diff --git a/p4app/controller.py b/p4app/controller.py
index e20a4d0..35f5724 100644
--- a/p4app/controller.py
+++ b/p4app/controller.py
@@ -48,11 +48,15 @@ class L2Controller(object):
     @staticmethod
     def prefix_to_net(net, mask):
         """ work around ipaddress bug """
-        return "{}0/{}".format(net, mask)
+        net = "{}0/{}".format(net, mask)
+        log.debug("net: {}".format(net))
+        return net
 
     @staticmethod
     def prefix_to_host(net, mask):
         """ work around ipaddress bug """
+        host = "{}1/{}".format(net, mask)
+        log.debug("host: {}".format(host))
         return "{}1/{}".format(net, mask)
 
     @staticmethod
@@ -151,6 +155,7 @@ class L2Controller(object):
     def commandline(self):
         parser = argparse.ArgumentParser(description='controller++')
         parser.add_argument('--mode', help='Select mode / settings to use', choices=self.modes)
+        parser.add_argument('--debug', help='Enable debug logging', action='store_true')
         args = parser.parse_args()
         self.mode = args.mode
 
@@ -171,5 +176,7 @@ if __name__ == "__main__":
     controller = L2Controller(sw_name)
 
     controller.commandline()
+    if controller.args.debug:
+        log.setLevel(logging.DEBUG)
     controller.config()
     controller.run_cpu_port_loop()