Yes, NOX can manipulate the flow table of a switch, for example by using the install_datapath_flow() method of components. A good example of this is in pyswitch.py, and you can find some additional information here: http://openflow.org/wk/index.php/GEC8Tutorial#Sending_OpenFlow_messages
Your basic understanding seems to be correct, but *you can write a controller without ever touching dpctl*. -- Murphy On Nov 21, 2010, at 3:12 PM, Kavitesh Singh wrote: > Hi, > > How do you add flows in the python controller. One way to achieve this is to > add using dpctl tool. I want to know if there are some inbuilt functions to > call such command in python code? > > Also, can someone verify my understanding: > After starting mininet and NOX controller, I would add initial flows using > dpctl tool with a timeout say 120 secs. Now after 120 secs the flow will > expire and generate flow removed event. Let us say I installed flowpath > between h2 and h3 using dpctl initially. This will expire now. So any packet > h2 sends to h3 will now arrive at NOX controller and controller will now > decide on the flow. To resume communication between h2 and h3, controller > will again set a flow between h2 and h3 again. I can use the dpctl again but > is there a way to do it in python code? > > Regards, > Kavitesh. > _______________________________________________ > nox-dev mailing list > nox-dev@noxrepo.org > http://noxrepo.org/mailman/listinfo/nox-dev_noxrepo.org _______________________________________________ nox-dev mailing list nox-dev@noxrepo.org http://noxrepo.org/mailman/listinfo/nox-dev_noxrepo.org
