What is MAC address or Layer 2 address or physical address

Media Access Control (MAC address or Layer 2 addresses or physical address or hardware address) addresses are 48 bit (six bytes) binary addresses represented in hexadecimals. The purpose of representing the binary address in hexadecimal format is to make it easier for humans to read and understand. MAC addresses are theoretically permanent numbers, which are burned into the network card.

Every network adapter has a MAC (Media Access Control) address assigned to it when it is manufactured. MAC (Media Access Control) addresses are hard-coded into network adapter.

MAC addresses are typically locally specific. The scope of a MAC address is limited within a Local Area Network (LAN).

MAC addresses are binary numbers which are represented in its hexadecimal equivalent. For example, the 48-bit MAC address 10101010.11110000.11000001.11100010.01110111.01010001 in binary can be represented as shorter hexadecimal equivalent AA.F0.C1.E2.77.51.

In a MAC address, one hexadecimal digit resembles a group of four contiguous binary bits, called a nibble. The first nibble 1010 from the left most byte in above example represent the first equivalent hexadecimal A in its hexadecimal representation, and the second nibble 1010 from the left most byte in above example represent the second equivalent hexadecimal A in its hexadecimal representation.

To view the MAC Address of your network card when you are using Windows Operating System, run command prompt, cmd (Right-click Start > Run > type cmd and click "OK").


Type the command "ipconfig /all" in the prompt and Enter. Do remember to remove double quotes.


The first three bytes of the MAC address identifies the vendor who manufactured the product (Example: a NIC Card), and is known as OUI (Organizationally Unique Identifier). OUI (Organizationally Unique Identifier) numbers are assigned by the IEEE to te manufacturer. Next three bytes are Network Interface Controller Specific number. Network Interface Controller specific number are assigned by manufacturer to the NIC.

Refer below image to understand OUI (Organizationally Unique Identifier) part and NIC specific part of MAC addresses.


You can search for the OUI listings in following URLs.


Refer the following table for easy conversion from binary to decimal and hexadecimal numbers.

Decimal Binary Hexadecimal
0 0 0
1 1 1
2 10 2
3 11 3
4 100 4
5 101 5
6 110 6
7 111 7
8 1000 8
9 1001 9
10 1010 A
11 1011 B
12 1100 C
13 1101 D
14 1110 E
15 1111 F


Following are some important MAC addresses you need to remember.

• MAC Address FF:FF:FF:FF:FF:FF is reserved for Broadcast type of communication. An Ethernet Switch will flood an Ethernet Frame with FF:FF:FF:FF:FF:FF as the destination MAC Address to all its connected ports.

• MAC Addresses 01:00:5E:00:00:00 - 01:00:5E:7F:FF:FF are reserved for IPv4 Multicast.

• MAC Addresses of the range 33:33:xx:xx:xx:xx are reserved for IPv6 Multicast.

Related Tutorials
Unicast, Multicast and Broadcast
Broadcast domain
Binary Decimal and Hexadecimal numbers and conversions
How to use calculator for binary, decimal and hexadecimal number conversions
TCP/IP model
Datalink layer of TCP/IP model
Ethernet Frame Format
MAC addresses
Broadcast MAC Address - ff:ff:ff:ff:ff:ff
IPv4 multicast MAC Addresses
Network layer of TCP/IP model
IPv4 Protocol, IPv4 header and fields of IPv4 header
IPv4 addresses
Class A networks and Class A IP addresses
Class B networks and Class B IP addresses
Class C networks and Class C IP addresses
Class D multicast IP addresses
IPv4 link-local multicast addresses
IPv4 Internetwork control block multicast addresses
IPv4 Source-Specific Multicast (SSM) address reservation
IPv4 GLOP multicast addresses
Administratively scoped multicast address block or Limited scope addresses
Multicast IPv4 address to MAC address mapping
What is limited broadcast in IPv4 and how limited broadcast works
What is directed broadcast in IPv4 and how directed broadcast works
Transport layer of TCP/IP model
TCP/IP Encapsulation and Decapsulation
What is multicast
What is multicast group
Advantages and disadvantages of multicast
Comparison of multicast with unicast and broadcast
Advantages and disadvantages of multicast
How IPv4 multicast works on LAN
Subnetting - Part 1
Subnetting - Part 2
Subnetting - Part 3
Subnetting - Part 4
Subnetting - Part 5
Subnetting - Part 6
Variable Length Subnet Masking, VLSM, IP V4 Subnetting, subnetting tutorials, IP study guides, IP documentation, IP tutorials
Supernetting, IP Supernetting, IP Supernetting tutorial, How to Supernet, Supernetting Guide, Supernetting Concepts
How to find out the Network Address and Broadcast Address of a subnetted IPv4 address
Address Resolution Protocol Tutorial, How ARP work, ARP Message Format
What is Gratuitous ARP