What is switch?

A switch is a device which connects various systems in a network.


Switch maintains MAC address table.


Packets are directly transferred to the destination without broadcasting.


Switch is considered as an intelligent device.


In switch , each packet gets th same speed.


A switch is Full-duplex (can forward & receive simultanously)


Packets are filtered by switches.


No concept of collision domain or No collision as it is full duplex.


Works in “Data link layer” layer 2 and in layer 3






There are two types of switches,


1.Managable switch – has console port,we can make configuration


2.Unmanagable switch – has no console port.






Cisco divided switches in 3 layers:


1.Access layer switches : It works in layer 2 as it understands MAC address only.It doesn’t understand IP address.Switches series – 1900 & 2900


2.Distribution layer and 3.Core layer switches: It works in layer 3 because it understands MAC address as well as IP address. Switches series – 7000 & 10000.


Distribution layer and core layer switches can access millions of packets per second - whereas - Router can access 1 lakh packets per second.