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my environment is mininet. what im trying to achieve is, that each time, a switch connects or disconnects to the pox controller, the controller should print all connected switches (their DPIDs).

def _handle_ConnectionUp (self, event):

print "Switch %s has come up." % event.dpid

is that something i can work with? and what do i need to implement before that i can use _handle_ConnectionUp ?

thanks in advance.

addict
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1 Answers1

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Best approach would be to define a set in your Controller Class and add the DPIDs of all switches there. So every time you have an event in the _handle_ConnectionUp you can get the DPID of the switch and add it accordingly.

In your main controller class init function

self.switches = set()

and the _handle_ConnectionUp function

def _handle_ConnectionUp(self, event):
        """
        Fired up openflow connection with the switch
        save the switch dpid
        Args:
            event: openflow ConnectionUp event
        Returns: Nada
        """
        self.switches.add(pox.lib.util.dpid_to_str(event.dpid))

Accordingly you should catch the event of Connection Down to remove the switch if needed. To get a list of all openflow events mixins currently available in the Dart version of the POX controller go to https://github.com/noxrepo/pox/blob/dart/pox/openflow/init.py line 336 at event mixins

 _eventMixin_events = set([
    ConnectionUp,
    ConnectionDown,
    FeaturesReceived,
    PortStatus,
    FlowRemoved,
    PacketIn,
    BarrierIn,
    ErrorIn,
    RawStatsReply,
    SwitchDescReceived,
    FlowStatsReceived,
    AggregateFlowStatsReceived,
    TableStatsReceived,
    PortStatsReceived,
    QueueStatsReceived,
    FlowRemoved,
  ])

For further assistance you can check the code of a fully functional SDN controller with Dart POX I have written for the Python Meetup in Thessaloniki Greece and can be found at https://github.com/tsartsaris/pythess-SDN

SotirisTsartsaris
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