Assigning a native VLAN ID to a trunk interface

Prerequisites
At least one defined VLAN.
Procedure
  1. Switch to configuration context with the command config.
  2. Switch to the trunk interface to which you want to assign the native VLAN ID with the command interface.
  3. Disable routing with the command no routing.
  4. Assign the native VLAN ID with the command vlan trunk native. If tagging is required, use the command vlan trunk native tag.
  5. Allow traffic tagged with the native VLAN ID to be transported by the trunk using the command vlan trunk allowed.

Example

This example assigns native VLAN ID 20 to trunk interface 1/1/2. 

switch# config
switch(config)# vlan 20
switch(config-vlan-20)# exit
switch(config)# interface 1/1/2
switch(config-if)# no routing
switch(config-if)# vlan trunk native 20

This example assigns native VLAN ID 40 to trunk interface 1/1/5, enables tagging, and allows traffic with VLAN ID 40 to be transported by the trunk. 

switch# config
switch(config)# vlan 40
switch(config-vlan-40)# exit
switch(config)# interface 1/1/5
switch(config-if)# no routing
switch(config-if)# vlan trunk native 40 tag
switch(config-if)# vlan trunk allow 40