From: James Ventre (messageboard@ventrefamily.com)
Date: Wed Oct 12 2005 - 15:02:47 GMT-3
Just set it up to tag all (don't use the physical interface - only use
sub interfaces)
interface FastEthernet0/0
no ip address
duplex auto
speed auto
!
interface FastEthernet0/0.1
encapsulation dot1Q 2
ip address 1.1.1.1 255.255.255.0
no snmp trap link-status
!
interface FastEthernet0/0.2
encapsulation dot1Q 4
ip address 2.2.2.2 255.255.255.0
no snmp trap link-status
!
James
De Witt, Duane wrote:
You’re right, but it’s a good place to start. With regard to
this, I haven’t seen a similar configuration on routers, so if you
were running router on a stick the router would be sending untagged
native vlan packets to a switch that is tagging all vlans. How does this
work?
------------------------------------------------------------------------
From: James Ventre [mailto:messageboard@ventrefamily.com]
Sent: 12 October 2005 07:51 PM
To: De Witt, Duane
Cc: Ed Lui; ccielab@groupstudy.com
Subject: Re: DOT1Q NATIVE VLAN STANDARD or NON-STANDARD
>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
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
This archive was generated by hypermail 2.1.4 : Sun Nov 06 2005 - 22:00:50 GMT-3