IP Address

As like telephone/cell number, every machine on the Internet has a unique number, called an IP address. In other term it is 32-bit number. It seems like this: 192.168.103.378

Dynamic IP address: It changes every time when you connect to the Internet like dial-up/ ISP and using PPP (Point to Point Protocol)
Static IP address: It is permanent IP address. It remains the same every time.

IP addresses are normally expressed in decimal format, called dotted decimal number.

The four numbers in IP address are called Octets. They each have eight position when viewed in binary form. Each octet can have any value from 0 to 255. The octets are split into two sections: NET & HOST (NODE). The Net section always contains the first octet. The Host/Node section always contains the last octet.
Class A: This class is for very large networks/big international company. IP address range from 1.0.0.1 to 126.255.255.254
Loopback: The IP address 127.0.0.1 is used as loopback address. It is used by the host computer to send a message back to itself. It is commonly used for troubleshooting and network testing.
Class B: This class is for medium size of networks like university/colleges. IP address range from 128.1.0.1 to 191.255.255.254
Class C: This class is for small size of networks. IP address range from 192.0.1.1 to 223.255.254.254
Class D: This class is reserved for multicast. IP address range from 224.0.0.0 to 239.255.255.254
Class E: It is also reserved like class-D. IP address range from 240.0.0.0 to 254.255.255.254

Private IP range:

• 10.0.0.0 to 10.255.255.255
• 172.16.0.0 to 172.31.255.255
• 192.168.0.0 to 192.168.255.255

Default Network: The IP address of 0.0.0.0 is used for the default network.
Broadcast: Messages that are intended for all computers on a network are sent as broadcasts. These messages always use the IP address 255.255.255.255