def is_valid_ip_addr(ip_addr):
    """Validates given string as IPv4 address for given string.

    Args:
        ip_addr (str): string to validate as IPv4 address.

    Returns:
        bool: True if string is valid IPv4 address, else False.
    """
    ip_addr_split = ip_addr.split('.')
    if len(ip_addr_split) != 4:
        return False
    for ip_addr_octet in ip_addr_split:
        if not ip_addr_octet.isdigit():
            return False
        ip_addr_octet_int = int(ip_addr_octet)
        if ip_addr_octet_int < 0 or ip_addr_octet_int > 255:
            return False
    return True
