Public IP Address - What Is a Public IP Address?ARP

An IP address is considered public if the IP number is valid and falls outside any of the IP address ranges reserved for private uses by Internet standards group. Public IP addresses are used by servers (including those for Web sites and DNS servers), network routers or any computer connected directly to the Internet via a modem.

IP Address Classes or Classful addressing

• IP addressing supports five different address classes: A, B, C, D and E. Only classes A, Band C are available for commercial use.

• We can find the class of an address when given the address in binary notation or dotted decimal notation.