Switch QoS

Continuing my notes..

3550 QoS

• "mls qos min-reserve [queue] [# of packets]" sets max number of packets per queue
• "wrr-queue cos-map [queue] [CoS]" is assigned per interface
• "wrr-queue bandwidth [weight Q1] [weight Q2] [weight Q3] [weight Q4]" assigns a weight per queue.
• "show mls qos interface [x] queuing" is one of the single most important QoS commands on a switch. Shows default/configured QoS settings per interface.
• "priority-queue out" enables PQ (which is Q4 on 3550) per interface.

3560 QoS

• "show mls qos maps dscp-input-queue" or "show mls qos map" shows default mappings
• You assign a queue and a threshold to traffic.
• "mls qos srr-queue input dscp-map queue [x] threshold [y] [dscp-values]" maps dscp values to a queue and threshold.
• "show mls qos input-queue" shows weights per queue and threshold.
• "mls qos srr-queue input threshold [queue [threshold1] [threshold2]"
• "mls qos srr-queue input-buffers" alters the # of packets per queue.
• "mls qos srr-queue input bandwidth [queue1] [queue2].." assigns bandwidth per queue.
• "mls qos srr-queue input priority-queue 1 bandwidth 20" would assign a weight of 20 to priority queue.
• 3560 has 2 input queues and 1 priority queue
• "show mls qos maps dscp-output" shows default dscp map for output.
• "mls qos srr-queue output dscp-map queue [x] threshold [y] [dscp values]" assigns dscp values to output queues/thresholds
• "show mls qos interface [x] buffers" shows QoS output queue buffers.
• "mls qos queue-set output [queue-set #] buffers [Q1] [Q2] [Q3].." assigns buffers to a queue-set.
• "queue-set [y]" assigns an interface to a queue set.
• "show mls qos queue-set" shows buffers, threshold, etc for each queue set.
• "srr queue bandwidth [share|shape] [weight Q1] [weight Q2].." - interface level command to assign bandwidth to interface.
• "srr-queue bandwidth limit [percent] limits bandwidth per interface.

Up next...multicast