Voice VLAN

[lagapidis (Lazarus Agapidis)]

Hello Aniket

I think you had the same post on another thread, but that’s ok, cause I can add something here.

@aniket.ghate2

However I have seen a working scenario wherein DATA VLAN is 135 & VOICE VLAN is 137, also switch port is not TRUNK, Native VLAN is 1. So how could DATA Vlan traffic will go untagged as DATA Vlan being 135…

If the native VLAN on a trunk is 1, then this VLAN will definitely function as the data VLAN in a scenario where a PC is connected to an IP phone connected to an access switch. VLAN 135 was not being piped through the phone to the connected PC in this particular instance. In order to answer more specifically, we’d need to see the actual configuration.

@aniket.ghate2

Also under switchport we are giving commnad as "Switchport mode access " for DATA vlan, then how can we put this interface in Trunk mode? (as per my understanding switchport would be either access or trunk port)

That’s the beauty of the voice VLAN configuration. It provides a third alternative to just access or trunk by allowing you to configure an access port but tag only voice packets so an IP phone can intercept them. See more about this in my reply to your other post:

802.1Q Native VLAN on Cisco IOS Switch

Hello Aniket There are two ways to implement the following scenario: [image] One is to configure the Gi0/1 interface as a trunk. Let’s say the voice VLAN on our network is 137 and the data VLAN is 135. We would configure the Gi0/1 interface as a trunk, with a native VLAN of 135 and an allowed VLAN of 137. This means that frames on VLAN 135 destined for H1 would exit the Gi0/1 interface untagged. Any such frames reaching the IP phone would continue on to H1. Any frames on VLAN 137 destine…

I hope this has been helpful!

Laz