A media access control address (MAC address) is a
unique identifier assigned to a
network interface controller
A network interface controller (NIC, also known as a network interface card, network adapter, LAN adapter or physical network interface, and by similar terms) is a computer hardware component that connects a computer to a computer network.
Ear ...
(NIC) for use as a
network address in communications within a
network segment. This use is common in most
IEEE 802
IEEE 802 is a family of Institute of Electrical and Electronics Engineers (IEEE) standards for local area networks (LAN), personal area network (PAN), and metropolitan area networks (MAN). The IEEE 802 LAN/MAN Standards Committee (LMSC) mainta ...
networking technologies, including
Ethernet
Ethernet () is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in 1 ...
,
Wi-Fi
Wi-Fi () is a family of wireless network protocols, based on the IEEE 802.11 family of standards, which are commonly used for local area networking of devices and Internet access, allowing nearby digital devices to exchange data by radio wav ...
, and
Bluetooth
Bluetooth is a short-range wireless technology standard that is used for exchanging data between fixed and mobile devices over short distances and building personal area networks (PANs). In the most widely used mode, transmission power is limi ...
. Within the
Open Systems Interconnection (OSI) network model, MAC addresses are used in the
medium access control
In IEEE 802 LAN/MAN standards, the medium access control (MAC, also called media access control) sublayer is the layer that controls the hardware responsible for interaction with the wired, optical or wireless transmission medium. The MAC sublay ...
protocol sublayer of the
data link layer
The data link layer, or layer 2, is the second layer of the seven-layer OSI model of computer networking. This layer is the protocol layer that transfers data between nodes on a network segment across the physical layer. The data link layer ...
. As typically represented, MAC addresses are recognizable as six groups of two
hexadecimal digits, separated by hyphens, colons, or without a separator.
MAC addresses are primarily assigned by device manufacturers, and are therefore often referred to as the burned-in address, or as an Ethernet hardware address, hardware address, or physical address. Each address can be stored in hardware, such as the card's
read-only memory
Read-only memory (ROM) is a type of non-volatile memory used in computers and other electronic devices. Data stored in ROM cannot be electronically modified after the manufacture of the memory device. Read-only memory is useful for storing sof ...
, or by a
firmware mechanism. Many network interfaces, however, support changing their MAC address. The address typically includes a manufacturer's
organizationally unique identifier (OUI). MAC addresses are formed according to the principles of two numbering spaces based on extended unique identifiers (EUIs) managed by the
Institute of Electrical and Electronics Engineers (IEEE): EUI-48—which replaces the obsolete term MAC-48—and EUI-64.
Network nodes with multiple network interfaces, such as
routers and
multilayer switches, must have a unique MAC address for each NIC in the same network. However, two NICs connected to two different networks can share the same MAC address.
Address details
The
IEEE 802
IEEE 802 is a family of Institute of Electrical and Electronics Engineers (IEEE) standards for local area networks (LAN), personal area network (PAN), and metropolitan area networks (MAN). The IEEE 802 LAN/MAN Standards Committee (LMSC) mainta ...
MAC address originally comes from the
Xerox Network Systems
Xerox Network Systems (XNS) is a computer networking protocol suite developed by Xerox within the Xerox Network Systems Architecture. It provided general purpose network communications, internetwork routing and packet delivery, and higher level f ...
Ethernet addressing scheme.
[
] This
48-bit
In computer architecture, 48-bit integers can represent 281,474,976,710,656 (248 or 2.814749767×1014) discrete values. This allows an unsigned binary integer range of 0 through 281,474,976,710,655 (248 − 1) or a signed two's complement ...
address space contains potentially 2
48 (over 281 trillion) possible MAC addresses. The
IEEE
The Institute of Electrical and Electronics Engineers (IEEE) is a 501(c)(3) professional association for electronic engineering and electrical engineering (and associated disciplines) with its corporate office in New York City and its operat ...
manages allocation of MAC addresses, originally known as MAC-48 and which it now refers to as EUI-48 identifiers. The IEEE has a target lifetime of 100 years (until 2080) for applications using EUI-48 space and restricts applications accordingly. The IEEE encourages adoption of the more plentiful EUI-64 for non-Ethernet applications.
The distinction between EUI-48 and MAC-48 identifiers is in name and application only. MAC-48 was used to address hardware interfaces within existing 802-based networking applications; EUI-48 is now used for 802-based networking and is also used to identify other devices and software, for example
Bluetooth
Bluetooth is a short-range wireless technology standard that is used for exchanging data between fixed and mobile devices over short distances and building personal area networks (PANs). In the most widely used mode, transmission power is limi ...
.
The IEEE now considers ''MAC-48'' to be an obsolete term.
''EUI-48'' is now used in all cases. In addition, the EUI-64 numbering system originally encompassed both MAC-48 and EUI-48 identifiers by a simple translation mechanism.
These translations have since been deprecated.
An
Individual Address Block (IAB) is an inactive registry activity which has been replaced by the MA-S (MA-S was previously named OUI-36 and have no overlaps in addresses with IAB
) registry product as of January 1, 2014. The IAB uses an OUI from MA-L (MAC address block large) registry was previously named OUI registry, the term OUI is still in use, but not for calling a registry
) belonging to the IEEE Registration Authority, concatenated with 12 additional IEEE-provided bits (for a total of 36 bits), leaving only 12 bits for the IAB owner to assign to their (up to 4096) individual devices. An IAB is ideal for organizations requiring not more than 4096 unique 48-bit numbers (EUI-48). Unlike an OUI, which allows the assignee to assign values in various different number spaces (for example, EUI-48, EUI-64, and the various context-dependent identifier number spaces, like for
SNAP or
EDID Extended Display Identification Data (EDID) and Enhanced EDID (E-EDID) are metadata formats for display devices to describe their capabilities to a video source (e.g. graphics card or set-top box). The data format is defined by a standard published ...
(VSDB field)), the Individual Address Block could only be used to assign EUI-48 identifiers. All other potential uses based on the OUI from which the IABs are allocated are reserved and remain the property of the IEEE Registration Authority. Between 2007 and September 2012, the OUI value 00:50:C2 was used for IAB assignments. After September 2012, the value 40:D8:55 was used. The owners of an already assigned IAB may continue to use the assignment.
MA-S (MAC address block small) registry activity includes both a 36-bit unique number used in some standards and the assignment of a block of EUI-48 and EUI-64 identifiers (while owner of IAB cannot assign EUI-64) by the IEEE Registration Authority. MA-S does not include assignment of an OUI.
There is also another registry which is called MA-M (MAC address block medium). The MA-M assignment block provides both 2
20 EUI-48 identifiers and 2
36 EUI-64 identifiers (that means first 28 bits are IEEE assigned bits). The first 24 bits of the assigned MA-M block are an OUI assigned to IEEE that will not be reassigned, so the MA-M does not include assignment of an OUI.
Universal vs. local (U/L bit)
Addresses can either be universally administered addresses (UAA) or locally administered addresses (LAA). A universally administered address is uniquely assigned to a device by its manufacturer. The first three octets (in transmission order) identify the organization that issued the identifier and are known as the
organizationally unique identifier (OUI).
The remainder of the address (three octets for EUI-48 or five for EUI-64) are assigned by that organization in nearly any manner they please, subject to the constraint of uniqueness. A locally administered address is assigned to a device by software or a network administrator, overriding the burned-in address for physical devices.
Locally administered addresses are distinguished from universally administered addresses by setting (assigning the value of 1 to) the second-
least-significant bit of the first octet of the address. This bit is also referred to as the ''U/L'' bit, short for ''Universal/Local'', which identifies how the address is administered.
[
][
] If the bit is 0, the address is universally administered, which is why this bit is 0 in all UAAs. If it is 1, the address is locally administered. In the example address the first octet is 06 (hexadecimal), the binary form of which is 00000110, where the second-least-significant bit is 1. Therefore, it is a locally administered address.
Even though many
hypervisor
A hypervisor (also known as a virtual machine monitor, VMM, or virtualizer) is a type of computer software, firmware or hardware that creates and runs virtual machines. A computer on which a hypervisor runs one or more virtual machines is called ...
s manage dynamic MAC addresses
within their own OUI, often it is useful to create an entire unique MAC within the LAA range.
Universal addresses that are administered locally
In
virtualisation, hypervisors such as
QEMU
QEMU is a free and open-source emulator (Quick EMUlator). It emulates the machine's central processing unit, processor through dynamic binary translation and provides a set of different hardware and device models for the machine, enabling it t ...
and
Xen have their own OUIs. Each new virtual machine is started with a MAC address set by assigning the last three bytes to be unique on the local network. While this is local administration of MAC addresses, it is not an LAA in the IEEE sense.
An historical example of this hybrid situation is the
DECnet protocol, where the universal MAC address (OUI AA-00-04, Digital Equipment Corporation) is administered locally. The DECnet software assigns the last three bytes for the complete MAC address to be where reflects the DECnet network address ''xx.yy'' of the host. This eliminates the need for DECnet to have an
address resolution protocol since the MAC address for any DECnet host can be determined from its DECnet address.
Unicast vs. multicast (I/G bit)
The least significant bit of an address's first octet is referred to as the ''I/G'', or ''Individual/Group'', bit.
When this bit is 0 (zero), the
frame is meant to reach only one receiving
NIC. This type of transmission is called
unicast. A unicast frame is transmitted to all nodes within the
collision domain
In physics, a collision is any event in which two or more bodies exert forces on each other in a relatively short time. Although the most common use of the word ''collision'' refers to incidents in which two or more objects collide with great fo ...
. In a modern wired setting the collision domain usually is the length of the Ethernet cable between two network cards. In a wireless setting, the collision domain is all receivers that can detect a given wireless signal. If a
switch
In electrical engineering, a switch is an electrical component that can disconnect or connect the conducting path in an electrical circuit, interrupting the electric current or diverting it from one conductor to another. The most common type of ...
does not know which port leads to a given MAC address, the switch will forward a unicast frame to all of its ports (except the originating port), an action known as
unicast flood
In computer networking, a unicast flood is when a switch receives a unicast frame and treats it as a broadcast frame, flooding the frame to all other ports on the switch.
Background
The term ''unicast'' refers to a one-to-one transmission from one ...
. Only the node with the matching hardware MAC address will accept the frame; network frames with non-matching MAC-addresses are ignored, unless the device is in
promiscuous mode
In computer networking, promiscuous mode is a mode for a wired network interface controller (NIC) or wireless network interface controller (WNIC) that causes the controller to pass all traffic it receives to the central processing unit (CPU) rath ...
.
If the least significant bit of the first octet is set to 1 (i.e. the second hexadecimal digit is odd) the frame will still be sent only once; however, NICs will choose to accept it based on criteria other than the matching of a MAC address: for example, based on a configurable list of accepted multicast MAC addresses. This is called
multicast addressing.
The IEEE has built in several special address types to allow more than one
network interface card to be addressed at one time:
* Packets sent to the
broadcast address, all one bits, are received by all stations on a local area network. In
hexadecimal the broadcast address would be . A broadcast frame is
flooded and is forwarded to and accepted by all other nodes.
* Packets sent to a
multicast address are received by all stations on a LAN that have been configured to receive packets sent to that address.
* Functional addresses identify one or more Token Ring NICs that provide a particular service, defined in IEEE 802.5.
These are all examples of ''group addresses'', as opposed to ''individual addresses''; the least significant bit of the first octet of a MAC address distinguishes individual addresses from group addresses. That bit is set to 0 in individual addresses and set to 1 in group addresses. Group addresses, like individual addresses, can be universally administered or locally administered.
Ranges of group and locally administered addresses
The U/L and I/G bits are handled independently, and there are
instances of all four possibilities.
IPv6 multicast uses locally administered, multicast MAC addresses in the range 33‑33‑xx‑xx‑xx‑xx (with both bits set).
Given the locations of the U/L and I/G bits, they can be discerned in a single digit in common MAC address notation as shown in the following table:
Applications
The following network technologies use the EUI-48 identifier format:
*
IEEE 802
IEEE 802 is a family of Institute of Electrical and Electronics Engineers (IEEE) standards for local area networks (LAN), personal area network (PAN), and metropolitan area networks (MAN). The IEEE 802 LAN/MAN Standards Committee (LMSC) mainta ...
networks
** Ethernet
**
802.11
IEEE 802.11 is part of the IEEE 802 set of local area network (LAN) technical standards, and specifies the set of media access control (MAC) and physical layer (PHY) protocols for implementing wireless local area network (WLAN) computer com ...
wireless networks (
Wi-Fi
Wi-Fi () is a family of wireless network protocols, based on the IEEE 802.11 family of standards, which are commonly used for local area networking of devices and Internet access, allowing nearby digital devices to exchange data by radio wav ...
)
**
Bluetooth
Bluetooth is a short-range wireless technology standard that is used for exchanging data between fixed and mobile devices over short distances and building personal area networks (PANs). In the most widely used mode, transmission power is limi ...
** IEEE 802.5
Token Ring
Token Ring network
IBM hermaphroditic connector with locking clip. Screen contacts are prominently visible, gold-plated signal contacts less so.
Token Ring is a computer networking technology used to build local area networks. It was introduc ...
*
Fiber Distributed Data Interface
Fiber Distributed Data Interface (FDDI) is a standard for data transmission in a local area network.
It uses optical fiber as its standard underlying physical medium, although it was also later specified to use copper cable, in which case it m ...
(FDDI)
*
Asynchronous Transfer Mode
Asynchronous Transfer Mode (ATM) is a telecommunications standard defined by American National Standards Institute (ANSI) and ITU-T (formerly CCITT) for digital transmission of multiple types of traffic. ATM was developed to meet the needs of ...
(ATM), switched virtual connections only, as part of an
NSAP address
*
Fibre Channel and
Serial Attached SCSI (as part of a
World Wide Name)
* The
ITU-T
The ITU Telecommunication Standardization Sector (ITU-T) is one of the three sectors (divisions or units) of the International Telecommunication Union (ITU). It is responsible for coordinating standards for telecommunications and Information Comm ...
G.hn standard, which provides a way to create a high-speed (up to 1 gigabit/s)
local area network
A local area network (LAN) is a computer network that interconnects computers within a limited area such as a residence, school, laboratory, university campus or office building. By contrast, a wide area network (WAN) not only covers a larger ...
using existing home wiring (
power lines
Electric power transmission is the bulk movement of electrical energy from a generating site, such as a power plant, to an electrical substation. The interconnected lines that facilitate this movement form a ''transmission network''. This is d ...
, phone lines and
coaxial cables). The G.hn Application Protocol Convergence (APC) layer accepts Ethernet frames that use the EUI-48 format and encapsulates them into G.hn
Medium Access Control
In IEEE 802 LAN/MAN standards, the medium access control (MAC, also called media access control) sublayer is the layer that controls the hardware responsible for interaction with the wired, optical or wireless transmission medium. The MAC sublay ...
Service Data Units (MSDUs).
Every device that connects to an IEEE 802 network (such as Ethernet and Wi-Fi) has an EUI-48 address. Common networked consumer devices such as PCs, smartphones and tablet computers use EUI-48 addresses.
EUI-64 identifiers are used in:
*
IEEE 1394
IEEE 1394 is an interface standard for a serial bus for high-speed communications and isochronous real-time data transfer. It was developed in the late 1980s and early 1990s by Apple in cooperation with a number of companies, primarily Sony an ...
(FireWire)
*
InfiniBand
InfiniBand (IB) is a computer networking communications standard used in high-performance computing that features very high throughput and very low latency. It is used for data interconnect both among and within computers. InfiniBand is also use ...
*
IPv6
Internet Protocol version 6 (IPv6) is the most recent version of the Internet Protocol (IP), the communications protocol that provides an identification and location system for computers on networks and routes traffic across the Internet. IPv ...
(Modified EUI-64 as the least-significant 64 bits of a unicast network address or link-local address when stateless address autoconfiguration is used.)
IPv6 uses a ''modified EUI-64'', treats MAC-48 as EUI-48 instead (as it is chosen from the same address pool) and inverts the local bit. This results in extending MAC addresses (such as IEEE 802 MAC address) to modified EUI-64 using only (and never ) and with the local bit inverted.
*
ZigBee /
802.15.4 /
6LoWPAN
6LoWPAN (acronym of "IPv6 over Low-Power Wireless Personal Area Networks") in '6LoWPAN: The Embedded Internet', Shelby and Bormann redefine the 6LoWPAN acronym as "IPv6 over lowpower wireless area networks," arguing that "Personal" is no longer re ...
wireless personal-area networks
*
IEEE 11073-20601 (IEEE 11073-20601 compliant medical devices)
Usage in hosts
On broadcast networks, such as Ethernet, the MAC address is expected to uniquely identify each
node
In general, a node is a localized swelling (a "knot") or a point of intersection (a vertex).
Node may refer to:
In mathematics
* Vertex (graph theory), a vertex in a mathematical graph
*Vertex (geometry), a point where two or more curves, lines ...
on that segment and allows frames to be marked for specific hosts. It thus forms the basis of most of the
link layer (OSI
layer 2) networking upon which upper-layer protocols rely to produce complex, functioning networks.
Many network interfaces support changing their MAC address. On most
Unix
Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, an ...
-like systems, the command utility
ifconfig
ifconfig (short for ''interface config'') is a system administration utility in Unix-like operating systems for network interface configuration.
The utility is a command-line interface tool and is also used in the system startup scripts of man ...
may be used to remove and add link address aliases. For instance, the ''active'' ifconfig directive may be used on
NetBSD to specify which of the attached addresses to activate.
Hence, various configuration scripts and utilities permit the randomization of the MAC address at the time of booting or before establishing a network connection.
Changing MAC addresses is necessary in
network virtualization
In computing, network virtualization is the process of combining hardware and software network resources and network functionality into a single, software-based administrative entity, a virtual network. Network virtualization involves platform vi ...
. In
MAC spoofing, this is practiced in exploiting security vulnerabilities of a computer system. Some modern operating systems, such as Apple iOS and Android, especially in mobile devices, are designed to randomize the assignment of a MAC address to network interface when scanning for wireless access points to avert tracking systems.
In
Internet Protocol
The Internet Protocol (IP) is the network layer communications protocol in the Internet protocol suite for relaying datagrams across network boundaries. Its routing function enables internetworking, and essentially establishes the Internet.
...
(IP) networks, the MAC address of an interface corresponding to an
IP address
An Internet Protocol address (IP address) is a numerical label such as that is connected to a computer network that uses the Internet Protocol for communication.. Updated by . An IP address serves two main functions: network interface ident ...
may be queried with the
Address Resolution Protocol (ARP) for
IPv4 and the
Neighbor Discovery Protocol
The Neighbor Discovery Protocol (NDP), or simply Neighbor Discovery (ND), is a protocol of the Internet protocol suite used with Internet Protocol Version 6 (IPv6). It operates at the link layer of the Internet model, and is responsible for gat ...
(NDP) for IPv6, relating OSI
layer 3
In the seven-layer OSI model of computer networking, the network layer is layer 3. The network layer is responsible for packet forwarding including routing through intermediate routers.
Functions
The network layer provides the means of transfe ...
addresses with layer 2 addresses.
Tracking
Randomization
According to
Edward Snowden, the US
National Security Agency
The National Security Agency (NSA) is a national-level intelligence agency of the United States Department of Defense, under the authority of the Director of National Intelligence (DNI). The NSA is responsible for global monitoring, collect ...
has a system that tracks the movements of mobile devices in a city by monitoring MAC addresses. To avert this practice,
Apple
An apple is an edible fruit produced by an apple tree (''Malus domestica''). Apple trees are cultivated worldwide and are the most widely grown species in the genus ''Malus''. The tree originated in Central Asia, where its wild ancestor, ' ...
has started using random MAC addresses in
iOS
iOS (formerly iPhone OS) is a mobile operating system created and developed by Apple Inc. exclusively for its hardware. It is the operating system that powers many of the company's mobile devices, including the iPhone; the term also include ...
devices while scanning for networks.
Other vendors followed quickly. MAC address randomization during scanning was added in Android starting from version 6.0,
Windows 10, and Linux kernel 3.18. The actual implementations of the MAC address randomization technique vary largely in different devices.
Moreover, various flaws and shortcomings in these implementations may allow an attacker to track a device even if its MAC address is changed, for instance its probe requests' other elements, or their timing.
If random MAC addresses are not used, researchers have confirmed that it is possible to link a real identity to a particular wireless MAC address.
Other information leakage
Using
wireless access points in
SSID-hidden mode (
network cloaking), a mobile wireless device may not only disclose its own MAC address when traveling, but even the MAC addresses associated to SSIDs the device has already connected to, if they are configured to send these as part of probe request packets. Alternative modes to prevent this include configuring access points to be either in beacon-broadcasting mode or probe-response with SSID mode. In these modes, probe requests may be unnecessary or sent in broadcast mode without disclosing the identity of previously known networks.
Anonymization
Notational conventions
The standard (
IEEE 802
IEEE 802 is a family of Institute of Electrical and Electronics Engineers (IEEE) standards for local area networks (LAN), personal area network (PAN), and metropolitan area networks (MAN). The IEEE 802 LAN/MAN Standards Committee (LMSC) mainta ...
) format for printing EUI-48 addresses in human-friendly form is six groups of two
hexadecimal digits, separated by hyphens () in transmission order (e.g. ). This form is also commonly used for EUI-64 (e.g. ).
Other conventions include six groups of two hexadecimal digits separated by colons (:) (e.g. ), and three groups of four hexadecimal digits separated by dots (.) (e.g. ); again in transmission order.
[
]
Bit-reversed notation
The standard notation, also called canonical format, for MAC addresses is written in transmission order with the
least significant bit of each byte transmitted first, and is used in the output of the
ifconfig
ifconfig (short for ''interface config'') is a system administration utility in Unix-like operating systems for network interface configuration.
The utility is a command-line interface tool and is also used in the system startup scripts of man ...
,
ip address
An Internet Protocol address (IP address) is a numerical label such as that is connected to a computer network that uses the Internet Protocol for communication.. Updated by . An IP address serves two main functions: network interface ident ...
, and
ipconfig
ipconfig (standing for "Internet Protocol configuration") is a console application program of some computer operating systems that displays all current TCP/IP network configuration values and refreshes Dynamic Host Configuration Protocol (DHCP) an ...
commands, for example.
However, since
IEEE 802.3 (Ethernet) and
IEEE 802.4 (Token Bus) send the bytes (octets) over the wire, left-to-right, with the least significant bit in each byte first, while
IEEE 802.5
Token Ring network
IBM hermaphroditic connector with locking clip. Screen contacts are prominently visible, gold-plated signal contacts less so.
Token Ring is a computer networking technology used to build local area networks. It was introduc ...
(Token Ring) and
IEEE 802.6 (FDDI) send the bytes over the wire with the most significant bit first, confusion may arise when an address in the latter scenario is represented with bits reversed from the canonical representation. For example, an address in canonical form would be transmitted over the wire as bits
01001000 00101100 01101010 00011110 01011001 00111101
in the standard transmission order (least significant bit first). But for Token Ring networks, it would be transmitted as bits
00010010 00110100 01010110 01111000 10011010 10111100
in most-significant-bit first order. The latter might be incorrectly displayed as . This is referred to as ''bit-reversed order'', ''non-canonical form'', ''MSB format'', ''IBM format'', or ''Token Ring format'', as explained in .
See also
*
Hot Standby Router Protocol
In computer networking, the Hot Standby Router Protocol (HSRP) is a Cisco proprietary redundancy protocol for establishing a fault-tolerant default gateway. Version 1 of the protocol was described in in 1998. Version 2 of the protocol includes ...
*
MAC filtering
*
Network management
Network management is the process of administering and managing computer networks. Services provided by this discipline include fault analysis, performance management, provisioning of networks and maintaining quality of service. Network managem ...
*
Sleep Proxy Service
Apple's Bonjour Sleep Proxy service is an open source component of zero-configuration networking, designed to assist in reducing power consumption of networked electronic devices.
A device acting as a sleep proxy server will respond to Multica ...
, which may spoof another device's MAC address during certain periods
*
Transparent bridging
A network bridge is a computer networking device that creates a single, aggregate network from multiple communication networks or network segments. This function is called network bridging. Bridging is distinct from routing. Routing allows mu ...
*
Virtual Router Redundancy Protocol
Notes
References
{{Reflist, 30em
External links
IEEE Registration Authority Tutorials*
ttp://standards-oui.ieee.org/oui/oui.txt IEEE Public OUI/MA-L listIEEE Public OUI-28/MA-M listIEEE Public OUI-36/MA-S listIEEE Public IAB listIEEE IAB and OUI MAC Address Lookup Database and APIRFC 7042. IANA Considerations and IETF Protocol and Documentation Usage for IEEE 802 ParametersIANA list of Ethernet Numbersan
MAC address list
Media access control
Network addressing
Unique identifiers