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Catalyst 2940 Switch Software Configuration Guide
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Chapter24 Configuring QoS Configuring QoS
Beginning in privileged EXEC mode, follow these steps to configure the port to trust the classification
of the traffic that it receives:
After you enter the mls qos trust cos command, the DSCP values are changed according to the values
listed in Table24-1.
Note CoS-to-DSCP values cannot be configured.
To return a trusted port to its unconfigured state, use the no mls qos trust interface configuration
command.
Command Purpose
Step1 configure terminal Enter global configuration mode.
Step2 interface interface-id Enter interface configuration mode, and specify the interface to be
trusted.
Valid interfaces include physical interfaces.
Step3 mls qos trust [cos] Configure the port trust state.
By default, the port is not trusted. All traffic is sent through one
egress queue.
Use the cos keyword to classify ingress packets with the packet CoS
values. The egress queue assigned to the packet is based on the
packet CoS value. When this keyword is entered, the traffic is sent
through the four QoS queues, as described in the “Configuring th e
Egress Queues” section on page 24-8.
For more information about this command, refer to the command
reference for this release.
Step4 end Return to privileged EXEC mode.
Step5 show mls qos interface [interface-id] Verify your entries.
Step6 copy running-config startup-config (Optional) Save your entries in the configuration file.
Table24-1 Default CoS-to-DSCP Map
CoS value0123456 7
DSCP value 0 8 16 24 32 40 48 56