IANA Considerations and IETF Protocol and Documentation Usage

for IEEE 802 Parameters

Abstract

Some IETF protocols make use of Ethernet frame formats and IEEE 802 parameters. This document discusses several uses of such parameters in IETF protocols, specifies IANA considerations for assignment of points under the IANA OUI (Organizationally Unique Identifier), and provides some values for use in documentation. This document obsoletes RFC 5342.

Status of This Memo

This memo documents an Internet Best Current Practice.

This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on BCPs is available in Section 2 of RFC 5741.

Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/rfc7042.

Copyright Notice

Copyright © 2013 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 (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.

Table of Contents

   1. Introduction ....................................................4
      1.1. Notations Used in This Document ............................4
      1.2. Changes from RFC 5342 ......................................5
      1.3. The IEEE Registration Authority ............................5
      1.4. The IANA OUI ...............................................5
   2. Ethernet Identifier Parameters ..................................5
      2.1. 48-Bit MAC Identifiers, OUIs, and Other Prefixes ...........6
           2.1.1. EUI-48 Assignments under the IANA OUI ...............6
           2.1.2. EUI-48 Documentation Values .........................7
           2.1.3. EUI-48 IANA Assignment Considerations ...............8
      2.2. 64-Bit MAC Identifiers .....................................8
           2.2.1. IPv6 Use of Modified EUI-64 Identifiers .............9
           2.2.2. EUI-64 IANA Assignment Considerations ..............10
           2.2.3. EUI-64 Documentation Values ........................12
      2.3. Other MAC-48 Identifiers Used by the IETF .................12
           2.3.1. Identifiers Prefixed "33-33" .......................12
           2.3.2. The 'CF Series' ....................................13
                  2.3.2.1. Changes to RFC 2153 .......................13
   3. Ethernet Protocol Parameters ...................................14
      3.1. Ethernet Protocol Assignment under the IANA OUI ...........16
      3.2. Documentation Protocol Number .............................16
   4. Other OUI-Based Parameters .....................................16
   5. IANA Considerations ............................................17
      5.1. Expert Review and IESG Ratification .......................17
      5.2. MAC Address AFNs and RRTYPEs ..............................19
      5.3. Informational IANA Web Page Material ......................19
      5.4. OUI Exhaustion ............................................19
      5.5. IANA OUI MAC Address Table ................................19
      5.6. SNAP Protocol Number Table and Assignment .................20
   6. Security Considerations ........................................20
   7. Acknowledgements ...............................................20
   8. References .....................................................21
      8.1. Normative References ......................................21
      8.2. Informative References ....................................21
   Appendix A. Templates .............................................24
      A.1. EUI-48/EUI-64 Identifier or Identifier Block Template .....24
      A.2. IANA OUI-Based Protocol Number Template ...................24
      A.3. Other IANA OUI-Based Parameter Template ...................25
   Appendix B. Ethertypes ............................................25
      B.1. Some Ethertypes Specified by the IETF .....................25
      B.2. Some IEEE 802 Ethertypes ..................................26
   Appendix C. Documentation Protocol Number .........................26

1. Introduction

Some IETF protocols use Ethernet or other IEEE 802-related communication frame formats and parameters [IEEE802]. These include MAC (Media Access Control) identifiers and protocol identifiers.

This document specifies IANA considerations for the assignment of code points under the IANA OUI. It also discusses several other uses by the IETF of IEEE 802 code points and provides some values for use in documentation. As noted in [RFC2606] and [RFC5737], the use of designated code values reserved for documentation and examples reduces the likelihood of conflicts and confusion arising from their duplication of code points assigned for some deployed use.

[RFC5226] is incorporated herein except where there are contrary provisions in this document. In this document, "IESG Ratification" is used in some cases, and it is specified in Section 5.1. This is not the same as "IESG Approval" in [RFC5226].

1.1. Notations Used in This Document

This document uses hexadecimal notation. Each octet (that is, 8-bit byte) is represented by two hexadecimal digits giving the value of the octet as an unsigned integer. Successive octets are separated by a hyphen. This document consistently uses IETF bit ordering although the physical order of bit transmission within an octet on an IEEE [802.3] link is from the lowest order bit to the highest order bit (i.e., the reverse of the IETF's ordering).

In this document:

   "AFN"    stands for Address Family Number [RFC4760].
   
   "EUI"    stands for Extended Unique Identifier.
   
   "IAB"    stands for Individual Address Block, not for Internet
            Architecture Board.
   
   "MAC"    stands for Media Access Control, not for Message
            Authentication Code.
   
   "OUI"    stands for Organizationally Unique Identifier.

"RRTYPE" stands for a DNS Resource Record type [RFC6895].

   "**"     indicates exponentiation.  For example, 2**24 is two to the
            twenty-fourth power.

1.2. Changes from RFC 5342

• Added MAC addresses and IANA OUI-based protocol and other values for use in documentation, and added relevant Security Considerations language.

• Eliminated any requirements for parallel unicast and multicast assignment unless requested. Such requirements had been included in [RFC5342] on the theory they would make bookkeeping easier for IANA but they have proved to be problematic in practice.

• Re-casted informational material about relevant IEEE assignment policies to take into account [RAC-OUI].

• Added AFNs and RRTYPEs for 48-bit and 64-bit MACs.

1.3. The IEEE Registration Authority

Originally the responsibility of Xerox Corporation, the registration authority for Ethernet parameters is now the IEEE Registration Authority, available on the web at:

      http://standards.ieee.org/regauth/

Anyone may apply to that Authority for parameters. They may impose fees or other requirements but commonly waive fees for applications from standards development organizations.

A list of some assignments and their holders is downloadable from the IEEE Registration Authority site.

1.4. The IANA OUI

The OUI 00-00-5E has been assigned to IANA.

There is no OUI value reserved at this time for documentation, but there are documentation code points under the IANA OUI specified below.

2. Ethernet Identifier Parameters

Section 2.1 discusses EUI-48 (Extended Unique Identifier 48) MAC identifiers, their relationship to OUIs and other prefixes, and assignments under the IANA OUI. Section 2.2 extends this to EUI-64 identifiers. Section 2.3 discusses other IETF MAC identifier use not under the IANA OUI.

[RAC-OUI] indicates that the IEEE Registration Authority Committee is exploring the feasibility of defining a new "EUI-128" identifier.

2.1. 48-Bit MAC Identifiers, OUIs, and Other Prefixes

48-bit MAC "addresses" are the most commonly used Ethernet interface identifiers. Those that are globally unique are also called EUI-48 identifiers. An EUI-48 is structured into an initial 3-octet OUI (Organizationally Unique Identifier) and an additional 3 octets assigned by the OUI holder or into a larger initial prefix assigned to an organization and a shorter sequence of additional bits so as to add up to 48 bits in total. For example, the IEEE has assigned IABs (Individual Address Blocks), where the first 4 1/2 octets (36 bits) are assigned, giving the holder of the IAB 1 1/2 octets (12 bits) they can control; however, IABs will become historic, and a wider range of prefix lengths will be made available [RAC-OUI].

The IEEE describes its assignment procedures and policies for IEEE 802-related identifiers in [802_O&A], which is being revised.

Two bits within the initial octet of an EUI-48 have special significance in MAC addresses: the Group bit (01) and the Local bit (02). OUIs and longer MAC prefixes are assigned with the Local bit zero and the Group bit unspecified. Multicast identifiers may be constructed by turning on the Group bit, and unicast identifiers may be constructed by leaving the Group bit zero.

The Local bit is zero for globally unique EUI-48 identifiers assigned by the owner of an OUI or owner of a longer prefix. If the Local bit is a one, the identifier has been considered by IEEE 802 to be a local identifier under the control of the local network administrator; however, there may be emerging recommendations from the IEEE Registration Authority on management of the local address space. If the Local bit is on, the holder of an OUI has no special authority over MAC identifiers whose first 3 octets correspond to their OUI.

An AFN and a DNS RRTYPE have been assigned for 48-bit MAC addresses (see Section 5.2).

2.1.1. EUI-48 Assignments under the IANA OUI

   The OUI 00-00-5E has been assigned to IANA as stated in Section 1.4
   above.  This includes 2**24 EUI-48 multicast identifiers from
   01-00-5E-00-00-00 to 01-00-5E-FF-FF-FF and 2**24 EUI-48 unicast
   identifiers from 00-00-5E-00-00-00 to 00-00-5E-FF-FF-FF.

Of these EUI-48 identifiers, the sub-blocks reserved or thus far assigned by IANA for purposes of documentation are as follows:

Unicast, all blocks of 2**8 addresses thus far:

      00-00-5E-00-00-00 through 00-00-5E-00-00-FF: reserved and require
      
         IESG Ratification for assignment (see Section 5.1).
      
      00-00-5E-00-01-00 through 00-00-5E-00-01-FF: assigned for the
         Virtual Router Redundancy Protocol (VRRP) [RFC5798].
      
      00-00-5E-00-02-00 through 00-00-5E-00-02-FF: assigned for the IPv6
         Virtual Router Redundancy Protocol (IPv6 VRRP) [RFC5798].
      
      00-00-5E-00-52-00 through 00-00-5E-00-52-FF: used for very small
         assignments.  Currently, 3 out of these 256 values have been
         assigned.
      
      00-00-5E-00-53-00 through 00-00-5E-00-53-FF: assigned for use in
         documentation.

Multicast:

      01-00-5E-00-00-00 through 01-00-5E-7F-FF-FF: 2**23 addresses
         assigned for IPv4 multicast [RFC1112].
      
      01-00-5E-80-00-00 through 01-00-5E-8F-FF-FF: 2**20 addresses
         assigned for MPLS multicast [RFC5332].
      
      01-00-5E-90-00-00 through 01-00-5E-90-00-FF: 2**8 addresses being
         used for very small assignments.  Currently, 4 out of these 256
         values have been assigned.
      
      01-00-5E-90-10-00 through 01-00-5E-90-10-FF: 2**8 addresses for
         use in documentation.
   
   For more detailed and up-to-date information, see the "Ethernet
   Numbers" registry at http://www.iana.org.

2.1.2. EUI-48 Documentation Values

The following values have been assigned for use in documentation:

      00-00-5E-00-53-00 through 00-00-5E-00-53-FF for unicast and

01-00-5E-90-10-00 through 01-00-5E-90-10-FF for multicast.

2.1.3. EUI-48 IANA Assignment Considerations

EUI-48 assignments under the current or a future IANA OUI (see Section 5.4) must meet the following requirements:

• must be for standards purposes (either for an IETF Standard or other standard related to IETF work),

• must be for a power-of-two size block of identifiers starting at a boundary that is an equal or greater power of two, including the assignment of one (2**0) identifier,

• must not be used to evade the requirement for vendors to obtain their own block of identifiers from the IEEE, and

• must be documented in an Internet-Draft or RFC.

In addition, approval must be obtained as follows (see the procedure in Section 5.1):

      Small to medium assignments of a block of 1, 2, 4, ..., 32768,
         65536 (2**0, 2**1, 2**2, ..., 2**15, 2**16) EUI-48 identifiers
         require Expert Review (see Section 5.1).
      
      Large assignments of 131072 (2**17) or more EUI-48 identifiers
         require IESG Ratification (see Section 5.1).

([RFC5342] had a requirement for parallel unicast and multicast assignments under some circumstances even when one of the types was not included in the application. That requirement has proved impractical and is eliminated in this document.)

2.2. 64-Bit MAC Identifiers

IEEE also defines a system of 64-bit MAC identifiers including EUI-64s. EUI-64 identifiers are currently used as follows:

• In a modified form to construct some IPv6 interface identifiers as described in Section 2.2.1

• In IEEE Std 1394 (also known as FireWire and i.Link)

• In IEEE Std 802.15.4 (also known as ZigBee)

• In [InfiniBand]

Adding a 5-octet (40-bit) extension to a 3-octet (24-bit) OUI, or a shorter extension to longer assigned prefixes [RAC-OUI] so as to total 64 bits, produces an EUI-64 identifier under that OUI or longer prefix. As with EUI-48 identifiers, the first octet has the same Group and Local bits.

An AFN and a DNS RRTYPE have been assigned for 64-bit MAC addresses (see Section 5.2).

The discussion below is almost entirely in terms of the "Modified" form of EUI-64 identifiers; however, anyone assigned such an identifier can also use the unmodified form as a MAC identifier on any link that uses such 64-bit identifiers for interfaces.

2.2.1. IPv6 Use of Modified EUI-64 Identifiers

MAC-64 identifiers are used to form the lower 64 bits of some IPv6 addresses (Section 2.5.1 and Appendix A of [RFC4291] and Appendix A of [RFC5214]). When so used, the MAC-64 is modified by inverting the Local/Global bit to form an IETF "Modified EUI-64 identifier". Below is an illustration of a Modified EUI-64 unicast identifier under the IANA OUI, where aa-bb-cc-dd-ee is the extension.

      02-00-5E-aa-bb-cc-dd-ee

The first octet is shown as 02 rather than 00 because, in Modified EUI-64 identifiers, the sense of the Local/Global bit is inverted compared with EUI-48 identifiers. It is the globally unique values (universal scope) that have the 02 bit on in the first octet, while those with this bit off are locally assigned and out of scope for global assignment.

   The Local/Global bit was inverted to make it easier for network
   operators to type in local-scope identifiers.  Thus, such Modified
   EUI-64 identifiers as 1, 2, etc. (ignoring leading zeros) are local.
   Without the modification, they would have to be
   02-00-00-00-00-00-00-01, 02-00-00-00-00-00-00-02, etc. to be local.

As with MAC-48 identifiers, the 01 bit on in the first octet indicates a group identifier.

When the first two octets of the extension of a Modified EUI-64 identifier are FF-FE, the remainder of the extension is a 24-bit value as assigned by the OUI owner for an EUI-48. For example:

      02-00-5E-FF-FE-yy-yy-yy
   or
      03-00-5E-FF-FE-yy-yy-yy

where yy-yy-yy is the portion (of an EUI-48 global unicast or multicast identifier) that is assigned by the OUI owner (IANA in this case). Thus, any holder of one or more EUI-48 identifiers under the IANA OUI also has an equal number of Modified EUI-64 identifiers that can be formed by inserting FF-FE in the middle of their EUI-48 identifiers and inverting the Local/Global bit.

(Note: [EUI-64] defines FF-FF as the bits to be inserted to create an IEEE EUI-64 identifier from a MAC-48 identifier. That document says the FF-FE value is used when starting with an EUI-48 identifier. The IETF uses only FF-FE to create Modified EUI-64 identifiers from 48-bit Ethernet station identifiers regardless of whether they are EUI-48 or MAC-48 local identifiers. EUI-48 and local MAC-48 identifiers are syntactically equivalent, and this doesn't cause any problems in practice.)

In addition, certain Modified EUI-64 identifiers under the IANA OUI are reserved for holders of IPv4 addresses as follows:

      02-00-5E-FE-xx-xx-xx-xx

where xx-xx-xx-xx is a 32-bit IPv4 address. The owner of an IPv4 address has both the unicast- and multicast-derived EUI-64 address. Modified EUI-64 identifiers from

      02-00-5E-FE-F0-00-00-00 to 02-00-5E-FE-FF-FF-FF-FF

are effectively reserved pending the specification of IPv4 Class E addresses. However, for Modified EUI-64 identifiers based on an IPv4 address, the Local/Global bit should be set to correspond to whether the IPv4 address is local or global. (Keep in mind that the sense of the Modified EUI-64 identifier Local/Global bit is reversed from that in (unmodified) MAC-64 identifiers.)

2.2.2. EUI-64 IANA Assignment Considerations

The following table shows which Modified EUI-64 identifiers under the IANA OUI are reserved, assigned, or available as indicated. As noted above, the corresponding MAC addresses can be determined by complementing the 02 bit in the first octet. In all cases, the corresponding multicast 64-bit MAC addresses formed by complementing the 01 bit in the first octet have the same status as the modified 64-bit unicast address blocks listed below.

      02-00-5E-00-00-00-00-00 to 02-00-5E-0F-FF-FF-FF-FF reserved
      
      02-00-5E-10-00-00-00-00 to 02-00-5E-10-00-00-00-FF assigned for
         documentation use
      
      02-00-5E-10-00-00-01-00 to 02-00-5E-EF-FF-FF-FF-FF, which is
         available for assignment
      
      02-00-5E-F0-00-00-00-00 to 02-00-5E-FD-FF-FF-FF-FF reserved
      
      02-00-5E-FE-00-00-00-00 to 02-00-5E-FE-FF-FF-FF-FF assigned to
         IPv4 address holders as described above
      
      02-00-5E-FF-00-00-00-00 to 02-00-5E-FF-FD-FF-FF-FF reserved
      
      02-00-5E-FF-FE-00-00-00 to 02-00-5E-FF-FE-FF-FF-FF assigned for
         holders of EUI-48 identifiers under the IANA OUI as described
         above
      
      02-00-5E-FF-FF-00-00-00 to 02-00-5E-FF-FF-FF-FF-FF reserved

The reserved identifiers above require IESG Ratification (see Section 5.1) for assignment. IANA EUI-64 identifier assignments under the IANA OUI must meet the following requirements:

• must be for standards purposes (either for an IETF Standard or other standard related to IETF work),

• must be for a power-of-two size block of identifiers starting at a boundary that is an equal or greater power of two, including the assignment of one (2**0) identifier,

• must not be used to evade the requirement for vendors to obtain their own block of identifiers from the IEEE, and

• must be documented in an Internet-Draft or RFC.

In addition, approval must be obtained as follows (see the procedure in Section 5.1):

      Small to medium assignments of a block of 1, 2, 4, ..., 134217728,
         268435456 (2**0, 2**1, 2**2, ..., 2**27, 2**28) EUI-64
         identifiers require Expert Review (see Section 5.1).
      
      Assignments of any size, including 536870912 (2**29) or more
         EUI-64 identifiers, may be made with IESG Ratification (see
         Section 5.1).

2.2.3. EUI-64 Documentation Values

The following blocks of unmodified 64-bit MAC addresses are for documentation use. The IPv4-derived addresses are based on the IPv4 documentation addresses [RFC5737], and the MAC-derived addresses are based on the EUI-48 documentation addresses above.

Unicast:

      00-00-5E-EF-10-00-00-00 to 00-00-5E-EF-10-00-00-FF general
      
      00-00-5E-FE-C0-00-02-00 to 00-00-5E-FE-C0-00-02-FF and
      00-00-5E-FE-C6-33-64-00 to 00-00-5E-FE-C6-33-64-FF and
      00-00-5E-FE-CB-00-71-00 to 00-00-5E-FE-CB-00-71-FF IPv4 derived
      
      00-00-5E-FF-FE-00-53-00 to 00-00-5E-FF-FE-00-53-FF EUI-48 derived
      
      00-00-5E-FE-EA-C0-00-02 and
      00-00-5E-FE-EA-C6-33-64 and
      00-00-5E-FE-EA-CB-00-71 IPv4 multicast derived from IPv4 unicast
         [RFC6034]

Multicast:

      01-00-5E-EF-10-00-00-00 to 01-00-5E-EF-10-00-00-FF general
      
      01-00-5E-FE-C0-00-02-00 to 01-00-5E-FE-C0-00-02-FF and
      01-00-5E-FE-C6-33-64-00 to 01-00-5E-FE-C6-33-64-FF and
      01-00-5E-FE-CB-00-71-00 to 01-00-5E-FE-CB-00-71-FF IPv4 derived
      
      01-00-5E-FE-EA-C0-00-02 and
      01-00-5E-FE-EA-C6-33-64 and
      01-00-5E-FE-EA-CB-00-71 IPv4 multicast derived from IPv4 unicast
         [RFC6034]
      
      01-00-5E-FF-FE-90-10-00 to 01-00-5E-FF-FE-90-10-FF EUI-48 derived

2.3. Other MAC-48 Identifiers Used by the IETF

There are two other blocks of MAC-48 identifiers that are used by the IETF as described below.

2.3.1. Identifiers Prefixed "33-33"

   All MAC-48 multicast identifiers prefixed "33-33" (that is, the 2**32
   multicast MAC identifiers in the range from 33-33-00-00-00-00 to
   33-33-FF-FF-FF-FF) are used as specified in [RFC2464] for IPv6
   multicast.  In all of these identifiers, the Group bit (the bottom

bit of the first octet) is on, as is required to work properly with existing hardware as a multicast identifier. They also have the Local bit on and are used for this purpose in IPv6 networks.

(Historical note: It was the custom during IPv6 design to use "3" for unknown or example values, and 3333 Coyote Hill Road, Palo Alto, California, is the address of PARC (Palo Alto Research Center, formerly "Xerox PARC"). Ethernet was originally specified by the Digital Equipment Corporation, Intel Corporation, and Xerox Corporation. The pre-IEEE [802.3] Ethernet protocol has sometimes been known as "DIX" Ethernet from the first letters of the names of these companies.)

2.3.2. The 'CF Series'

The Informational [RFC2153] declared the 3-octet values from CF-00-00 through CF-FF-FF to be OUIs available for assignment by IANA to software vendors for use in PPP [RFC1661] or for other uses where vendors do not otherwise need an IEEE-assigned OUI. It should be noted that, when used as MAC-48 prefixes, these values have the Local and Group bits on, while all IEEE-assigned OUIs thus far have those bits off. The Group bit is meaningless in PPP. To quote [RFC2153]: "The 'CF0000' series was arbitrarily chosen to match the PPP NLPID 'CF', as a matter of mnemonic convenience."

      CF-00-00 is reserved, and IANA lists multicast identifier
      CF-00-00-00-00-00 as used for Ethernet loopback tests.
   
   In over a decade of availability, only a handful of values in the
   'CF Series' have been assigned.  (See "Ethernet Numbers"
   <http://www.iana.org/assignments/ethernet-numbers> and "PPP Numbers"
   <http://www.iana.org/assignments/ppp-numbers>).

2.3.2.1. Changes to RFC 2153

The IANA Considerations in [RFC2153] were updated as follows by the approval of [RFC5342] (no technical changes were made at that time):

• Use of these identifiers based on IANA assignment was deprecated.

• IANA was instructed not to assign any further values in the 'CF Series'.

3. Ethernet Protocol Parameters

Ethernet protocol parameters provide a means of indicating the contents of a frame -- for example, that its contents are IPv4 or IPv6.

The concept has been extended to labeling by "tags". A tag in this sense is a prefix whose type is identified by an Ethertype that is then followed by either another tag, an Ethertype, or an LSAP (Link- Layer Service Access Point) protocol indicator for the "main" body of the frame, as described below. Traditionally, in the [802_O&A] world, tags are a fixed length and do not include any encoding of their own length. Any device that is processing a frame cannot, in general, safely process anything in the frame past an Ethertype it does not understand. An example is the C-Tag (formerly the Q-Tag) [802.1Q]. It provides customer VLAN and priority information for a frame.

There are two types of protocol identifier parameters that can occur in Ethernet frames after the initial MAC-48 destination and source identifiers:

Ethertypes: These are 16-bit identifiers appearing as the initial

two octets after the MAC destination and source (or after a tag), which, when considered as an unsigned integer, are equal to or larger than 0x0600.

LSAPs: These are 8-bit protocol identifiers that occur in pairs

immediately after an initial 16-bit (two-octet) remaining frame length, which is in turn after the MAC destination and source (or after a tag). Such a length must, when considered as an unsigned integer, be less than 0x5DC, or it could be mistaken as an Ethertype. LSAPs occur in pairs where one is intended to indicate the source protocol handler and one the destination protocol handler; however, use cases where the two are different have been relatively rare.

Neither Ethertypes nor LSAPs are assigned by IANA; they are assigned by the IEEE Registration Authority (see Section 1.3 above and Appendix B). However, both LSAPs and Ethertypes have extension mechanisms so that they can be used with five-octet Ethernet protocol identifiers under an OUI, including those assigned by IANA under the IANA OUI.

When using the IEEE 802 Logical Link Control (LLC) format (Subnetwork Access Protocol (SNAP)) [802_O&A] for a frame, an OUI-based protocol identifier can be expressed as follows:

      xx-xx-AA-AA-03-yy-yy-yy-zz-zz

where xx-xx is the frame length and, as above, must be small enough not to be confused with an Ethertype; "AA" is the LSAP that indicates this use and is sometimes referred to as the SNAP Service Access Point (SAP); "03" is the LLC control octet indicating datagram service; yy-yy-yy is an OUI; and zz-zz is a protocol number, under that OUI, assigned by the OUI owner. The odd five-octet length for such OUI-based protocol identifiers was chosen so that, with the LLC control octet ("03"), the result is 16-bit aligned.

When using an Ethertype to indicate the main type for a frame body, the special "OUI Extended Ethertype" 88-B7 is available. Using this Ethertype, a frame body can begin with

      88-B7-yy-yy-yy-zz-zz

where yy-yy-yy and zz-zz have the same meaning as in the SNAP format described above.

It is also possible, within the SNAP format, to use an arbitrary Ethertype. Putting the Ethertype as the zz-zz field after an all- zeros OUI (00-00-00) does this. It looks like

      xx-xx-AA-AA-03-00-00-00-zz-zz

where zz-zz is the Ethertype.

(Note that, at this point, the 802 protocol syntax facilities are sufficiently powerful that they could be chained indefinitely. Whether support for such chaining is generally required is not clear, but [802_O&A] requires support for

         xx-xx-AA-AA-03-00-00-00-88-B7-yy-yy-yy-zz-zz

although this could be more efficiently expressed by simply pinching out the "00-00-00-88-B7" in the middle.)

As well as labeling frame contents, 802 protocol types appear within NBMA (Non-Broadcast Multi-Access) Next Hop Resolution Protocol [RFC2332] messages. Such messages have provisions for both two-octet Ethertypes and OUI-based protocol types.

3.1. Ethernet Protocol Assignment under the IANA OUI

Two-octet protocol numbers under the IANA OUI are available, as in

      xx-xx-AA-AA-03-00-00-5E-qq-qq

where qq-qq is the protocol number.

A number of such assignments have been made out of the 2**16 protocol numbers available from 00-00-5E-00-00 to 00-00-5E-FF-FF (see [IANA]). The extreme values of this range, 00-00-5E-00-00 and 00-00-5E-FF-FF, are reserved and require IESG Ratification for assignment (see Section 5.1). New assignments of SNAP SAP protocol (qq-qq) numbers under the IANA OUI must meet the following requirements:

• the assignment must be for standards use (either for an IETF Standard or other standard related to IETF work),

• it must be documented in an Internet-Draft or RFC, and

• such protocol numbers are not to be assigned for any protocol that has an Ethertype (because that can be expressed by putting an all-zeros "OUI" before the Ethertype as described above).

In addition, the Expert Review (or IESG Ratification for the two reserved values) must be obtained using the procedure specified in Section 5.1.

3.2. Documentation Protocol Number

0x0042 is a protocol number under the IANA OUI (that is, 00-00-5E-00-42) to be used for documentation purposes.

4. Other OUI-Based Parameters

Some IEEE 802 and other protocols provide for parameters based on an OUI beyond those discussed above. Such parameters most commonly consist of an OUI plus one octet of additional value. They are usually called "vendor specific" parameters, although "organization specific" might be more accurate. They would look like

      yy-yy-yy-zz

where yy-yy-yy is the OUI and zz is the additional specifier. An example is the Cipher Suite Selector in IEEE [802.11].

Values may be assigned under the IANA OUI for such other OUI-based parameter usage by Expert Review except that, for each use, the additional specifier values consisting of all zero bits and all one bits (0x00 (00-00-5E-00) and 0xFF (00-00-5E-FF) for a one-octet specifier) are reserved and require IESG Ratification (see Section 5.1) for assignment; also, the additional specifier value 0x42 (00-00-5E-42) is assigned for use in documentation.

Assignments of such other IANA OUI-based parameters must be for standards use (either for an IETF Standard or other standard related to IETF work) and be documented in an Internet-Draft or RFC. The first time a value is assigned for a particular parameter of this type, an IANA registry will be created to contain that assignment and any subsequent assignments of values for that parameter under the IANA OUI. The Expert will specify the name of the registry.

If different policies from those above are required for such a parameter, a BCP or Standards Track RFC must be adopted to update this BCP and specify the new policy and parameter.

5. IANA Considerations

The entirety of this document concerns IANA considerations for the assignment of Ethernet parameters in connection with the IANA OUI and related matters.

As this document replaces [RFC5342], references to [RFC5342] in IANA registries have been replaced by references to this document. In addition, any references in the registries to [DOC-ADDR], which has been combined into this document, have been replaced by references to this document.

This document does not create any new IANA registries.

This document assigns MAC address values for documentation. These values had been previously assigned by [DOC-ADDR]; as noted above, any references in the registries to [DOC-ADDR] have been replaced by references to this document.

The only other assignment that has been made by this document is a protocol number for documentation. See Section 5.6 for details.

No existing assignment is changed by this document.

5.1. Expert Review and IESG Ratification

This section specifies the procedure for Expert Review and IESG Ratification of MAC, protocol, and other IANA OUI-based identifiers. The Expert(s) referred to in this document shall consist of one or more persons appointed by and serving at the pleasure of the IESG.

The procedure described for Expert Review assignments in this document is fully consistent with the IANA Expert Review policy described in [RFC5226].

While finite, the universe of code points from which Expert-judged assignments will be made is felt to be large enough that the requirements given in this document and the Experts' good judgment are sufficient guidance. The idea is for the Expert to provide a light sanity check for small assignments of EUI identifiers, with increased scrutiny by the Expert for medium-sized assignments of EUI identifiers and assignments of protocol identifiers and other IANA OUI-based parameters. However, it can make sense to assign very large portions of the MAC identifier code point space. (Note that existing assignments include one for 1/2 of the entire multicast IANA EUI-48 code point space and one for 1/16 of that multicast code point space.) In those cases, and in cases of the assignment of "reserved" values, IESG Ratification of an Expert Review approval recommendation is required as described below. The procedure is as follows:

The applicant always completes the appropriate template from

Appendix A below and sends it to IANA <iana@iana.org>.

IANA always sends the template to an appointed Expert. If the

Expert recuses themselves or is non-responsive, IANA may choose an alternative appointed Expert or, if none is available, will contact the IESG.

In all cases, if IANA receives a disapproval from an Expert

selected to review an application template, the application will be denied.

If the assignment is based on Expert Review:

If IANA receives approval and code points are available, IANA will make the requested assignment.

If the assignment is based on IESG Ratification:

The procedure starts with the first steps above for Expert Review. If the Expert disapproves the application, they simply inform IANA; however, if the Expert believes the application should be approved, or is uncertain and believes that the circumstances warrant the attention of the IESG, the Expert will inform IANA about their advice, and IANA will forward the application, together with the reasons for approval or uncertainty, to the IESG. The IESG must decide whether the assignment will be granted. This can be accomplished by a management item in an IESG telechat as is done for other types of requests. If the IESG decides not to ratify a favorable opinion by the Expert or decides against an application where the Expert is uncertain, the application is denied; otherwise, it is granted. The IESG will communicate its decision to the Expert and to IANA.

5.2. MAC Address AFNs and RRTYPEs

IANA has assigned Address Family Numbers (AFNs) for MAC addresses as follows:

         AFN         Decimal     Hex      Reference
      ----------     -------    ------    ---------
      48-bit MAC      16389     0x4005    [RFC7042]
      64-bit MAC      16390     0x4006    [RFC7042]

IANA has assigned DNS RRTYPEs [RFC6895] for MAC addresses as follows:

                                RRTYPE Code
         Data       Mnemonic   Decimal   Hex      Reference
      ----------    --------   -------  ------   -----------
      48-bit MAC     EUI48       108    0x006C   [RFC7043]
      64-bit MAC     EUI64       109    0x006D   [RFC7043]

5.3. Informational IANA Web Page Material

IANA maintains an informational listing on its web site concerning Ethertypes, OUIs, and multicast addresses assigned under OUIs other than the IANA OUI. The title of this informational registry is "IEEE 802 Numbers". IANA has merged in those Ethertypes listed in Appendix B that were not already included. IANA will update that informational registry when changes are provided by the Expert.

5.4. OUI Exhaustion

When the available space for either multicast or unicast EUI-48 identifiers under OUI 00-00-5E has been 90% or more exhausted, IANA should request an additional OUI from the IEEE Registration Authority for further IANA assignment. The appointed Expert(s) should monitor for this condition and notify IANA.

5.5. IANA OUI MAC Address Table

No changes have been made in the "IANA Unicast 48-bit MAC Addresses" and "IANA Multicast 48-bit MAC Addresses" tables except for the updates to references as specified in the first part of Section 5.

5.6. SNAP Protocol Number Table and Assignment

The "SNAP PROTOCOL IDs" table has been renamed the "SNAP Protocol Numbers" table. "PID" has been replaced by "Protocol Number".

IANA has assigned 0x0042 as the SNAP protocol number under the IANA OUI to be used for documentation purposes.

6. Security Considerations

This document is concerned with assignment of parameters under the IANA OUI and closely related matters. It is not directly concerned with security except as follows.

Confusion and conflict can be caused by the use of MAC addresses or other OUI-derived protocol parameters as examples in documentation. Examples used "only" in documentation can end up being coded and released or cause conflicts due to later real use and the possible acquisition of intellectual property rights in such addresses or parameters. The reservation herein of MAC addresses and parameters for documentation purposes will minimize such confusion and conflict.

See [RFC7043] for security considerations in storing MAC addresses in the DNS.

7. Acknowledgements

The comments and suggestions of the following people, listed in alphabetic order, are gratefully acknowledged:

This document:

David Black, Adrian Farrel, Bob Grow, Joel Jaeggli, Pearl Liang, Glenn Parsons, Pete Resnick, and Dan Romascanu.

RFC 5342:

Bernard Aboba, Scott O. Bradner, Ian Calder, Michelle Cotton, Lars Eggert, Eric Gray, Alfred Hoenes, Russ Housley, Charlie Kaufman, Erik Nordmark, Dan Romascanu, Geoff Thompson, and Mark Townsley.

8. References

8.1. Normative References

   [802_O&A]  "IEEE Standard for Local and Metropolitan Area Networks:
              Overview and Architecture", IEEE Std 802-2001, 8 March
              2002.

"IEEE Standard for Local and Metropolitan Area Networks: Overview and Architecture / Amendment 1: Ethertypes for Prototype and Vendor-Specific Protocol Development", IEEE Std 802a-2003, 18 September 2003.

   [RFC5226]  Narten, T. and H. Alvestrand, "Guidelines for Writing an
              IANA Considerations Section in RFCs", BCP 26, RFC 5226,
              May 2008.

8.2. Informative References

   [802.1Q]   "IEEE Standard for Local and metropolitan area networks /
              Media Access Control (MAC) Bridges and Virtual Bridge
              Local Area Networks", IEEE Std 802.1Q-2011, 31 August
              2011.
   
   [802.3]   "IEEE Standard for Ethernet", IEEE Std 802.3-2012, 28
              December 2012.
   
   [802.11]   "IEEE Standard for Information technology /
              Telecommunications and information exchange between
              systems / Local and metropolitan area networks / Specific
              requirements / Part 11: Wireless LAN Medium Access Control
              (MAC) and Physical Layer (PHY) Specifications", IEEE Std
              802.11-2012, 29 March 2012.
   
   [DOC-ADDR] Abley, J., "EUI-48 and EUI-64 Address Assignments for use
              in Documentation", Work in Progress, March 2013.
   
   [EUI-64]   IEEE Registration Authority, "Guidelines for 64-bit Global
              Identifier (EUI-64(TM))", <http://standards.ieee.org/
              regauth/oui/tutorials/EUI64.html>, November 2012.
   
   [IANA]     Internet Assigned Numbers Authority,
              <http://www.iana.org>.
   
   [IEEE802]  IEEE 802 LAN/MAN Standards Committee,
              <http://www.ieee802.org>.

[InfiniBand]

InfiniBand Trade Association, "InfiniBand Architecture Specification Volume 1", November 2007.

   [RAC-OUI]  Parsons, G., "OUI Registry Restructuring", Work in
              Progress, September 2013.
   
   [RFC1112]  Deering, S., "Host extensions for IP multicasting", STD 5,
              RFC 1112, August 1989.
   
   [RFC1661]  Simpson, W., Ed., "The Point-to-Point Protocol (PPP)", STD
              51, RFC 1661, July 1994.
   
   [RFC2153]  Simpson, W., "PPP Vendor Extensions", RFC 2153, May 1997.
   
   [RFC2332]  Luciani, J., Katz, D., Piscitello, D., Cole, B., and N.
              Doraswamy, "NBMA Next Hop Resolution Protocol (NHRP)", RFC
              2332, April 1998.
   
   [RFC2464]  Crawford, M., "Transmission of IPv6 Packets over Ethernet
              Networks", RFC 2464, December 1998.
   
   [RFC2606]  Eastlake 3rd, D. and A. Panitz, "Reserved Top Level DNS
              Names", BCP 32, RFC 2606, June 1999.
   
   [RFC3092]  Eastlake 3rd, D., Manros, C., and E. Raymond, "Etymology
              of "Foo"", RFC 3092, April 1 2001.
   
   [RFC4291]  Hinden, R. and S. Deering, "IP Version 6 Addressing
              Architecture", RFC 4291, February 2006.
   
   [RFC4760]  Bates, T., Chandra, R., Katz, D., and Y. Rekhter,
              "Multiprotocol Extensions for BGP-4", RFC 4760, January
              2007.
   
   [RFC5214]  Templin, F., Gleeson, T., and D. Thaler, "Intra-Site
              Automatic Tunnel Addressing Protocol (ISATAP)", RFC 5214,
              March 2008.
   
   [RFC5332]  Eckert, T., Rosen, E., Ed., Aggarwal, R., and Y. Rekhter,
              "MPLS Multicast Encapsulations", RFC 5332, August 2008.
   
   [RFC5342]  Eastlake 3rd, D., "IANA Considerations and IETF Protocol
              Usage for IEEE 802 Parameters", BCP 141, RFC 5342,
              September 2008.
   
   [RFC5737]  Arkko, J., Cotton, M., and L. Vegoda, "IPv4 Address Blocks
              Reserved for Documentation", RFC 5737, January 2010.
   
   [RFC5798]  Nadas, S., Ed., "Virtual Router Redundancy Protocol (VRRP)
              Version 3 for IPv4 and IPv6", RFC 5798, March 2010.
   
   [RFC6034]  Thaler, D., "Unicast-Prefix-Based IPv4 Multicast
              Addresses", RFC 6034, October 2010.
   
   [RFC6895]  Eastlake 3rd, D., "Domain Name System (DNS) IANA
              Considerations", BCP 42, RFC 6895, April 2013.
   
   [RFC7043]  Abley, J., "Resource Records for EUI-48 and EUI-64
              Addresses in the DNS", RFC 7043, October 2013.

Appendix A. Templates

This appendix provides the specific templates for IANA assignments of parameters. Explanatory words in parentheses in the templates below may be deleted in a completed template as submitted to IANA.

A.1. EUI-48/EUI-64 Identifier or Identifier Block Template

Applicant Name:

Applicant Email:

Applicant Telephone: (starting with country code)

Use Name: (brief name of Parameter use such as "Foo Protocol" [RFC3092])

Document: (ID or RFC specifying use to which the identifier or block of identifiers will be put.)

Specify whether this is an application for EUI-48 or EUI-64 identifiers:

   Size of Block requested: (must be a power-of-two-sized block, can be
   a block of size one (2**0))

Specify multicast, unicast, or both:

A.2. IANA OUI-Based Protocol Number Template

Applicant Name:

Applicant Email:

Applicant Telephone: (starting with country code)

Use Name: (brief name of use of code point such as "Foo Protocol")

Document: (ID or RFC specifying use to which the protocol identifier will be put.)

Note:

         (any additional note)

A.3. Other IANA OUI-Based Parameter Template

Applicant Name:

Applicant Email:

Applicant Telephone: (starting with country code)

Protocol where the OUI-Based Parameter for which a value is being requested appears: (such as: Cipher Suite selection in IEEE 802.11)

Use Name: (brief name of use of code point to be assigned, such as "Foo Cipher Suite" [RFC3092])

Document: (ID or RFC specifying use to which the other IANA OUI-based parameter value will be put.)

Note:

         (any additional note)

Appendix B. Ethertypes

This appendix lists some Ethertypes specified for IETF protocols or by IEEE 802 as known at the time of publication. A more up-to-date list may be available on the IANA web site, currently at [IANA]. The IEEE Registration Authority page of Ethertypes, http://standards.ieee.org/regauth/ethertype/eth.txt, may also be useful. See Section 3 above.

B.1. Some Ethertypes Specified by the IETF

   0x0800  Internet Protocol Version 4 (IPv4)
   0x0806  Address Resolution Protocol (ARP)
   0x0808  Frame Relay ARP
   0x22F3  TRILL
   0x22F4  L2-IS-IS
   0x8035  Reverse Address Resolution Protocol (RARP)
   0x86DD  Internet Protocol Version 6 (IPv6)
   0x880B  Point-to-Point Protocol (PPP)
   0x880C  General Switch Management Protocol (GSMP)
   0x8847  MPLS
   0x8848  MPLS with upstream-assigned label
   0x8861  Multicast Channel Allocation Protocol (MCAP)
   0x8863  PPP over Ethernet (PPPoE) Discovery Stage
   0x8864  PPP over Ethernet (PPPoE) Session Stage
   0x893B  TRILL Fine Grained Labeling (FGL)
   0x8946  TRILL RBridge Channel

B.2. Some IEEE 802 Ethertypes

   0x8100  IEEE Std 802.1Q   - Customer VLAN Tag Type (C-Tag, formerly
                                called the Q-Tag) (initially Wellfleet)
   0x8808  IEEE Std 802.3    - Ethernet Passive Optical Network (EPON)
   0x888E  IEEE Std 802.1X   - Port-based network access control
   0x88A8  IEEE Std 802.1Q   - Service VLAN tag identifier (S-Tag)
   0x88B5  IEEE Std 802      - Local Experimental Ethertype
   0x88B6  IEEE Std 802      - Local Experimental Ethertype
   0x88B7  IEEE Std 802      - OUI Extended Ethertype
   0x88C7  IEEE Std 802.11   - Pre-Authentication (802.11i)
   0x88CC  IEEE Std 802.1AB  - Link Layer Discovery Protocol (LLDP)
   0x88E5  IEEE Std 802.1AE  - Media Access Control Security
   0x88F5  IEEE Std 802.1Q   - Multiple VLAN Registration Protocol
                                (MVRP)
   0x88F6  IEEE Std 802.1Q   - Multiple Multicast Registration
                                Protocol (MMRP)
   0x890D  IEEE Std 802.11   - Fast Roaming Remote Request (802.11r)
   0x8917  IEEE Std 802.21   - Media Independent Handover Protocol
   0x8929  IEEE Std 802.1Qbe - Multiple I-SID Registration Protocol
   0x8940  IEEE Std 802.1Qbg - ECP Protocol (also used in 802.1BR)

Appendix C. Documentation Protocol Number

Below is the template based on which an IANA OUI-based protocol number value was assigned for document use. (See Section 3 and Appendix A.2.)

Applicant Name: Donald E. Eastlake 3rd

   Applicant Email: d3e3e3@gmail.com
   
   Applicant Telephone: 1-508-333-2270
   
   Use Name: Documentation

Document:

This document.

Note:

         Request value 0x0042

Authors' Addresses

   Donald E. Eastlake 3rd
   Huawei Technologies
   155 Beaver Street
   Milford, MA  01757
   USA
   
   Phone: +1-508-634-2066
   EMail: d3e3e3@gmail.com
   
   Joe Abley
   Dyn, Inc.
   470 Moore Street
   London, ON  N6C 2C2
   Canada
   
   Phone: +1 519 670 9327
   EMail: jabley@dyn.com