Cisco Catalyst 3750 - Enabling Qos Globally; Configuring Ingress Classification by Using Port Trust States; Configuring a Trusted Boundary to Ensure Port Security; Configuring the Cos Value for an Interface

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Catalyst 3750 Metro Switch Software Configuration Guide
78-15870-01
Chapter 26 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 Ingress Classification by Using Port Trust States
These sections describe how to classify inbound traffic through 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 an Ingress QoS Policy” section on page 26-48:
• Configuring the Trust State on Ports Within the QoS Domain, page 26-42
• Configuring the CoS Value for an Interface, page 26-45
• Configuring a Trusted Boundary to Ensure Port Security, page 26-46
• Configuring the DSCP Trust State on a Port Bordering Another QoS Domain, page 26-47
Configuring the Trust State on Ports Within the QoS Domain
Packets entering a QoS domain are classified at the edge of the QoS domain. The switch port within the
QoS domain can then be configured to one of the trusted states because there is no need to classify the
packets at every switch within the domain. Figure 26-13 shows a sample network topology.
Command Purpose
Step 1
configure terminal Enter global configuration mode.
Step 2
mls qos Enable QoS globally.
QoS runs from the default settings described in the “Default
Standard QoS Configuration” section on page 26-38 and the
“Default Hierarchical QoS Configuration” section on
page 26-76.
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.