16- and 36-Port Ethernet Switch Module for Cisco 2600 Series, Cisco 3600 Series, and Cisco 3700 Series
Configuration Tasks
90
Cisco IOS Release 12.2(2)XT, 12.2(8)T, and 12.2(15)ZJ
To return to the default setting, use the no mls qos cos {default-cos | override} interface configuration
command.
Note
The mls qos cos command replaced the switchport priority command in Cisco IOS Release
12.1(6)EA2.
Configuring a QoS Policy
Configuring a QoS policy typically requires classifying traffic into classes, configuring policies applied
to those traffic classes, and attaching policies to interfaces.
For background information, see the
“Classification” section on page 32
and the
“Policing and Marking”
section on page 34
.
This section contains this configuration information:
•
Classifying Traffic by Using ACLs, page 91
•
Classifying Traffic by Using Class Maps, page 93
•
Classifying, Policing, and Marking Traffic by Using Policy Maps, page 94
Step 3
mls qos cos {default-cos | override}
Configures the default CoS value for the port.
For default-cos, specify a default CoS value to be assigned to a port. If the
port is CoS trusted and packets are untagged, the default CoS value becomes
the CoS value for the packet. The CoS range is 0 to 7. The default is 0.
Use the override keyword to override the previously configured trust state
of the incoming packets and to apply the default port CoS value to all
incoming packets. By default, CoS override is disabled.
Use the override keyword when all incoming packets on certain ports
deserve higher priority than packets entering from other ports. Even if a port
was previously set to trust DSCP, this command overrides the previously
configured trust state, and all the incoming CoS values are assigned the
default CoS value configured with this command. If an incoming packet is
tagged, the CoS value of the packet is modified with the default CoS of the
port at the ingress port.
Step 4
end
Returns to privileged EXEC mode.
Step 5
show mls qos interface
Verifies your entries.
Step 6
copy running-config startup-config
(Optional) Saves your entries in the configuration file.
Command
Purpose