How to change Native VLAN on Cisco Switch

What is Native VLAN on Cisco Switch?

I will explain about VLAN technology on Cisco switches. With VLAN encapsulation techniques dot1q or ISL, trunk port on Cisco switch can carry frames of different VLANs traffic with VLAN tagging. This allows for multiple VLANs to exist on a single Switch or Topology. A trunk port on a switch is defined to be in a Native VLAN, and Trunk Port on Cisco switch will not add tag to the Native VLAN frames that are going in/out of the Trunk port. Any Ethernet device would be capable of reading frames for the Native VLANs. The Native VLAN is important on an 802.1Q trunk link.

1. Native VLAN is like another VLAN but Cisco Switch having VLAN 1 as default with Cisco IOS.
2. In Cisco Switch, By default all ports belong to VLAN 1 or native VLAN.
3. VLAN 1 is also used for management purposes; you can manage the device remotely when you need to configure your device, however you can chose another VLAN also.

Switch(config)#interface FastEthernet0/6
Switch(config-if)#switchport mode trunk
Switch(config-if)#switchport trunk encapsulation dot1q
Switch(config-if )#switchport trunk native vlan 10

Configure the Native VLAN on both sides of the Trunk Port:

If both sides of the Trunk link do not agree on the Native VLAN, the trunk will not operate properly.Be sure to remember to configure the same VLAN as a native VLAN on both sides of the trunk link or you will get error like below.

*Jun 06:35:01: %CDP-4-NATIVE_VLAN_MISMATCH: Native VLAN mismatch discovered on FastEthernet0/6 (1), with switch1 FastEthernet0/6 (10).

They come in once every minute (CDP updates go every 60 seconds by default) and if disabled cdp on switch, you will not get this messages. This is also one good reason to enable CDP protocol on Cisco Switches. Find the Native VLAN configuration on below example:

Cisco-switch-1:
Cisco-switch-1(config)# int fa0/6
Cisco-switch-1(config-if)#switchport trunk encapsulation dot1q
Cisco-switch-1(config-if)#switchport trunk native vlan 10
Cisco-switch-1(config-if)#switchport mode trunk

Cisco-switch-2:
Cisco-switch-2(config)#interface FastEthernet0/6
Cisco-switch-2(config-if)#switchport trunk encapsulation dot1q
Cisco-switch-2(config-if)#switchport mode trunk
Cisco-switch-2(config-if)#switchport trunk native vlan 10

Verify the Native VLAN status on Cisco Switch:

Cisco-Switch-1#sh int fa0/6 trunk

Port        Mode         Encapsulation  Status        Native vlan
Fa0/6      on           802.1q         trunking      10

Cisco-switch-1#sh int fa0/6 switch | i Native VLAN
Administrative Native VLAN tagging: enabled

Cisco-switch-1#sh interfaces trunk

Port        Mode         Encapsulation  Status        Native vlan
Fa0/6      trunk           802.1q           other           10

Filed Under: VLAN/VTP

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  1. M.Mashayekhi says:

    really appretiate, helped me alot

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