先决条件 – 网络设备
中心：
集线器是一种网络设备，用于将信号传输到每个端口(一个端口除外)以响应接收信号。集线器在物理层上运行。在这个包过滤是不可用的。它有两种类型：主动集线器、被动集线器。
转变：
交换机是一种网络设备，用于根据需要实现连接建立和连接终止。交换机在数据链路层上运行。在这个包过滤是可用的。它是一种全双工传输模式，也称为高效桥接器。
集线器和交换机的区别：
| S.NO | HUB | SWITCH |
|---|---|---|
| 1. | Hub is operated on Physical layer of OSI model. | While switch is operated on Data link layer of OSI Model. |
| 2. | Hub is a broadcast type transmission. | While switch is a Unicast, multicast and broadcast type transmission. |
| 3. | Hub have 4/12 ports. | While switch can have 24 to 48 ports. |
| 4. | In hub, there is only one collision domain. | While in switch, different ports have own collision domain. |
| 5. | Hub is a half duplex transmission mode. | While switch is a full duplex transmission mode. |
| 6. | In hub, Packet filtering is not provided. | While in switch, Packet filtering is provided. |
| 7. | Hub cannot be used as a repeater. | While switch can be used as a repeater. |
| 8. | Hub is not an intelligent device that sends message to all ports hence it is comparatively inexpensive. | While switch is an intelligent device that sends message to selected destination so it is expensive. |
| 9. | Hub is simply old type of device and is not generally used. | While switch is very sophisticated device and widely used. |
| 10. | Hacking of systems attached to hub is complex. | Hacking of systems attached to switch is little easy. |