How many bits are in a MAC address?
The correct answer and explanation is:
A MAC (Media Access Control) address is composed of 48 bits.
A MAC address is a unique identifier assigned to network interfaces for communication on a network. It is primarily used in Ethernet and Wi-Fi networking. The MAC address is essential for devices to identify and communicate with each other on the local network.
A MAC address is structured as a sequence of 48 bits, typically represented as 12 hexadecimal characters. Each hexadecimal character corresponds to 4 bits, so 12 characters make up 48 bits in total. The format of the MAC address usually follows this pattern:
XX:XX:XX:XX:XX:XX
Where each “XX” represents two hexadecimal digits. Since each hexadecimal digit represents 4 bits, two digits (XX) represent 8 bits. Therefore, six pairs of hexadecimal digits, or 12 characters, equal 48 bits.
This address is divided into two parts: the first 24 bits are the Organizationally Unique Identifier (OUI), which is assigned to the manufacturer by the IEEE (Institute of Electrical and Electronics Engineers). The remaining 24 bits are the Network Interface Controller (NIC) specific identifier, which is assigned by the manufacturer, ensuring the uniqueness of the MAC address for each device they produce.
Because the MAC address is hardcoded into the device’s network interface card, it plays a crucial role in local network communication, such as identifying devices in protocols like Ethernet and Wi-Fi. It is used by devices to distinguish themselves from others on the network and route data accurately to the correct device.
Although a MAC address is not used for global routing or across the Internet (as that is handled by IP addresses), it is vital for communication within local networks.