A little background on what Kavit is trying to do here is to build a tunneling mechanism through the controller for a (very small!) number of packets between hosts connected on two different OF switches connected to the same controller.
The application is essentially just a learning switch except: 1) It builds a global L2 table spanning all connected switches that includes DPID as well as MAC and port for all learned MAC addresses 2) When a Multicast DNS packet is sent as a Packetin to the controller the controller sends the received packet as a PacketOut to a different switch based upon a DB lookup of "paired" source and dest MACs. It uses the global L2 table to find the DPID of the dest MAC. I took a quick look at the ofp_packet_out class in pox/openflow/libopenflow_01.py and it looks like probably the easiest way to do this is to use the ofp_packet_out to build a new packet and then pack the data from the Packetin into the new PacketOut. What Kavit is currently doing is sending the packet received by the controller back out directly using sendToDPID. --Chris Small ====== I think sendToDPID() just doesn't do what you think it does. It is for sending OpenFlow commands to a switch -- the same as connection.send(), except it looks up the connection for you based on DPID. I believe you're trying to use it to send a packet out of some port on a switch. There's an obvious piece of information missing here -- sendToDPID takes a DPID, but how would it know which port you want to send the packet out of? What you need to do is create an ofp_packet_out() which has an output action to the appropriate port and the data you want to send as the 'data' attribute. This is similar to the flood() function in l2_learning which is in your source. There are even closer examples in other modules (e.g., misc.dhcpd). Then send *that* using sendToDPID(), or in your case -- just use connection.send(). -- Murphy On Jul 5, 2013, at 12:52 PM, Kavit Shah wrote: > Command line with log, my code and screen shot of the wireshrak are attached > in the text and png files. > > I am using HP Pro curve switch, i think it supports OF 1.0 spec. > > > ##################################### > ##################################### > > Important part of my code in the attached file > > ##################################### > ##################################### > > Questions: > > 1) sendToDPID function is not working the way I expect it to work. According > to me if that function works I should see packet out in wireshark. > > 2) Am I extracting dpid of the switch correctly ? > > 3) What is the reason for getting an error while switch connects to the POX > controller ? > > ERROR:openflow.of_01:[00-16-b9-ce-2f-40|800 1] OpenFlow Error: > [00-16-b9-ce-2f-40|800 1] Error: header: > [00-16-b9-ce-2f-40|800 1] Error: version: 1 > [00-16-b9-ce-2f-40|800 1] Error: type: 1 (OFPT_ERROR) > [00-16-b9-ce-2f-40|800 1] Error: length: 20 > [00-16-b9-ce-2f-40|800 1] Error: xid: 7 > [00-16-b9-ce-2f-40|800 1] Error: type: OFPET_BAD_REQUEST (1) > [00-16-b9-ce-2f-40|800 1] Error: code: OFPBRC_BAD_TYPE (1) > [00-16-b9-ce-2f-40|800 1] Error: datalen: 8 > [00-16-b9-ce-2f-40|800 1] Error: 0000: 01 12 00 08 00 00 00 07 > ........ > > > <sendToDPID_question.txt><sendToDPID_wireshark.png>_______________________________________________ > mininet-discuss mailing list > mininet-discuss at > lists.stanford.edu<http://lists.noxrepo.org/listinfo.cgi/pox-dev-noxrepo.org> > https://mailman.stanford.edu/mailman/listinfo/mininet-discuss
