0.2. Intended Audience
We've written this book for system administrators and
technically minded users. Some chapters are suitable for a wide
audience, while others are thoroughly technical and intended for
computer and networking professionals.
0.2.1. End-User Audience
Do you have two or more computer accounts on different machines? SSH
lets you connect one to another with a high degree of security. You
can copy files between accounts, remotely log into one account from
the other, or execute remote commands, all with the confidence that
nobody can intercept your username, password, or data in transit.
Do you connect from a personal computer to an Internet service
provider (ISP)? In particular, do you connect to a Unix shell account
at your ISP? If so, SSH can make this connection significantly more
secure. An increasing number of ISPs are running SSH servers for
their users. In case your ISP doesn't, we'll show you how
to run a server yourself.
Do you develop software? Are you creating distributed applications
that must communicate over a network securely? Then don't
reinvent the wheel: use SSH to encrypt the connections. It's a
solid technology that may reduce your development time.
Even if you have only a single computer account, as long as
it's connected to a network, SSH can still be useful. For
example, if you've ever wanted to let other people use your
account, such as family members or employees, but didn't want
to give them unlimited use, SSH can provide a carefully controlled,
limited access channel into your account.
0.2.1.1. Prerequisites
We assume you are familiar with computers and networking as found in
any modern business office or home system with an Internet
connection. Ideally, you are familiar with the Telnet and FTP
applications. If you are a Unix user, you should be familiar with the
programs rsh, rlogin, and
rcp, and with the basics of writing shell scripts.
0.2.2. System-Administrator Audience
If you're a Unix system administrator, you probably know that
the Berkeley r-commands (
rsh,
rcp,
rlogin, rexec, etc.) are
inherently insecure. SSH provides secure, drop-in replacements,
eliminates
.rhosts and
hosts.equiv files, and can authenticate users by
cryptographic key. SSH also can increase the security of other
TCP/IP-based applications on your system by transparently
"tunneling" them through SSH encrypted connections. You
will love SSH.
0.2.2.1. Prerequisites
In addition to the end-user prerequisites in the previous section,
you should be familiar with Unix accounts and groups, networking
concepts such as TCP/IP and packets, and basic encryption techniques.
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| 0. Preface |  | 0.3. Reading This Book |
