Cisco Systems 3750E Limiting the Bandwidth on an Egress Interface, Mls qos Enable QoS on a switch

Chapter 36 Configuring QoS

Configuring Standard QoS

Beginning in privileged EXEC mode, follow these steps to enable the egress expedite queue. This procedure is optional.

	Command	Purpose
Step 1
	configure terminal	Enter global configuration mode.
Step 2
	mls qos	Enable QoS on a switch.
Step 3
	interface interface-id	Specify the egress port, and enter interface configuration mode.
Step 4
	priority-queue out	Enable the egress expedite queue, which is disabled by default.
		When you configure this command, the SRR weight and queue size ratios
		are affected because there is one fewer queue participating in SRR. This
		means that weight1 in the srr-queue bandwidth shape or the srr-queue
		bandwidth share command is ignored (not used in the ratio calculation).
Step 5
	end	Return to privileged EXEC mode.
Step 6
	show running-config	Verify your entries.
Step 7
	copy running-config startup-config	(Optional) Save your entries in the configuration file.

To disable the egress expedite queue, use the no priority-queue out interface configuration command.

This example shows how to enable the egress expedite queue when the SRR weights are configured. The egress expedite queue overrides the configured SRR weights.

Switch(config)# interface gigabitethernet1/0/1

Switch(config-if)#srr-queue bandwidth shape 25 0 0 0

Switch(config-if)#srr-queue bandwidth share 30 20 25 25

Switch(config-if)# priority-queue out

Switch(config-if)# end

Limiting the Bandwidth on an Egress Interface

You can limit the bandwidth on an egress port. For example, if a customer pays only for a small percentage of a high-speed link, you can limit the bandwidth to that amount.

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 limit the bandwidth on an egress port. This procedure is optional.

	Command		Purpose
Step 1	configure terminal		Enter global configuration mode.
Step 2	interface interface-id		Specify the port to be rate limited, and enter interface configuration mode.
Step 3	srr-queue bandwidth limit weight1		Specify the percentage of the port speed to which the port should be
			limited. The range is 10 to 90.
			By default, the port is not rate limited and is set to 100 percent.
Step 4	end		Return to privileged EXEC mode.
		Catalyst 3750-E and 3560-E Switch Software Configuration Guide
36-80			OL-9775-02