Interactively Connecting to an SSH Server

Chapter B. Stupendous OpenSSH Tricks

In This Chapter

• Interactively connecting to a remote SSH server

• Installing and starting an OpenSSH server

• Noninteractively executing commands on remote computers

• Using OpenSSH port forwarding

• Using Public/Private Keys

• Using ssh-agent

• Creating an encrypted wireless network using OpenSSH

Secure Shell (SSH) is a set of network protocols that lets you create a secure — encrypted — communication channel between two computers. Tatu Ylonen created SSH in 1995 to replace the nonencrypted communication applications then in use.

SSH creates an encrypted connection between two computers that protects your private communication. SSH enables you to securely communicate with other computers interactively and noninteractively.

OpenSSH is an open source version of the SSH protocol. OpenSSH is an amazing system that at first glance provides a simple and secure method for interacting with other computers. But dig a little under the surface and OpenSSH provides many more capabilities.

The open source OpenSSH suite of security communication tools is compatible with the commercial SSH suite. In this appendix, I say "connect to an SSH server" when describing the process of connecting to either an SSH or OpenSSH server.

This appendix shows you how to configure and use OpenSSH. It also describes how to use some of OpenSSH's lesser-known capabilities, such as authenticating without passwords and creating an encrypted wireless network using unencrypted access points. OpenSSH is a truly amazing piece of software.

Interactively Connecting to an SSH Server

Using the OpenSSH client to connect to an OpenSSH, or commercial SSH, server is simple. For instance, do the following if you want to use OpenSSH to connect to your computer account on another SSH server on another computer:

1. Open a GNOME Terminal Emulator window by clicking the GNOME Applications menu and choosing AccessoriesTerminal.

2. Type ssh username@computername.

   For instance, I type ssh paul@ssh.swcp.com to connect to my Internet service provider's (ISP) account.

3. Type your password when prompted.

You can work on the remote computer at this point.