Internet Engineering Task Force (IETF) D. Eastlake 3rd

Internet Engineering Task Force (IETF) D. Eastlake 3rd
Request for Comments: 9542 Independent
BCP: 141 J. Abley
Obsoletes: 7042 Cloudflare
Category: Best Current Practice Y. Li
ISSN: 2070-1721 Huawei Technologies
April 2024

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 aspects of such
parameters and their use in IETF protocols, specifies IANA
considerations for assignment of points under the IANA
Organizationally Unique Identifier (OUI), and provides some values
for use in documentation. This document obsoletes RFC 7042.

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 7841.

Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc9542.

Copyright Notice

Copyright (c) 2024 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
(https://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 Revised BSD License text as described in Section 4.e of the
Trust Legal Provisions and are provided without warranty as described
in the Revised BSD License.

Table of Contents

1. Introduction
1.1. Notations Used in This Document
1.2. The IEEE Registration Authority
1.3. The IANA Organizationally Unique Identifier
1.4. CFM Code Points
2. Ethernet Identifier Parameters
2.1. 48-Bit MAC Identifiers, OUIs, and Other Prefixes
2.1.1. Special First Octet Bits
2.1.2. OUIs and CIDs
2.1.3. 48-Bit MAC Assignments under the IANA OUI
2.1.4. 48-Bit MAC Documentation Values
2.1.5. 48-Bit IANA MAC Assignment Considerations
2.2. 64-Bit MAC Identifiers
2.2.1. IPv6 Use of Modified EUI-64 Identifiers
2.2.2. EUI-64 IANA Assignment Considerations
2.2.3. EUI-64 Documentation Values
2.3. Other 48-Bit MAC Identifiers Used by the IETF
2.3.1. Identifiers with a '33-33' Prefix
2.3.2. The CF Series
2.4. CBOR Tags
3. Ethernet Protocol Parameters
3.1. Ethernet Protocol Assignment under the IANA OUI
3.2. Documentation Protocol Number
4. Other OUI/CID-Based Parameters
4.1. LLDP IETF Organizationally Specific TLV Type
5. IANA Considerations
5.1. Expert Review and IESG Ratification
5.1.1. Expert Review Guidance
5.1.2. Expert Review and IESG Ratification Procedure
5.2. IANA Registry Group (Web Page) Name Changes
5.3. MAC Address AFNs and RRTYPEs
5.4. Informational IANA Registry Group Material
5.5. EtherType Assignment Process
5.6. OUI Exhaustion
5.7. IANA OUI MAC Address Table
5.8. IANA LLDP TLV Subtypes
5.9. CBOR Tag Assignments
6. Security Considerations
7. References
7.1. Normative References
7.2. Informative References
Appendix A. Templates
A.1. EUI-48/EUI-64 Identifier or Identifier Block Template
A.2. IANA OUI/CID-Based Protocol Number Template
A.3. Other IANA OUI/CID-Based Parameter Template
Appendix B. EtherTypes
B.1. IESG Statement on EtherTypes
Appendix C. Changes from RFC 7042
Acknowledgements
Authors' Addresses

1. Introduction

Some IETF protocols use Ethernet or other communication frame formats
and parameters related to IEEE 802 [IEEE802]. These include Media
Access Control (MAC) addresses and protocol identifiers. The IEEE
Registration Authority [IEEE_RA] manages the assignment of
identifiers used in IEEE 802 networks, in some cases assigning blocks
of such identifiers whose sub-assignment is managed by the entity to
which the block is assigned. The IEEE RA also provides a number of
tutorials concerning these parameters [IEEEtutorials].

IANA has been assigned an Organizationally Unique Identifier (OUI) by
the IEEE RA and an associated set of MAC addresses and other
organizationally unique code points based on that OUI. This document
specifies IANA considerations for the assignment of code points under
that IANA OUI, including MAC addresses and protocol identifiers, 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 such code points conflicting with code points
assigned for some deployed use. This document also discusses several
other uses by the IETF of IEEE 802 code points, including IEEE 802
Connectivity Fault Management (CFM) code points [RFC7319] and IEEE
802 Link Local Discovery Protocol (LLDP) [IEEE802.1AB] Vendor-
Specific TLV Sub-Types [RFC8520]. It also specifies Concise Binary
Object Representation (CBOR) tags for MAC addresses and OUIs /
Company Identifiers (CIDs).

Descriptions herein of [IANA] policies and procedures are
authoritative, but descriptions of IEEE registration policies,
procedures, and standards are only informative; for authoritative
IEEE information, consult the IEEE sources.

[RFC8126] is incorporated herein except where there are contrary
provisions in this document. In this document, "IESG Ratification",
specified in Section 5.1, refers to a combination of Expert Review
and IESG Approval as those are defined in [RFC8126], where IESG
Approval is required only if the Expert does not reject the request.
It is NOT the same as just "IESG Approval" in [RFC8126].

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 ("network") bit
ordering although the physical order of bit transmission within an
octet on an IEEE [IEEE.802.3_2012] 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" Address Family Number [RFC4760].

"CBOR" Concise Binary Object Representation [RFC8949].

"CFM" Connectivity Fault Management [RFC7319].

"CID" Company Identifier. See Section 2.1.2.

"DSAP" Destination Service Access Point. See Section 3.

"EUI" Extended Unique Identifier.

"EUI-48" 48-bit EUI

"IEEE" Institute of Electrical and Electronics Engineers [IEEE].

"IEEE 802" The LAN/MAN Standards Committee [IEEE802].

"IEEE RA" IEEE Registration Authority [IEEE_RA].

"IEEE SA" IEEE Standards Association [IEEE_SA].

"LLC" Logical Link Control. The type of frame header where the
protocol is identified by source and destination LSAP
fields. See Section 3.

"LSAP" Link-Layer Service Access Point. See Section 3.

"MA-L" MAC Address Block Large.

"MA-M" MAC Address Block Medium.

"MA-S" MAC Address Block Small.

"MAC" Media Access Control, not Message Authentication Code.

"MAC-48" A 48-bit MAC address. This term is obsolete. If
globally unique, use EUI-48.

"OUI" Organizationally Unique Identifier. See Section 2.1.2.

"RRTYPE" A DNS Resource Record type [RFC6895].

"SLAP" IEEE 802 Structured Local Address Plan [IEEE802_OandA].
See Section 2.1.1.

"SNAP" Subnetwork Access Protocol. See Section 3.

"SSAP" Source Service Access Point. See Section 3.

"tag" "Tag" is used in two contexts in this document. For
"Ethernet tag", see Section 3. For "CBOR tag", see
Section 2.4.

"TLV" Type-Length-Value.

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

1.2. The IEEE Registration Authority

Originally the responsibility of the Xerox Corporation, the
registration authority for Ethernet parameters since 1986 has been
the IEEE Registration Authority, available on the Web at [IEEE_RA].

The IEEE Registration Authority operates under the direction of the
IEEE Standards Association (IEEE SA) Board of Governors, with
oversight by the IEEE Registration Authority Committee (IEEE RAC).
The IEEE RAC is a committee of the Board of Governors.

Anyone may apply to that authority for parameter assignments. The
IEEE Registration Authority may impose fees or other requirements but
commonly waives fees for applications from standards development
organizations. Lists of assignments and their holders are
downloadable from the IEEE Registration Authority site.

1.3. The IANA Organizationally Unique Identifier

The Organizationally Unique Identifier (OUI) 00-00-5E has been
assigned to IANA by the IEEE Registration Authority.

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

1.4. CFM Code Points

IEEE Std 802.1Q [IEEE.802.1Q_2014] allocates two blocks of 802
Connectivity Fault Management (CFM) code points to the IETF, one for
CFM OpCodes and one for CFM TLV Types. For further information, see
[RFC7319]. The IANA "Connectivity Fault Management (CFM) OAM IETF
Parameters" registry has subregistries for these code points. This
document does not further discuss these blocks of code points.

2. Ethernet Identifier Parameters

This section includes information summarized from [IEEE802_OandA]
that is being provided for context. The definitive information,
which prevails in case of any discrepancy, is in [IEEE802_OandA].

Section 2.1 discusses 48-bit MAC identifiers, their relationship to
OUIs and other prefixes, and assignment under the IANA OUI.
Section 2.2 extends this to 64-bit identifiers. Section 2.3
discusses other IETF MAC identifier uses not under the IANA OUI.
Section 2.4 specifies CBOR tags for MAC addresses and OUIs/CIDs.

| Historical Note: [RAC_OUI] is an expired Internet-Draft that
| provides additional historic information on [IEEE802]
| registries.

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 (Extended Unique Identifier 48). An EUI-48 is structured
into an initial prefix assigned by the IEEE Registration Authority
and additional bits assigned by the prefix owner. As of 2024, there
are three lengths of prefixes assigned, as shown in the table below;
however, some prefix bits can have special meaning, as shown in
Figure 1.

+=======================+======+=========================+
| Prefix Length in Bits | Name | Owner Supplied Bits for |
| | | 48-bit MAC Addresses |
+=======================+======+=========================+
| 24 | MA-L | 24 |
+-----------------------+------+-------------------------+
| 28 | MA-M | 20 |
+-----------------------+------+-------------------------+
| 36 | MA-S | 12 |
+-----------------------+------+-------------------------+

Table 1

The bottom (least significant) four bits of the first octet of the
6-octet 48-bit MAC have special meaning, as shown in Figure 1, and
are referred to below as the M, X, Y, and Z bits.

0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| . . . . Z Y X M| . . . . . . . .| octets 0+1
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| . . . . . . . .| . . . . . . . .| octets 2+3
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| . . . . . . . .| . . . . . . . .| octets 4+5
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+

Figure 1: 48-Bit MAC Address Structure

For global addresses, X = 0 and a MAC address begins with 3 octets or
a larger initial prefix indicating the assignee of the block of MAC
addresses. This prefix is followed by a sequence of additional
octets so as to add up to the total MAC address length. For example,
the IEEE assigns MAC Address Block Small (MA-S), where the first four
and a half octets (36 bits) are assigned, giving the holder of the
MA-S one and a half octets (12 bits) they can control in constructing
48-bit MAC addresses; other prefix lengths are also available
[IEEEtutorials].

An AFN, a DNS RRTYPE, and a CBOR tag have been assigned for 48-bit
MAC addresses, as discussed in Sections 2.4, 5.3, and 5.9.

IEEE Std 802 describes assignment procedures and policies for
identifiers related to IEEE 802 [IEEE802_OandA]. IEEE RA
documentation on EUIs, OUIs, and CIDs is available at
[IEEEtutorials].

2.1.1. Special First Octet Bits

There are bits within the initial octet of an IEEE MAC address that
have special significance [IEEE802_OandA], as described as follows:

M bit - This bit is frequently referred to as the "group" or
"multicast" bit. If it is zero, the MAC address is unicast. If
it is a one, the address is groupcast (multicast or broadcast).
This meaning is independent of the values of the X, Y, and Z bits.

X bit - This bit is also called the "universal/local" bit (formerly
called the Local/Global bit). If it is zero, the MAC address is a
global address under the control of the owner of the IEEE-assigned
prefix. Previously, if it was a one, the MAC address was
considered "local" and under the assignment and control of the
local network operator (but see Section 2.3). If it is a one and
if the IEEE 802 Structured Local Address Plan (SLAP) is in effect,
the nature of the MAC address is optionally determined by the Y
and Z bits, as described below.

Y&Z bits - These two bits have no special meaning if the X bit is
zero. If the X bit is one and if the IEEE 802 Structured Local
Address Plan (SLAP) is in effect, these two bits divide the
formerly uniform "local" MAC address space into four quadrants as
follows and further described below:

+=======+=======+===========================+
| Y bit | Z bit | Quadrant |
+=======+=======+===========================+
| 0 | 0 | Administratively Assigned |
+-------+-------+---------------------------+
| 0 | 1 | Extended Local |
+-------+-------+---------------------------+
| 1 | 0 | Reserved |
+-------+-------+---------------------------+
| 1 | 1 | Standard Assigned |
+-------+-------+---------------------------+

Table 2

While a local network administrator can assign any addresses with the
X bit a one, the optional SLAP characterizes the four quadrants of
the "local" address space using the Y and Z bits as follows:

Administratively Assigned - MAC addresses in this quadrant are
called Administratively Assigned Identifiers. This is intended
for arbitrary local assignment, such as random assignment;
however, see Section 2.3.1.

Extended Local - MAC addresses in this quadrant are called Extended
Local Identifiers. These addresses are not actually "local" under
SLAP. They are available to the organization that has been
assigned the CID (see Section 2.1.2) specifying the other 20 bits
of the 24-bit prefix with X, Y, and Z bits having the values 1, 0,
and 1, respectively.

Reserved - MAC addresses in this quadrant are reserved for future
use under the SLAP. Until such future use, they could be locally
assigned as Administratively Assigned Identifiers are assigned,
but there is a danger that future SLAP use would conflict with
such local assignments.

Standard Assigned - MAC addresses in this quadrant are called
Standard Assigned Identifiers (SAIs). An SAI is assigned by a
protocol specified in an IEEE 802 standard, for example,
[IEEE802.1CQ] (but see the first NOTE below).

NOTE: While the SLAP has MAC addresses assigned through a local
protocol in the SAI quadrant and assigned by a protocol
specified in an IEEE 802 standard, the SLAP is optional. Local
network administrators may use the IETF protocol provisions in
[RFC8947] and [RFC8948], which support assignment of a MAC
address in the local MAC address space using DHCPv6 [RFC8415]
or other protocol methods.

NOTE: There isn't any automated way to determine if or to what extent
a local network is configured for and/or operating according to SLAP.

2.1.2. OUIs and CIDs

MA-L, MA-M, and MA-S MAC prefixes are assigned with the Local bit
zero. The assignee of an OUI is exclusively authorized to assign
group MAC addresses by extending a modified version of the assigned
OUI in which the M bit (see Figure 1) is set to 1 [IEEEtutorials].

The Local bit is zero for globally unique EUI-48 identifiers assigned
by the owner of a MAC-L or owner of a longer prefix. If the Local
bit is a one, the identifier has historically been a local identifier
under the control of the local network administrator; however, there
are now recommendations on optional management of the local address
space, as discussed in Section 2.1.1. If the Local bit is a one, the
holder of an OUI has no special authority over MAC identifiers whose
first 3 octets correspond to their OUI or the beginning of their
longer prefix.

A CID is a 24-bit Company Identifier. It is assigned for
organizations that need such an identifier that can be used in place
of an OUI but do not need to assign subsidiary global MAC addresses.
A CID has X and Z bits equal to 1 and its Y bit equal to 0 (see
Figure 1).

An AFN and a CBOR tag have been assigned for OUIs/CIDs, as discussed
in Sections 2.4, 5.3, and 5.9.

2.1.3. 48-Bit MAC Assignments under the IANA OUI

The OUI 00-00-5E has been assigned to IANA, as stated in Section 1.3
above. This includes 2**24 48-bit 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 identifiers, the sub-blocks reserved or thus far assigned
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. As of 2024, 4 out of these 256 values have been
assigned. See [EthernetNum].

00-00-5E-00-53-00 through 00-00-5E-00-53-FF: assigned for use in
documentation by this document.

00-00-5E-90-01-00 through 00-00-5E-90-01-FF: used for very small
assignments that need parallel unicast and multicast MAC
addresses. As of 2024, 1 out of these 256 values has been
assigned. See [EthernetNum].

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. As of 2024, 4 out of these
256 values have been assigned. See [EthernetNum].

01-00-5E-90-01-00 through 01-00-5E-90-01-FF: used for very small
assignments that need parallel unicast and multicast MAC
addresses. As of 2024, 1 out of these 256 values has been
assigned. See [EthernetNum].

01-00-5E-90-10-00 through 01-00-5E-90-10-FF: 2**8 addresses
assigned for use in documentation by this document.

For more detailed and up-to-date information, see the "IANA OUI
Ethernet Numbers" registry at [EthernetNum].

2.1.4. 48-Bit MAC 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.

2.1.5. 48-Bit IANA MAC Assignment Considerations

48-bit assignments under the current or a future IANA OUI (see
Section 5.6) 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-sized 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 network interface
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).

2.2. 64-Bit MAC Identifiers

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

* In IEEE Std 1394 [IEEE1394] (also known as FireWire and i.Link)

* In IEEE Std 802.15.4 [IEEE802.15.4] (also known as Zigbee)

* In [InfiniBand]

* In a modified form to construct some IPv6 Interface Identifiers,
as described in Section 2.2.1, although this use is now deprecated

Adding a 5-octet (40-bit) extension to a 3-octet (24-bit) assignment,
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
special low-order bits.

An AFN, a DNS RRTYPE, and CBOR tag have been assigned for 64-bit MAC
addresses, as discussed in Sections 2.4, 5.3, and 5.9.

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

The approach described below for constructing IPv6 Interface
Identifiers is now deprecated, and the method specified in [RFC8064]
is recommended.

EUI-64 identifiers have been 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 EUI-64 is modified by
inverting the X (universal/local) 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 X bit is inverted compared with
EUI-48 identifiers. It is the globally unique values (universal
scope) that have the 0x02 bit (also known as the X or universal/local
bit) on in the first octet, while those with this bit off are
typically locally assigned and out of scope for global assignment.

The X (universal/local) 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 48-bit MAC identifiers, the M bit (0x01) on in the first
octet indicates a group identifier (multicast or broadcast).

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 universal/local bit.

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 a 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 [RFC1112]. However, for Modified EUI-64 identifiers based
on an IPv4 address, the universal/local 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 universal/local
bit is reversed from that in (unmodified) EUI-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. These values are
prefixed with 02-00-5E to form unicast modified EUI-64 addresses.

+==================================+===================+===========+
| Addresses | Usage | Reference |
+==================================+===================+===========+
| 00-00-00-00-00 to 0F-FF-FF-FF-FF | Reserved | RFC 9542 |
+----------------------------------+-------------------+-----------+
| 10-00-00-00-00 to 10-00-00-00-FF | Documentation | RFC 9542 |
+----------------------------------+-------------------+-----------+
| 10-00-00-01-00 to EF-FF-FF-FF-FF | Unassigned | |
+----------------------------------+-------------------+-----------+
| FD-00-00-00-00 to FD-FF-FF-FF-FF | Reserved | RFC 9542 |
+----------------------------------+-------------------+-----------+
| FE-00-00-00-00 to FE-FF-FF-FF-FF | IPv4 Addr Holders | RFC 9542 |
+----------------------------------+-------------------+-----------+
| FF-00-00-00-00 to FF-FD-FF-FF-FF | Reserved | RFC 9542 |
+----------------------------------+-------------------+-----------+
| FF-FE-00-00-00 to FF-FE-FF-FF-FF | IANA EUI-48 | RFC 9542 |
| | Holders | |
+----------------------------------+-------------------+-----------+
| FF-FF-00-00-00 to FF-FF-FF-FF-FF | Reserved | RFC 9542 |
+----------------------------------+-------------------+-----------+

Table 3: IANA 64-bit MAC Addresses

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-sized 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 network interface
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).

* Large assignments of 536870912 (2**29) or more EUI-64 identifiers
require 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 values for documentation use:

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 values for documentation use:

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 48-Bit MAC Identifiers Used by the IETF

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

2.3.1. Identifiers with a '33-33' Prefix

All 48-bit multicast MAC identifiers prefixed with "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, but any Ethernet using standard IPv6 multicast
should note that these addresses will be used for that purpose.
These multicast MAC addresses fall into the Administratively Assigned
SLAP quadrant (see Section 2.1.1).

| Historical Notes: 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
| [IEEE.802.3_2012] 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. When used as
48-bit MAC prefixes, these values have all of the Z, Y, X (Local) and
M (Group) special bits at the bottom of the first octet equal to one,
while all IEEE-assigned OUIs thus far have the X and M bits as zero
and all CIDs have the Y and M bits as zero; thus, there can be no
conflict between CF series "OUIs" and IEEE-assigned OUIs/CIDs.
Multicast MAC addresses constructed with a CF series OUI would fall
into the Standard Assigned SLAP quadrant (see Section 2.1.1). 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." (For further information on Network
Layer Protocol Identifiers (NLPIDs), see [RFC6328].)

CF-00-00 is reserved. CF-00-00-00-00-00 is a multicast identifier
listed by IANA 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 the "IANA OUI Ethernet Numbers"
[EthernetNum] and "Point-to-Point (PPP) Protocol Field Assignments"
[PPPNum] registry groups.)

2.3.2.1. Changes to RFC 2153

The IANA Considerations in [RFC2153] were updated as follows by the
approval of [RFC5342] and remain so updated (no technical changes
have been made):

* Use of these CF series identifiers based on IANA assignment was
deprecated.

* IANA was instructed not to assign any further values in the CF
series.

2.4. CBOR Tags

The Concise Binary Object Representation (CBOR) [RFC8949] is a data
format whose design goals include the possibility of very small code
size, fairly small message size, and extensibility. In CBOR, a data
item can be enclosed by a CBOR tag to give it some additional
semantics identified by that tag. CBOR-tagged data items (fields)
are not used in actual IEEE 802 address fields but may be used in
CBOR-encoded parts of protocol messages.

IANA has assigned 48 as the CBOR tag to indicate a MAC address. The
enclosed data item is an octet string. The length of the octet
string indicates whether a 48-bit (6 octet) or 64-bit (8 octet) MAC
address is encoded. Should some other multiple of 8 bits be used in
the future for the length of MAC addresses, such as a 128-bit
(16-octet) MAC address, the 48 tag will be used.

IANA has assigned 1048 as the CBOR tag to indicate an OUI, CID, or CF
series organizational identifier. The enclosed data item is an octet
string of length 3 to hold the 24-bit OUI or CID (see Section 2.1.2).

3. Ethernet Protocol Parameters

Ethernet protocol parameters provide a means of indicating, near the
beginning of a frame, the contents of that frame -- for example, that
it contains IPv4 or IPv6.

There are two types of protocol identifier parameters (see
[EthernetNum]) that can occur in Ethernet frames:

EtherTypes:
These are 16-bit identifiers that, when considered as an unsigned
integer, are equal to or larger than 0x0600. Figure 2 shows the
simplest case where the EtherType of the protocol data in the
frame appears immediately after the destination and source MAC
addresses. [IEEE802_OandA] specifies two EtherTypes for local,
experimental use: 0x88B5 and 0x88B6.

LSAPs:
These are 8-bit protocol identifiers that occur in pairs after a
field that gives the frame length. Such a length must, when
considered as an unsigned integer, be less than 0x5DD, or it could
be mistaken as an EtherType. However, the LLC encapsulation
EtherType 0x8870 [IEEE802.1AC] may also be used in place of such a
length as a "length indication" of nonspecific length. LSAPs
occur in pairs, where one is intended to indicate the source
protocol handler (SSAP) and the other the destination protocol
handler (DSAP); however, use cases where the two are different
have been relatively rare. See Figure 3 for the simplest case
where the length field appears immediately after the destination
and source MAC addresses. In that figure, the CTL (control) field
value of 3 indicates datagram service. This type of protocol
identification is sometimes called "LLC" (Logical Link Control).

0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| Destination MAC Address ///
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| Source MAC Address ///
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| EtherType, greater than or equal to 0x0600 |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| Protocol Data ///
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+

Figure 2: EtherType Frame Protocol Labeling

0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| Destination MAC Address ///
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| Source MAC Address ///
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| Frame length (or 0x8870) |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| DSAP | SSAP |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| CTL = 0x03 | Protocol Data ///
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+

Figure 3: LSAP Frame Protocol Labeling

The concept of EtherType labeling has been extended to labeling by
Ethernet "tags". An Ethernet 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 LLC Link-Layer Service Access Point
(LSAP) protocol indicator for the "main" body of the frame.
Customarily, in the world of [IEEE802_OandA], tags are a fixed length
and do not include any encoding of their own length. An example is
the C-Tag (formerly the Q-Tag) [IEEE.802.1Q_2014]. It provides
customer VLAN and priority information for a frame. Any device that
is processing a frame cannot, in general, safely process anything in
the frame past an EtherType it does not understand.

Neither EtherTypes nor LSAPs are assigned by IANA; they are assigned
by the IEEE Registration Authority [IEEE_RA] (see Section 1.2 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)) [IEEE802_OandA] 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 (SNAP 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 five-octet length for such
OUI-based protocol identifiers results, with the LLC control octet
("0x03"), in the preservation of 16-bit alignment.

When using an EtherType to indicate the main type for a frame body,
the special "OUI Extended EtherType" 0x88B7 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; however, this format with EtherType 0x88B7 does not
preserve 16-bit alignment.

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.

As well as labeling frame contents, IEEE 802 protocol types appear
within Non-Broadcast Multi-Access (NBMA) Next Hop Resolution Protocol
[RFC2332] messages. Such messages have provisions for both two-octet
EtherTypes and OUI-based protocol types. 16-bit EtherTypes also occur
in the Generic Routing Encapsulation (GRE) [RFC2784] header and in
the Generic Network Virtualization Encapsulation (Geneve) [RFC8926]
encapsulation header.

3.1. Ethernet Protocol Assignment under the IANA OUI

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

88-B7-00-00-5E-qq-qq

or

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
[EthernetNum]). 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 protocol numbers
(qq-qq) 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),

* the protocol must include a version field at a fixed offset or an
equivalent marking such that later versions can be indicated in a
way recognizable by earlier versions,

* the protocol 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. (That EtherType can be used directly, or -- in
the LSAPs case -- it can be used with the SNAP SAP by putting an
all-zero "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 as an example for documentation purposes.

4. Other OUI/CID-Based Parameters

Some IEEE 802 and other protocols provide for parameters based on an
OUI or CID beyond those discussed above. Such parameters commonly
consist of an OUI or CID plus one octet of additional value. They
are called Organizationally Specific parameters (sometimes informally
and less accurately referred to as "vendor specific"). They would
look like

yy-yy-yy-zz

where yy-yy-yy is the OUI/CID and zz is the additional specifier. An
example is the Cipher Suite Selector in [IEEE.802.11_2012].

Values may be assigned under the IANA OUI for 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 for a one octet specifier, right justified and
filled with zeros on the left if the specifier is more than one
octet) is assigned for use as an example in documentation.

Assignments of 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 may specify the name of the registry.

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

4.1. LLDP IETF Organizationally Specific TLV Type

An example of an "other IANA OUI-based parameter" is specified in
[RFC8520]. This provides for an Organizationally Specific TLV type
for announcing a Manufacturer Usage Description (MUD) Uniform
Resource Locator (URL) in the IEEE Link Local Discovery Protocol
(LLDP) [IEEE802.1AB]. Additional IETF use of code points in this
space have been proposed [BGP11dp]. (See also Section 5.8.)

5. IANA Considerations

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

Note: The "IANA OUI Ethernet Numbers" registry group (web page) is
for registries of numbers assigned under the IANA OUI, while the
"IEEE 802 Numbers" registry group has informational lists of
numbers assigned by the IEEE Registration Authority.

This document does not create any new IANA registries.

The MAC address values assigned for documentation and the protocol
number for documentation were both assigned by [RFC7042].

No existing assignment is changed by this document.

5.1. Expert Review and IESG Ratification

This section specifies the procedures 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.

5.1.1. Expert Review Guidance

The procedure described for Expert Review assignments in this
document is consistent with the IANA Expert Review policy described
in [RFC8126].

While finite, the universe of MAC code points from which Expert-
judged assignments will be made is considered 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 reasonableness check for small assignments of MAC
identifiers, with increased scrutiny by the Expert for medium-sized
assignments of MAC identifiers and assignments of protocol
identifiers and other IANA OUI-based parameters.

5.1.2. Expert Review and IESG Ratification Procedure

It can make sense to assign very large portions of the MAC identifier
code point space. (Note that existing assignments include one for
half of the entire multicast IANA 48-bit code point space and one for
a sixteenth 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. This can be viewed as a combination of Expert Review and IESG
Approval as defined in [RFC8126]. IESG Approval is required only
when the Expert does not reject the request. The procedure is as
follows:

The applicant always completes the appropriate template from
Appendix A below and sends it to IANA <[email protected]>.

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. The Expert should provide a reason for refusal, which
IANA will communicate back to the applicant.

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, who in turn informs the applicant that their
request is denied; 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 provided by
the Expert 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. In case of refusal,
the IESG should provide a reason, which IANA will communicate
to the applicant.

5.2. IANA Registry Group (Web Page) Name Changes

For clarity and parallelism with the IANA "IEEE 802 Numbers" registry
group, the IANA "Ethernet Numbers" registry group has been renamed
the "IANA OUI Ethernet Numbers" registry.

As this document replaces [RFC7042], references to [RFC7042] in IANA
registries in both the "IEEE 802 Numbers" and the "IANA OUI Ethernet
Numbers" registry groups have been replaced by references to this
document. Other IANA registry references to [RFC7042] are not
changed.

5.3. 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] |
+------------+---------+--------+-----------+
| OUI | 16391 | 0x4007 | [RFC7961] |
+============+=========+========+===========+
| Lower 24 bits of a 48-bit MAC address: |
+============+=========+========+===========+
| MAC/24 | 16392 | 0x4008 | [RFC7961] |
+============+=========+========+===========+
| Lower 40 bits of a 64-bit MAC address: |
+============+=========+========+===========+
| MAC/40 | 16393 | 0x4009 | [RFC7961] |
+------------+---------+--------+-----------+

Table 4

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] |
+------------+----------+---------+--------+-----------+

Table 5

5.4. Informational IANA Registry Group Material

IANA maintains an informational registry group, currently implemented
as a web page, concerning EtherTypes, OUIs, and multicast addresses
assigned under OUIs other than the IANA OUI. The title of this
informational registry group is "IEEE 802 Numbers". IANA updates
that informational registry group when changes are provided by or
approved by the Expert(s).

5.5. EtherType Assignment Process

Applying to the IEEE Registration Authority for an EtherType needed
by an IETF protocol requires IESG Approval, as stated in Appendix B.
To minimize confusion, this process will normally be done by the
primary expert for the informational "EtherType" registry within the
"IEEE 802 Numbers" registry group, as described below (see also
Section 5.4).

After IESG Approval of the requirement for an EtherType, the IESG
should refer the matter to IANA. In any case, IANA will ask the
"EtherType" registry expert to execute the IEEE Registration
Authority [IEEE_RA] EtherType request process. This path is
specified because the IESG usually deals with IANA for assignment
actions and because IANA should be aware of which "EtherType"
registry expert(s) are available, normally referring the making of
the EtherType assignment request to the primary expert.

Here is sample text for an Internet-Draft where both IANA and IEEE
assignments are required, where "YYY" would be replaced by an
explanation of for what/why the EtherType is needed in whatever level
of detail is necessary and would normally include a reference or
references to other appropriate parts of the Internet-Draft:

| X. Assignment Considerations
|
| X.1. IEEE Assignment Considerations
|
| The IESG is requested to approve applying to the IEEE
| Registration Authority for an EtherType for YYY. (The IESG
| should communicate its approval to IANA and to those concerned
| with this document. IANA will forward the IESG Approval to the
| registry expert of the "EtherType" registry from the "IEEE 802
| Numbers" registry group who will make the application to the
| IEEE Registration Authority, keeping IANA informed.)
|
| X.2. IANA Considerations
|
| ...

5.6. 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.

5.7. IANA OUI MAC Address Table

The following changes are made by this document to the Notes for the
"IANA Unicast 48-bit MAC Addresses", the "IANA Multicast 48-bit MAC
Addresses", and the "IANA 64-bit MAC Addresses" registries. In
addition, the references in those registries are updated, as
specified in Section 5.2.

The Notes for the "IANA Unicast 48-bit MAC Addresses" registry and
for the "IANA Multicast 48-bit MAC Addresses" registry are changed to
the following:

| These values are prefixed with 00-00-5E. See Section 2.1.3 of RFC
| 9542.

The Note for the "IANA 64-bit MAC Addresses" registry is changed to
the following:

| These values are prefixed with 00-00-5E to form unicast MAC
| addresses, with 01-00-5E to form multicast MAC addresses, with
| 02-00-5E to form unicast modified EUI-64 addresses, and with
| 03-00-5E to form multicast modified EUI-64 addresses. See RFC
| 9542, particularly Section 2.2.2, for more details.

5.8. IANA LLDP TLV Subtypes

IANA has moved the "IANA Link Layer Discovery Protocol (LLDP) TLV
Subtypes" registry from the "IEEE 802 Numbers" registry group to the
"IANA OUI Ethernet Numbers" registry group, since code points within
it are assigned by IANA, and has added RFC 9542 as an additional
reference for that registry.

In addition, IANA has updated three entries in that registry as
follows:

+=======+==================================+===========+
| Value | Description | Reference |
+=======+==================================+===========+
| 0 | Reserved | RFC 9542 |
+-------+----------------------------------+-----------+
| 42 | Example for use in documentation | RFC 9542 |
+-------+----------------------------------+-----------+
| 255 | Reserved | RFC 9542 |
+-------+----------------------------------+-----------+

Table 6

The entries for 1 (MUD), 2-41 (unassigned), and 43-254 (unassigned)
are unchanged.

5.9. CBOR Tag Assignments

IANA has assigned two CBOR Tags as shown below in the "Concise Binary
Object Representation (CBOR) Tags" registry.

+======+=============+==================+===========+
| Tag | Data Item | Semantics | Reference |
+======+=============+==================+===========+
| 48 | byte string | IEEE MAC Address | RFC 9542 |
+------+-------------+------------------+-----------+
| 1048 | byte string | IEEE OUI/CID | RFC 9542 |
+------+-------------+------------------+-----------+

Table 7

6. Security Considerations

This document is concerned with assignment of IEEE 802 parameters
allocated to IANA, particularly those 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 that are "only" to be used 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.

MAC addresses are identifiers provided by a device to the network.
On certain devices, MAC addresses are not static and can be
configured. The network should exercise caution when using these
addresses to enforce policy because addresses can be spoofed and
previously seen devices can return to the network with a new address.

MAC addresses identify a physical or virtual interface and can be
used for tracking the device with that interface. Thus, they can be
used to track users associated with that device. See [madinas] for
related privacy considerations and a discussion of MAC address
randomization to partially mitigate this threat. Also, see [RFC7043]
for the security and privacy considerations of publishing MAC
addresses in DNS.

7. References

7.1. Normative References

[IEEE.802.1Q_2014]
IEEE, "IEEE Standard for Local and metropolitan area
networks--Bridges and Bridged Networks", IEEE 802.1Q-2014,
DOI 10.1109/ieeestd.2014.6991462, 18 December 2014,
<http://ieeexplore.ieee.org/servlet/
opac?punumber=6991460>.

[IEEE802.1AB]
IEEE, "IEEE Standard for Local and metropolitan area
networks - Station and Media Access Control Connectivity
Discovery", IEEE Std 802.1AB-2016,
DOI 10.1109/IEEESTD.2016.7433915, March 2016,
<https://doi.org/10.1109/IEEESTD.2016.7433915>.

[IEEE802_OandA]
IEEE, "IEEE Standard for Local and Metropolitan Area
Networks: Overview and Architecture", IEEE Std 802-2014,
DOI 10.1109/IEEESTD.2014.6847097, June 2014,
<https://doi.org/10.1109/IEEESTD.2014.6847097>.

IEEE, "IEEE Standard for Local and Metropolitan Area
Networks: Overview and Architecture -- Amendment 2: Local
Medium Access Control (MAC) Address Usage", IEEE Std 802c-
2017, DOI 10.1109/IEEESTD.2017.8016709, August 2017,
<https://doi.org/10.1109/IEEESTD.2017.8016709>.

[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/info/rfc8126>.

7.2. Informative References

[BGP11dp] Lindem, A., Patel, K., Zandi, S., Haas, J., and X. Xu,
"BGP Logical Link Discovery Protocol (LLDP) Peer
Discovery", Work in Progress, Internet-Draft, draft-acee-
idr-lldp-peer-discovery-17, 4 January 2024,
<https://datatracker.ietf.org/doc/html/draft-acee-idr-
lldp-peer-discovery-17>.

[EthernetNum]
IANA, "IANA OUI Ethernet Numbers",
<https://www.iana.org/assignments/ethernet-numbers>.

[IANA] IANA, "Internet Assigned Numbers Authority",
<https://www.iana.org>.

[IEEE] IEEE, "Institute of Electrical and Electronics Engineers",
<https://www.ieee.org>.

[IEEE.802.11_2012]
IEEE, "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 802.11-2012, DOI 10.1109/ieeestd.2012.6178212, 5
April 2012, <http://ieeexplore.ieee.org/servlet/
opac?punumber=6178209>.

[IEEE.802.3_2012]
IEEE, "IEEE Standard for Ethernet", IEEE 802.3-2012,
DOI 10.1109/ieeestd.2012.6419735, 24 January 2013,
<http://ieeexplore.ieee.org/servlet/
opac?punumber=6419733>.

[IEEE1394] IEEE, "IEEE Standard for a High-Performance Serial Bus",
IEEE Std 1394-2008, DOI 10.1109/IEEESTD.2008.4659233,
October 2008,
<https://doi.org/10.1109/IEEESTD.2008.4659233>.

[IEEE802] IEEE 802, "IEEE 802 LMSC", <https://www.ieee802.org>.

[IEEE802.15.4]
IEEE, "IEEE Standard for Low-Rate Wireless Networks", IEEE
Std 802.15.4-2020, DOI 10.1109/IEEESTD.2020.9144691, July
2020, <https://doi.org/10.1109/IEEESTD.2020.9144691>.

[IEEE802.1AC]
IEEE 802, "IEEE Standard for Local and metropolitan area
networks -- Media Access Control (MAC) Service
Definition", IEEE Std 802.1AC-2016,
DOI 10.1109/IEEESTD.2017.7875381, March 2017,
<https://doi.org/10.1109/IEEESTD.2017.7875381>.

[IEEE802.1CQ]
IEEE, "Draft Standard for Local and Metropolitan Area
Networks: Multicast and Local Address Assignment", draft
0.8, IEEE Std 802.1CQ/D0.8, July 2022.

[IEEEtutorials]
IEEE, "Guidelines for Use of Extended Unique Identifier
(EUI), Organizationally Unique Identifier (OUI), and
Company ID (CID)", August 2017,
<https://standards.ieee.org/wp-
content/uploads/import/documents/tutorials/eui.pdf>.

[IEEE_RA] IEEE, "Registration Authority",
<https://standards.ieee.org/products-programs/regauth/>.

[IEEE_SA] IEEE, "IEEE Standards Association",
<https://standards.ieee.org>.

[InfiniBand]
InfiniBand Trade Association, "InfiniBand Architecture
Specification Volume 1", November 2007,
<https://www.infinibandta.org/>.

[madinas] Zúñiga, JC., Bernardos, CJ., Ed., and A. Andersdotter,
"Randomized and Changing MAC Address state of affairs",
Work in Progress, Internet-Draft, draft-ietf-madinas-mac-
address-randomization-12, 28 February 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-madinas-
mac-address-randomization-12>.

[PPPNum] IANA, "Point-to-Point (PPP) Protocol Field Assignments",
<https://www.iana.org/assignments/ppp-numbers>.

[RAC_OUI] Parsons, G., "OUI Registry Restructuring", Work in
Progress, Internet-Draft, draft-ieee-rac-oui-
restructuring-01, 9 September 2013,
<https://datatracker.ietf.org/doc/html/draft-ieee-rac-oui-
restructuring-01>.

[RFC1112] Deering, S., "Host extensions for IP multicasting", STD 5,
RFC 1112, DOI 10.17487/RFC1112, August 1989,
<https://www.rfc-editor.org/info/rfc1112>.

[RFC1661] Simpson, W., Ed., "The Point-to-Point Protocol (PPP)",
STD 51, RFC 1661, DOI 10.17487/RFC1661, July 1994,
<https://www.rfc-editor.org/info/rfc1661>.

[RFC2153] Simpson, W., "PPP Vendor Extensions", RFC 2153,
DOI 10.17487/RFC2153, May 1997,
<https://www.rfc-editor.org/info/rfc2153>.

[RFC2332] Luciani, J., Katz, D., Piscitello, D., Cole, B., and N.
Doraswamy, "NBMA Next Hop Resolution Protocol (NHRP)",
RFC 2332, DOI 10.17487/RFC2332, April 1998,
<https://www.rfc-editor.org/info/rfc2332>.

[RFC2464] Crawford, M., "Transmission of IPv6 Packets over Ethernet
Networks", RFC 2464, DOI 10.17487/RFC2464, December 1998,
<https://www.rfc-editor.org/info/rfc2464>.

[RFC2606] Eastlake 3rd, D. and A. Panitz, "Reserved Top Level DNS
Names", BCP 32, RFC 2606, DOI 10.17487/RFC2606, June 1999,
<https://www.rfc-editor.org/info/rfc2606>.

[RFC2784] Farinacci, D., Li, T., Hanks, S., Meyer, D., and P.
Traina, "Generic Routing Encapsulation (GRE)", RFC 2784,
DOI 10.17487/RFC2784, March 2000,
<https://www.rfc-editor.org/info/rfc2784>.

[RFC3092] Eastlake 3rd, D., Manros, C., and E. Raymond, "Etymology
of "Foo"", RFC 3092, DOI 10.17487/RFC3092, April 2001,
<https://www.rfc-editor.org/info/rfc3092>.

[RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing
Architecture", RFC 4291, DOI 10.17487/RFC4291, February
2006, <https://www.rfc-editor.org/info/rfc4291>.

[RFC4760] Bates, T., Chandra, R., Katz, D., and Y. Rekhter,
"Multiprotocol Extensions for BGP-4", RFC 4760,
DOI 10.17487/RFC4760, January 2007,
<https://www.rfc-editor.org/info/rfc4760>.

[RFC5214] Templin, F., Gleeson, T., and D. Thaler, "Intra-Site
Automatic Tunnel Addressing Protocol (ISATAP)", RFC 5214,
DOI 10.17487/RFC5214, March 2008,
<https://www.rfc-editor.org/info/rfc5214>.

[RFC5332] Eckert, T., Rosen, E., Ed., Aggarwal, R., and Y. Rekhter,
"MPLS Multicast Encapsulations", RFC 5332,
DOI 10.17487/RFC5332, August 2008,
<https://www.rfc-editor.org/info/rfc5332>.

[RFC5342] Eastlake 3rd, D., "IANA Considerations and IETF Protocol
Usage for IEEE 802 Parameters", RFC 5342,
DOI 10.17487/RFC5342, September 2008,
<https://www.rfc-editor.org/info/rfc5342>.

[RFC5737] Arkko, J., Cotton, M., and L. Vegoda, "IPv4 Address Blocks
Reserved for Documentation", RFC 5737,
DOI 10.17487/RFC5737, January 2010,
<https://www.rfc-editor.org/info/rfc5737>.

[RFC5798] Nadas, S., Ed., "Virtual Router Redundancy Protocol (VRRP)
Version 3 for IPv4 and IPv6", RFC 5798,
DOI 10.17487/RFC5798, March 2010,
<https://www.rfc-editor.org/info/rfc5798>.

[RFC6034] Thaler, D., "Unicast-Prefix-Based IPv4 Multicast
Addresses", RFC 6034, DOI 10.17487/RFC6034, October 2010,
<https://www.rfc-editor.org/info/rfc6034>.

[RFC6328] Eastlake 3rd, D., "IANA Considerations for Network Layer
Protocol Identifiers", BCP 164, RFC 6328,
DOI 10.17487/RFC6328, July 2011,
<https://www.rfc-editor.org/info/rfc6328>.

[RFC6895] Eastlake 3rd, D., "Domain Name System (DNS) IANA
Considerations", BCP 42, RFC 6895, DOI 10.17487/RFC6895,
April 2013, <https://www.rfc-editor.org/info/rfc6895>.

[RFC7042] Eastlake 3rd, D. and J. Abley, "IANA Considerations and
IETF Protocol and Documentation Usage for IEEE 802
Parameters", BCP 141, RFC 7042, DOI 10.17487/RFC7042,
October 2013, <https://www.rfc-editor.org/info/rfc7042>.

[RFC7043] Abley, J., "Resource Records for EUI-48 and EUI-64
Addresses in the DNS", RFC 7043, DOI 10.17487/RFC7043,
October 2013, <https://www.rfc-editor.org/info/rfc7043>.

[RFC7319] Eastlake 3rd, D., "IANA Considerations for Connectivity
Fault Management (CFM) Code Points", BCP 191, RFC 7319,
DOI 10.17487/RFC7319, July 2014,
<https://www.rfc-editor.org/info/rfc7319>.

[RFC7961] Eastlake 3rd, D. and L. Yizhou, "Transparent
Interconnection of Lots of Links (TRILL): Interface
Addresses APPsub-TLV", RFC 7961, DOI 10.17487/RFC7961,
August 2016, <https://www.rfc-editor.org/info/rfc7961>.

[RFC8064] Gont, F., Cooper, A., Thaler, D., and W. Liu,
"Recommendation on Stable IPv6 Interface Identifiers",
RFC 8064, DOI 10.17487/RFC8064, February 2017,
<https://www.rfc-editor.org/info/rfc8064>.

[RFC8415] Mrugalski, T., Siodelski, M., Volz, B., Yourtchenko, A.,
Richardson, M., Jiang, S., Lemon, T., and T. Winters,
"Dynamic Host Configuration Protocol for IPv6 (DHCPv6)",
RFC 8415, DOI 10.17487/RFC8415, November 2018,
<https://www.rfc-editor.org/info/rfc8415>.

[RFC8520] Lear, E., Droms, R., and D. Romascanu, "Manufacturer Usage
Description Specification", RFC 8520,
DOI 10.17487/RFC8520, March 2019,
<https://www.rfc-editor.org/info/rfc8520>.

[RFC8926] Gross, J., Ed., Ganga, I., Ed., and T. Sridhar, Ed.,
"Geneve: Generic Network Virtualization Encapsulation",
RFC 8926, DOI 10.17487/RFC8926, November 2020,
<https://www.rfc-editor.org/info/rfc8926>.

[RFC8947] Volz, B., Mrugalski, T., and C. Bernardos, "Link-Layer
Address Assignment Mechanism for DHCPv6", RFC 8947,
DOI 10.17487/RFC8947, December 2020,
<https://www.rfc-editor.org/info/rfc8947>.

[RFC8948] Bernardos, CJ. and A. Mourad, "Structured Local Address
Plan (SLAP) Quadrant Selection Option for DHCPv6",
RFC 8948, DOI 10.17487/RFC8948, December 2020,
<https://www.rfc-editor.org/info/rfc8948>.

[RFC8949] Bormann, C. and P. Hoffman, "Concise Binary Object
Representation (CBOR)", STD 94, RFC 8949,
DOI 10.17487/RFC8949, December 2020,
<https://www.rfc-editor.org/info/rfc8949>.

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 the country code)

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

Document: (I-D 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/CID-Based Protocol Number Template

Applicant Name:

Applicant Email:

Applicant Telephone: (starting with the country code)

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

Document: (I-D or RFC specifying use to which the protocol identifier
will be put)

Note: (any additional note)

A.3. Other IANA OUI/CID-Based Parameter Template

Applicant Name:

Applicant Email:

Applicant Telephone: (starting with the country code)

Protocol where the OUI/CID-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: (I-D 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 provides a copy of the IESG Statement issued in May
2023 on obtaining new IETF EtherTypes in Appendix B.1. Note that
there is an informational IANA registry of some important EtherTypes
specified for IETF protocols or by IEEE 802 available, currently at
[IANA]. The IEEE Registration Authority page on EtherTypes
<https://standards.ieee.org/regauth/ethertype/eth.txt> may also be
useful. See Section 3 above.

B.1. IESG Statement on EtherTypes

From: IESG
Date: 1 May 2023

The IEEE Registration Authority (IEEE RA) assigns EtherTypes with
oversight from the IEEE Registration Authority Committee (IEEE RAC).

(See https://standards.ieee.org/products-programs/regauth/
ethertype/.) Some IETF protocol specifications make use of
EtherTypes. All EtherType applications are subject to IEEE RA
technical review for consistency with policy.

Since EtherTypes are a fairly scarce resource, the IEEE RAC has let
us know that they will not assign a new EtherType to a new IETF
protocol specification until the IESG has approved the protocol
specification for publication as an RFC. In exceptional cases, the
IEEE RA is willing to consider "early allocation" of an EtherType for
an IETF protocol that is still under development as long as the
request comes from and has been vetted by the IESG.

To let the IEEE RAC know that the IESG has approved the request for
an Ethernet assignment for an IETF protocol, all future requests for
assignment of EtherTypes for IETF protocols will be made by the IESG.

Note that Local Experimental ("playpen") EtherTypes have been
assigned in IEEE 802 [1] use during protocol development and
experimentation.

[1] IEEE Std 802. IEEE standard for Local and Metropolitan Area
Networks: Overview and Architecture.

Appendix C. Changes from RFC 7042

This document obsoletes [RFC7042] and makes the changes listed below.
However, the completed application template based upon which an IANA
OUI-based protocol number value was assigned for document use remains
that in Appendix C of [RFC7042].

* Add information on MA-M (28-bit) and MA-S (36-bit) EUI prefixes
that the IEEE Registration Authority assigns.

* Add information on the restructuring of the "local" MAC address
space into four quadrants under the Structured Local Address Plan
(SLAP) [IEEE802_OandA].

* Include the IESG Statement on EtherTypes (see Appendix B.1) and
more detailed IETF procedures for applying to the IEEE
Registration Authority for an EtherType for use in an IETF
protocol (see Section 5.5).

* Mention that IEEE 802 CFM code points have been allocated to the
IETF (see Section 1.4).

* Mention the Organizationally Specific LLDP data element that has
been assigned under the IANA OUI and the registry set up for
future such assignments (see Section 4.1).

* Clarify minor details in Section 5.1 on Expert Review and IESG
Ratification.

* Specify CBOR tags for MAC addresses and OUIs/CIDs (see
Section 2.4).

* Add a version field requirement for the allocation of protocol
numbers under the IANA OUI (see Section 3.1).

* Mention that EtherTypes are used in the Geneve [RFC8926]
encapsulation header (see Section 3).

* Add "a combination of Expert Review and IESG Approval" as part of
the specification for "IESG Ratification".

Acknowledgements

The comments and suggestions of the following persons and
organizations are gratefully acknowledged:

Comments and suggestions leading to this document:

Carsten Bormann, Bob Hinden, the IEEE 802.1 Working Group, Éric
Vyncke, Dale Worley, and Amanda Baber

Comments and suggestions leading to [RFC7042] (which is obsoleted
by this document):

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

Authors' Addresses

Donald E. Eastlake 3rd
Independent
2386 Panoramic Circle
Apopka, Florida 32703
United States of America
Phone: +1-508-333-2270
Email: [email protected], [email protected]

Joe Abley
Cloudflare
Amsterdam
The Netherlands
Phone: +31 45 56 36 34
Email: [email protected]

Yizhou Li
Huawei Technologies
101 Software Avenue
Nanjing
Jiangsu, 210012
China
Phone: +86-13809002299
Email: [email protected]