In a network, multiple devices are interconnected. To ensure that information reaches the correct destination, we need addresses. There are two types of addresses.

  • MAC address

    • Definition: unique hardware address assigned to a device’s network interface card
    • Format: 48 bits - colon separated hexadecimal
      • for readability, this sequence is split into six groups of 8 bits
    • Scope: works within a single local network (LAN)

  • IP address

    • Definition: logical identifier assigned to a device to enable communication across networks
    • Versions
      • IPv4: 32-bit
      • IPv6: 128-bit
    • Scope: works across different networks
    • Format: 32-bit binary sequence
ifconfig

MAC Address and Manufacturer

A MAC address is not just a random identifier. The first 24 bits known as the Organizationally Unique Identifier (OUI) are assigned by the IEEE to hardware manufacturers. This ensures that each device produced by a vendor has a unique address.

  • OUI (first 3 bytes) - identifies the manufacturer
  • Device-specific portion (last 3 bytes) - uniquely identifies a specific network interface card made by that manufacturer

Examples of IP to organization:

8.8.8.8 - Google DNS