def _break_ip_address(cidr_ip_address):
    """ Function divides the input parameter into IP address and network mask.

    :param cidr_ip_address: IP address in format of IP/prefix_size
    :return: IP, prefix_size
    """

    if "/" in cidr_ip_address:
        ip_address, prefix_size = cidr_ip_address.split("/")
    else:
        ip_address = cidr_ip_address
        prefix_size = 0

    return ip_address, prefix_size