=+= Classes of IP Address =+=

IP addresses are divided into five IP classes:
IP address class A
IP address class B
IP address class C
IP address class D
IP address class E

All IP addresses are placed in a particular class based on the decimal values of their first octets. In the first octet, an IP address can start with a decimal value between 1 and 255.

IP class A addresses have first octets with a decimal number from 1 to 127.
Example:
27.x.y.z
102.x.y.z

IP class B addresses have first octets with a decimal number from 128 to 191.
Example:
128.x.y.z
151.x.y.z

IP class C addresses have first octets with a decimal number from 192 to 223.
Example:
192.x.y.z
223.x.y.z

IP class D addresses have decimal values from 224 to 239 in the first octet, and the 4 leftmost bits are 1110.
Example:
224.x.y.z
239.x.y.z

The last IP address class of addresses is IP class E. IP class E addresses range from 240 to 255 in the first octet, and the 4 leftmost bits are 1111.
Example:
240.x.y.z
255.x.y.z