Re: MSTP & PVST+ interoperation

Hi Carlos,

In the boundary switch between the MSTP and PVST, as this router see the
*ROOT* is actually not in the MSTP domain, this device push the
interface in an inconsistency state *BKN* althoudh they see the root
bridge through this port. This case is really like the scenario 3:
*PVST+ and MSTP interoperation* in the blog:
http://blog.ine.com/2008/09/24/mstp-tutorial-part-ii-outside-a-region/

But the problem we have is that we cannot change the Root bridge to the
domain of MSTP as mentions in the example.

That's why I search for a solution which is like the VLAN master in
topology-group of Brocade that permit resolving this case.

Thanks,

Viet

On 09/26/2012 11:46 AM, Carlos G Mendioroz wrote:
> Why do you say "the MST region wants to have the Root Bridge inside" ?
> As you say you control the MST area, this "wants" relates to which
> entity ? MST has internal regional root and "global" root bridges.
>
> AFAIK, cisco's MST implementation knows how to merge into a PVST area.
> And that is reflected by the "Bound(PVST)" label (region boundary, PVST).
>
> Are your areas multiply connected ?
>
> -Carlos
>
> Viet-Hung Ton @ 25/09/2012 21:01 -0300 dixit:
>> Hi,
>>
>> I have a region of MSTP that must communicate with a zone of PVST.
>> Because of historical reason, I must leave the Root bridge in the
>> PVST+ zone, but in theory, the MSTP region want to have the Root
>> Bridge inside, that's why interfaces of routers in this region are in
>> the unfunctional state when doing a "show spanning-tree":
>>
>> Root BKN* 20000 128.1 P2p Bound(PVST) *PVST
>>
>> Do you have any ideas how to resolve this problem considering that I
>> can just change the configuration in the MSTP zone but not to PVST
>> zones?
>>
>> Is there any things of Cisco like Topology-group with the Master Vlan
>> of Brocade, where we can take a Vlan in mode PVST and mapping all
>> others Vlans to this Vlan (only one instance of PVST)?
>>
>> Thanks for your help,
>>
>> Viet
>>
>>
>> Blogs and organic groups at http://www.ccie.net
>>
>> _______________________________________________________________________
>> Subscription information may be found at:
>> http://www.groupstudy.com/list/CCIELab.html

Blogs and organic groups at http://www.ccie.net
Received on Wed Sep 26 2012 - 12:04:41 ART