Cisco WS-C3560E-48PD-SF Command Reference - Page 274

mls qos cos Chapter 2 Catalyst 3560 Switch 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. mls qos cos {default-cos | override} no mls qos cos {default-cos | override} Syntax Description default-cos override Assign a default CoS value to a port. If packets are untagged, the default CoS value becomes the packet CoS value. 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. Defaults The default CoS value for a port is 0. CoS override is disabled. Command Modes Interface configuration Command History Release 12.1(19)EA1 Modification This command was introduced. Usage Guidelines You can use the default value to assign a CoS and Differentiated Services Code Point (DSCP) value to all incoming packets that are untagged (if the incoming packet does not have a CoS value). You also can assign a default CoS and DSCP value to all incoming packets 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 is previously set to trust DSCP, CoS, or IP precedence, this command overrides the previously configured 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. 2-242 Catalyst 3560 Switch Command Reference 78-16405-05