Feb 12th, 2014 at 11:10 AM

Address class Description Class A Assigned to networks with a large number of hosts. The high-order bit in a class A address is always set to 0. The next seven bits, completing the first octet, complete the network identifier. The remaining 24 bits — the last three octets — represent the host identifier. This accommodates 126 networks, 128 minus two reserved addresses, and over 16 million hosts for each network. Class B Assigned to networks with a medium to large number of hosts. The two high-order bits in a class B address are always set to 10. The next 14 bits — completing the first two octets — complete the network identifier. The remaining 16 bits — the last two octets — represent the host identifier. This accommodates 16,384 networks and more than 65,000 hosts for each network. Class C Assigned to networks with a small number of hosts, specifically, local area networks (LANs). The three high-order bits in a class C address are always set to 110. The next 21 bits — completing the first three octets — complete the network identifier. The remaining 8 bits — the last octet — represent the host identifier. This accommodates more than 2 million networks and 254 hosts for each network. Class D Used for multicasting to a number of hosts. Packets are passed to a selected subset of hosts on a network. Only those hosts registered for the multicast address accept the packet. The four high-order bits in a class D address are always set to 1110. The remaining bits are for the address that registered hosts will recognize. Windows Embedded CE supports class D addresses for applications to multicast data to hosts. Class E Reserved for future use. An experimental address. High-order bits in a class E address are set to 1111.