Mls Qos Cos - Cisco Catalyst 2950 Command Reference Manual

Chapter 2 Cisco IOS Commands

mls qos cos

Use the mls qos cos interface configuration command to define the default class of service (CoS) value
of a port or to assign the default CoS to all incoming packets on the port. Use the no form of this
command to return to the default setting.
Syntax Description
default-cos
override
Defaults
The default CoS value for a port is 0.
CoS override is disabled.
Command Modes Interface configuration
Command History Release
12.1(6)EA2
Usage Guidelines You can use the default value to assign CoS and DSCP values to all packets entering a port if the port
has been configured by using the override keyword.
Use the override keyword when all incoming packets on certain ports deserve higher or lower priority
than packets entering from other ports. Even if a port was previously set to trust DSCP or CoS, this
command overrides that trust state, and all the incoming CoS values are assigned the default CoS value
configured with the mls qos cos 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.
Examples
This example shows how to configure the default port CoS to 4:
Switch(config)# interface gigabitethernet0/1
Switch(config-if)# mls qos trust cos
Switch(config-if)# mls qos cos 4
78-11381-05
mls qos cos {default-cos | override}
no mls qos cos {default-cos | override}
Assign a default CoS value to a port. If the port is CoS trusted and packets are
untagged, the default CoS value becomes a CoS value used to select one output
queue to index into the CoS-to-Differentiated Services Code Point (DSCP) map. The
CoS range is 0 to 7.
Override the CoS of the incoming packets, and apply the default CoS value on the
port to all incoming packets.
Modification
This command was first introduced.
Catalyst 2950 Desktop Switch Command Reference
mls qos cos
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