Cisco Systems 3750E Configuring the CoS Value for an Interface, Show mls qos interface, 36-40

Chapter 36 Configuring QoS

Configuring Standard QoS

	Command	Purpose
Step 3
	mls qos trust [cos dscp ip-precedence]	Configure the port trust state.
		By default, the port is not trusted. If no keyword is specified, the
		default is dscp.
		The keywords have these meanings:
		• cos—Classifies an ingress packet by using the packet CoS value.
		For an untagged packet, the port default CoS value is used. The
		default port CoS value is 0.
		• dscp—Classifies an ingress packet by using the packet DSCP
		value. For a non-IP packet, the packet CoS value is used if the
		packet is tagged; for an untagged packet, the default port CoS is
		used. Internally, the switch maps the CoS value to a DSCP value
		by using the CoS-to-DSCP map.
		• ip-precedence—Classifies an ingress packet by using the packet
		IP-precedence value. For a non-IP packet, the packet CoS value
		is used if the packet is tagged; for an untagged packet, the default
		port CoS is used. Internally, the switch maps the CoS value to a
		DSCP value by using the CoS-to-DSCP map.
Step 4
	end	Return to privileged EXEC mode.
Step 5
	show mls qos interface	Verify your entries.
Step 6
	copy running-config startup-config	(Optional) Save your entries in the configuration file.

To return a port to its untrusted state, use the no mls qos trust interface configuration command.

For information on how to change the default CoS value, see the “Configuring the CoS Value for an Interface” section on page 36-40. For information on how to configure the CoS-to-DSCP map, see the “Configuring the CoS-to-DSCP Map” section on page 36-63.

Configuring the CoS Value for an Interface

QoS assigns the CoS value specified with the mls qos cos interface configuration command to untagged frames received on trusted and untrusted ports.

Beginning in privileged EXEC mode, follow these steps to define the default CoS value of a port or to assign the default CoS to all incoming packets on the port:

	Command	Purpose
Step 1
	configure terminal	Enter global configuration mode.
Step 2
	interface interface-id	Specify the port to be configured, and enter interface configuration mode.
		Valid interfaces include physical ports.

	Catalyst 3750-E and 3560-E Switch Software Configuration Guide
36-40	OL-9775-02