| 27 |  | The software can be downloaded from the following places: | 
          
            | 28 |  |  | 
          
            | 29 |  | * !OpenFlow reference system: http://www.openflowswitch.org/wp/downloads/ | 
          
            | 30 |  | * NOX-core: http://noxrepo.org/wp/ | 
          
            | 31 |  |  | 
          
            | 32 |  | The former is a simple implementation that comes with a few tests; latter is a full-blown network operating system/ development tool that comes with a Network API that can be used to write and develop your own controller in C++ or Python. | 
          
            | 33 |  |  | 
          
            | 34 |  | Both can also be installed using Git. Git can be installed with the following command: | 
          
            | 35 |  | {{{ | 
          
            | 36 |  | apt-get install git-core | 
          
            | 37 |  | }}} | 
          
            |  | 27 | Update and Upgrade Packages: | 
          
            |  | 28 | {{{sudo apt-get update && sudo apt-get upgrade}}} | 
          
            |  | 29 |  |