This chapter explains how to use Linux to connect to remote
servers. First, it explains how to use
wvdial, a
program that makes it easy to connect to the Internet via a PPP
connection provided by an ISP. Then, the chapter explains basic TCP/IP
network concepts that you must know in order to administer a Linux
system connected to the Internet or a local area network. So that you
can use your knowledge of TCP/IP effectively, the chapter explains how
to use
pppconfig to configure and administer a
system that connects to a local area network and to a remote server
via PPP. Next, the chapter describes several popular network client
applications available under Linux, including a web browser and an FTP
client. The chapter then describes the use of
minicom and
seyon, which provide
dial-out capabilities like those of Window's
hyperterminal. Finally, the chapter shows how to
make a PPP connection manually, by using
minicom.
Most Internet service providers (ISPs) offer two primary types of
service: shell accounts and PPP (point-to-point protocol)
accounts. Shell accounts were more popular before the advent of the
Web. A shell account lets you use your computer much as if it were a
virtual console associated with a remote computer. You can type
commands, which are interpreted by the remote computer, and view the
resulting output on your computer. Although a few web browsers, such
as Lynx, can operate via a shell account, they don't generally support
the highly graphical, multimedia pages which web surfers have come to
expect.
In contrast, a PPP account connects your computer directly to the
Internet. While your computer is connected to the Internet, you can
use it to surf the Web with your favorite browser. If your ISP allows,
you can even run a web server, providing pages that can be viewed by
others around the world.
You can compare the two types of Internet accounts - shell
and PPP - with two kinds of postal service. Imagine that no mail
carrier actually comes to your home to pick and deliver mail. Instead,
every time you want to conduct postal business, you go to the post
office. This resembles a shell account: The computer that connects you
to the Internet is remote, and every time you want to do something on
the Internet you must open a terminal, or telnet, session to that
computer. PPP, on the other hand, is like home delivery: The Internet
comes right to your doorstep, and your computer is literally placed on
the Internet by the machine at your ISP that you connect to.
Under Microsoft Windows, you use
hyperterminal to
access a shell account and Dial-Up Networking to access a PPP
account. Under Linux, you can choose from among several programs that
let you access a shell account. The most commonly used programs are
minicom and
seyon. To access a
PPP account under Linux, you use the PPP daemon,
pppd. The next section describes how to use
wvdial to make the process of establishing a PPP
connection simple.
