Network Working Group R. Droms INTERNET DRAFT Bucknell University Obsoletes: draft-ietf-dhc-options-opt127-00.txt February 1996 Expires August 1996 An Extension to the DHCP Option Codes Status of this memo This document is an Internet-Draft. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as ``work in progress.'' To learn the current status of any Internet-Draft, please check the ``1id-abstracts.txt'' listing contained in the Internet-Drafts Shadow Directories on ftp.is.co.za (Africa), nic.nordu.net (Europe), munnari.oz.au (Pacific Rim), ds.internic.net (US East Coast), or ftp.isi.edu (US West Coast). Abstract The Dynamic Host Configuration Protocol (DHCP) provides a framework for passing configuration information to hosts on a TCP/IP network. This document defines a new option to extend the available option codes. Introduction The Dynamic Host Configuration Protocol (DHCP) [1] provides a framework for passing configuration information to hosts on a TCP/IP network. Configuration parameters and other control information are carried in tagged data items that are stored in the 'options' field of the DHCP message. The data items themselves are also called "options." Each option is assigned a one-octet option code. Options 128-254 are reserved for local use and at this time over half of the available options in the range 0-127 and option 255 have been assigned. This document defines a new option to extend the available option codes. Droms [Page 1] DRAFT An extension to the DHCP Option Codes February 1996 Definition of option 127 Option code 127 indicates that the DHCP option has a two-octet extended option code. The format of these options is: Extended Code Len option code Data... +-----+-----+-----+-----+-----+-----+---- | 127 | XXX | oh | ol | d1 | d2 | ... +-----+-----+-----+-----+-----+-----+---- Other than the two-octet extended option code, these options are encoded and carried in DHCP messages identically to the options defined in RFC 1533 [2]. The high-order and low-order octets of the extended option code are stored in 'oh' and 'ol', respectively. The number of octets given in the 'len' field includes the two-octet extended option code. The two-octet extended option codes will be assigned through the mechanisms defined for the assignment of new options [3] after the current one-octet option codes have been exhausted. References [1] Droms, R., "Dynamic Host Configuration Protocol", RFC 1531, Bucknell University, October 1993. [2] Alexander, S. and R. Droms, "DHCP Options and BOOTP Vendor Extensions", RFC 1533, Lachman Associates, October 1993. [3] Droms, R., "Procedure for Defining New DHCP Options", Work in progress, February, 1996. Security Considerations Security issues are not discussed in this document. Author's Address Ralph Droms Computer Science Department 323 Dana Engineering Bucknell University Lewisburg, PA 17837 Phone: (717) 524-1145 EMail: droms@bucknell.edu Droms [Page 2]