Administrator Guide

Layer 2 Switching Commands 847
Default Configuration
The default DSCP value is 46. The default CoS is 5 for untrusted ports. The
default is tagged voice VLAN traffic. The default data priority is to trust the
received CoS value. The default override-authentication value is to require
authentication. No voice VLAN ID is configured by default. The default
802.1p value is none.
Command Mode
Interface Configuration (Ethernet) mode.
User Guidelines
Enable voice VLAN using the following steps:
• Create the voice VLAN on the switch.
• Configure the interface in access or general mode.
• Enable voice VLAN globally and on the desired interfaces.
• Optionally configure 802.1X MAC or port-based authentication on the
interface and globally.
If using MAC based authentication, also:
• Configure one or more RADIUS servers on the switch.
• Configure the RADIUS servers to send the VSA traffic-class = voice in the
Access-Accept.
• Enable 802.1X authentication on the phone.
• Ensure the IP phone connected ports are configured in general mode.
• Optionally enable critical voice VLAN.
If using auto authentication:
• Optionally configure the interface to override authentication. If
authentication is not overridden, the IP phone must authenticate using
802.1X.
Voice VLAN may be configured on general or access mode ports. It is not
supported on trunk mode ports.
Use the switchport voice vlan vlan-id command to enable voice VLAN on an
interface.