X11 Forwarding using Xming and PuTTY

We can run graphical programs on Linux machines on campus remotely and display them on your desktop computer running Windows. We can do this by using running two applications together on your Windows machine: Xming and PuTTY.

What is Xming?

Xming is a PC X Window Server. This enables programs being run remotely to be displayed on your desktop. Download and run the installation program from: http://sourceforge.net/projects/xming/

1- Navigate to the Files section and download:
*Xming setup from the Xming folder
*The fonts package installer from the Xming-fonts folder

   2- By default both programs will be installed into the same location, so don’t the worry about over writing files. We cannot work without both packages.
3- Once installed, running All Programs > Xming > XLaunch is a good idea to see what the configuration looks like. In most cases, the default options should be just fine.
4-Finally run All Programs > Xming > Xming to start the PC X Server. The “X” icon should be visible on the Windows Taskbar, as in the image below. The X Server must be started before setting up a SSH connection to a campus machine.

Xming on Windows 7 Taskbar

What is PuTTY?

PuTTY is a free SSH client. Through PuTTY we connect to a remote machine on the UT Dallas campus. Download the single Windows executable file from: http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html There is no setup required, you can run by simply double clicking putty.exe.

Configuring PuTTY

1-Under Session, enter the hostname you want to connect to: on port 22. Make sure the connection type is ssh.


 1-Next, scroll to Connection > SSH > X11. Check the box next to Enable X11 Forwarding. The remote authentication should be set to MIT-Magic-Cookie-1

2-Finally go back to Session. You can save your session too, and load it each time you want to connect.

3-Click Open to bring up the terminal and login using your netid/password .


Now with the ready configuration, will connect to the server.

Note: At this point it is important to log in with the User that will run the graphical interface.


Run the program



 That is all.
Any doubts I am available.


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How to Block Ping (ICMP) Responses in Linux System

Blocking ping responses from system can prevent system from hackers to ICMP flood dos attacks. So it can be a best practice for system security but most of online monitoring systems uses ping requests for monitoring system.
Disable Ping using iptables

You can simply block icmp responses directly from firewall in any Linux systems.

# iptables -A INPUT -p icmp --icmp-type echo-request -j DROP

Block Ping with Kernel Parameter

We can also block ping responses from system by directly updating kernel parameters. In this we can block ping responses temporarily or permanently as below.

Block Ping Temporarily

You can block temporarily block ping responses temporarily using following command

# echo "1" >  /proc/sys/net/ipv4/icmp_echo_ignore_all

Block Ping Permanently

In place of blocking ping temporarily, You can block it permanently by adding following parameter in /etc/sysctl.conf configuration file.

net.ipv4.icmp_echo_ignore_all = 1

Now execute following command to apply settings immediately without rebooting system.

# sysctl -p
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