Over the last few days I’ve started to the play with the OpenDaylight Test VM Image. This image is was easy to get up and running and have a playground with mininet and a pre-baked OpenDaylight (ODL) controller to play with. After deploying the OVA file in Virtualbox poking around the file system I got down to “business” with getting a test topology in place. I made some changes to initial mininet configuration startup file to make the topology more complex and changing the startup command to look like the following,
sudo mn --controller 'remote,ip=127.0.0.1,port=6633' --topo tree,3
This yielded a 8 hosts and 7 switches topology. At one point I have 63 hosts and some number of switches things broke pretty hard so I dialed it back a little bit. I want over to the webui for the controller and after some fiddling Names and Tiers on the switches. My test topology in the ODL console is show in the following screenshot.
I also had full reachability from all of the mininet hosts.
mininet> pingall *** Ping: testing ping reachability h1 > h2 h3 h4 h5 h6 h7 h8 h2 > h1 h3 h4 h5 h6 h7 h8 h3 > h1 h2 h4 h5 h6 h7 h8 h4 > h1 h2 h3 h5 h6 h7 h8 h5 > h1 h2 h3 h4 h6 h7 h8 h6 > h1 h2 h3 h4 h5 h7 h8 h7 > h1 h2 h3 h4 h5 h6 h8 h8 > h1 h2 h3 h4 h5 h6 h7 *** Results: 0% dropped (56/56 received)
Now that I had things working it was time to find ways to break it. Diving into the flow rules I threw together a basic Drop rule on one of the transit links.
As expected the network was split into two.
mininet> pingall *** Ping: testing ping reachability h1 > h2 h3 h4 X X X X h2 > h1 h3 h4 X X X X h3 > h1 h2 h4 X X X X h4 > h1 h2 h3 X X X X h5 > X X X X h6 h7 h8 h6 > X X X X h5 h7 h8 h7 > X X X X h5 h6 h8 h8 > X X X X h5 h6 h7 *** Results: 57% dropped (24/56 received)
Lets see about black holing a single host now.
mininet> pingall *** Ping: testing ping reachability h1 > X X X X X X X h2 > X h3 h4 h5 h6 h7 h8 h3 > X h2 h4 h5 h6 h7 h8 h4 > X h2 h3 h5 h6 h7 h8 h5 > X h2 h3 h4 h6 h7 h8 h6 > X h2 h3 h4 h5 h7 h8 h7 > X h2 h3 h4 h5 h6 h8 h8 > X h2 h3 h4 h5 h6 h7 *** Results: 25% dropped (42/56 received)
OpenDaylight has always peaked my interested, I’ve been trying to follow the mailing lists and some of the discussions out there and the Test VM is a nice way to start to get under the hood. I have a lot more to learn and there are a ton of other plugins to start to explore. Not to mention to start to think about the API and writing some code against it.
- If you do not set switch roles properly end hosts my not show up on the topology.
- Flow rule names can not have spaces in them.
- The controller had the Access switches properly classified in the Tier however the transit switches were not set to either Distribution or Core.