What is IP Address?
In the most widely installed level of the Internet Protocol (IP)
today, 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. This is 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 Addresses can be divided into following categories:
• Class A addresses 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 addresses 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 addresses are for small networks (supports 254 hosts
on each of 2 million networks ). The first octet starts from 192 to 223.
• Class D addresses are multicast addresses. The first octet
starts with 224.
• Class E addresses 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.