Native vlan question?

[Leonardo Pena Davila]

I have defined 15 vlans on my network, I have an access switch connected via a Trunk link, all ports on my access switch are access ports to vlan 20, Should my native vlan be vlan 20?

I have an stack of 9 3750 switches all my ports are configured to acces only vlan 10, Should my native vlan be vlan 10, in this case?

What is the best use to native vlan?

Thanks a lot

Regards

Lp

[Jon Marshall]

Hi

The native vlan is used on 802.1q trunks. All packets sent on a trunk link are tagged with the vlan id except packets which are in the native vlan which are sent untagged.

Cisco recommend that you use a vlan id that is not used for any data ports or for management. They recommend vlan 999 but it can be any unused number. The vlan should not have a routed SVI associated with it.

You should configure the trunk on both ends of you switch to have the same native vlan.

HTH