The key difference between a network hub and a network switch lies in how they handle incoming data: a hub broadcasts data to all connected devices, while a switch selectively forwards data only to the intended recipient.
Here's a more detailed breakdown:
Hub:
- Broadcast Mechanism: When a hub receives a data packet, it copies and sends the packet to every device connected to it. This is like announcing something over a loudspeaker to everyone in a room, regardless of whether they need to hear it.
- Collision Domain: All devices connected to a hub share the same collision domain. This means only one device can transmit at a time, or a collision will occur, requiring devices to retransmit. This limits overall network performance.
- Dumb Device: Hubs operate at the physical layer (Layer 1) of the OSI model. They are essentially simple repeaters and do not analyze the data they transmit.
- Cost: Hubs are generally cheaper than switches.
- Obsolete Technology: Hubs are largely obsolete in modern networks due to their inefficiency.
Switch:
- Intelligent Forwarding: Switches examine the destination Media Access Control (MAC) address of incoming data packets. They maintain a MAC address table that maps MAC addresses to specific ports. Using this table, a switch forwards the data packet only to the port connected to the device with the matching MAC address. This is like delivering a letter directly to the person it's addressed to.
- Separate Collision Domains: Each port on a switch represents a separate collision domain. This allows multiple devices to transmit simultaneously without causing collisions, significantly improving network performance.
- Smart Device: Switches operate at the data link layer (Layer 2) of the OSI model.
- Cost: Switches are generally more expensive than hubs.
- Modern Technology: Switches are the standard for modern network infrastructure.
Comparison Table:
| Feature | Hub | Switch |
|---|---|---|
| Data Handling | Broadcasts to all devices | Forwards only to the intended device |
| Collision Domain | Single collision domain for all ports | Separate collision domain per port |
| Intelligence | Simple repeater (Layer 1) | Learns MAC addresses (Layer 2) |
| Performance | Lower | Higher |
| Cost | Lower | Higher |
| Usage | Obsolete | Standard in modern networks |
In summary, a switch is a more intelligent and efficient device than a hub, leading to better network performance and reduced collisions. While hubs were once a cost-effective solution, they are now largely replaced by switches in modern networks.
