Final answer:
In the classful IP scheme, organizations could choose from Class A, Class B, or Class C network ID categories, which supported varying numbers of networks and hosts per network. Class A supported very large organizations, Class B was for medium-sized entities, and Class C targeted small organizations.
Step-by-step explanation:
In the classful IP addressing scheme used in the early days of the Internet, organizations could choose from three main network ID categories for their networks: Class A, Class B, and Class C. Each class defines the ranges of IP addresses that could be used and is determined by the first few bits of the IP address.
- Class A was designed for very large organizations, as it supports up to 16 million hosts on each of 128 networks.
- Class B was used by medium-sized organizations, with up to 65,000 hosts on each of 16,000 networks.
- Class C was intended for small organizations, with up to 254 hosts on each of 2 million networks.
This method of classification allowed for a standardized way of allocating IP addresses, but it was eventually replaced by the more flexible Classless Inter-Domain Routing (CIDR) method due to inefficiencies and the exhaustion of IP addresses.