Cisco 300 Series User Manual

Quality of Service (QoS) Commands
OL-32830-01 Command Line Interface Reference Guide 752
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Command Mode
Policy-map Class Configuration mode.
User Guidelines
This command is relevant only when QoS is in advanced, ports-not-trusted mode.
Trust indicates that traffic is sent to the queue according to the packet’s QoS
parameters (UP or DSCP).
Use this command to distinguish the QoS trust behavior for certain traffic from
others. For example, incoming traffic with certain DSCP values can be trusted. A
class map can be configured to match and trust the DSCP values in the incoming
traffic.
The type of trust is determined in qos advanced-mode trust.
Trust values set with this command supersede trust values set on specific
interfaces with the qos trust (Interface) Interface Configuration mode command.
The trust and set commands are mutually exclusive within the same policy map.
Policy maps, which contain set or trust commands or that have ACL classification
to an egress interface, cannot be attached by using the service-policy Interface
Configuration mode command.
If specifying trust cos, QoS maps a packet to a queue, the received or default port
CoS value, and the CoS-to-queue map.
Example
The following example creates an ACL, places it into a class map, places the class
map into a policy map and configures the trust state using the DSCP value in the
ingress packet.
switchxxxxxx(config)# ip access-list extended ip1
switchxxxxxx(config-ip-al)#
permit ip any any
switchxxxxxx(config-ip-al)#
exit
switchxxxxxx(config)# class-map c1
switchxxxxxx(config-cmap)#
match access-group ip1
switchxxxxxx(config-cmap)#
exit
switchxxxxxx(config)# policy-map p1
switchxxxxxx(config-pmap)#
class c1
switchxxxxxx(config-pmap-c)#
trust cos-dscp

Cisco 300 Series Specifications

General

Brand	Cisco
Model	300 Series
Category	Switch
Language	English