Cisco Catalyst 3750 Metro Command Reference Manual page 45

Chapter 2 Catalyst 3750 Metro Switch Cisco IOS Commands
The switch applies the auto-QoS-generated commands as if the commands were entered from the
Note
command-line interface (CLI). An existing user configuration can cause the application of the generated
commands to fail, or the user configuration might be overridden by the generated commands. These
actions occur without warning. If all the generated commands are successfully applied, any user-entered
configuration that was not overridden remains in the running configuration. Any user-entered
configuration that was overridden can be retrieved by reloading the switch without saving the current
configuration to memory. If the generated commands are not applied, the previous running configuration
is restored.
If this is the first port on which you have enabled auto-QoS, the auto-QoS-generated global configuration
commands are executed, followed by the interface configuration commands. If you enable auto-QoS on
another port, only the auto-QoS-generated interface configuration commands for that port are executed.
When you enable the auto-QoS feature on the first port, these automatic actions occur:
QoS is globally enabled (mls qos global configuration command), and other global configuration
•
commands are added.
When you enter the auto qos voip cisco-phone interface configuration command on a port at the
•
edge of the network that is connected to a Cisco IP phone, the switch enables the trusted boundary
feature. The switch uses the Cisco Discovery Protocol (CDP) to detect the presence or absence of a
Cisco IP phone. When a Cisco IP phone is detected, the ingress classification on the port is set to
trust the QoS label received in the packet. When a Cisco IP phone is absent, the ingress classification
is set to not trust the QoS label in the packet. The switch configures ingress queues and the egress
queue-set on the port according to the settings in
When you enter the auto qos voip cisco-softphone interface configuration command on a port at
•
the edge of the network that is connected to a device running the Cisco SoftPhone, the switch uses
policing to decide whether a packet is in or out of profile and to specify the action on the packet. If
the packet does not have a DSCP value of 24, 26, or 46 or is out of profile, the switch changes the
DSCP value to 0. The switch configures ingress and egress queues on the port according to the
settings in
When you enter the auto qos voip trust interface configuration command on a port connected to the
•
interior of the network, the switch trusts the CoS value for nonrouted ports or the DSCP value for
routed ports in ingress packets (the assumption is that traffic has already been classified by other
edge devices). The switch configures the ingress queues and the egress queue-set on the port
according to the settings in
You can enable auto-QoS on static, dynamic-access, voice VLAN access, and trunk ports. When
enabling auto-QoS with a Cisco IP Phone on a routed port, you must assign a static IP address to the IP
phone.
To display the QoS commands that are automatically generated when auto-QoS is enabled or disabled,
enable debugging before you enable auto-QoS. Use the debug auto qos privileged EXEC command to
enable auto-QoS debugging. For more information, see the
When a device running Cisco SoftPhone is connected to a switch or routed port, the switch supports only
Note
one Cisco SoftPhone application per port.
After auto-QoS is enabled, do not modify a policy map or aggregate policer that includes AutoQoS in its
name. If you need to modify the policy map or aggregate policer, make a copy of it, and change the
copied policy map or policer. To use the new policy map instead of the generated one, remove the
generated policy map from the interface, and apply the new policy map.
OL-9645-10
Table 2-2 and Table 2-3.
Table 2-2
Table 2-2 and
and Table 2-3.
debug auto qos
Catalyst 3750 Metro Switch Command Reference
auto qos voip
Table 2-3.
command.
2-17