Understanding IP Addressing

Understanding IP Addressing

As you know from the section “The Internet Layer Protocols” earlier in this chapter, IP moves data between computer systems in the form of a series of one or more packets, often making up
a TCP or UDP datagram, and each datagram is delivered to the IP destination system and to the port number (on that system) that is contained in the encapsulated TCP or UDP header. This
destination socket, or port and address combination, is a standard 48-bit number (a 32-bit IP address and a 16-bit port number) that contains enough information to identify the receiving network, the host for which the datagram is intended on that network, and the application running on that host.
        In this section, you’ll learn what IP addresses are, why they are so necessary, and how they are used in TCP/IP networking. But first, let’s clear up a possible source of confusion: Ethernet addresses and IP addresses.