

To: iana@isi.edu
Subject: Request for three DHCP option numbers
Date: Mon, 11 Nov 1996 16:35:13 -0500
From: Ralph E. Droms <droms@charcoal.eg.bucknell.edu>



                 An Extension to the DHCP Option Codes
                 <draft-ietf-dhc-options-opt127-02.txt>

   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
   and new option to request the parameters represented by those new
   option codes.

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 | ...
   +-----+-----+-----+-----+-----+-----+----

Definition of option 126

   This option is used by a DHCP client to request values for specified
   configuration paramaters that are identified by extended option codes
   as defined above.  The list of n requested parameters is specified as
   2n octets, where each pair of octets is a valid extended option code.

   The client MAY list the options in order of preference.  The DHCP
   server is not required to return the options in the requested order,
   but MUST try to insert the requested options in the order requested
   by the client.

   The code for this option is 126.  Its minimum length is 2.

                Extended
    Code   Len  option codes
   +-----+-----+-----+-----+-----+-----+----
   | 126 | XXX | c1h | c1l | c2h | c2l | ...
   +-----+-----+-----+-----+-----+-----+----

