Cisco Catalyst 3560-X Series, Software Configuration Manual

Page: 957 / 1538

1-43
Catalyst 3750-X and 3560-X Switch Software Configuration Guide
OL-25303-03
Chapter 1 Configuring QoS
Configuring Standard QoS
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 1-49 :
•
Configuring the Trust State on Ports within the QoS Domain, page 1-43
• Configuring the CoS Value for an Interface, page 1-44
•
Configuring a Trusted Boundary to Ensure Port Security, page 1-45
• Enabling DSCP Transparency Mode, page 1-46
•
Configuring the DSCP Trust State on a Port Bordering Another QoS Domain, page 1-47
Configuring the Trust State on Ports within the QoS Domain
Packets entering a QoS domain are classified at the edge of the QoS domain. 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 1-14
shows a sample network topology.
Figure 1-14 Port Trusted States within the QoS Domain
101236
Trunk
Trusted interface
Traffic classification
performed here
Trusted boundary
IP
P1 P3