def proto_check(proto):
    """
    proto_check is called from all_check.
    proto_check takes input of the protocol variable in the acl_data dictionary
    and checks to make sure the protocol is ip of icmp only.
    """
    if proto == 'NA':
        print ("Proto value not provided")
        return False
    if proto == 'icmp' or proto == '':
        return True
    else:
        print ("Protocol Check Failed")
        return False