def wake_up(self, mac):
        import socket,sys
        # TODO autodetect
        DEST = "192.168.0.255"
        # http://gsd.di.uminho.pt/jpo/software/wakeonlan/mini-howto/wol-mini-howto-2.html#ss2.4
        magic_packet = [255 for i in xrange(1,8)]
        mac_hex = []
        for i in mac.split(':'):
            mac_hex.append(int(i, 16))
        for i in xrange(0, 16):
            magic_packet.extend(mac_hex)
        magic_packet = ''.join([chr(x) for x in magic_packet])

        s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        s.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, True)
        s.sendto(magic_packet, (DEST, 15911))