RFC 2939 (rfc2939) - Page 2 of 7
Procedures and IANA Guidelines for Definition of New DHCP Options and Message Types
Alternative Format: Original Text Document
RFC 2939 Procedures for New DHCP Options September 2000
DHCP protocol messages are identified by the 'DHCP Message Type'
option (option code 51). Each message type is defined by the data
value carried in the 'DHCP Message Type' option.
This document describes the procedure for defining new DHCP options
and message types. The procedure will guarantee that:
* allocation of new option numbers and message type numbers is
coordinated from a single authority,
* new options and message types are reviewed for technical
correctness and appropriateness, and
* documentation for new options and message types is complete and
published.
As indicated in, "Guidelines for Writing an IANA Considerations
Section in RFCs", (see references), IANA acts as a central authority
for assignment of numbers such as DHCP option and message type codes.
The new procedure outlined in this document will provide guidance to
IANA in the assignment of new option and message type codes.
This document updates and replaces RFC 2489.
2. Overview and background
This document specifies procedures for defining new option codes and
message types.
2.1 New DHCP option codes
The procedure described in this document modifies and clarifies the
procedure for defining new options in RFC 2131 [2]. The primary
modification is to the time at which a new DHCP option is assigned an
option number. In the procedure described in this document, the
option number is not assigned until specification for the option is
about to be published as an RFC.
Since the publication of RFC 2132, the option number space for
publicly defined DHCP options (1-127) has almost been exhausted.
Many of the defined option numbers have not been followed up with
Internet Drafts submitted to the DHC WG. There has been a lack of
specific guidance to IANA from the DHC WG as to the assignment of
DHCP option numbers.
The procedure as specified in RFC 2132 does not clearly state that
new options are to be reviewed individually for technical
correctness, appropriateness and complete documentation. RFC 2132
also does not require that new options are to be submitted to the
IESG for review, and that the author of the option specification is
Droms Best Current Practice