Catalyst 1000 Series: Enabling Native VLAN Tagging

[netstudent88]

Hello Cisco Community,

I’m working with a Cisco Catalyst 1000 Series Switch running IOS. I’m trying to enable Administrative Native VLAN Tagging to tag the native VLAN traffic on trunk ports, but the command vlan dot1q tag native isn’t working.

Can these switches do this?

What is the procedure for doing this?

Thanks!

[liviu.gheorghe]

Hello @netstudent88 ,

the purpose of a native Vlan on a trunk port is that it carries untagged traffic. You will have different frames passing through a trunk port, all tagged with their respective Vlan tags, but the Vlan which is configured as native will only carry untagged frames.

What the command vlan dot1q tag native is supposed to do - I never tested this -is that a trunk will always do tagging on the outgoing frames, the native VLAN setting is ignored and all frames are tagged with the corresponding tag value. Untagged frames arriving at a trunk port will be dropped without being forwarded further.

I will test this in the lab today and get back to you with my findings.

HTH

[Mancunian]

vlan dot1q tag native command is typically supported on switches running Cisco IOS-XE, such as the Catalyst 9000 series. The Catalyst 1000 series runs a more basic version of IOS that does not include this feature.

[netstudent88]

Is there documentation anywhere to support that? Can i get this functionality some other way?

[MHM Cisco World]

how you know it not working ?

MHM

[netstudent88]

I'll have physical access to the switch later today, but when i attempted to execute vlan dot1q tag native it did not recognize the command. I'm pretty sure i was inside the configuration terminal in the correct trunked interface. I can confirm later today.

[MHM Cisco World]

Not all SW accept this command 

Instead you change native vlan to any unuse vlan' this will make SW tag vlan (previous was native)

MHM