access vlan

[suthomas1]

Hi,

If an access vlan port is configured in following way, is it wrong?

what is the use of  "switchport trunk native vlan 52" in below configuration and if correct, what function does it do.

interface FastEthernet1/11

description aadg_GFM

switchport

switchport access vlan 52

switchport trunk native vlan 52

switchport mode access

Thank you all.

[Edison Ortiz]

It's doing nothing as the port is set to mode access.

If the switch was changed to mode trunk, Vlan52 would be the native Vlan.

[andrew.prince]

That config is not required, as the switchport is in "Access" mode and not "Trunking".  If the port was in trunking mode - any layer 2 frames on the port with no 802.1q tag will be placed into VLAN 52.

[suthomas1]

thank you, that helped me grasp it.

Last question, in which scenario is it possible that frames on a trunked port will come without 802.1q tag. And what happens if a trunk is not configured with native vlan. what are the consequences of it.

thank you.

[Edison Ortiz]

With the use of the native vlan keyword, you are able to send frames without 802.1q tags. In your case, Vlan 52 would be untagged if you were to configure the switchport as trunk.

If the port is not configured with the native vlan, it will use Vlan 1 as the default native vlan. In other words, only Vlan 1 traffic will be sent untagged.

Regards,

Edison