Switch :-

What is a network switch and what is a router? The two pieces of equipment look similar and perform some similar functions, but each has its own distinct function to perform on a network.

What is a Network Switch?

To understand basic networking, you first need to answer the question, "What is a network switch?"
Most business networks today use switches to connect computers, printers and servers within a building or campus. A switch serves as a controller, enabling networked devices to talk to each other efficiently. Through information sharing and resource allocation, switches save businesses money and increase employee productivity.

What is a Network Switch: Unmanaged Switches

An unmannaged switch works right out of the box. It's not designed to be configured, so you don't have to worry about installing or setting it up correctly. Unmanaged switches have less network capacity than managed switches. You'll usually find unmanaged switches in home networking equipment.

What is a Network Switch: Managed Switches

A managed network switch is configurable, offering greater flexibility and capacity than an unmanaged switch. You can monitor and adjust a managed switch locally or remotely, to give you greater network control.


Characteristic of Switch

  • Switch have many ports.
  • Switch can have different port speeds like fastEthernet & Gigabit .
  • Fast internet switching 
  • large buffers.
Different types switches modes 
  1.  Cut-through
  2. Store-and-forward
  3. Fragment-free
1 Cut-through Switches: The switch will start forwarding the frame before the whol frame has entered the switch. The switch only needs to know the destination MAC address so as soon as it reads it it can start forwarding . This is fast but less reliable if you have corrupt frames.

2 Store-and-forward: The switch will receive the complete frame, check if it's errors free and then forward it, if's corrupt it will be discarded.
3 Fragment-free:  The switch will check if the first 64 bytes are OK, basically this is a trade-off between cut-through and store-and-forward switching.




What is VLAN
VLAN is a logical grouping of networking devices. When we create VLAN, we actually break large broadcast domain in smaller broadcast domains. Consider VLAN as a subnet. Same as two different subnets cannot communicate with each other without router, different VLANs also requires router to communicate


feature of VLAN

1 It Reduce the size of broadcast domain
2 Increase the no of broadcast domain
3 easy to manage Switches on VLAN
4 Range of VLAN (0-4095)
5 VLAN 1 Active by default 
6 2-1001 can create 
7 1002-1005 default (non-active)
8 1006 -4094 extended Vlan range

 
1 All switches by default in VLAN 1
2 types of Vlan
  • Static Vlan membership assign by the basic of switch port.
  • dynamic Vlan membership assign on the basis of mac address.
  1. to create this we need to make VMPS server by Cisco.
  2. it's very expensive.