def startServer(queue, port): 
  reactor.listenUDP(port, DhtResponseHandler(queue)) 
  reactor.run() 

def sendUdpMsg(self, addr, msg): 
  socketHandler = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) 
  socketHandler.bind(("", self.port)) 
  socketHandler.sendto(msg, addr) 
  socketHandler.close() 

socketHandler.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) 

sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) 
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) 
sock.bind(("", port)) 
data, address = sock.recvfrom(4096) 

class Port(abstract.FileHandle): 
  def __init__(self, port, proto, interface='', maxPacketSize=8192, 
         reactor=None): 
    """ 
    Initialize with a numeric port to listen on. 
    """ 
    self.port = port 
    self.protocol = proto 
    self.readBufferSize = maxPacketSize 
    self.interface = interface 
    self.setLogStr() 
    self._connectedAddr = None 
 
    abstract.FileHandle.__init__(self, reactor) 
 
    skt = socket.socket(self.addressFamily, self.socketType) 
    addrLen = _iocp.maxAddrLen(skt.fileno()) 
    self.addressBuffer = _iocp.AllocateReadBuffer(addrLen) 
    # WSARecvFrom takes an int 
    self.addressLengthBuffer = _iocp.AllocateReadBuffer( 
        struct.calcsize('i')) 
 
  def startListening(self): 
    """ 
    Create and bind my socket, and begin listening on it. 
 
    This is called on unserialization, and must be called after creating a 
    server to begin listening on the specified port. 
    """ 
    self._bindSocket() 
    self._connectToProtocol() 
 
 
  def createSocket(self): 
    return self.reactor.createSocket(self.addressFamily, self.socketType) 
 
 
  def _bindSocket(self): 
    try: 
      skt = self.createSocket() 
      skt.bind((self.interface, self.port)) 
    except socket.error, le: 
      raise error.CannotListenError, (self.interface, self.port, le) 
 
    # Make sure that if we listened on port 0, we update that to 
    # reflect what the OS actually assigned us. 
    self._realPortNumber = skt.getsockname()[1] 
 
    log.msg("%s starting on %s" % ( 
        self._getLogPrefix(self.protocol), self._realPortNumber)) 
 
    self.connected = True 
    self.socket = skt 
    self.getFileHandle = self.socket.fileno 

class MulticastPort(MulticastMixin, Port): 
  """ 
  UDP Port that supports multicasting. 
  """ 
 
  implements(interfaces.IMulticastTransport) 
 
 
  def __init__(self, port, proto, interface='', maxPacketSize=8192, 
         reactor=None, listenMultiple=False): 
    Port.__init__(self, port, proto, interface, maxPacketSize, reactor) 
    self.listenMultiple = listenMultiple 
 
 
  def createSocket(self): 
    skt = Port.createSocket(self) 
    if self.listenMultiple: 
      skt.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) 
      if hasattr(socket, "SO_REUSEPORT"): 
        skt.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEPORT, 1) 
    return skt 

reactor.listenMulticast(port, DhtResponseHandler(queue), listenMultiple=True) 
reactor.run()