RFC5494

Network Working Group J. Arkko Request for Comments: 5494 Ericsson Updates: 826, 951, 1044, 1329, 2131, C. Pignataro

     2132, 2176, 2225, 2834, 2835,                     Cisco Systems
     3315, 4338, 4361, 4701                               April 2009

Category: Standards Track

 IANA Allocation Guidelines for the Address Resolution Protocol (ARP)

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) 2009 IETF Trust and the persons identified as the document authors. All rights reserved.

This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents in effect on the date of publication of this document (http://trustee.ietf.org/license-info). Please review these documents carefully, as they describe your rights and restrictions with respect to this document.

Abstract

This document specifies the IANA guidelines for allocating new values in the Address Resolution Protocol (ARP). This document also reserves some numbers for experimentation purposes. The changes also affect other protocols that employ values from the ARP name spaces.

Introduction

This document specifies the IANA guidelines RFC5226 for allocating new values for various fields in the Address Resolution Protocol (ARP) RFC0826. The change is also applicable to extensions of ARP that use the same message format, such as RFC0903, RFC1931, and RFC2390.

The change also affects other protocols that employ values from the ARP name spaces. For instance, the ARP hardware address type (ar$hrd) number space is also used in the "htype" (hardware address type) fields in the Bootstrap Protocol (BOOTP) RFC0951 and Dynamic Host Configuration Protocol (DHCP) RFC2131, as well as in the "hardware type" field in the DHCP Unique Identifiers in DHCPv6 RFC3315. These protocols are therefore affected by the update in the IANA rules. Other affected specifications include the specialized address resolution mechanisms in:

o HYPERchannel RFC1044

o DHCP options RFC2132 RFC4361

o ATM (Asynchronous Transfer Mode) ARP RFC2225

o HARP (High-Performance Parallel Interface ARP) RFC2834 RFC2835

o Dual MAC (Media Access Control) FDDI (Fiber Distributed Data

  Interface) ARP RFC1329

o MAPOS (Multiple Access Protocol over Synchronous Optical Network/

  Synchronous Digital Hierarchy) ARP RFC2176

o FC (Fibre Channel) ARP RFC4338

o DNS DHCID Resource Record RFC4701

The IANA guidelines are given in Section 2. Previously, no IANA guidance existed for such allocations. The purpose of this document is to allow IANA to manage number assignments based on these guidelines in a consistent manner.

This document also reserves some numbers for experimentation purposes. These numbers are given in Section 3.

IANA Considerations

The following rules apply to the fields of ARP:

ar$hrd (16 bits) Hardware address space

  Requests for ar$hrd values below 256 or for a batch of more than
  one new value are made through Expert Review RFC5226.

  Note that certain protocols, such as BOOTP and DHCPv4, employ
  these values within an 8-bit field.  The expert should determine
  that a need to allocate the new values exists and that the
  existing values are insufficient to represent the new hardware
  address types.  The expert should also determine the applicability
  of the request and assign values higher than 255 for requests that
  do not apply to BOOTP/DHCPv4.  Similarly, the expert should assign
  1-octet values for requests that apply to BOOTP/DHCPv4, as for
  example the "IPsec tunnel" with value 31 RFC3456.  Conversely,
  ARP-only uses, without a foreseeable reason to use the same value
  in BOOTP/DHCPv4, should favor 2-octet values.

  Requests for individual new ar$hrd values that do not specify a
  value, or where the requested value is greater than 255, are made
  through First Come First Served RFC5226.  The assignment will
  always result in a 2-octet value.

ar$pro (16 bits) Protocol address space

  These numbers share the Ethertype space.  The Ethertype space is
  administered as described in RFC5342.

ar$op (16 bits) Opcode

  Requests for new ar$op values are made through IETF Review or IESG
  Approval RFC5226.

Allocations Defined in This Document

When testing new protocol extension ideas, it is often necessary to use an actual constant in order to use the new function, even when testing in a closed environment. This document reserves the following numbers for experimentation purposes in ARP:

o Two new ar$hrd values are allocated for experimental purposes:

  HW_EXP1 (36) and HW_EXP2 (256).  Note that these two new values
  were purposely chosen so that one would be below 256 and the other
  would be above 255, and so that there would be different values in
  the least and most significant octets.

o Two new values for the ar$op are allocated for experimental

  purposes: OP_EXP1 (24) and OP_EXP2 (25).

Note that Appendix B.2 of RFC5342 lists two Ethertypes that can be used for experimental purposes.

In addition, for both ar$hrd and ar$op, the values 0 and 65535 are marked as reserved. This means that they are not available for allocation.

Security Considerations

This specification does not change the security properties of the affected protocols.

However, a few words are necessary about the use of the experimental code points defined in Section 3. Potentially harmful side effects from the use of the experimental values need to be carefully evaluated before deploying any experiment across networks that the owner of the experiment does not entirely control. Guidance given in RFC3692 about the use of experimental values needs to be followed.

Acknowledgments

The lack of any current rules has come up as new values were requested from IANA, who contacted the IESG for advice. The author would like to thank Michelle Cotton in particular for bringing up this issue. The author would also like to thank Brian Carpenter, Thomas Narten, Scott Bradner, Donald Eastlake, Andrew G. Malis, Brian Haberman, Robert Sparks, Larry Zhu, and Dave Thaler for feedback.

References

Normative References

RFC0826 Plummer, D., "Ethernet Address Resolution Protocol: Or

          converting network protocol addresses to 48.bit Ethernet
          address for transmission on Ethernet hardware", STD 37,
          RFC 826, November 1982.

RFC0951 Croft, B. and J. Gilmore, "Bootstrap Protocol", RFC 951,

          September 1985.

RFC1044 Hardwick, K. and J. Lekashman, "Internet Protocol on

          Network System's HYPERchannel: Protocol specification",
          STD 45, RFC 1044, February 1988.

RFC1329 Kuehn, P., "Thoughts on Address Resolution for Dual MAC

          FDDI Networks", RFC 1329, May 1992.

RFC2131 Droms, R., "Dynamic Host Configuration Protocol",

          RFC 2131, March 1997.

RFC2132 Alexander, S. and R. Droms, "DHCP Options and BOOTP Vendor

          Extensions", RFC 2132, March 1997.

RFC2176 Murakami, K. and M. Maruyama, "IPv4 over MAPOS Version 1",

          RFC 2176, June 1997.

RFC2225 Laubach, M. and J. Halpern, "Classical IP and ARP over

          ATM", RFC 2225, April 1998.

RFC2834 Pittet, J., "ARP and IP Broadcast over HIPPI-800",

          RFC 2834, May 2000.

RFC2835 Pittet, J., "IP and ARP over HIPPI-6400 (GSN)", RFC 2835,

          May 2000.

RFC3315 Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C.,

          and M. Carney, "Dynamic Host Configuration Protocol for
          IPv6 (DHCPv6)", RFC 3315, July 2003.

RFC3692 Narten, T., "Assigning Experimental and Testing Numbers

          Considered Useful", BCP 82, RFC 3692, January 2004.

RFC4338 DeSanti, C., Carlson, C., and R. Nixon, "Transmission of

          IPv6, IPv4, and Address Resolution Protocol (ARP) Packets
          over Fibre Channel", RFC 4338, January 2006.

RFC4361 Lemon, T. and B. Sommerfeld, "Node-specific Client

          Identifiers for Dynamic Host Configuration Protocol
          Version Four (DHCPv4)", RFC 4361, February 2006.

RFC4701 Stapp, M., Lemon, T., and A. Gustafsson, "A DNS Resource

          Record (RR) for Encoding Dynamic Host Configuration
          Protocol (DHCP) Information (DHCID RR)", RFC 4701,
          October 2006.

RFC5226 Narten, T. and H. Alvestrand, "Guidelines for Writing an

          IANA Considerations Section in RFCs", BCP 26, RFC 5226,
          May 2008.

RFC5342 Eastlake. , D., "IANA Considerations and IETF Protocol

          Usage for IEEE 802 Parameters", BCP 141, RFC 5342,
          September 2008.

Informative References

RFC0903 Finlayson, R., Mann, T., Mogul, J., and M. Theimer,

          "Reverse Address Resolution Protocol", STD 38, RFC 903,
          June 1984.

RFC1931 Brownell, D., "Dynamic RARP Extensions for Automatic

          Network Address Acquisition", RFC 1931, April 1996.

RFC2390 Bradley, T., Brown, C., and A. Malis, "Inverse Address

          Resolution Protocol", RFC 2390, September 1998.

RFC3456 Patel, B., Aboba, B., Kelly, S., and V. Gupta, "Dynamic

          Host Configuration Protocol (DHCPv4) Configuration of
          IPsec Tunnel Mode", RFC 3456, January 2003.

Appendix A. Changes from the Original RFCs

This document specifies only the IANA rules associated with various fields in ARP. The specification of these rules also affects the allocation of corresponding fields in protocols listed in Section 1 that share the registry. This document does not make any changes in the operation of these protocols themselves.

Authors' Addresses

Jari Arkko Ericsson Jorvas 02420 Finland

EMail: [email protected]

Carlos Pignataro Cisco Systems 7200-12 Kit Creek Road Research Triangle Park, NC 27709 USA

EMail: [email protected]