Final answer:
In classful network addressing, the network and host parts of an IP address are divided based on the class of the network. Class A networks have a network part of one octet and a host part of three octets, Class B networks have a network part of two octets and a host part of two octets, and Class C networks have a network part of three octets and a host part of one octet.
Step-by-step explanation:
In classful network addressing, the network and host parts of an IP address are divided based on the class of the network. In Class A networks, the first octet represents the network part and the remaining three octets represent the host part. In Class B networks, the first two octets represent the network part and the remaining two octets represent the host part. In Class C networks, the first three octets represent the network part and the last octet represents the host part.