There are five classes of available IP ranges: Class A, Class B, Class C, Class D and Class E, while only A, B and C are commonly used. Each class allows for a range of valid IP addresses
Class A1.0.0.1 to126.255.255.254 Supports16 million hosts on each of127 networks.
Class B128.1.0.1 to191.255.255.254 Supports65,000 hosts on each of16,000 networks.
Class C192.0.1.1 to223.255.254.254 Supports254 hosts on each of2 million networks.
Class D224.0.0.0 to239.255.255.255 Reserved for multicast groups.
Class E240.0.0.0 to254.255.255.254 Reserved
