Network Working Group J. Littlefield
Request for Comments: 3925 Cisco Systems, Inc.
Category: Standards Track October 2004
Vendor-Identifying Vendor Options for
Dynamic Host Configuration Protocol version 4 (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 (2004).
Abstract
The Dynamic Host Configuration Protocol (DHCP) options for Vendor
Class and Vendor-Specific Information can be limiting or ambiguous
when a DHCP client represents multiple vendors. This document
defines two new options, modeled on the IPv6 options for vendor class
and vendor-specific information, that contain Enterprise Numbers to
remove ambiguity.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Conventions Used in This Document. . . . . . . . . . . . 2
2. Supporting Multiple Vendor Instances . . . . . . . . . . . . . 3
3. Vendor-Identifying Vendor Class Option . . . . . . . . . . . . 3
4. Vendor-Identifying Vendor-Specific Information Option . . . . 5
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
6. Security Considerations . . . . . . . . . . . . . . . . . . . 7
7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 8
7.1. Normative References . . . . . . . . . . . . . . . . . . 8
7.2. Informative References . . . . . . . . . . . . . . . . . 8
8. Author's Address . . . . . . . . . . . . . . . . . . . . . . . 8
9. Full Copyright Statement . . . . . . . . . . . . . . . . . . . 9
Littlefield Standards Track [Page 1]
RFC 3925 Vendor-Identifying Vendor Options October 2004
1. Introduction
The DHCP protocol for IPv4, RFC 2131 [2], defines options that allow
a client to indicate its vendor type (option 60), and the DHCP client
and server to exchange vendor-specific information (option 43) [5].
Although there is no prohibition against passing multiple copies of
these options in a single packet, doing so would introduce ambiguity
of interpretation, particularly if conveying vendor-specific
information for multiple vendors. The vendor identified by option 60
defines the interpretation of option 43, which itself carries no
vendor identifier. Furthermore, the concatenation of multiple
instances of the same option, required by RFC 2131 and specified by
RFC 3396 [4], means that multiple copies of options 60 or 43 would
not remain independent.
In some circumstances, an implementation may need to support
multiple, independently defined forms of vendor-specific information.
For example, implementations that must conform to an industry-
standard use of DHCPv4, to allow interoperability in a particular
technology space, may be required to support the vendor-specific
options of that industry group. But the same implementation may also
require support for vendor-specific options defined by the
manufacturer. In particular, this is an issue for vendors of devices
supporting CableLabs [9] standards, such as DOCSIS, CableHome, and
PacketCable, as those standards define an industry-specific use for
options 60 and 43.
This document defines two new options, modeled on the IPv6 options
for vendor class and vendor-specific information defined in RFC 3315
[6], that contain IANA-assigned Enterprise Numbers [3] to remove
ambiguity about the interpretation of their contents. If desired,
these new options can be used in addition to the current vendor class
and vendor information options, whose definition is unaffected by
this document.
1.1. Conventions Used in This Document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in BCP 14, RFC 2119 [1].
Littlefield Standards Track [Page 2]
RFC 3925 Vendor-Identifying Vendor Options October 2004
2. Supporting Multiple Vendor Instances
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