RFC3679

Network Working Group R. Droms Request for Comments: 3679 Cisco Systems Category: Informational January 2004

 Unused Dynamic Host Configuration Protocol (DHCP) Option Codes

Status of this Memo

This memo provides information for the Internet community. It does not specify an Internet standard of any kind. Distribution of this memo is unlimited.

Copyright Notice

Copyright (C) The Internet Society (2004). All Rights Reserved.

Abstract

Prior to the publication of RFC 2489 (which was updated by RFC 2939), several option codes were assigned to proposed Dynamic Host Configuration Protocol (DHCP) options that were subsequently never used. This document lists those unused option codes and directs IANA to make these option codes available for assignment to other DHCP options in the future.

The document also lists several option codes that are not currently documented in an RFC but should not be made available for reassignment to future DHCP options.

Introduction

Section 2 of this document lists the unused DHCP option codes from the IANA list of BOOTP and DHCP option codes [1]. Each option code includes any known documentation and contact information from the IANA list. IANA will make these option codes available for assignment to other DHCP options in the future.

Section 3 lists several DHCP option codes that are not currently documented in an RFC but should not be made available for reassignment to future DHCP options.

Unused DHCP Option Codes to be Reassigned to Future DHCP Options

The option codes listed in this section are to be returned to IANA for reassignment to new options. Responses from associated contact persons are noted where they have been received.

Service Location Protocol Naming Authority

Code: 80 Name: Service Location Protocol Naming Authority Defined in: (expired Internet-Draft) Contact: Charlie Perkins Reason to recover: Never published as standard and not in general use

Relay Agent Options

Codes: 83, 84 Name: Relay Agent Options Defined in: Early draft of RFC 3046 [2] Contact: (none) Reason to recover: Not defined in RFC 3046 as published

IEEE 1003.1 POSIX Timezone

Code: 88 Name: IEEE 1003.1 POSIX Timezone Defined in: (expired Internet-Draft) Contact: Mike Carney Reason to recover: Never published as standard and not in general use

FQDNs in DHCP Options

Code: 89 Name: FQDNs in DHCP Options Defined in: (expired Internet-Draft) Contact: Ralph Droms; agrees that option code should be

                  reassigned

Reason to recover: Never published as standard and not in general use

VINES TCP/IP Server

Code: 91 Name: VINES TCP/IP Server Defined in: (none) Contact: (none) Reason to recover: Never published as Internet-Draft

Server Selection

Code: 92 Name: Server Selection Defined in: (none) Contact: (none) Reason to recover: Never published as Internet-Draft

IPv6 Transition

Code: 96 Name: IPv6 Transition Defined in: (expired Internet-Draft) Contact: Dan Harrington; agrees that option code should be

                  reassigned

Reason to recover: Never published as standard and not in general use

Printer Name

Code: 100 Name: Printer Name Defined in: (none) Contact: (none) Reason to recover: Never published as Internet-Draft

Multicast Assignment through DHCP

Code: 101 Name: Multicast Assignment through DHCP Defined in: (expired Internet-Draft) Contact: Baiju Patel, Munil Shah Reason to recover: Never published as standard and not in general use

2.10. Swap Path

Code: 108 Name: Swap Path Defined in: (none) Contact: (none) Reason to recover: Never published as Internet-Draft

2.11. IPX Compatibility

Code: 110 Name: IPX Compatibility Defined in: (none) Contact: Juan Luciani; agrees that option code should be

                  reassigned

Reason to recover: Never published as Internet-Draft

2.12. Failover

Code: 115 Name: Failover Defined in: Early revisions of "DHCP Failover Protocol" [3] Contact: Kim Kinnear Reason to recover: Current version of "DHCP Failover Protocol" does

                  not use a DHCP option

Option codes to be reserved by IANA

The option codes listed in this section are the subject of ongoing work in the DHC Working Group (WG). These option codes should remain on the IANA list of assigned option codes [1] until the DHC WG has made a final decision about their disposition.

Option codes used in PXE Specification

The following option codes are used in the "Preboot Execution Environment (PXE) Specification, Version 2.1" [4]. However, although these options are in widespread use by devices that use PXE, none of these option codes have been described in a published RFC.

The DHC WG will endeavor to have specifications for these options published.

Client System

Code: 93 Name: Client System Defined in: "Preboot Execution Environment (PXE)

                  Specification, Version 2.1" [4]

Contact: Michael Johnston

                  ([email protected])

Client NDI

Code: 94 Name: Client NDI Defined in: "Preboot Execution Environment (PXE)

                  Specification, Version 2.1" [4]

Contact: Michael Johnston

                  ([email protected])

UUID/GUID Client Identifier

Code: 97 Name: UUID/GUID Client Identifier Defined in: "Preboot Execution Environment (PXE)

                  Specification, Version 2.1" [4] (and an expired
                  Internet-Draft)

Contact: Dan Harrington, Michael Johnston

                  ([email protected])

In Use by Apple

The following option codes are used by devices from Apple Computer. However, none of these option codes have been described in a published RFC.

The DHC WG will endeavor to have specifications for these options published.

LDAP Servers

Code: 95 Name: LDAP Servers Defined in: (none) Contact: Dieter Siegmund, [email protected] Reason to recover: Never published in an RFC

Netinfo Parameters

Codes: 112, 113 Name: Netinfo Address, Netinfo Tag Defined in: (none) Contact: Dieter Siegmund, [email protected] Reason to recover: Never published in an RFC

URL

Code: 114 Name: URL Defined in: (none) Contact: Dieter Siegmund, [email protected] Reason to recover: Never published in an RFC

Option Code Extensions

Note that these option codes are identified in "Extending DHCP Options Codes" [5] as part of a mechanism for extending the set of option codes available to DHCP. If these option codes are not used for DHCP option code extension, they will be returned to IANA for reassignment to other DHCP options.

Codes: 126, 127 Name: Option Code Extensions Defined in: (expired Internet-Draft) Contact: Ralph Droms

Already Returned for Reassignment

The option codes 99, 102-107, 109 and 111 have already been returned for reassignment to future DHCP options.

Security Considerations

This document has no known security implications, as none of the reclaimed options are known to be in use.

IANA Considerations

IANA has returned the DHCP option codes listed in Section 2 to the list of available option codes. These option codes may be reassigned to new DHCP options, according to the procedures in RFC 2939 [6]. IANA is requested to reassign these option codes after the list of option codes that have never been assigned or have previously been returned has been exhausted.

Informative References

[1] Assigned Numbers Editor, IANA., "BOOTP and DHCP Parameters",

    http://www.iana.org/assignments/bootp-dhcp-parameters, February
    2003.

[2] Patrick, M., "DHCP Relay Agent Information Option", RFC 3046,

    January 2001.

[3] Droms, R., Kinnear, K., Stapp, M., Volz, B., Gonczi, S., Rabil,

    G., Dooley, M. and A. Kapur, "DHCP Failover Protocol", Work in
    Progress.

[4] Intel Corporation, "Preboot Execution Environment (PXE)

    Specification Version 2.1", http://www.pix.net/software/pxeboot/
    archive/pxespec.pdf, September 1999.

[5] Volz, B., Droms, R. and T. Lemon, "Extending DHCP Options

    Codes", Work in Progress.

[6] Droms, R., "Procedures and IANA Guidelines for Definition of New

    DHCP Options and Message Types", BCP 43, RFC 2939, September
    2000.

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Author's Address

Ralph Droms Cisco Systems 1414 Massachusetts Avenue Boxborough, MA 01719 USA

Phone: +1 978 936 1674 EMail: [email protected]

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