“Media Access Control” is the abbreviation for “Media Access Control Address.”
Over a network, an address is a unique identifier for an Ethernet or network device. It’s also known as a hardware address, a physical address, or a burned-in address.
Because the MAC Address is built into every network card, such as an Ethernet or Wi-Fi card, it cannot be modified. It distinguishes between distinct network interfaces and is used in a variety of network technologies, including the majority of IEEE 802 networks, such as Ethernet.
MAC addresses appear in the OSI model’s Media Access Control protocol sub-layer. Because a single NIC or Ethernet port is represented by a Media Access Control Address, these addresses are commonly referred to as unicast Ethernet addresses.
The word “unicast” simply refers to the fact that the address reflects only one Ethernet LAN port.
To send/receive data successfully, each device’s Media Access Control Address must be unique. When your computer (or host, as the Internet protocol refers to it) connects to the Internet, a correspondence table links your IP address to your computer’s Media Access Control Address (physical) address on the LAN.
The format of MAC Address
The rules of the three numbering namespaces, which are administered by the Institute of Electrical and Electronic Engineers, are used to create the Media Access Control Address (IEEE). Six sets of two numerals or characters are separated by hyphens in this format.
Most computers display Media Access Control Address as 12-digit hexadecimal digits for simplicity. 30-65-EC-6F-C4-58 is an example of a MAC address. Some manufacturers, such as Dell, include an Organizationally Unique Identifier (OUI) in the Media Access Control Address, which is used to identify the manufacturer.
Some well-known companies’ OUIs are:
- Dell: 00-14-22.
- Cisco: 00-40-96.
- Nortel: 00-04-DC.
Some firms may have more than one MAC address.
Types of MAC Address
- Unicast – A frame with a Unicast address is only sent to the interface that leads to a specific NIC. When the LSB (least significant bit) of an address’s first octet is set to zero, the frame is intended for only one receiving NIC. The source machine’s Media Access Control Address is always Unicast.
- The source can deliver a frame to a group of devices using a multicast address. The LSB (least significant bit) of the first octet of an address is set to one in Layer-2 (Ethernet) Multicast addresses. The address block 01-80-C2-xx-xx-xx (01-80 C2-00-00-00 to 01-80-C2-FF-FF-FF) has been assigned to group addresses for use by standard protocols by IEEE.
- Broadcast – Broadcast is feasible on the underlying layer, just like it is on the network layer ( Data Link Layer). The broadcast address is defined as Ethernet frames with ones in all bits of the destination address (FF-FF-FF-FF-FF-FF . Frames with the MAC address FF-FF-FF-FF-FF-FF
How to find a MAC address of network device?
Users can find the MAC address of a machine using a variety of command-line and GUI programmes provided by operating systems.
- On Unix variants including Solaris and Linux support
“ifconfig -a”, “ip link list” or “ip address show” the command that displays Media Access Control Address of the network device among other useful information.
- In Windows
“ipconfig /all” the command that displays MAC address.
- On a macOS, one can find MAC address by opening “System Preferences”, then select “Network”.
Networks and MAC addresses
The MAC addresses of all devices on the same network subnet are distinct. The Media Access Control Address is extremely helpful in troubleshooting network difficulties, such as IP address issues.
In contrast to a dynamic IP address, which can vary from time to time, MAC addresses are useful for network diagnostics since they never change. As a result, a MAC address provides a more trustworthy means for a network administrator to identify senders and recipients of data on the network.