If your topology is simple/static and depending on how your application works, you really may not need anything particularly complicated to solve the problem (e.g., not necessarily a full spanning tree). For example, it's often the case that only floods are problematic and you can just rethink your flooding and/or disable flooding on some ports and be done.
You also may be able to make use of the openflow.spanning_tree component, though it's may well be overkill. -- Murphy On Oct 21, 2014, at 5:22 PM, Brian Krisler <bkris...@bbn.com> wrote: > Good point. I was thinking I had a check for that. But your point is dead on, > as soon as I broke the loop, all was fine. > > Guess I need a spanning tree. > > Thanks. > > Brian > > > >> On Oct 21, 2014, at 8:18 PM, Murphy McCauley <murphy.mccau...@gmail.com> >> wrote: >> >> If they're in a ring and you therefore have a loop... if you're not careful, >> you'll get looping packets, which can certainly overwhelm the network and >> switches, exhaust buffers, and starve the control channel if it's on the >> same network. >> >> -- Murphy >> >>> On Oct 21, 2014, at 5:15 PM, Brian Krisler <bkris...@bbn.com> wrote: >>> >>> I started to remove switches and discovered one was causing issues. I have >>> not yet investigated why. >>> >>> What I am trying to accomplish is a proof of concept with 4 switches in a >>> ring topology. Two of the four switches are connected to different subnets. >>> So 192.168.0.x is connected to switch1 and 192.168.1.x is connected to >>> switch3. >>> >>> All switches are controlled by a single controller, and the goal is to be >>> able to dynamically reroute traffic between the subnets within the ring >>> based on higher-level rules passed into the controller. >>> >>> So in normal traffic flows from switch1 to switch3, a rule can tell the >>> controller to route switch1 to switch2 to switch4, for example. >>> >>> I basically have it working, I am now trying to get statistics setup to >>> report on existing traffic flows. >>> >>> Brian >>> >>> >>> >>>> On Oct 21, 2014, at 5:40 PM, Murphy McCauley <murphy.mccau...@gmail.com> >>>> wrote: >>>> >>>> Maybe you could start off by describing your setup a bit. What is your >>>> network like, what POX components are you running, what are you trying to >>>> accomplish, etc.? >>>> >>>> -- Murphy >>>> >>>>> On Oct 21, 2014, at 11:16 AM, Brian Krisler <bkris...@bbn.com> wrote: >>>>> >>>>> Hi, >>>>> >>>>> In my controller, I keep getting the error messages below, >>>>> or I get a stream of “DEBUG:openflow.of_01:deferred sender is sending!” >>>>> messages. >>>>> >>>>> I have now reduced my handle_PacketIn method to be: >>>>> >>>>> def handle_PacketIn(self, event): >>>>> packet = event.parsed >>>>> msg = of.ofp_packet_out(data = event.ofp) >>>>> msg.actions.append(of.ofp_action_output(port = of.OFPP_NORMAL)) >>>>> event.connection.send(msg) >>>>> return None >>>>> >>>>> And I still get this issues. How do I figure out the cause? >>>>> >>>>> Thanks >>>>> >>>>> Brian >>>>> >>>>> >>>>> >>>>> ERROR:openflow.of_01:[08-00-27-21-24-cc 6] OpenFlow Error: >>>>> [08-00-27-21-24-cc 6] Error: header: >>>>> [08-00-27-21-24-cc 6] Error: version: 1 >>>>> [08-00-27-21-24-cc 6] Error: type: 1 (OFPT_ERROR) >>>>> [08-00-27-21-24-cc 6] Error: length: 36 >>>>> [08-00-27-21-24-cc 6] Error: xid: 53974 >>>>> [08-00-27-21-24-cc 6] Error: type: OFPET_BAD_REQUEST (1) >>>>> [08-00-27-21-24-cc 6] Error: code: OFPBRC_BUFFER_UNKNOWN (8) >>>>> [08-00-27-21-24-cc 6] Error: datalen: 24 >>>>> [08-00-27-21-24-cc 6] Error: 0000: 01 0d 00 18 00 00 d2 d6 00 00 05 2a >>>>> 00 01 00 08 |...........*....| >>>>> [08-00-27-21-24-cc 6] Error: 0010: 00 00 00 08 ff fa 00 00 >>>>> |........ | >>>>> ERROR:openflow.of_01:[08-00-27-21-24-cc 6] OpenFlow Error: >>>>> [08-00-27-21-24-cc 6] Error: header: >>>>> [08-00-27-21-24-cc 6] Error: version: 1 >>>>> [08-00-27-21-24-cc 6] Error: type: 1 (OFPT_ERROR) >>>>> [08-00-27-21-24-cc 6] Error: length: 36 >>>>> [08-00-27-21-24-cc 6] Error: xid: 53975 >>>>> [08-00-27-21-24-cc 6] Error: type: OFPET_BAD_REQUEST (1) >>>>> [08-00-27-21-24-cc 6] Error: code: OFPBRC_BUFFER_UNKNOWN (8) >>>>> [08-00-27-21-24-cc 6] Error: datalen: 24 >>>>> [08-00-27-21-24-cc 6] Error: 0000: 01 0d 00 18 00 00 d2 d7 00 00 05 2b >>>>> 00 03 00 08 |...........+....| >>>>> [08-00-27-21-24-cc 6] Error: 0010: 00 00 00 08 ff fa 00 00 >>>>> |........ | >>>>> ERROR:openflow.of_01:[08-00-27-21-24-cc 6] OpenFlow Error: >>>>> [08-00-27-21-24-cc 6] Error: header: >>>>> [08-00-27-21-24-cc 6] Error: version: 1 >>>>> [08-00-27-21-24-cc 6] Error: type: 1 (OFPT_ERROR) >>>>> [08-00-27-21-24-cc 6] Error: length: 36 >>>>> [08-00-27-21-24-cc 6] Error: xid: 53976 >>>>> [08-00-27-21-24-cc 6] Error: type: OFPET_BAD_REQUEST (1) >>>>> [08-00-27-21-24-cc 6] Error: code: OFPBRC_BUFFER_UNKNOWN (8) >>>>> [08-00-27-21-24-cc 6] Error: datalen: 24 >>>>> [08-00-27-21-24-cc 6] Error: 0000: 01 0d 00 18 00 00 d2 d8 00 00 05 2c >>>>> 00 01 00 08 |...........,....| >>>>> [08-00-27-21-24-cc 6] Error: 0010: 00 00 00 08 ff fa 00 00 >>>>> |........ | >>
