Cisco Catalyst 3550 Series User Manual

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Catalyst 3550 Multilayer Switch Software Configuration Guide
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Chapter 14 Configuring Voice VLAN
Displaying Voice VLAN
Configuring the IP Phone to Trust the CoS Priority of Incoming Data Frames
You can connect a PC or other data device to a Cisco 7960 IP Phone port. The PC can generate packets
with an assigned CoS value. You can configure the switch to trust the priority of frames arriving on the
IP phone port from connected devices.
Beginning in privileged EXEC mode, follow these steps to trust the CoS priority received from the
nonvoice port on the Cisco 7960 IP Phone:
Use the no switchport priority extend interface configuration command or the switchport priority
extend cos 0 interface configuration command to return the port to its default setting.
Displaying Voice VLAN
To display voice VLAN for an interface, use the show interfaces interface-id switchport privileged
EXEC command.
For detailed information about the fields in the display, refer to the command reference for this release.
Command Purpose
Step 1
configure terminal Enter global configuration mode.
Step 2
interface interface-id Enter interface configuration mode, and specify the interface connected to
the IP phone.
Step 3
switchport priority extend trust Set the IP phone access port to trust the priority received from the PC or the
attached device.
Step 4
end Return to privileged EXEC mode.
Step 5
show interfaces interface-id
switchport
Verify your entries.
Step 6
copy running-config startup-config (Optional) Save your entries in the configuration file.

Cisco Catalyst 3550 Series Specifications

General

Brand	Cisco
Model	Catalyst 3550 Series
Category	Network Router
Language	English