The pfifo queuing discipline ---------------------------- Parameters. limit NUMBER This is maximum number of packets that can be on this queue. Enqueuing a packet when the queue is at this limit causes the packet to be dropped. If not specified this parameter defaults to the queue length of the underlying device. This is the qlen parameter printed by "ip link list". Classes. The pfifo queuing discipline does not have classes. Scheduling. The pfifo queuing discipline has not have a scheduler. The packets are sent in the order they are received. Policing. Enqueuing a packet when the queue already contains the number of packets defined by the limit parameter will cause the packet to be dropped. Classifier. The pfifo queuing discipline does not classify packets. Rate limiting. The pfifo queuing discipline does not rate limit traffic. Comments. - pfifo polices the length of the queue, ensuring it does not grow beyond the maximum limit defined by it parameter. That is all it does.