native vlan

[patrickybiernas37]

hi cisco tac

what will happen if the switch have different native vlan

[psicsic]

HI Patrick,

you can have several Native VLANs per LAN Switches, but only one per trunk ( interface )

rgds

Patrick

[Deepak Kumar]

Hi,

What is your meaning "if the switch have different native vlan"?

If you are asking between two switches then you will get CDP error message "Native VLAN match".  There are many chances as looping, no communication due to VLAN mismatch. It will depend on your environment and configuration.

Regards,

Deepak Kumar

[psicsic]

Hello Deepak

Navite means VLAN without tagging.  Each trunk have a native VLAN and one or More VLAN with Tagging.

2 Swithes will communicate with Native VLAN on both side, but if one of the 2 got a specifiv VLAN with Tagging you will need specific confiration to allow communication over this VLAN.

rgds

Patrick

[skt82276@gmail.com]

Hi Patrik,

   By default you have VLAN 1 as a native or management Vlan.But you can change the Vlan id other than VLAN 1 to use as a native VLAN.

using following command.

Switch(Config)#int f0/0

Switch(Config-if)#switchport trunk native vlan 4   //if you want to use VLAN 4 as a native VLAN.

Switch# Sh run int f0/0   //To check current config

you will receive a error %CDP-4  NATIVE VLAN MISMATCH discovered on f0/0.

that is because if we do not have the same native VLAN  at all the Switches configured for that trunk link.

So you will have to change the native VLAN at all the switches.

Regards//

Shashi