Cisco 300 Series User Manual

Quality of Service (QoS) Commands
777 OL-32830-01 Command Line Interface Reference Guide
39
no qos trust
Parameters
• cos— Specifies that ingress packets are classified with packet CoS values.
Untagged packets are classified with the default port CoS value.
• dscp—Specifies that ingress packets are classified with packet DSCP
values.
Default Configuration
CoS is the default trust mode.
Command Mode
Global Configuration mode
User Guidelines
This command can be used only in QoS basic mode.
Packets entering a QoS domain are classified at its edge. When the packets are
classified at the edge, the switch port within the QoS domain can be configured to
one of the trusted states because there is no need to classify the packets at every
switch within the domain.
Use this command to specify whether the port is trusted and which fields of the
packet to use to classify traffic.
When the system is configured with trust DSCP, the traffic is mapped to the queue
by the DSCP-queue map.
When the system is configured with trust CoS, the traffic is mapped to the queue
by the CoS-queue map.
For an inter-QoS domain boundary, configure the port to the DSCP-trusted state
and apply the DSCP-to-DSCP-mutation map if the DSCP values are different in the
QoS domains.
Example
The following example configures the system to the DSCP trust state.
switchxxxxxx(config)# qos trust dscp

Cisco 300 Series Specifications

General

Model	Cisco 300 Series
Category	Switch
Dimensions	Varies by model
Weight	Varies by model
Power over Ethernet (PoE)	Available on select models
Management	Web-based GUI, SNMP, CLI
VLANs	Up to 256
Security Features	ACLs, 802.1X, Port Security
Humidity	10% to 90% non-condensing
Ports	8, 16, 24, 48