Specifications

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2 Connecting to Remote Computers
Use this chapter to learn the commands to connect to remote
computers.
Connecting to remote computers helps you manage and configure resources
efficiently. This chapter covers using Secure Shell (SSH) and Telnet to connect to remote
computers.
Understanding SSH
SSH 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. While the connection is open, commands you enter
are performed on the remote computer.
Note: You can use any 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 is a
description of an SSH session:
1 The local and remote computers exchange public keys.
If the local computer has never encountered a given public key, SSH and your web
browser prompt you whether to accept the unknown key.
2 The two computers use the public keys to negotiate a session key used to encrypt
subsequent session data.
3 The remote computer attempts to authenticate the local computer using RSA or DSA
certificates. If this is not possible, the local computer is prompted for a standard
user-name/password combination.
4 After successful authentication, the session begins and remote shell, a secure file
transfer, a remote command, or other action is begun through the encrypted tunnel.