Remotely Control Other Computers on your Network

Task #92

Difficulty Level 4

You can remotely control other computers on the network in much the same way as your own. Using the command-line application Terminal and the command-line program ssh, you can remotely launch applications, work with files, and even shut down computers without walking into another room.

Before you get started remotely controlling a remote computer, you need to take one last walk to it and activate remote access for it. You will also need to make sure that you have an account on the remote machine.

Back on your own computer, launch the Terminal application. Now you are ready to control the remote machine with ssh. ssh ships with Mac OS X Panther; it is a command-line-only program and has no graphical user interface. You can read all about ssh by typing man ssh.

When you connect to a remote computer, it is as if you are sitting in front of it — almost. You cannot use the mouse to control the remote machine with ssh, but you can use any installed command-line program. For example, you can launch iTunes by typing only two lines of text in Terminal.

Caution

The ssh tool is extremely powerful; in the wrong hands, it can cause considerable problems for you. Create accounts in System Preferences only for trustworthy people. You should also restrict administrative accounts to those whom you especially trust. It is a common security principle that a safe machine is a disconnected machine. Whenever you are not using remote login, it is a good idea to deactivate it in the Sharing pane of System Preferences. The “bad guys” cannot connect via ssh if you have this turned off. The same holds true for all items in the Sharing pane. If you are not using the FTP server, turn it off. Your machine will be more secure, and it will eat up less CPU power.