What is MAC Address?

A MAC address (Media Access Control address) is a unique identifier assigned to network interfaces for communications on a physical network segment. It is a hardware address that uniquely identifies each device on a network at the data link layer of the OSI model.

Key characteristics of a MAC address:

• Uniqueness: Each network interface card (NIC) or network adapter has a globally unique MAC address. No two devices should have the same MAC address.
• Format: A MAC address is typically represented as a series of six pairs of hexadecimal digits (0-9 and A-F), separated by colons or hyphens. For example, a MAC address might look like 00:1A:2B:3C:4D:5E.
• Assignment: MAC addresses are assigned by the manufacturer of the network interface. The first half of the MAC address (the first three pairs) often represents the vendor's unique identifier, known as the OUI (Organizationally Unique Identifier).
• Roles: MAC addresses play a crucial role in the functioning of network protocols, such as Ethernet. They are used to uniquely identify devices on a local network and are essential for the proper delivery of data frames within that network.
• Layer in the OSI Model: MAC addresses operate at the data link layer (Layer 2) of the OSI model. They are used to identify devices on the same physical network segment and are not routable across different network segments.
• Persistence: MAC addresses are usually hard-coded into the network interface hardware by the manufacturer. However, some devices, particularly in virtualized environments, allow for the configuration of a virtual MAC address.
• Role in Networking: MAC addresses are crucial for local network communication. When devices communicate within the same local network, they use MAC addresses to address and deliver data frames directly to the intended recipient.

It's important to note that while MAC addresses are essential for local network communication, devices on different network segments communicate using IP addresses. MAC addresses are used within a local network, and IP addresses are used for communication across networks.

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