2-291
Catalyst 3750 Metro Switch Command Reference
OL-9645-10
Chapter 2 Catalyst 3750 Metro Switch Cisco IOS Commands
mls qos queue-set output threshold
Usage Guidelines Use the mls qos queue-set output qset-id buffers global configuration command to allocate a fixed
number of buffers to the four queues in a queue-set.
The drop-threshold percentages can exceed 100 percent and can be up to the maximum (if the maximum
threshold exceeds 100 percent).
Note The egress queue-set default settings are suitable for most situations. You should change them only when
you have a thorough understanding of the queues and if these settings do not meet your QoS solution.
The switch uses a buffer allocation scheme to reserve a minimum amount of buffers for each egress
queue-set, to prevent any queue or port from consuming all the buffers and depriving other queues, and
to control whether to grant buffer space to a requesting queue. The switch detects whether or not the
target queue has consumed more buffers than its reserved amount (under-limit), whether it has consumed
all of its maximum buffers (over-limit), and whether the common pool is empty (no free buffers) or not
empty (free buffers). If the queue is not over-limit, the switch can allocate buffer space from the reserved
pool or from the common pool (if it is not empty). If there are no free buffers in the common pool or if
the queue is over-limit, the switch drops the frame.
Examples This example shows how to map a port to queue-set 2. It configures the drop thresholds for queue 2 to
40 and 60 percent of the allocated memory, guarantees (reserves) 100 percent of the allocated memory,
and configures 200 percent as the maximum memory that this queue can have before packets are
dropped.
Switch(config)# mls qos queue-set output 2 threshold 2 40 60 100 200
Switch(config)# interface fastethernet1/0/1
Switch(config-if)# queue-set 2
You can verify your settings by entering the show mls qos interface [interface-id] buffers or the show
mls qos queue-set privileged EXEC command.
Related Commands Command Description
mls qos queue-set output buffers Allocates buffers to a queue-set.
queue-set Maps a port to a queue-set.
show mls qos interface buffers Displays buffer allocation information.
show mls qos queue-set Displays settings for the queue-set.
To Next Page
Loading...
