Switch is a networking device which connects multiple computers/network device together. Switch maintains the MAC address of the devices connected to it. When we send data(packets) from one network device to other network device via switch then the data(packets) will receive only by the receiver network device. Switch do not broadcast receiver’s data to each and every device connected to it.
Switch works in FULL DUPLEX MODE that means at the same time packets can be send as well as receive by the network devices via switch. Switch operates at data link layer (Layer 2) of OSI (Open Systems Interconnection) model. Once a device is connected to a switch, the switch notes its media access control (MAC) address, a code that’s baked into the device’s network-interface card (NIC) that attaches to an ethernet cable that attaches to the switch. The switch uses the MAC address to identify which attached device outgoing packets are being sent from and where to deliver incoming packets. So the MAC address identifies the physical device.
When a device sends a packet to another device, it enters the switch and the switch reads its header to determine what to do with it. It matches the destination address or addresses and sends the packet out through the appropriate ports that leads to the destination devices. To reduce the chance for collisions between network traffic going to and from a switch and a connected device at the same time, most switches offer full-duplex functionality in which packets coming from and going to a device have access to the full bandwidth of the switch connection. (Picture two people talking on a cell phone as opposed to a walkie-talkie).
Advantages of Switching
- Switch increases the bandwidth of the network.
- It reduces the workload on individual PCs as it sends the information to only that device which has been addressed.
- It increases the overall performance of the network by reducing the traffic on the network.
- There will be less frame collision as switch creates the collision domain for each connection.
Disadvantage of Switching
- A Switch is more expensive than network bridges.
- A Switch cannot determine the network connectivity issues easily.
- Proper designing and configuration of the switch are required to handle multicast packets.