VTP advertisements are sent to a data-link-layer multicast
01-00-0C-CC-CC-CC. The SNAP type is 2003 which distinguishes the frame from
other Cisco frames that use that multicast (CDP and DISL, for example).
As I said before, the router would have to be sitting in the middle of a
Layer-2 topology. For example, a one-armed router would pass VTP from one
subinterface to another, wouldn't it??
I'm just trying to explain the statement from a CIT book about the router
being in VTP transparent mode, which was the original question. Perhaps
someone else has more details.
Priscilla
At 06:29 PM 9/5/01, Jeff Smith wrote:
>Does a VTP advertisement have a layer 3 address? I thought these were
>only heard within a broadcast domain. How does the router know who to
>pass these to on the other side?
>
>
>>From: "Priscilla Oppenheimer"
>>Reply-To: "Priscilla Oppenheimer"
>>To: [EMAIL PROTECTED]
>>Subject: Re: does vtp can span the router [7:18545]
>>Date: Wed, 5 Sep 2001 13:51:37 -0400
>>
>>A VTP transparent device does not advertise its VLAN configuration and does
>>not synchronize its VLAN configuration based on received advertisements.
>>However, VTP-transparent devices do forward received VTP advertisements to
>>other devices.
>>
>>I can imagine a situation where a router with VLANs implemented is sitting
>>in the middle of a Layer 2 topology and you want the router to be in VTP
>>transparent mode so that it passes VTP advertisements onto switches on the
>>other side of it. It doesn't seem like a very good design, but it could
>>happen.
>>
>>Priscilla
>>
>>At 10:19 AM 9/5/01, Guest wrote:
>> >I believe it means that the router will not listen to the vtp messages.
>>It
>> >will also not pass them along- it is strictly layer 2.
>> >pass them along,you mean just transfer it ,right?but i don't know where
it
>> >go,see my
>> >last message,i dont
>> >know which vlan can carry vtp,or like cdp-a purely layer 2 protocol,
>> >does vtp indepent of vlan,it runs on native vlan??
>> >i dont find ways to prove it.
>> >anyway ,thanks a lot
>>________________________
>>
>>Priscilla Oppenheimer
>>http://www.priscilla.com
>_________________________________________________________________
>Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp
>
________________________
Priscilla Oppenheimer
http://www.priscilla.com
Message Posted at:
http://www.groupstudy.com/form/read.php?f=7&i=18667&t=18545
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