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. 1. 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. 2. 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. Droms Informational [Page 1] RFC 3679 Unused DHCP Option Codes January 2004 2.1. 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 2.2. 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 2.3. 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 2.4. 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 2.5. VINES TCP/IP Server Code: 91 Name: VINES TCP/IP Server Defined in: (none) Contact: (none) Reason to recover: Never published as Internet-Draft 2.6. Server Selection Code: 92 Name: Server Selection Defined in: (none) Contact: (none) Reason to recover: Never published as Internet-Draft Droms Informational [Page 2] RFC 3679 Unused DHCP Option Codes January 2004 2.7 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 2.8. Printer Name Code: 100 Name: Printer Name Defined in: (none) Contact: (none) Reason to recover: Never published as Internet-Draft 2.9. 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 Droms Informational [Page 3] RFC 3679 Unused DHCP Option Codes January 2004 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 3. 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. 3.1. 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. 3.1.1. Client System Code: 93 Name: Client System Defined in: "Preboot Execution Environment (PXE) Specification, Version 2.1" [4] Contact: Michael Johnston (frenchy@quiet-like-a-panther.org) 3.1.2. Client NDI Code: 94 Name: Client NDI Defined in: "Preboot Execution Environment (PXE) Specification, Version 2.1" [4] Contact: Michael Johnston (frenchy@quiet-like-a-panther.org) Droms Informational [Page 4] RFC 3679 Unused DHCP Option Codes January 2004 3.1.3. 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 (frenchy@quiet-like-a-panther.org) 3.2. 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. 3.2.1. LDAP Servers Code: 95 Name: LDAP Servers Defined in: (none) Contact: Dieter Siegmund, dieter@apple.com Reason to recover: Never published in an RFC 3.2.2. Netinfo Parameters Codes: 112, 113 Name: Netinfo Address, Netinfo Tag Defined in: (none) Contact: Dieter Siegmund, dieter@apple.com Reason to recover: Never published in an RFC 3.2.3. URL Code: 114 Name: URL Defined in: (none) Contact: Dieter Siegmund, dieter@apple.com Reason to recover: Never published in an RFC Droms Informational [Page 5] RFC 3679 Unused DHCP Option Codes January 2004 3.3. 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 4. Already Returned for Reassignment The option codes 99, 102-107, 109 and 111 have already been returned for reassignment to future DHCP options. 5. Security Considerations This document has no known security implications, as none of the reclaimed options are known to be in use. 6. 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. Droms Informational [Page 6] RFC 3679 Unused DHCP Option Codes January 2004 [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. Intellectual Property Statement The IETF takes no position regarding the validity or scope of any intellectual property or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; neither does it represent that it has made any effort to identify any such rights. Information on the IETF's procedures with respect to rights in standards-track and standards-related documentation can be found in BCP-11. Copies of claims of rights made available for publication and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementors or users of this specification can be obtained from the IETF Secretariat. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights which may cover technology that may be required to practice this standard. Please address the information to the IETF Executive Director. Author's Address Ralph Droms Cisco Systems 1414 Massachusetts Avenue Boxborough, MA 01719 USA Phone: +1 978 936 1674 EMail: rdroms@cisco.com Droms Informational [Page 7] RFC 3679 Unused DHCP Option Codes January 2004 Full Copyright Statement Copyright (C) The Internet Society (2004). All Rights Reserved. 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