Switchport Priority Extend - Cisco catalyst 3750 Command Reference Manual

Chapter 2 Catalyst 3750 Switch Cisco IOS Commands

switchport priority extend

Use the switchport priority extend interface configuration command to set a port priority for the
incoming untagged frames or the priority of frames received by the IP phone connected to the specified
port. Use the no form of this command to return to the default setting.
Syntax Description
cos value
trust
Defaults
The default port priority is set to a CoS value of 0 for untagged frames received on the port.
Command Modes
Interface configuration
Command History Release
12.1(11)AX
Usage Guidelines
When voice VLAN is enabled, you can configure the switch to send the Cisco Discovery Protocol (CDP)
packets to instruct the IP phone how to send data packets from the device attached to the access port on
the Cisco IP Phone. You must enable CDP on the switch port connected to the Cisco IP Phone to send
the configuration to the Cisco IP Phone. (CDP is enabled by default globally and on all switch
interfaces.)
You should configure voice VLAN on switch access ports. You can configure a voice VLAN only on
Layer 2 ports.
Before you enable voice VLAN, we recommend that you enable quality of service (QoS) on the switch
by entering the mls qos global configuration command and configure the port trust state to trust by
entering the mls qos trust cos interface configuration command.
Examples
This example shows how to configure the IP phone connected to the specified port to trust the received
IEEE 802.1p priority:
Switch(config)# interface gigabitethernet1/0/2
Switch(config-if)# switchport priority extend trust
You can verify your settings by entering the show interfaces interface-id switchport privileged EXEC
command.
OL-8552-07
switchport priority extend {cos value | trust}
no switchport priority extend
Set the IP phone port to override the IEEE 802.1p priority received from the PC or
the attached device with the specified class of service (CoS) value. The range is 0 to
7. Seven is the highest priority. The default is 0.
Set the IP phone port to trust the IEEE 802.1p priority received from the PC or the
attached device.
Modification
This command was introduced.
switchport priority extend
Catalyst 3750 Switch Command Reference
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