def ip_in_ipmask(ip, ipmask):
    '''
    Checks whether an ip is contained in an ip subnet where the subnet is a string with the notation ip/mask (e.g. 192.168.1.1/24 or 192.168.1.1/255.255.255.0)
    '''
    mask_ip, mask = str_to_ipmask(ipmask)
    return ip_in_ip_mask(ip, mask_ip, mask)