Networking Basic

                                               


Networking:
” Sharing of information or transmission of data between 2 or more computers connected though a communication channel.”
When a computer sends a piece of information to other computer, it sends using a communication medium, physical or wireless.

Physical:  Wire, Ethernet cables, Hubs, Switches, Routers.
Wireless:  Wi-Fi, Bluetooth, cellular data services.

History:
The first internet was designed between one host and one router in the year of 1967. And the year of 1969 they design the network using 4 node which is known as ARPANet. It was designed basically  for defence operation. The earlier protocol they used was NCP(Network Control Protocol). But to give more flexibility to the network they designed different set of NCP protocols called as IPs.

Devices:
Hub: It allow us to connect to computer using ethernet cables.
Switch: It allow to connect many devices to connect in a network.
Router: It’s a device where it connect one local computer to another local computer.
Firewall: It’s for network security where it monitor and control the network traffic.
Modem: It’s device which modulate and demodulate electrical signals coming from cable lines.

Topology:
Topology is a arrangement of network elements via Physical or logically.

Point-to-Point:  Direct link between the two end points.
Bus:  Each node in the network are connected into a cable, where that cable is the centralized connection point.
Star:  Each network host is connected to a central Hub using Point-to-Point connection.
Ring:  It’s like a bus topology where it form a ring like structure where data travels around the loop.
Mesh:  It’s like ring but every node is connected with every other node in the loop network.
Hybrid: This uses two or more topology connection combine together to form a new connections.

IPv4  and IPv6:

IPv4: It’s a Internet Protocol Version 4 which uses packets and switches to form a connection less network . It uses 32 bit addressing scheme divided in 4 octet, where each octet contain 8 bits in binary 0s and 1s.
Ex: 172.20.60.1

IPv6: It’s a Internet Protocol Version 6 also uses packets and switches to form a connection but it provide end to end data transmission across the IP network. It’s uses 128 bit addressing scheme divided in 8 groups each having 16 bits in hexadecimal values.
Ex: 2001:0db8:0000:0000:0000:ff00:0042:8329

CIDR:
As we know IP addresses consists of two parts, which determines the network and Host, which in tern CIDR define it whole using ‘/ ‘ and  “number”. Using  ‘/ ‘  and  “number”  we can minimize the growth of routing table and can get it’s IP address, routing prefix, or subnet mask.
Ex: 192.168.100.0/24, which will have:
IP: 192.168.100.0
Subnet: 255.255.255.0

Routing: 
It’s a process of determining a path for data flow across the IP network. For that it uses many schemes like:
Unicast: Transmit message to only one node in a network.
Multicast: Transmit message to group of node who are expecting it to receive in a network.
Broadcast: It transmit message to every node inside the network.
Anycast: Send message to one node in a group of nodes.
Geocast: Transmit messages to a geographical areas.

Cloud:
Sharing of same data across geographical regions.
Service Models:
SaaS:  Software as a Service
PaaS: Platform as a Service
IaaS: Infrastructure as a Service