• सुखार्थी त्यजते विद्यं विध्यार्थी त्यजते सुखम्सु sखर्थीन: कुतॊ विद्या कुतॊ विध्यार्थीन: सुखम् ||
  • “Luxury people leave knowledge, but a student leaves Luxury No knowledge for one who seeks Luxury, No luxury for student”
  • न चोर हार्यं न च राज हार्यं न भात्रू भाज्यं न च भारकारि |व्ययं कृते वर्धत एव नित्यं विद्याधनं सर्वधनप्रधानम ||
  • Cannot be snatched away by thief, cannot be snatched away by king, Cannot be divided among brothers, Not heavy either If spent daily, it always keeps growing. The wealth of knowledge is the precious of wealth of all”

Layer Two Switch




Layer-2 Switch

While using a term switch we  should be mention whether it is a Layer -2 switch or Layer-3 switch

 

A Layer-3  switch is used at the network layer; it is a kind of router. While a Layer-2  switch performs at the physical and data link layers.

 

A Layer-2 switch is a bridge with many ports and a design that allows better (faster) performance. 


A Layer-2 switch is able to allocate a unique port to each station, with each station on its own independent entity. This means no competing traffic or no collision

 

A Layer-2 switch,  makes a filtering decision based on the MAC address of the frame it received.

 

A Layer-2 switch is more sophisticated than bridge as it can have a buffer to hold the frames for processing.

 

Earlier bridges, used software to create and manage a Content Addressable Memory (CAM) filter table,

 

Fast  switches use application-specific integrated circuits (ASICs) to build and maintain their MAC filter tables.

 

Layer 2 switches are faster than routers because they don’t take up time looking at the Network layer header information. 



Advantages of using Layer 2 switching over Bridges.

  1. Hardware-based bridging (ASICs  - application-specific integrated circuits )
  2. Wire speed
  3. Low latency
  4. Low cost

Functions of Layer 2 Switches

There are three distinct functions of layer 2 switching:



1. Address learning,


2. Forward/filter decisions.


3. Loop avoidance.