In our blog on “OSI Model,” we have seen that the MAC address works at the second layer of the OSI model the “Data Link Layer” where it is responsible for transmitting the data packets that arrive from the network to the main host, which is MAC address.
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MAC Address
MAC Address is a “Media Access Control” which is a unique and permanent address of networking devices that cannot be changed because its permanent. It is used to identify the device over the network, To make the connectivity of the device to the network there is a need for NIC which is a “Network Interface Card”. NIC helps devices provide a connection to the internet so that devices can connect with the network. And, We require two more addresses to communicate between two networked devices that are: an IP address and a MAC address.
MAC address is also known as Physical and hardware address, which is assigned by the manufacturer when the device is produced.
Example of MAC Address
00:1B:44:11:3A:B7
The first six digits 00:1B:44 is provided by the manufacturer and the rest of the digit is 11:3A: B7 which is NIC Address.
OUI
It stands for the Organizationally unique identifier (OUI) which refers to a 24-bit number. It is assigned by the vendors or we can say, the manufacturer.
NIC
It stands for “Network Interface Card” which refers to a 48-bit unique serial number. This address helps to connect the network device to the network via the internet.
Types of MAC Address
There are mainly three types of MAC addresses:
- Unicast
- Multicast
- Broadcast
1) Unicast MAC Address
Unicast MAC Address is an address that is assigned to NIC (Network Interface Card). In unicast “Uni” means one and “Cast” means sending/sharing, which means it is used to send single files from one place the one destination device. It is basically known as “Unicast MAC Address”.
In the given diagram the green line shows the sharing of data from one to another device in a LAN network.
2) Broadcast MAC Address
Broadcast address means sending the data to all which mean that device 1 can share the file with all the other device over the network which is required to send it. It is known as “Broadcast MAC Address”.
In Broadcast MAC addresses, there are two types:
- Limited Broadcast
- Direct Broadcast
Suppose there are two areas of the network “Network A” & “Network B”, So In the limited broadcast the packets send to all the host devices within a specific network area or we can say the Home network area. If the message sends to all within Network A, it is known as a “Limited Broadcast”. On the other hand, Direct broadcast sends the data to all from Network A to Network B. It is basically known as “Direct Broadcast.
3) Multicast MAC Address
In multicast MAC addresses, the files can be sent to a group of computers over the LAN network. It is known as “Multicast MAC Address”.Multicast IP addresses fall within the range 224.0.0.0 – 239.255.255.255.
