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Catalyst 6500 Series Switch Cisco IOS Software Configuration Guide—Release 12.1 E
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Chapter 31 Configuring PFC QoS
Configuring PFC QoS
Note Configuring a Layer 2 LAN port for VLAN-based PFC QoS preserves the policy map port configuration.
The no mls qos vlan-based port command reenables any previously configured port commands.
Configuring the Trust State of Ethernet LAN and OSM Ingress Ports
By default, all ingress ports are untrusted. You can configure the ingress port trust state on all Ethernet
LAN ports except non-Gigabit Ethernet 1q4t/2q2t ports (see the “Ingress LAN Port Features” section
on page 31-12). You can configure the ingress port trust state on OSM ports (see the “Ingress OSM Port
Features” section on page 31-11).
To configure the trust state of an ingress port, perform this task:
When configuring the trust state of an ingress port, note the following:
• With no other keywords, the mls qos trust command is equivalent to mls qos trust dscp.
• The mls qos trust cos command enables receive-queue drop thresholds. To avoid dropping traffic
because of inconsistent CoS values, configure ports with the mls qos trust cos command only when
the received traffic is ISL or 802.1Q frames carrying CoS values that you know to be consistent with
network policy.
• Use the no mls qos trust command to set the port state to untrusted.
This example shows how to configure Gigabit Ethernet port 1/1 with the trust cos keywords:
Router# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)# interface gigabitethernet 1/1
Router(config-if)# mls qos trust cos
Router(config-if)# end
Router#
This example shows how to verify the configuration:
Router# show queueing interface gigabitethernet 1/1 | include trust
Trust state: trust COS
Router#
Command Purpose
Step 1 Router(config)# interface {{type1 slot/port} |
{port-channel number}}
1. type = ethernet, fastethernet, gigabitethernet, tengigabitethernet, ge-wan, pos, or atm.
Selects the interface to configure.
Step 2 Router(config-if)# mls qos trust [dscp |
ip-precedence | cos2]
2. Not supported for pos or atm interface types.
Configures the trust state of the port.
Router(config-if)# no mls qos trust Reverts to the default trust state (untrusted).
Step 3 Router(config-if)# end Exits configuration mode.
Step 4 Router# show mls qos Verifies the configuration.