# Ethernet Addressing (MAC)

* [Ethernet](https://app.gitbook.com/@mudassirs46/s/network-fundamentals/~/drafts/-MRZ8l67L5MHnaQIEh9W/an-ethernet) Address is also called MAC Address (Media Access Control).
* MAC Address is 6 Bytes, 48 bits Hexadecimal Address.  
* This MAC Address is made up of 6 Sets & each Set includes 8 bits of Hexadecimal characters separated by periods.
* MAC Address is pre-programmed in every NIC card.
* IEEE Assigns the first 3 Bytes unique to the NIC card called the Organizationally Unique Identifier (OUI). And the manufacturer assigns the remaining 3 Bytes unique to every NIC card that they manufacture.
* In this way, No two NIC cards will have the same MAC Address. Hence MAC Address is also called a Unicast Ethernet Address, LAN address, Ethernet address, hardware address, burned-in address, physical address & universal address.

  **6 Bytes (48 Bits) MAC Address:**

  |       OUI      |     Vendor     |
  | :------------: | :------------: |
  |     24bits     |     24bits     |
  |    00 60 2F    |    3A 07 BC    |
  | (6 Hex digits) | (6 Hex digits) |

### Group Address:

Apart from the Unicast Ethernet Address, Ethernet also uses Group Addresses which are divided into two categories:

* **Broadcast Address:**
  * Frame sent to this address will be delivered to all the devices of that LAN. It is FF:FF:FF:FF:FF:FF
* **Multicast Address:**

  * Frame sent to this address will be copied & delivered to a group belonging to that specific Multicast address & not to all the devices.    

  **Reference:**

  CCNA 200-301 OCG, Volume 1, Pg. 50-51 - Wendell Odom.


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