The Lazy Networker

A MAC Address (Media Access Control Address) is a unique hardware identifier given to every network interface card (NIC), whether it’s wired (Ethernet) or wireless (Wi-Fi).

Think of it like a permanent serial number for your network card, used at the data link layer (Layer 2) of the OSI model.

✅ Format of a MAC Address

• 48-bit address (6 pairs of hexadecimal numbers).
• Written as: 00:1A:2B:3C:4D:5E (colon separated) 00-1A-2B-3C-4D-5E (hyphen separated)
• First 3 pairs → identify the manufacturer (called OUI – Organizationally Unique Identifier).
• Last 3 pairs → uniquely assigned to the device.

✅ Example

D4:6D:6D:A2:34:BC

• D4:6D:6D → Vendor (e.g., Intel, Cisco, etc.)
• A2:34:BC → Unique device ID.

✅ Uses of MAC Address

1. Device Identification – Every networked device has a unique MAC.
2. LAN Communication – Switches use MAC addresses to forward data within a local network.
3. Filtering & Security – Wi-Fi routers can allow/block devices using MAC filtering.
4. Troubleshooting – Network admins track devices using their MAC.
5. ARP (Address Resolution Protocol) – Maps IP address → MAC address to deliver packets.

👉 In simple terms:

• IP Address = Logical address (can change, given by network).
• MAC Address = Permanent hardware address (burned into NIC).