Classes of IP addresses

There are five classes of IP addresses :

Class A: ranges from 1.0.0.0 to 127.0.0.1

Class B: ranges from 128.0.0.1 to 191.255.255.255

Class C: ranges from 192.0.0.0 to 223.255.255.255

Class D: ranges from 224.0.0.0 to 239.255.255.255

Class E: ranges from 240.0.0.0 to 255.255.255.255

There are five classes of IP addresses. In class A first 8 bits represent network ID and last 24 bits represent host ID. Then in class B the 16 bits represent network ID and the last 16 bits represent the host ID. Class C first 24 bits represent the network ID and last 8 bits represent host ID.  In Class D all the 32 bits represent the multicast group ID.