From: Ed Lui (edwlui@gmail.com)
Date: Wed Oct 12 2005 - 15:41:15 GMT-3
Larry,
In other words, vlan 1 is the default native vlan. Even if I shut it
down, it is still there in shutdown state. In the meantime, frames
going thru the trunk port are all tagged and the router doesn't care
if there are untagged frames as long as the router is told which tag
goes on which sub-interface.
In conclusion, native vlan is there all the time even it is shutdown
and not being used. Native vlan(untagged) is not to be defined
mandatory just like ISL.
Correct ?
On 10/12/05, Larry Letterman (lletterm) <lletterm@cisco.com> wrote:
>
> Ed,
>
> it will still assign a native vlan as 1 per the default, even if you
> shut vlan 1 down....and all non-tagged data will still use that...
>
>
> Larry Letterman
> INS-NW-WEST
> Cisco Systems
>
>
>
>
> ________________________________
From: Ed Lui [mailto:edwlui@gmail.com]
> Sent: Wednesday, October 12, 2005 11:39 AM
> To: Larry Letterman (lletterm)
> Cc: ccielab@groupstudy.com
> Subject: Re: DOT1Q NATIVE VLAN STANDARD or NON-STANDARD
>
>
>
>
>
>
> Larry,
>
> What if I set up HSRP and sub interfaces on both routers without defining native and vlan 1 shutdown ? In my router on a stick scenario, it worked. Any idea ?
>
>
> R1(vlan3,8)===========|vlan3,8(dot1q trunk w/o native)
> |---------------3550EMI---------------
> R2(vlan3,8)===========|vlan3,8(dot1q trunk w/o native)
>
> Thanks,
> Ed Lui
>
> On 10/12/05, Larry Letterman (lletterm) <lletterm@cisco.com> wrote:
> > Ed,
> >
> > Set up two routers with dot1q sub-interfaces...connect the FaEthernets
> > to a 3550/3750,
> > Set the trunk ports for that switch so that the data vlan is the native
> > vlan. Setup the hsrp
> > On the routers, and you'll see that the native vlan being set
> > incorrectly will alter the
> > Opeartion of things..you can always leave it to the default of vlan 1..
> >
> >
> >
> > Larry Letterman
> > INS-NW-WEST
> > Cisco Systems
> >
> >
> > -----Original Message-----
> > From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
> > Ed Lui
> > Sent: Wednesday, October 12, 2005 11:03 AM
> > 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
> >
> > _______________________________________________________________________
> > Subscription information may be found at:
> > http://www.groupstudy.com/list/CCIELab.html
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