Re: MSTP & PVST+ interoperation

After some more thinking ... if the merging code agrees to a vlan to be
used as "designed" CST on the PVST side, then it would work. I guess
that is the Brocade master vlan. Nice to know, and an interesting thing
if cisco does not support something on the line.

-Carlos

Tony Singh @ 26/09/2012 08:17 -0300 dixit:
> Not sure of the solutions for this but afaik you would be breaking stp rules hence port inconsistent state!
>
> Schedule an outage and migrate to mst.
>
> --
> BR
>
> Tony
>
> Sent from my iPhone on 3
>
> On 26 Sep 2012, at 11:04, Viet-Hung TON <vton_at_integra.fr> wrote:
>
>> 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
>>
>> _______________________________________________________________________
>> Subscription information may be found at:
>> http://www.groupstudy.com/list/CCIELab.html
>
>
> Blogs and organic groups at http://www.ccie.net
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
>
>
>
>
>
>
>

-- 
Carlos G Mendioroz  <tron_at_huapi.ba.ar>  LW7 EQI  Argentina
Blogs and organic groups at http://www.ccie.net