SDN Playground – getting started with OpenFlow

Most every big Networking company has announced something related to SDN. Whether simple marketing to concrete legit solutions, its a question of time until the market is filled with SDN-related products. It is thus essential to start getting familiar with it, and you know damn well there’s nothing like getting your hands dirty. So here are some helper-notes on getting started with sandboxing OpenFlow (OF) environments.

To do so I’m using Mininet – a VM created part of an OpenSource Project to emulate a whole complete environment with a Switch, an OF Controller, and even three linux hosts. Also note I’m using my desktop as a Host, with VirtualBox.

So what you’ll need:

  • If you don’t have it yet, download VirtualBox, or another PC hyper-visor Software such as VMware Player. VirtualBox has the advantage of being free for Windows, Linux and Mac.
  • Download Mininet VM OVF image.
  • After decompressing the image, import the OVF.

VB Import Applicance

  • In order to establish terminal session to your VM, you’ll need to add a Host-only Adaptor on the Mininet VM. So first (before adding the adaptor on the VM itself) go to VirtualBox > Preferences. Then select the Networking tab, and add and adaptor.


  • Next edit Vm Settings, and add an Host-only Adaptor. Save it and boot the VM.
  • User: mininet       Password: mininet
  • Type sudo dhclient eth1 (or if you haven’t added another adaptor and simply changed the default Adaptor from NAT to Host-only adaptor then type eth0 instead of eth1) to enable DHCP service on that interface.
  • Type ifconfig eth1 to get the IP address of the adaptor.
  • Establish an SSH session to the Mininet VM. Open terminal, and type ssh -X [user]@[IP-Address-Eth1], where the default mininet user is “mininet” and IP address is what you got after ifconfig. So in my case it was: ssh -X mininet@
  • Mininet has its own basics tutorial – the Walkthrough. Also interesting is the OpenFlow tutorial.

The Mininet Walkthrough is designed for less than an hour tutorial. Here are some simple shortcuts to speedup your playing around:

  • Type sudo mn –topo single,3 –mac –switch ovsk –controller remote. This will fire up the emulated environment of the switch, OF controller, and 3 linux hosts.

OF topology

  • Type nodes to confirm it. “h” stands for hosts, “s” for switch and “c” for controller. If you want, for instance, to now the addresses of a specific node such as Host2, type h2 ifconfig. If you want to establish a terminal session to the same host, type xterm h2. Note that xterm command only works if you first established ssh session by typing ssh -X

This should already get you started.

Have fun!

HP SDN beta-testing

HP is beta-testing its Security SDN-based solution: Sentinel.

The article describes a School implementing HP still to come SDN Security solution. The school implemented a hybrid OpenFlow solution – the most likely usual implementation in this initial SDN phase – where “intelligent” switchs are used running all usual old-school networking protocols simultaneously with OpenFlow enabled. OpenFlow is used to forward all DNS request to HP Security Controller – Sentinel. Sentinel uses HP’s IPS DB – Tipping Point’s Reputation DB – which is updated every 2 hours with spoted Internet suspicious threats.  Sentinel accepts or rejects traffic forwarding to a certain IP, based on what network administrator choose to do. The network admin can configure Sentinel to follow all Tipping Point recommendations, or rather specify his prefered alternatives. Thus when an OpenFlow switch requests what to do with a certain DNS querry, the controller simply “tells” what to do with related packets by populating its OpenFlow table.

This might be a very simplistic security implementation. However the most interesting is the promising margin for development. As this solution gains increasing intelligent, this may well start suiting as low-cost IPS/firewall solutions, using a distributed computing model with already existing OpenFlow switchs. I find this model very appealing for instance for ROBO sites.

Another alternative use-case is HP’s Beta-testing example in the article: BYOD. Securing devices at the edge perimeter greatly simplifies network security.

SDN might be a simple reengineering of the way things are done. Still, it’s a cool one in deed…

Disclamer: note that these are my own notes. HP is not responsable for any of the content here provided.