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Catalyst 3750 SwitchSoftware Configuration Guide
OL-8550-09
Chapter15 Configuring Voice VLAN
Configuring Voice VLAN
This example shows how to configure a port connected to a Cisco IP Phone to use the CoS value to
classify incoming traffic, to use IEEE 802.1p priority tagging for voice traffic, and to use the default
native VLAN (VLAN0) to carry all traffic:
Switch# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)# interface gigabitethernet1/0/1
Switch(config-if)# mls qos trust cos
Switch(config-if)# switchport voice vlan dot1p
Switch(config-if)# end
To return the port to its default setting, use the no switchport voice vlan interface configuration
command.
This example shows how to enable switchport voice detect on a Cisco IP Phone:
Switch# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)# interface fastethernet 0/1
Switch(config-if)# switchport voice?
detect detection enhancement keyword
vlan VLAN for voice traffic
Switch(config-if)# switchport voice detect?
cisco-phone Cisco IP Phone
Switch(config-if)# switchport voice detect cisco-phone?
Step4 switchport voice {detect
cisco-phone [full-duplex] | vlan
{vlan-id | dot1p | none | untagged}}
Configure how the Cisco IP Phone carries voice traffic:
detect—Configure the interface to detect and recognize a Cisco IP
phone.
cisco-phone—When you initially implement the switchport voice detect
command, this is the only allowed option. The default is no switchport
voice detect cisco-phone [full-duplex].
full-duplex—(Optional) Configure the switch to only accept a
full-duplex Cisco IP phone.
vlan-id—Configure the phone to forward all voice traffic through the
specified VLAN. By default, the Cisco IP Phone forwards the voice
traffic with an IEEE 802.1Q priority of 5. Valid VLAN IDs are
1 to 4094.
dot1p—Configure the phone to use IEEE 802.1p priority tagging for
voice traffic and to use the default native VLAN (VLAN 0) to carry all
traffic. By default, the Cisco IP Phone forwards the voice traffic with an
IEEE 802.1p priority of 5.
none—Allow the phone to use its own configuration to send untagged
voice traffic.
untagged—Configure the phone to send untagged voice traffic.
Step5 end Return to privileged EXEC mode.
Step6 show interfaces interface-id
switchport or
show running-config interface
interface-id
Verify your voice VLAN entries.
Verify your QoS and voice VLAN entries.
Step7 copy running-config startup-config (Optional) Save your entries in the configuration file.
Command Purpose