Chapter 28
Configuring QoS
Note
The egress queue default settings are suitable for most situations. You should change them only when
you have a thorough understanding of the egress queues and if these settings do not meet your QoS
solution.
Beginning in privileged EXEC mode, follow these steps to assign the shaped weights and to enable
bandwidth shaping on the four egress queues mapped to a port. This procedure is optional.
Command
Step 1
configure terminal
Step 2
interface interface-id
Step 3
srr-queue bandwidth shape weight1
weight2 weight3 weight4
Step 4
end
Step 5
show mls qos interface interface-id
queueing
Step 6
copy running-config startup-config
To return to the default setting, use the no srr-queue bandwidth shape interface configuration
command.
This example shows how to configure bandwidth shaping on queue 1. Because the weight ratios for
queues 2, 3, and 4 are set to 0, these queues operate in shared mode. The bandwidth weight for queue 1
is 1/8, which is 12.5 percent:
Switch(config)# interface gigabitethernet0/1
Switch(config-if)# srr-queue bandwidth shape 8 0 0 0
78-16156-01
Purpose
Enter global configuration mode.
Specify the port of the outbound traffic, and enter interface configuration
mode.
Assign SRR weights to the egress queues.
By default, weight1 is set to 25; weight2, weight3, and weight4 are set to 0,
and these queues are in shared mode.
For weight1 weight2 weight3 weight4, enter the weights to control the
percentage of the port that is shaped. The inverse ratio (1/weight) controls
the shaping bandwidth for this queue. Separate each value with a space.
The range is 0 to 65535.
If you configure a weight of 0, the corresponding queue operates in shared
mode. The weight specified with the srr-queue bandwidth shape
command is ignored, and the weights specified with the srr-queue
bandwidth share interface configuration command for a queue come into
effect. When configuring queues in the same queue-set for both shaping
and sharing, make sure that you configure the lowest number queue for
shaping.
The shaped mode overrides the shared mode.
Return to privileged EXEC mode.
Verify your entries.
(Optional) Save your entries in the configuration file.
Catalyst 3560 Switch Software Configuration Guide
Configuring Standard QoS
28-61