• 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”

Introduction







Introduction to Network Layer

The network layer is responsible for carrying data from end to end. It allocate logical addresses to hosts, and identify them uniquely . Network layer takes data units from Transport Layer and divides them in to smaller unit called Data Packet. Network layer defines the route that the packets should follow to reach the destination. Routers work on this layer. TCP/IP protocol suite is used by majority of the internet. This suite is a combination of protocols for different purposes and need. IP protocol Internet Protocol works at the network layer and provides a mechanism to uniquely define an IP address or logical address. IP  does not guarantee that packets would be delivered to the destined host, but it will do its best to reach the destination. 

IPv4 Addresses

Internet Protocol version 4 uses 32-bit logical address.



Subnet Mask

The 32-bit IP address contains information about the host and its network. Router uses Subnet Mask and IP address to find out network ID. Subnet Mask is also 32 bits long. If the IP address in binary is bit wise ANDed with its Subnet Mask, the result yields the Network address.

For example, say the IP Address is 141.14.72.24 and the Subnet Mask is 255.255.0.0 then: Network address is found by bitwise AND operation between IP address and Default Mask, resulting in Network address 141.14.0.0