What is IP Address?
An IP address is a 32-bit number that identifies each sender or receiver of information that is sent in packets across the Internet. The IP address is usually expressed as four decimal numbers, each representing eight bits, separated by periods. It sometimes known as the dot address and, more technically, as dotted quad notation. For example, 127.0.0.1 could be an IP address.
The IP Address can be divided into following categories:
Class A IP address ranges are for large networks with many devices (supports 16 million hosts on each of 126 networks). The first octet starts from 1 to 126.
Class B IP address ranges are for medium-sized networks (supports 65,000 hosts on each of 16,000 networks). The first octet starts from 128 to 191.
Class C IP address ranges are for small networks (supports 254 hosts on each of 2 million networks ). The first octet starts from 192 to 223.
Class D IP address ranges are multicast addresses. The first octet starts with 224.
Class E IP address with the first octet of 225 is used for experimental purposes only.
The IP address 127.0.0.1 is used as the loopback address. This means that it is used by the host computer to send a message back to itself. It is commonly used for troubleshooting and network testing.