Prepare your system
Install following package
sudo apt-get install python-tk
Now you need to download .tgz file from here
Now extract the file using the following command
tar xzvf namebench-1.1.tgz
Now you have namebench-1.1 directory.If you double click on this you have two options if you want to run immediately you can do by double clicking on namebench.py file.
If you want to install permanently using the following command
sudo python setup.py install
Once it opens you should see similar to the following screen here click on Start Benchmark
The results are compared to Google’s DNS and the system will compare against your current DNS settings. The fastest DNS will be listed at the top.