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29-29
Catalyst 3550 Multilayer Switch Software Configuration Guide
78-11194-09
Chapter 29 Configuring QoS
Configuring Standard QoS
Configuring Classification By Using Port Trust States
These sections describe how to classify incoming traffic by using port trust states:
•
Configuring the Trust State on Ports within the QoS Domain, page 29-29
•
Configuring the CoS Value for an Interface, page 29-31
•
Configuring a Trusted Boundary to Ensure Port Security, page 29-32
•
Enabling Pass-Through Mode, page 29-33
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Configuring the DSCP Trust State on a Port Bordering Another QoS Domain, page 29-34
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.
shows a sample network topology.
Figure 29-9 Port Trusted States within the QoS Domain
74709
Catalyst
3550-12T switch
Trunk
Trusted interface
Classification
of traffic
performed here
Trusted boundary
Catalyst 3550
wiring closet
IP
P1
P3