title: Clone from GitHub.com "Temporary failure in name resolution" error
body: <p>I encountered problems to download floodlight from GitHub. I have googled and tried various methods to clone it. Below is the error:</p>
  
  <pre><code>  mininet@mininet-vm:~$ git clone git://github.com/floodlight/floodlight.git
    Cloning into 'floodlight'...
    fatal: unable to connect to github.com:
    github.com:Temporary failure in name resolution
  </code></pre>
  
  <p>I'm currently running mininet in a virtual machine and i have tried with https/http instead of git. Still, I encountered errors when trying to download floodlight from GitHub.</p>
  
  <p>My virtual machine network is connected with NAT and GitHub.com is up and running. However, when I tried to ping to GitHub.com it won't work. How do I resolve this DNS server issue?</p>