What is a Hub?
. A networking device used to connect multiple computers, servers to make them work in a single network.
. Hub works in 'Physical Layer' of OSI model.
. It is a small box containing number of ports to connect multiple devices.
. It receives signals, amplify them and sends to multiples devices in network.
. When it receives signals from one port, it sends the signal to all the ports.
Types of Hubs:
Active Hub:
. It amplifies or regenerate the incoming signal and send it to all connecting devices.
. Also known as Multiport repeater.
Passive Hub:
. Works as simple bridge to connect devices in network.
. It just receives signals and pass them to other devices without regernating.
Intelligent Hub:
. Performs tasks of both Active and Passive hubs.
. Increases speed and effectiveness of total network.
Drawbacks:
. Creates lot of traffic.
. User cannot send data to a particular device.
. If it receives signal at one port, it forwards to all devices wasting bandwidth.
. Collisions occur due to unwanted signal transmission sometimes.
What is a Switch?
. Switch sends data from one of the multiple ports to required destination in the network.
. Works on Data link layer of OSI model.
. It is similar to Hub like connecting multiple devices in a network but it is smarter.
. It checks the IP address or MAC address in the packet it received and sends that packet to the required destination instead of forwarding to each device.
. In some Routers, Switch is inbuilt present with less number of ports.
. In small offices, organizations, Switches are connected after Router to connect to multiple devices.
Switch Vs Hub:
| Property | Switch | Hub |
|---|---|---|
| Device Type | Multicasting Device | Broadcasting Device |
| Layer | Operates on Data Link Layer | Operates on Physical Layer |
| Data form | Transmits data as packets | Transmits data in bits or electric signals |
| Used in | LAN | LAN |
| Traffic | It only sends data to required destination. Doesn't create traffic | Sends data to all the devices so it creates traffic |
| Memory Table | Uses Content Accessible Memory (CAM) to store MAC and IP Addresses | It cannot store MAC or IP addresses |
| Cost | Expensive than a Hub | Cheaper than Switch |