What is mac address?

February 18, 2015
What is mac address?

MAC (media access control) is a unique identifying network device address. The address length is 6 bytes and is written in hexadecimal.

Let's take a closer look at what a MAC address is and what it is for.

The concept of MAC address

In terms of the OSI / RM Open Systems Interconnection Reference Model, the MAC address represents the lower link layer sublayer of the OSI / RM model (Media Access Control).

Mac address is hardware and almost never can be changed, by its value you can determine the manufacturer of network equipment (three high bytes). The Mac address is assigned to the device to identify it on the network. All data transmitted over an Ethernet network contains the MAC of the sender and receiver, and the type of the MAC address is identified by the value of the first bit.

Types of MAC Addresses

  1. Unique (unicast). The oldest (leftmost) bit is always 0.
  2. Group mailing (multicast). Always contains 1 in the most significant bit of the high byte. The remaining bits can take any value.
  3. Broadcast (broadcast). Consists of 1 in all 48 digits (FF: FF: FF: FF: FF: FF).