Switching is the process of sending data to the correct device inside a Local Area Network (LAN) using a network switch.
What Problem Switching Solves
Without switching:
- Data would be sent to every device
- Networks would be slow and congested
Switching ensures data goes only to the intended device.
What a Switch Does (In Simple Terms)
A network switch:
- Connects devices in a LAN
- Learns which device is on which port
- Sends data only where it is needed
How Switching Works (Step-by-Step)
- Frame Arrives
- A device sends an Ethernet frame to the switch
- MAC Address Check
- The switch reads the destination MAC (Media Access Control) address
- MAC Address Table Lookup
- The switch checks its MAC address table to find the correct port
- Forwarding Decision
- If the MAC address is known → send frame to one port
- If unknown → flood the frame to all ports (except the one it came from)
- Learning
- The switch records the source MAC address and the port it arrived on
Key Functions That Enable Switching
Learning
- Builds the MAC address table automatically
Forwarding
- Sends frames to the correct port
Filtering
- Prevents frames from being sent to unnecessary ports
Flooding
- Used when the destination MAC is unknown or for broadcast frames
Example
- PC A sends data to PC B
- The switch learns PC A’s MAC address
- The switch forwards data only to PC B’s port
Where Switching Is Used
- Home networks
- School and office LANs
- Data centers
In One Sentence
Switching allows Ethernet frames to be delivered efficiently to the correct device within a LAN.
