IANA Allocation Guidelines For Values In the Internet Protocol and Related Headers (RFC2780)
Original Publication Date: 2000-Mar-01
Included in the Prior Art Database: 2019-Feb-10
Internet Society Requests For Comment (RFCs)
S. Bradner: AUTHOR [+1]
This memo provides guidance for the IANA to use in assigning parameters for fields in the IPv4, IPv6, ICMP, UDP and TCP protocol headers. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements.
Network Working Group S. Bradner Request for Comments: 2780 Harvard University BCP: 37 V. Paxson Category: Best Current Practice ACIRI March 2000
IANA Allocation Guidelines For Values In the Internet Protocol and Related Headers
Status of this Memo
This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements. Distribution of this memo is unlimited.
Copyright (C) The Internet Society (2000). All Rights Reserved.
This memo provides guidance for the IANA to use in assigning parameters for fields in the IPv4, IPv6, ICMP, UDP and TCP protocol headers.
For many years the Internet Assigned Numbers Authority (IANA) (www.iana.org) has allocated parameter values for fields in protocols which have been created or are maintained by the Internet Engineering Task Force (IETF). Starting a few years ago the IETF began to provide the IANA with guidance for the assignment of parameters for fields in newly developed protocols. Unfortunately this type of guidance was not consistently provided for the fields in protocols developed before 1998. This memo attempts to codify existing IANA practice used in the assignment of parameters in the specific case of some of these protocols. It is expected that additional memos will be developed in the future to codify existing practice in other cases.
This memo addresses the fields within the IPv4, IPv6, ICMP, UDP and TCP protocol headers for which the IANA assigns values.
The terms "Specification Required", "Expert Review", "IESG Approval", "IETF Consensus", and "Standards Action", are used in this memo to refer to the processes described in [CONS].
Bradner & Paxson Best Current Practice [Page 1]
RFC 2780 IANA Assignments March 2000
2. Temporary Assignments
From time to time temporary assignments are made in the values for fields in these headers for use in experiments. IESG Approval is required for any such temporary assignments.
3. Version field in the IP header.
The first field in the IP header of all current versions of IP is the Version field. New values in the Version field define new versions of the IP protocol and are allocated only after an IETF Standards Action. It should be noted that some of the Version number bits are used by TCP/IP header compression schemes. Specifically, the hi-order bit of the Version field is also used by TCP/IP header compression [HC], while the three hi-order bits are used by IP Header Compression [IPHC].
4. IANA Considerations for fields in the IPv4 header
The IPv4 header [V4] contains the following fields that carry values assigned by the IANA: Version, Type of Service, Protocol, Source Address, Destination Address, and Option Type.
4.1 IPv4 IP Version field
The IPv4 Version field is always 4.
4.2 IPv4 Type of Service field
The Type of Service field described in [V4] has been superseded[DIFF] by the 6-bit Differentiated Services (DS) field and a 2-bit field which...