Experimental Values In IPv4, IPv6, ICMPv4, ICMPv6, UDP, and TCP Headers
RFC 4727
| Document | Type |
RFC - Proposed Standard
(November 2006; No errata)
Was draft-fenner-iana-exp-2780 (individual in int area)
|
|
|---|---|---|---|
| Last updated | 2015-10-14 | ||
| Stream | IETF | ||
| Formats | plain text pdf html bibtex | ||
| Stream | WG state | (None) | |
| Document shepherd | No shepherd assigned | ||
| IESG | IESG state | RFC 4727 (Proposed Standard) | |
| Consensus Boilerplate | Unknown | ||
| Telechat date | |||
| Responsible AD | Jari Arkko | ||
| Send notices to | (None) | ||
Network Working Group B. Fenner
Request for Comments: 4727 AT&T Labs - Research
Category: Standards Track November 2006
Experimental Values
in IPv4, IPv6, ICMPv4, ICMPv6, UDP, and TCP Headers
Status of This Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The IETF Trust (2006).
Abstract
When experimenting with or extending protocols, it is often necessary
to use some sort of protocol number or constant in order to actually
test or experiment with the new function, even when testing in a
closed environment. This document reserves some ranges of numbers
for experimentation purposes in specific protocols where the need to
support experimentation has been identified, and it describes the
numbers that have already been reserved by other documents.
Fenner Standards Track [Page 1]
RFC 4727 Experimental Values in Headers November 2006
1. Introduction
[RFC3692] recommends assigning option numbers for experiments and
testing. This document documents several such assignments for the
number spaces whose IANA considerations are documented in [RFC2780].
This document generally follows the form of [RFC2780].
When using these values, carefully consider the advice in Sections 1
and 1.1 of [RFC3692]. It is not appropriate to simply select one of
these values and hard code it into a system.
Note: while [RFC3692] says that it may not be necessary to allocate
values for UDP and TCP ports, Sections 6 and 7.1 explicitly reserve
ports for this purpose to avoid any possible conflict.
2. Fields in the IPv4 Header
The IPv4 header [RFC0791] contains the following fields that carry
values assigned by the IANA: Version, Type of Service, Protocol,
Source Address, Destination Address, and Option Type.
2.1. IP Version Field in the IPv4 Header
The Version field in IPv4 packets is always 4.
2.2. IPv4 Type of Service Field
[RFC2474] defines Pool 2 (all code points xxxx11, where 'x' refers to
either '0' or '1') as Experimental/Local Use, so no additional code
points should be needed. The Explicit Congestion Notification (ECN)
field [RFC3168] has no free code points to assign.
2.3. IPv4 Protocol Field
[RFC3692] allocates two experimental code points (253 and 254) for
the IPv4 Protocol field.
2.4. IPv4 Source and Destination Addresses
2.4.1. IPv4 Unicast
No experimental IPv4 addresses are defined. For certain experiments,
the address ranges set aside for Private Internets in [RFC1918] may
be useful. It is not appropriate to use other special-purpose IPv4
addresses [RFC3330] for experimentation.
Fenner Standards Track [Page 2]
RFC 4727 Experimental Values in Headers November 2006
At the time of this writing, some Internet Registries have policies
allowing experimental assignments from number spaces that they
control. Depending on the experiment, the registry, and their
policy, this may be an appropriate path to pursue.
2.4.2. IPv4 Multicast
The globally routable group 224.0.1.20 is set aside for
experimentation. For certain experiments, the administratively
scoped multicast groups defined in [RFC2365] may be useful. This
document assigns a single link-local scoped group, 224.0.0.254, and a
single scope-relative group, 254.
2.5. IPv4 Option Type Field
This document assigns a single option number, with all defined values
of the "copy" and "class" fields, resulting in four distinct option
type codes. See Section 8 for the assigned values.
3. Fields in the IPv6 Header
The IPv6 header [RFC2460] contains the following fields that carry
values assigned from IANA-managed name spaces: Version, Traffic
Class, Next Header, Source and Destination Address. In addition, the
IPv6 Hop-by-Hop Options and Destination Options extension headers
include an Option Type field with values assigned from an IANA-
Show full document text