def port_to_tcp(port=None):
    """Returns local tcp address for a given `port`, automatic port if `None`"""
    #address = 'tcp://' + socket.gethostbyname(socket.getfqdn())
    domain_name = socket.getfqdn()
    try:
        addr_list = socket.getaddrinfo(domain_name, None)
    except Exception:
        addr_list = socket.getaddrinfo('127.0.0.1', None)
    family, socktype, proto, canonname, sockaddr = addr_list[0]
    host = convert_ipv6(sockaddr[0])
    address =  'tcp://' + host
    if port is None:
        port = ()
    if not isinstance(port, int):
        # determine port automatically
        context = zmq.Context()
        try:
            socket_ = context.socket(zmq.REP)
            socket_.ipv6 = is_ipv6(address)
            port = socket_.bind_to_random_port(address, *port)
        except Exception:
            print('Could not connect to {} using {}'.format(address, addr_list))
            pypet_root_logger = logging.getLogger('pypet')
            pypet_root_logger.exception('Could not connect to {}'.format(address))
            raise
        socket_.close()
        context.term()
    return address + ':' + str(port)
Returns local tcp address for a given `port`, automatic port if `None`