MAC address is also known as Media access Control Address. it is a unique identifier an ethernet and Network adapter over a network. It is also known as an Ethernet address, hardware address or physical address. It is assigned in hardware fixed by manufacture.It cannot be changed unless you change the hardware. but their is many way to fool the others by using some tools.

This is used in most in IEEE 802 technologies including ethernet,wifi and Bluetooth.This are recognizable as six groups of two hexadecimal digits, separated by hyphens, colons, or without a separator. Mac address is stored in hardware like cards which are read only memory or by Firmware mechanism.

Also Read: What is IP address?

Address details

The original IEEE 802 MAC address comes from the original Xerox Network Systems Ethernet addressing scheme. This 48-bit address space contains potentially 248 (over 281 trillion) possible Mac

The IEEE 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. 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


  • Bluetooth
  • WIFI
  • Ethenet
  • ATM(Asynchronous Transfer Mode)
  • Ipv6
  • Firewire(IEEE 1394)


MAC Address is a 12-digit hexadecimal number (6-Byte binary number), which is mostly represented by Colon-Hexadecimal notation. First 6-digits (say 00:40:96) of MAC Address identifies the manufacturer, called as OUI (Organizational Unique Identifier). IEEE Registration Authority Committee assign these MAC prefixes to its registered vendors.


CC:46:D6 - Cisco 
3C:5A:B4 - Google, Inc.
3C:D9:2B - Hewlett Packard
Mac address format


  • Unicast
  • Broadcast
  • Multicast