A network switch is a hardware device that connects multiple devices within a Local Area Network (LAN) and directs data only to the device for which it is intended. Unlike a hub, which broadcasts data to all devices, a switch intelligently routes information.
2. How Switches Work (Step-by-Step)
Each device on a LAN has a MAC address.
When a device sends data, the switch reads the packet and records the sender's MAC address and the port it arrived on.
The switch checks its MAC address table to see which port is assigned to the recipient's MAC address.
If found, it forwards the data to that port only. If not, it broadcasts the packet.
3. Key Functions of a Switch
MAC address learning and filtering.
Full-duplex communication (simultaneous send/receive).
Segmentation of collision domains.
Packet switching for efficiency.
4. Types of Switches
Unmanaged Switch: Plug-and-play, no configuration.
Managed Switch: Provides control via CLI or web GUI (VLANs, QoS, monitoring).
Layer 2 Switch: Operates at Data Link layer (MAC-based switching).
Layer 3 Switch: Performs routing functions based on IP addresses.
PoE Switch: Powers devices like IP cameras or phones over Ethernet cables.
5. Real-World Use Cases
Offices: Connect computers, printers, and phones in a LAN.
Data Centers: Handle massive internal traffic between servers.
Homes: Smart TVs, NAS, and PCs connected via Ethernet.
Security Systems: PoE switches used to power and connect IP cameras.
6. Benefits of Using Switches
Reduces network traffic and collisions.
Increases performance and efficiency.
Scalable for growing networks.
Supports advanced networking features in managed variants.
7. Limitations / Challenges
More expensive than hubs.
Managed switches require technical knowledge.
Layer 3 switches can be complex and costly.
8. Switch vs Hub vs Router
Device
Purpose
Intelligence
Layer
Switch
Connects devices in LAN
Medium (MAC-based)
Layer 2/3
Hub
Broadcasts to all ports
Low
Layer 1
Router
Connects different networks
High (IP-based)
Layer 3
9. Common Misunderstandings
Switches do not assign IP addresses (DHCP comes from routers or servers).
Adding a switch does not automatically increase internet speed — it improves local traffic.
Managed switches require setup; unmanaged ones do not.
10. Key Takeaways
Switches are smarter than hubs and more focused on internal LAN efficiency.
Managed switches offer flexibility and advanced features for enterprise use.
Essential for building reliable, high-performance local networks.