The idea of networking is probably as old
as telecommunications itself. Consider people living in the Stone
Age, when drums may have been used to transmit messages between
individuals. Suppose caveman A wants to invite caveman B over for a
game of hurling rocks at each other, but they live too far apart for B
to hear A banging his drum. What are A's options? He could 1) walk
over to B's place, 2) get a bigger drum, or 3) ask C, who lives
halfway between them, to forward the message. The last option is
called networking.
Of course, we have come a long way from the primitive pursuits and devices of
our forebears. Nowadays, we have computers talk to each other over vast
assemblages of wires, fiber optics, microwaves, and the like, to make an
appointment for Saturday's soccer match.[1]
In the following description, we will deal with the means and ways by which
this is accomplished, but leave out the wires, as well as the soccer part.
We will describe three types of networks in this guide. We will focus on
TCP/IP most heavily because it is the most popular protocol suite in use on
both Local Area Networks (LANs) and Wide Area Networks (WANs), such as the
Internet. We will also take a look at UUCP and IPX. UUCP was once commonly
used to transport news and mail messages over dialup telephone connections.
It is less common today, but is still useful in a variety of situations. The
IPX protocol is used most commonly in the Novell NetWare environment and we'll
describe how to use it to connect your Linux machine into a Novell network.
Each of these protocols are networking protocols and are used to carry data
between host computers. We'll discuss how they are used and introduce you to
their underlying principles.
We define a network as
a collection of hosts that are able to
communicate with each other, often by relying on the services of a
number of dedicated hosts that relay data between the
participants. Hosts are often computers, but need not be; one can also
think of X terminals or intelligent printers as hosts. Small
agglomerations of hosts are also called sites.
Communication is
impossible without some sort of language or code. In computer
networks, these languages are collectively referred to as
protocols. However, you shouldn't think of
written protocols here, but rather of the highly formalized code of
behavior observed when heads of state meet, for instance. In a very
similar fashion, the protocols used in computer networks are nothing
but very strict rules for the exchange of messages between two or more
hosts.
