33-40
Catalyst 2960 and 2960-S Switch Software Configuration Guide
OL-8603-09
Chapter 33 Configuring QoS
Configuring Standard QoS
Enabling QoS Globally
By default, QoS is disabled on the switch.
Beginning in privileged EXEC mode, follow these steps to enable QoS. This procedure is required.
To disable QoS, use the no mls qos global configuration command.
Configuring Classification Using Port Trust States
These sections describe how to classify incoming traffic by using port trust states. Depending on your
network configuration, you must perform one or more of these tasks or one or more of the tasks in the
“Configuring a QoS Policy” section on page 33-47:
Configuring the Trust State on Ports within the QoS Domain, page 33-40
Configuring the CoS Value for an Interface, page 33-42
Configuring a Trusted Boundary to Ensure Port Security, page 33-43
Enabling DSCP Transparency Mode, page 33-44
Configuring the DSCP Trust State on a Port Bordering Another QoS Domain, page 33 -45

Configuring the Trust State on Ports within the QoS Domain

Note Catalyst 2960-S switches do not support ingress queueing.
Packets entering a QoS domain are classified at the edge of the QoS domain. When the packets are
classified at the edge, the switch port within the QoS domain can be configured to one of the trusted
states because there is no need to classify the packets at every switch within the QoS domain.
Figure 33-10 shows a sample network topology.
Command Purpose
Step 1 configure terminal Enter global configuration mode.
Step 2 mls qos Enable QoS globally.
QoS runs with the default settings described in the “Default Standard QoS
Configuration” section on page 33-36, the “Queueing and Scheduling on
Ingress Queues” section on page 33-15, and the “Queueing and Scheduling
on Egress Queues” section on page 33-17.
Step 3 end Return to privileged EXEC mode.
Step 4 show mls qos Verify your entries.
Step 5 copy running-config startup-config (Optional) Save your entries in the configuration file.