Overview

In this chapter we shall examine the addressing scheme used by the Internet Protocol Suite, why it is required, the format of addresses used, and the problems that such a scheme potentially introduces. Internet users are under extreme pressures to conserve a rapidly diminishing address space but why? Surely the designers could have foreseen the requirements of todays computer reliant generation? Do we need an addressing scheme anyway? If we do, why aren't existing schemes capable of providing us with a scheme that is flexible enough?

This chapter attempts to provide answers to these questions and more, and in so doing defines a framework without which the Internet Protocol Suite cannot exist.

4.1 The Need for an Addressing Scheme

It is a requirement that each station on a network must have a unique address. The postal service cannot deliver letters to you unless they are clearly marked with a unique address. In just the same way, stations on networks cannot receive data unless they too possess a unique address.

We have already seen that each station has a unique address in the form of its Layer 2 (Data Link) or MAC address. So why the need to complicate matters further by the introduction of another scheme? Is the scheme used by Ethernet, or that used by Token Ring or FDDI, inadequate for our needs? Or is it just that the architects failed to see the usefulness of existing schemes?

Simply, the answer to all of the questions...