Class addressing of IP networks.

• To simplify the classification of networks on the Internet, class addressing was used in the period from 1981 to 1993: IP addresses of the fourth version were divided into five categories:

1) A — for large networks,
2) B — for medium,
3) C — for small,
4) D and E are service networks.

• Classes D and E, due to their specificity, are not usually used by end users.

• Currently, IP address classes are not used.