I just want to put in a recommendation for Nick Feamster’s excellent Software Defined Networking course. It’s free on Coursera, and not only does he do a great job of clearly explaining SDN, network virtualization, and related topics, he has also created some excellent videos explaining the usage, design, and rationale for the Mininet system, which is also being used for programming assignments and labs in the course.
There are also interesting interviews with notable people like Martin Casado, David Clark, and Teemu Koponen. It’s quite excellent, very approachable for anyone who has a basic networking background, and highly recommended:
One of Mininet’s key features is that it makes it very easy to create
a complete virtual network including hosts, switches, links and
OpenFlow controllers. By default, Mininet runs Open vSwitch
in OpenFlow mode, which requires an OpenFlow controller.
As you probably know, Mininet comes with built-in Controller() classes to
support several controllers, including the OpenFlow reference controller
(controller), Open vSwitch’s ovs-controller,
and the now-deprecated NOX Classic.
You can easily choose which one you want when you invoke the mn command:
Each of the above examples uses a controller which turns your OVS switches
into Ethernet bridges (aka learning switches.)
Note that ovsc is easy to install but only supports 16 switches.
You can install the reference controller (patched to support many switches)
using install.sh -f. (As of this writing, you can also install NOX
Classic using install.sh -x.)
The manual way: using remote controllers
But what do you do if you want another controller like POX? Well, one
way is to start up POX (or Beacon, Floodlight, etc.) in another terminal
window and then use --controller remote:
sudo mn --controller remote,ip=127.0.0.1
If your controller is running locally, you can just use
sudo mn --controller remote
You might be asking: is there a way for Mininet to automatically start
up my controller so that I don’t have to do it manually? The answer is,
of course, yes!
The automatic way #1: using the command line
The latest Mininet master branch allows you to change the command and
arguments for --controller ref to invoke another controller as
desired. For example, here’s how you could invoke POX:
With this class saved into pox.py, you can now do the following:
sudo mn --custom pox.py --controller pox
Additionally you can use the custom class in your Mininet scripts
#!/usr/bin/pythonfrommininet.logimportsetLogLevelfrommininet.netimportMininetfrommininet.topolibimportTreeTopofrommininet.cliimportCLI# We assume you are in the same directory as pox.py# or that it is loadable via PYTHONPATHfrompoximportPOXsetLogLevel('info')net=Mininet(topo=TreeTopo(depth=2,fanout=2),controller=POX)net.start()CLI(net)net.stop()
Note that in this custom class we’ve simply changed
__init__, but in a more complicated example you might
wish to change the start() and stop() methods as
In the last few years, the Mininet community has grown from a few users at Stanford to an active mailing list with over 500 members in academia, startups, and industry.
Version 2 (“HiFi”) is a major upgrade that expands Mininet’s scope from functional testing (“does my network control plane work?”) to performance testing (“how well does my custom congestion control perform with 10 Mb/s links?”). New APIs now allow you to create links with specified bandwidths, latencies and loss rates, and to limit the CPU usage of virtual hosts. Using these new features, 37 students in Stanford University’s Advanced Topics in Networking course (CS244) replicated 16 published research experiments; you’re encouraged to browse their stories at The Reproducing Network Research Blog.
The old website had an obscure, needed-Google-to-find-it address, and was generated server-side, so it could be a bit slow. The new page you’re seeing was built with Octopress and is hosted on GitHub Pages. Since it’s all statically generated pages now, it should load super-quick, and it’ll be easier to add blog entries and do page customization.