You are just creating a message, but that's not enough -- you have to send it to a switch. This section of the POX manual may be of help: https://noxrepo.github.io/pox-doc/html/#communicating-with-datapaths-switches
You also might take a look at some of the sample POX components, particularly ones in the forwarding/ directory. But I think you've got bigger problems. By default, POX actually clears the tables on switches when they connect -- sending a command much like the one you've constructed. So I think switches aren't connecting to POX. Depending on what version of POX you're running, one possibility is that POX's OpenFlow component isn't running. You might look at the documentation for the of_01 component in the manual: https://noxrepo.github.io/pox-doc/html/#openflow-of-01 The manual mentions that POX will generally automatically load the of_01 (OpenFlow 1.0) component if another component that uses OpenFlow is loaded. Since you're entering stuff in the CLI, maybe you aren't loading any OpenFlow-using component? In that case, you'll need to launch of_01 manually. If you're just running POX without any commandline arguments at all, you should probably read: https://noxrepo.github.io/pox-doc/html/#invoking-pox Ultimately, you should see some log messages in POX about the switches connecting. Are you? Not really related to the above, but you mention how packets being dropped means the table entry is still there. That's not true, generally speaking. In general, an OpenFlow switch without any table entries doesn't forward any traffic (though it may encapsulate at least the headers and send it to the controller). -- Murphy On Wed, Mar 13, 2019 at 8:36 PM Sukheja, Himanshu <hxs...@psu.edu> wrote: > have created a simple topology using Mininet in which I have created a > single switch and connected it to a remote controller (POX). I installed a > simple flow rule using Mininet CLI which commands the switch to drop all > packets. > > sh ovs-ofctl add-flow s1 priority=40000,hard_timeout=30,actions=drop > > Now In POX CLI I run the following command > > msg = of.ofp_flow_mod(command=of.OFPFC_DELETE) > > Although now when I do a Dump-flow command on mininet terminal it still > shows the flow is installed > Also, I tried to ping h1 and h2, and the packets are being dropped (which > means that the flow is still there) > > > Could you please point out the error in my execution here. > > Thanks > *********************************************** > ************************************************************************ > Himanshu Sukheja >
