MAC Full Form

MAC Full Form

Full Form of MAC is – Media Access Control

What is MAC Address

The Media Access Control (MAC) address is a binary number that a computer network adapter uniquely identifies. The purpose of each identifier is to be unique to a particular device.

These numbers, sometimes also called hardware addresses or physical addresses, are embedded in network hardware, or stored in firmware, during the manufacturing process, and are not modified.

Some people call them Ethernet addresses for historical reasons, but all types of networks, including Ethernet, Wi-Fi, and Bluetooth, use MAC addressing.

MAC address is formed according to the rules of three numbering namespace, which is managed by the Institute of Electrical and Electronic Engineers (IEEE).

MAC addresses are often assigned by the manufacturer of the Network Interface Controller (NIC) and stored in its hardware, such as the card’s read-only memory or some other firmware mechanism.

When assigned by the manufacturer, the MAC address usually encodes the manufacturer’s registered identification number and can be referred to as a burned-in address (BIA).

It is also known as Ethernet hardware address (EHA), hardware address or physical address.

In short, MAC address remains unchanged for the entire life time of any device, but IP address is like a postal code which can be changed.

In IEEE 802 standard, the data link layer is divided into two sub-layers –

Logical Link Control(LLC) Sublayer

Media Access Control(MAC) Sublayer

The MAC address is used by the Media Access Control (MAC) sub-layer of the Data-Link Layer. MAC address is a broad term, since there are millions of network devices and we need to uniquely identify each one.

MAC Address Used For?

An application of MAC addresses is a filtering process on wireless networks. To prevent strangers from accessing the network, the router can only accept specific MAC addresses.

This way, if the IP address changes, for example in the case of a dynamic IP address, the MAC address can still identify the device.

Filtering can be used to track network users and limit their access. It may also have other uses, such as detecting when unknown devices are connected to the network.

For these reasons, many companies and institutions require the MAC addresses of their members’ devices.

Therefore, it is important that the device owner should not disclose his/her MAC address to anyone except an authorized staff.

What is the format of MAC address?

A MAC address consists of six sets of two characters, each set separated by a colon.

Traditional MAC addresses are 12 digit (6 bytes or 48 bits) hexadecimal numbers. They are usually written in one of the following three formats:

MM:MM:MM:SS:SS:SS

MM-MM-MM-SS-SS-SS

MMM.MMM.SSS.SSS

The first 6-digit of the MAC address identifies the manufacturer, which is called OUI (Organizational Unique Identifier). The IEEE Registration Authority Committee assigns these MAC prefixes to its registered vendors.

Here are some OUIs from famous manufacturers:

CC:46:D6 – Cisco
3C:5A:B4 – Google, Inc.
3C:D9:2B – Hewlett Packard
00:9A:CD – HUAWEI TECHNOLOGIES CO.,LTD

The six digits of the right represent the Network Interface Controller, which is assigned by the manufacturer.

As discussed above, MAC addresses are represented by Colon-Hexadecimal notation. But this is just a conversion, not mandatory. MAC address can be presented using any of the following formats –

Hypen-Hexadecimal Notation:

00-0a-83-b1-c0-8e

Colon-Hexadecimal Notation:

00:0aL83:b1:c0:8e

Period-Separated Hexadecimal Notation:

000.a83.b1c.08e

What is 64-bit MAC Addresses?

While all traditional MAC addresses are 48 bits, some types of networks require 64-bit addresses instead.

For example, ZigBee wireless home automation and other similar networks based on IEEE 802.15.4 require 64-bit MAC addresses to be configured on their hardware devices.

TCP/IP networks over IPv6 also apply a different approach to communicating with MAC addresses than over IPv4. Instead of a 64-bit hardware address, IPv6 automatically translates a 48-bit MAC address into a 64-bit address by inserting a fixed (hardcoded) 16-bit FFFE value between the vendor prefix and the device identifier.

IPv6 calls these numbers “identifiers” to distinguish them from true 64-bit hardware addresses.

Leave a Reply

Your email address will not be published.