The Secure Shell (SSH) in Linux is used to log into the machine in an encrypted and safe manner. This helps in providing a secure channel to streamline all requests to the Ubuntu server. SSH uses cryptographic keys to log into the server.

On Windows, the most common tool to perform a secure shell to a Linux server is putty. In this chapter, we will learn how to use putty to Secure Shell into a server.

Step 1 − Download putty from the http://www.putty.org/ site.

Step 2 − Before connecting to use putty, we need to know the IP address of our Ubuntu box. To do this, type ifconfig in the command shell of the Ubuntu server.

From the above screenshot, we know that the IP address of the server is 192.168.0.20

Step 3 − Next step is installing SSH on the server. In order to SSH to a server, you need to make sure it is installed. Run the following command in the Ubuntu server command prompt session.

sudo apt-get install openssh-server

Step 4 − Launch PuTTY. Enter the IP address of the Ubuntu server and click the Open button.

Step 5 − The next screen requests to accept the encrypted key sent from the server.

Step 6 − Finally, enter the username and password to log into the server. We have successfully established a secure shell to the server.