110 CHAPTER 12: V OICE VLAN C ONFIGURATION■ Voice VLAN function can be effective only for the static VLAN. Once a dynamicVLAN is enabled with voice VLAN function, it automatically changes to staticVLAN.■ When a voice VLAN operates in the security mode, the devices in it only permitpackets whose source addresses are the voice OUI addresses that can beidentified. Packets whose source addresses cannot be identified, includingcertain authentication packets (such as 802.1x authentication packets), will bedropped. So, do not transmit both voice data and service data in a voice VLAN.If you have to do so, make sure the voice VLAN do not operate in the securitymode.■ After the voice VLAN function is enabled on a port, you cannot enable theQinQ feature on the port, and vice versa, that is, after the QinQ feature isenabled on a port, you cannot enable the voice VLAN function on the port.■ A voice VLAN-enabled port will automatically learn OUI addresses, withoutbeing limited by the function of prohibiting MAC address learning and thespecified maximum number of MAC addresses to be learnt.■ The voice VLAN legacy feature realizes the communication between 3Com’sdevices and other vendor’s voice devices by automatically adding the voiceVLAN tag to the voice data coming from other vendors’ voice devices. Thevoice vlan legacy command can be executed before voice VLAN is enabledglobally and on a port, but it takes effect only after voice VLAN is enabledglobally and on the port.Displaying andMaintaining VoiceVLAN ConfigurationAfter the above configurations, you can execute the display command in anyview to view the running status and verify the configuration effect.Voice VLANConfigurationExampleVoice VLANConfiguration Example(Automatic Mode)Network requirements■ Configure Ethernet2/0/1 port as a Trunk port, with VLAN 6 as the default port.Bind VLAN 2 to Ethernet 2/0/1 as a voice VLAN.■ Ethernet2/0/1 port can be added to/removed from the voice VLANautomatically according to the type of the data stream that reaches the port.Configuration procedure# Create VLAN 2.Table 61 Display configurations of a Voice VLANOperation Command DescriptionDisplay the voice VLANconfiguration statusdisplay voice vlan status You can execute the displaycommand in any view.Display the currently valid OUIaddressesdisplay voice vlan ouiDisplay the ports operating inthe current voice VLANdisplay vlan vlan-id
