Classful addressing divides IPv4 addresses into how many groups?

Classful addressing divides IPv4 addresses into five distinct groups, known as classes. These classes are categorized as Class A, Class B, Class C, Class D, and Class E. Each class serves different purposes and has a unique way of allocating IP addresses.

Class A is designed for very large networks, allowing for a vast number of hosts by utilizing a wide range in the first octet. Class B is meant for medium-sized networks, facilitating more than 65,000 hosts, while Class C addresses are used for smaller networks with a maximum of 254 hosts. Class D is designated for multicast traffic, where packets are sent from one source to multiple destinations. Lastly, Class E, although not commonly used in practice, is reserved for experimental purposes.

Understanding these classes is crucial for network design and management, as they dictate how IP addresses are allocated and structured within different environments, ensuring efficient use of the available address space.