Cisco Catalyst 2950 Software Configuration Manual page 550

Configuring Standard QoS
Beginning in privileged EXEC mode, follow these steps to configure trusted boundary on a switch port:
Command
Step 1 configure terminal
Step 2 cdp enable
Step 3
interface interface-id
Step 4 cdp enable
Step 5 mls qos trust device cisco-phone
Step 6
mls qos trust cos
Step 7
end
Step 8 show mls qos interface [interface-id]
[policers]
Step 9 copy running-config startup-config
When you enter the no mls qos trust interface configuration command, trusted boundary is not disabled.
If this command is entered and the port is connected to a Cisco IP Phone, the port does not trust the
classification of traffic that it receives. To disable trusted boundary, use the no mls qos trust device
interface configuration command
If you enter the mls qos cos override interface configuration command, the port does not trust the
classification of the traffic that it receives, even when it is connected to a Cisco IP Phone.
You cannot enable trusted boundary if auto-QoS is already enabled and vice-versa. If auto-QoS is
enabled and a Cisco IP Phone is absent on a port, the port does not trust the classification of traffic that
it receives.
Catalyst 2950 and Catalyst 2955 Switch Software Configuration Guide
29-24
Purpose
Enter global configuration mode.
Enable CDP globally. By default, it is enabled.
Specify the interface to be trusted, and enter interface configuration
mode.
Valid interfaces include physical interfaces.
Enable CDP on the interface. By default, CDP is enabled.
Configure the Cisco IP Phone as a trusted device on the interface.
You cannot enable both trusted boundary and auto-QoS (auto qos
voip interface configuration command) at the same time; they are
mutually exclusive.
Configure the port trust state to trust the CoS value of the ingress
packet.
By default, the port is not trusted.
Note In software releases earlier than Cisco IOS
Release 12.1(11)EA1, the mls qos trust cos command is
available only when the switch is running the EI.
For more information on this command, see the command reference
for this release.
Return to privileged EXEC mode.
Verify your entries.
(Optional) Save your entries in the configuration file.
Chapter 29 Configuring QoS
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