Re: Native Vlan Application

Hi Asim,

You can find this in pretty much all the Switching books out there but what
I'd like to add to enrich this query is a simple scenario: configure 2
switches (SW1 and SW2) using dot1q and set up a "semi-trunk" link between
them. How? easy. instead of a trunk configure your link like an access port
and see what you can see! you need "monitor session" and several ports in
"different" VLANs and start generating some traffic- what do you reckon?
what's going to happen to your tagged traffic when they get to a link with
no knowledge of any tagging concept? how stupid your CAT could be? reckon
not much?

If you do have access to the equipment you might wish to extend your lab by
hooking up a PC (with VMWare and several VMs) with trunk link between its
NIC and your SW2. Keep the rest of the scenario the same as above. Install
Wireshark (or TCPdump) on your servers and again try to see the "very
thing".

This experiment walks you through some nice stuff. I'd imagine if a data
center track ever comes along you see stuff like this in it!

HTH
Kambiz Agahian

CCIE Instructor/Consultant
CCIE# 25341, CCSI# 33326, MCSE, MCSA

On Sat, Aug 7, 2010 at 6:40 PM, Asim Riaz <ariaz78_at_gmail.com> wrote:

> Hi List,
> I am sure this topic has discussed before, can someone give me application
> for the native vlan when using 802.1Q trunking?
>
> I know the theory that if an untag frame arrive on the trunk, it will be
> forwarded to native vlan, why would I need an untag frame when two of my
> interconnected switches speak 802.1Q and can forward traffic for the vlans
> across switch boundaries?
>
>
>
> Thanks
>
> Asim
>
>
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Received on Sun Aug 08 2010 - 13:40:33 ART