Specifications

27
Learn about using the command-line on computers
remotely.
If you need to run command-line tools on remote computers, there are tools to help
you. This chapter discusses some of the most commonly used tools and provides
some tips for getting started. It also describes three methods for connecting to the
command-line environment of a remote computer:
SSH Â
Apple Remote Desktop Â
X11 Â
SSH
SSH (Secure Shell) lets you send secure, encrypted commands to a computer
remotely, as if you were sitting at the computer. You use the ssh tool in Terminal to
open a command-line connection to a remote computer, and while the connection
is open, you enter commands to be performed on the remote computer.
You can also use any other application that supports SSH to connect to a computer
running Mac OS X or Mac OS X Server.
How SSH Works
SSH works by setting up encrypted tunnels using public and private keys. Here’s
a description of an SSH session:
The local and remote computers exchange public keys. Â
If the local computer has never encountered a given public key, SSH and your web
browser prompt you to accept the unknown key.
The two computers use the public keys to negotiate a session key used to encrypt Â
subsequent session data.
4
Connecting to Remote Computers