From: James Ventre (messageboard@ventrefamily.com)
Date: Wed Oct 12 2005 - 14:50:50 GMT-3
>Bottom line is that there is always a native VLAN in Dot1Q
Always is a pretty strong word:
IOS_4507R(config)#vlan dot1q tag native ?
<cr>
CatOS_6500(enable) set dot1q-all-tagged enable ?
<cr>
James
De Witt, Duane wrote:
The basics here are that Dot1Q has a native VLAN which is a VLAN that
doesn't have a VLAN tag. ISL doesn't have this since all VLAN's are
tagged.
If you don't define a native VLAN it defaults to VLAN 1. The default can
be changed to make any VLAN native which simply means it will not carry
a VLAN tag in the header. Bottom line is that there is always a native
VLAN in Dot1Q, whether you define it or not.
Does that answer your question?
-----Original Message-----
From: nobody@groupstudy.com [ mailto:nobody@groupstudy.com ] On Behalf Of
Ed Lui
Sent: 12 October 2005 06:03 PM
To: ccielab@groupstudy.com Subject: DOT1Q NATIVE VLAN STANDARD or NON-STANDARD
Hi group,
I have no luck finding out why we need native vlan in dot1q. I
understand
that native vlan should be defined on a trunk port. I came across a
router
on a stick lab scenario, which I did not define the native vlan and it
is
still working fine. Read through the dot1q standard on
ieee.org <http://ieee.org> but still can not figure out my question.
So, what is the difference between having a native and not having a
native
vlan defined ? The only thing I can think of is, tagged frame can carry
QoS
information. Other than that, what is the benefit or difference between
tagged and untagged frames ? Why define a native ?
Thanks in advance for any help or hint,
Ed Lui
TRUNK W/O NATIVE VLAN
2621=============================3550
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