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Can you have a native vlan on a access port

GlynnNewey0470
Level 1
Level 1

On a trunked port for a wap we enable a native vlan for non tagged traffic to be passed to the port which I understand.

I have noticed on some non Cisco hardware that you can define the native vlan on a access port as well as a trunked port. So any non tagged data can be passed to a access port if there is no tagged data.

Can you define a native vlan on a Cisco switch access port (I am guessing yes with all the functionality Cisco offers).

What would be a scenario that would require a native vlan for a access port ? other than just untagged data

17 Replies 17

For the Access Port I think cannot change the default which is untag the frame 
for trunk, cisco have command to make it SW compatible with other vendor that tag the native VLAN 
the command you need is
 
vlan dot1q tag native

KJK99
Level 3
Level 3

Interesting, but then I wonder how such a port would be different from a general port untagged in the “native” VLAN and with its PVID set to the VID of that VLAN. Or, it’s just another way of achieving the same.

Kris K

Indeed it can be another way.

In other threads I've described using a trunk ports to support VoIP phones with a PC, before access ports provided a voice VLAN setting.

I've also described connecting an access port with voice VLAN to a trunk port and that it will support two VLANs between switches.

I've also described connecting different VLANs using access ports or a trunk port's native VLAN.

Such examples to demonstrate, between devices (don't forget router subinterfaces too), you have tagged or untagged frames.  It's the device configuration which determines what device should be sending and what device should expect.

Since frames don't convey all such expectations of expected usage, you can intentionally or accidentally "break the rules".

Cisco's CDP, though, will often complain when you "break the rules".  (IMO a good thing.)