new_contents: import zmq
  import sys
  
  sub_port = 5556
  pub_port = 5557
  
  if len(sys.argv) > 2:
      sub_port = sys.argv[1]
      pub_port = sys.argv[2]
  
  subscribe_to = "tcp://*:{}".format(sub_port)
  publish_to = "tcp://*:{}".format(pub_port)
  
  try:
      context = zmq.Context()
      frontend = context.socket(zmq.SUB)
      frontend.bind(subscribe_to)
      frontend.setsockopt(zmq.SUBSCRIBE, "")
  
      backend = context.socket(zmq.PUB)
      backend.bind(publish_to)
  
      zmq.device(zmq.FORWARDER, frontend, backend)
  except KeyboardInterrupt:
      print "Bye!"
  except Exception:
      print "Bringing down FORWARDER"
      raise
  finally:
      frontend.close()
      backend.close()
      context.term()
  
subject: Add a stable message router (bound to a known IP)