Technical data

90362-01 IP Addressing C-1
IP Addressing C
All the computers on the world-wide Internet have unique Internet
addresses called IP addresses. The essential point to understand about IP
addresses is that each gateway on an IP network knows of or can determine
the existence of all others. This means that they can route packets of infor-
mation to their destination through the quickest routes, which makes for an
extremely flexible network. If your computer can get a properly addressed
packet of information from your LAN to a remote NetBlazer’s LAN (or to
the Internet), that gateway will worry about how to deliver the packet.
IP addresses are numbers, similar to a ZIP code or telephone number, which
uniquely identify a location on the network. To simplify routing, IP
addresses are in two sections, a
network ID and a host ID. The network ID
identifies the network to which a host is attached, and the host ID uniquely
identifies the host on that network. Thus, the IP addresses of all hosts on a
given network share a common network ID.
An IP address is a 32-bit number, broken down into two sections: the host
ID section and the network ID section. The length of the section depends on
the class of the address. Figure B-1 shows the primary classes of IP
addresses used on the Internet.