Routing and Switching

Switching moves data within a local network (Layer 2), while routing moves data between different networks (Layer 3). Together, they form the backbone of how data travels from source to destination across the Internet and private networks.

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Switching — Layer 2

A switch connects devices on the same local area network (LAN) and forwards frames based on MAC addresses.

How a Switch Works

1. A frame arrives at a switch port
2. The switch reads the source MAC address and records it in the MAC address table (also called the CAM table)
3. The switch looks up the destination MAC address in the table
4. If found, the frame is forwarded to the specific port (unicast)
5. If not found, the frame is flooded to all ports except the source (unknown unicast)

MAC Address Table (CAM Table):

| MAC Address        | Port |
|--------------------|------|
| AA:BB:CC:DD:EE:01  | 1    |
| AA:BB:CC:DD:EE:02  | 3    |
| AA:BB:CC:DD:EE:03  | 5    |

Switch Features