HP 200 Series Services And Applications page 110

Internet Protocol Routing Service
IP Addressing Scheme
Description
An IP address consists of 32 bits divided into two or three fields: either
network number and host number or else network number, subnet number,
and host number. (An IP network generally comprises a single company or
location.) The interconnection of IP networks is an internetwork. The most
widely used internetwork is the Internet, which includes public and private
IP networks. At the destination network, the subnet number (if any) is used
to send the packet to the correct subnetwork. After that, the packet is sent to
the correct host number. (A host is a node or network device that supports IP
communication on the network.)
The address field length of an IP address depends on the address class.
The class A address assigns 8 bits to the network field and a total of 24 bits
to the rest of the address. This address class can address almost 17 million
different nodes on an IP network. The class A address is used for very large
networks.
The class B address assigns 16 bits to the network field and a total of 16 bits
to the rest of the address. This can address over 65 thousand different nodes
on a network.
The class C address assigns 24 bits to the network field and 8 bits to the rest
of the address. This can address 254 different nodes on a network.
class A
class B
class C
2-58
IP Addresses
network
or
network subnet
IP Addresses
network
8 bits
network
16 bits
network
24 bits
host 32 bits
host 32 bits
24 bits
16 bits
8 bits