address class (n)~ A predefined grouping of Internet addresses with each class defining networks of a certain size. The range of numbers that can be assigned for the first octet in the IP address is based on the address class. Class A networks (values 1 to 127) are the largest with more than 16 million hosts per network. Class B networks (128 to 191) have up to 65534 hosts per network and Class C (192 to 223) can have up to 254 hosts per network.