Using PuTTY

How to use PuTTY to connect to your Cloud via SSH

Blue Light Tech

This software enables you to work as if you were remotely logged into a console session. A server running an SSH daemon can be connected to easily using PuTTY which is free open-source for UNIX and Windows systems.

  1. Obtaining and Running PuTTY
  2. Running Remote Graphical Applications
  3. Using SSH Tunnels

Obtaining and Running PuTTY

The PuTTY download page is where you can find this software. In the following examples we will be using the Windows version. Once you save it and run, the screen below appears:

To begin an SSH session, enter the hostname or IP address of the system you need to view and click “Open”. A warning will appear if you have not used PuTTY previously to log into this system as shown in the representation below:

The warning implies that someone could be eavesdropping by posing as a server you are attempting to log into which will require you to verify the server you are logging into is who it says it is. Since the fingerprints are expected to match, click “Yes” for warning to be accepted and cache the host key in the registry. This is not expected to happen again and an investigation should be done if it does and such a connection is not to be trusted. 22 is the default port for SSH, but if not, it should be specified on the “Session” screen after hostname.

Running Remote Graphical Applications over SSH

To run graphical applications hosted on a remote Linux server you need an X11 server for Windows. Xming is a free X11 server and can be downloaded from Xming Sourceforge . Once you accept the defaults by the installer and the process of installation is complete, your X11 server will be ready. For X11 forwarding to function appropriately, you need to install xauth on your remote server. Ensure you are logged in as root and use the command below to get it installed:

Debian or Ubuntu :

apt-get install xauth


CentOS or Fedora :

yum install xauth

Forwarding X11 connections to the desktop through the help of PuTTY can be done by going to Connection -> SSH -> X11. Check the box for “Enable X11 Forwarding”. In “X display location” you should write “localhost:0”. To test this, start any graphical application hosted into the remote server once you log into it. The xcalc application on a remote server is shown in the diagram below, but you can run any X11 program using the same method:

Using SSH Tunnels

If you are not willing to allow public access to SSL or where the service you are seeking does not run over SSL, then SSH tunnels provide you access to network services running on a remote server through a secure channel. For instance, tunneling can be used to access a MySQL server running on a remote server. The default port for MySQL is 3306, so we shall use this port in the example. Connection -> SSH -> Tunnels screen in PuTTY. “3306” is entered for “Source port” field and “127.0.1:3306” for the “Destination” field, as shown in the representation below:

Directing your local MySQL client to localhost:3306 is possible once you have connected to the remote server which has this tunnel configuration. This provides access to your database without having to run MySQL on a public IP, and it will be encrypted through SSH due to connection to the remote MySQL server.


JimmiNi - 22/10/2017 06:53:10


JimmiNu - 11/09/2017 05:14:05