-profit, nonsectarian, research university located in Los Angeles, California, United States. USC was founded in 1880, making it California's oldest private research university...
(USC) Information Sciences Institute
Information Sciences Institute
The Information Sciences Institute is a research and development unit of the University of Southern California's Viterbi School of Engineering which focuses on computer and communications technology and information processing...
(ISI) to assume the editorship and publishing responsibilities (under the direction of the IAB).
Sandy Ginoza joined USC/ISI in 1999 to work on RFC editing, and Alice Hagens in 2005.
Bob Braden
Bob Braden
Robert Braden is an American computer scientist who played a role in the development of the Internet. His research interests include end-to-end network protocols, especially in the transport and internetwork layers.-Career:...
took over the role of RFC project lead, while Joyce K. Reynolds
Joyce K. Reynolds
Joyce K. Reynolds is a computer scientist.Reynolds holds bachelor's and master's degrees from the University of Southern California, United States. She has been active in the development of the protocols underlying the Internet...
continued to be part of the team until October 13, 2006.
In July 2007, "streams" of RFCs were defined, so the editing duties could be divided. IETF documents came from IETF working groups or submissions sponsored by an IETF area director from the Internet Engineering Steering Group
Internet Engineering Steering Group
The Internet Engineering Steering Group is a body composed of the Internet Engineering Task Force chair and area directors.It provides the final technical review of Internet standards and is responsible for day-to-day management of the IETF...
. The IAB can publish its own documents. A research stream of documents comes from the Internet Research Task Force
Internet Research Task Force
The Internet Research Task Force focuses on longer term research issues related to the Internet while the parallel organization, the Internet Engineering Task Force , focuses on the shorter term issues of engineering and standards making...
(IRTF), and and independent stream includes documents from other outside sources.
A new model was proposed in 2008, refined, and published in August 2009, splitting the task into several roles.
The streams were also refined in December 2009, with standards defined for their style.
In January 2010 the RFC editor function was moved to a contractor, Association Management Solutions with Glenn Kowack serving as interim series editor.
Production and evolution
The RFC Editor assigns each RFC a unique serial numberSerial number
A serial number is a unique number assigned for identification which varies from its successor or predecessor by a fixed discrete integer value...
. Once assigned a number and published, an RFC is never rescinded or modified; if the document requires amendments, the authors publish a revised document. Therefore, some RFCs supersede others; the superseded RFCs are said to be deprecated, obsolete, or even obsoleted (sic). Together, the serialized RFCs compose a continuous historical record of the evolution of Internet standards and practices. For more details about RFCs and the RFC process, see RFC 2026, "The Internet Standards Process, Revision 3".
The RFC production process differs from the standardization
Standardization
Standardization is the process of developing and implementing technical standards.The goals of standardization can be to help with independence of single suppliers , compatibility, interoperability, safety, repeatability, or quality....
process of formal standards organizations such as ISO
International Organization for Standardization
The International Organization for Standardization , widely known as ISO, is an international standard-setting body composed of representatives from various national standards organizations. Founded on February 23, 1947, the organization promulgates worldwide proprietary, industrial and commercial...
. Internet technology experts may submit an Internet Draft
Internet Draft
Internet Drafts is a series of working documents published by the IETF. Typically, they are drafts for RFCs, but may be other works in progress not intended for publication as RFCs. It is considered inappropriate to rely on Internet Drafts for reference purposes...
without support from an external institution. Standards-track RFCs are published with approval from the IETF, and are usually produced by experts participating in working groups, which first publish an Internet Draft. This approach facilitates initial rounds of peer review before documents mature into RFCs.
The RFC tradition of pragmatic, experience-driven, after-the-fact standards authorship accomplished by individuals or small working groups can have important advantages over the more formal, committee-driven process typical of ISO and national standards bodies.
Most RFCs use a common set of terms such as "MUST" and "NOT RECOMMENDED" (as defined by RFC 2119), Augmented Backus–Naur Form
Augmented Backus–Naur form
In computer science, Augmented Backus–Naur Form is a metalanguage based on Backus–Naur Form , but consisting of its own syntax and derivation rules. The motive principle for ABNF is to describe a formal system of a language to be used as a bidirectional communications protocol...
(ABNF) (as defined by RFC 5234) as a metalanguage, and simple text-based formatting, in order to keep the RFCs consistent and easy to understand.
Sub-series
The RFC series contains three sub-series for IETFInternet Engineering Task Force
The Internet Engineering Task Force develops and promotes Internet standards, cooperating closely with the W3C and ISO/IEC standards bodies and dealing in particular with standards of the TCP/IP and Internet protocol suite...
RFCs:
BCP: Best Current Practice; mandatory IETF RFCs not on standards track, see below.
FYI: For Your Information; informational RFCs promoted by the IETF as specified in RFC 1150 (FYI 1). In 2011 RFC 6360 obsoleted FYI 1 and concluded this sub-series.
STD: Standard
Internet standard
In computer network engineering, an Internet Standard is a normative specification of a technology or methodology applicable to the Internet. Internet Standards are created and published by the Internet Engineering Task Force .-Overview:...
; this used to be the third and highest maturity level of the IETF standards track specified in RFC 2026 (BCP 9). In 2011 RFC 6410 (a new part of BCP 9) reduced the standards track to two maturity levels.
Streams
There are four streams of RFCs: (1) IETFInternet Engineering Task Force
The Internet Engineering Task Force develops and promotes Internet standards, cooperating closely with the W3C and ISO/IEC standards bodies and dealing in particular with standards of the TCP/IP and Internet protocol suite...
, (2) IRTF
Internet Research Task Force
The Internet Research Task Force focuses on longer term research issues related to the Internet while the parallel organization, the Internet Engineering Task Force , focuses on the shorter term issues of engineering and standards making...
, (3) IAB
Internet Architecture Board
The Internet Architecture Board is the committee charged with oversight of the technical and engineering development of the Internet by the Internet Society ....
, and (4) independent submission. Only the IETF creates BCPs and RFCs on standards track. An independent submission is checked by the IESG
Internet Engineering Steering Group
The Internet Engineering Steering Group is a body composed of the Internet Engineering Task Force chair and area directors.It provides the final technical review of Internet standards and is responsible for day-to-day management of the IETF...
for conflicts with IETF work; the quality is assessed by an independent submission editorial board. In other words, IRTF and independent RFCs are supposed to contain relevant info or experiments for the Internet at large not in conflict with IETF work, compare RFC 4846, RFC 5742, and RFC 5744.
Obtaining RFCs
The official source for RFCs on the World Wide WebWorld Wide Web
The World Wide Web is a system of interlinked hypertext documents accessed via the Internet...
is the RFC Editor. Almost any individual published RFC, for example RFC 5000, can be retrieved via the URL
Uniform Resource Locator
In computing, a uniform resource locator or universal resource locator is a specific character string that constitutes a reference to an Internet resource....
:
Every RFC is submitted as plain ASCII
ASCII
The American Standard Code for Information Interchange is a character-encoding scheme based on the ordering of the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that use text...
text and is published in that form, but may also be available in other formats
File format
A file format is a particular way that information is encoded for storage in a computer file.Since a disk drive, or indeed any computer storage, can store only bits, the computer must have some way of converting information to 0s and 1s and vice-versa. There are different kinds of formats for...
. However, the definitive
version of any standards-track
Internet standard
In computer network engineering, an Internet Standard is a normative specification of a technology or methodology applicable to the Internet. Internet Standards are created and published by the Internet Engineering Task Force .-Overview:...
specification is the ASCII version.
For easy access to the metadata of an RFC, including abstract, keywords, author(s), publication date, errata, status,
and especially later updates, the RFC Editor site offers a search form with many
features. A redirection sets some efficient parameters, example:
http://purl.net/net/rfc/5000The official International Standard Serial Number
International Standard Serial Number
An International Standard Serial Number is a unique eight-digit number used to identify a print or electronic periodical publication. Periodicals published in both print and electronic form may have two ISSNs, a print ISSN and an electronic ISSN...
(ISSN) of the RFC series is 2070-1721.
Status
Not all RFCs are standards. Each RFC is assigned a designation with regard to status within the Internet standardization process. This status is one of the following: Informational, Experimental, Best Current Practice (BCP), Standards Track, or Historic (sic). Standards-track documents are further divided into Proposed Standard, Draft Standard, and Internet Standard documents. The term Historic is applied to deprecated standards-track documents or obsolete RFCs that were published before the standards track was established. Only the IETF, represented by the Internet Engineering Steering GroupInternet Engineering Steering Group
The Internet Engineering Steering Group is a body composed of the Internet Engineering Task Force chair and area directors.It provides the final technical review of Internet standards and is responsible for day-to-day management of the IETF...
(IESG), can approve standards-track
Internet standard
In computer network engineering, an Internet Standard is a normative specification of a technology or methodology applicable to the Internet. Internet Standards are created and published by the Internet Engineering Task Force .-Overview:...
RFCs.
Each RFC is static; if the document is changed, it is submitted again and assigned a new RFC number. If an RFC becomes an Internet Standard (STD), it is assigned an STD number but retains its RFC number; however, when an Internet Standard is updated, its number stays the same and it simply refers to a different RFC or set of RFCs. A given Internet Standard, STD n, may be RFCs x and y at a given time, but later the same standard may be updated to be RFC z instead. For example, in 2007 RFC 3700 was an Internet Standard—STD 1—and in May 2008 it was replaced with RFC 5000, so RFC 3700 changed to Historic, RFC 5000 became an Internet Standard, and STD 1 is RFC 5000. When STD 1 is updated again, it will simply refer to a newer RFC that will have completed the standards track, but it will still be STD 1. Best Current Practices work in a similar fashion; BCP n refers to a certain RFC or set of RFCs, but which RFC or RFCs may change over time.
The definitive list of Internet Standards is itself an Internet Standard, STD 1: Internet Official Protocol Standards.
Status "informational"
An informational RFC can be nearly anything from April 1 jokes over proprietary protocols up to widely recognized essential RFCs like Domain Name SystemDomain name system
The Domain Name System is a hierarchical distributed naming system for computers, services, or any resource connected to the Internet or a private network. It associates various information with domain names assigned to each of the participating entities...
Structure and Delegation (RFC 1591). Some informational RFCs formed the FYI sub-series. Some old FYIs are still interesting, e.g., the Internet User's Glossary RFC 1983 (FYI 18), and The Tao of IETF RFC 4677 (FYI 17).
Status "experimental"
An experimental RFC can be an IETF document or an individual submission to the 'RFC Editor'. In theory it is indeed experimental; in practice some documents are not promoted on standards track because there are no volunteers for the procedural details.Status "best current practice"
The best current practice (BCP) subseries collects administrative documents and other texts which are considered as official rules and not only informational, but which do not affect over the wire data. The border between standards track and BCP is often unclear. If a document only affects the Internet Standards Process, like BCP 9, or IETF administration, it is clearly a BCP. If it only defines rules and regulations for Internet Assigned Numbers AuthorityInternet Assigned Numbers Authority
The Internet Assigned Numbers Authority is the entity that oversees global IP address allocation, autonomous system number allocation, root zone management in the Domain Name System , media types, and other Internet Protocol-related symbols and numbers...
(IANA) registries it is less clear; most of these documents are BCPs, but some are on the standards track.
The BCP series also covers technical recommendations for how to practice Internet standards; for instance the recommendation to use source filtering to make DoS attacks more difficult (RFC 2827: "Network Ingress Filtering: Defeating Denial of Service Attacks which employ IP Source Address Spoofing") is BCP 38.
Status "historic"
A historic RFC is one that has been made obsolete by a newer version, documents a protocol that is not considered interesting in the current Internet, or has been removed from the standards track for other reasons. Some obsolete RFCs are not classified as historic, because the Internet standards process generally does not allow normative references from a standards track RFC to another RFC with lower status. Also, few are interested in working through the required procedural details to get RFCs classified as historic and update all RFCs normatively depending on it.Status "unknown"
Status unknown is used for some very old RFCs, where it is unclear which status the document would get if it were published today. Some of these RFCs would not be published at all today; an early RFC was often just that: a simple request for comments, not intended to specify a protocol, administrative procedure, or anything else for which the RFC series is used today.External links
- RFC Editor
- IETF's RFC page
- RFC Index (HTML) With the text of each RFC, also mentions what other RFCs this one "updates" or is "updated by".