RFC 3396 (rfc3396) - Page 1 of 9
Encoding Long Options in the Dynamic Host Configuration Protocol (DHCPv4)
Alternative Format: Original Text Document
Network Working Group T. Lemon
Request for Comments: 3396 Nominum, Inc.
Updates: 2131 S. Cheshire
Category: Standards Track Apple Computer, Inc.
November 2002
Encoding Long Options
in the Dynamic Host Configuration Protocol (DHCPv4)
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 Internet Society (2002). All Rights Reserved.
Abstract
This document specifies the processing rules for Dynamic Host
Configuration Protocol (DHCPv4) options that appear multiple times in
the same message. Multiple instances of the same option are
generated when an option exceeds 255 octets in size (the maximum size
of a single option) or when an option needs to be split apart in
order to take advantage of DHCP option overloading. When multiple
instances of the same option appear in the options, file and/or sname
fields in a DHCP packet, the contents of these options are
concatenated together to form a single option prior to processing.
1. Introduction
This document updates RFC 2131 [3] by clarifying the rules for option
concatenation specified in section 4.1. It is expected that the
reader will be familiar with this portion of RFC 2131. The text in
section 4.1 that reads "Options may appear only once, unless
otherwise specified in the options document." should be considered
as deleted.
The DHCP protocol [3] specifies objects called "options" that are
encoded in the DHCPv4 packet to pass information between DHCP
protocol agents. These options are encoded as a one-byte type code,
a one-byte length, and a buffer consisting of the number of bytes
specified in the length, from zero to 255.
Lemon & Cheshire Standards Track
