DATA
💻
Client
192.168.1.10
AA:AA:AA:AA:AA:AA
🌐
Router
Gateway
☁️
Server
10.0.0.50
DD:DD:DD:DD:DD:DD
Live Packet Inspector
Layer 3: IP Header (Logical)
Src IP
--
Dst IP
--
Layer 2: Ethernet Header (Physical)
Src MAC
--
Dst MAC
--

IP Address

  • Logical Address: Assigned via software. Changes if you switch networks.
  • Scope: Global. Used for end-to-end delivery across the entire internet.
  • Layer: Network Layer (Layer 3).

MAC Address

  • Physical Address: Burned into hardware. Usually permanent.
  • Scope: Local. Only used to jump from one device to the next in a local link.
  • Layer: Data Link Layer (Layer 2).

The Postal Analogy

Imagine sending a letter. The IP Address is the name and home address on the envelope—it never changes. The MAC Address is the vehicle carrying the letter. First, it's a mail truck, then a plane, then a delivery bike. The vehicle changes at every "hop," but the destination on the envelope stays the same.