How to use SSH

Secure Shell, or SSH, is an encrypted way of accessing a remote server. It allows secure access to a shell over an otherwise insecure network. It is also used as the protocol which allows other secure interactions with a remote server, such as copying and writing files (SCP/SFTP).

In a unix-based system such as linux the shell is where one types in commands to execute. SSH allows a user to access a shell remotely and remotely run the same commands someone with physical access would be able to run. What this means is that someone can use a remote computer in the same way they would be able to a local computer. They can log into a server halfway across the world using SSH and be able to run the same commands as someone who has physically connected a keyboard and monitor to that computer.

Windows users can also use SSH to log into remote servers. Though there are rumors that Windows will one day natively support SSH currently you must download a program such as PuTTY. PuTTY is a free SSH and telnet tool for Windows users.

If you ever plan on working on a remote unix-based system you will be using SSH. Lucky, logging onto a remote server through SSH is fairly simple. The most simple usage is:

[email protected] 

You simply type in the username @ the remote server and then you are prompted for the password of that user on that remote system. So say I am going to log in as the user "john" on a computer called "" I would type

[email protected]

and then enter my password when prompted. The server does not need to be a domain name. It can be an IP address. If I were trying to SSH into a server with IP I would simply

[email protected]

And again enter the password. Simple.

Of course there are other ways of using SSH. The default port number is 22, but you can change this if the server you are attempting to log into is running SSH on a different port. As with most unix commands there are a bunch of flags you can use to specify how you want SSH to act.

Be aware that to use SSH the remote computer you are attempting to log into must be running an SSH server. So you not only need a client local, but you need the remote host to also run SSH.