RE: Merging MSTP and PVST regions

Hello emir,

If you are looking at introducing this on a live network then you will want
to try to lab it up first, of course. I think you will find that if the
root bridge is outside of the MST region, then the potential root port on
the MST border switch will block. In my experience, the root of the CIST
needs to be within the MST region. Note that introducing a new root bridge
does not necessarily mean that any ports that were forwarding will go to
blocking, even temporarily. That depends on the topology.

Just my 2 cents,

Bob Sinclair CCIE 10427 CCSI 30427
CIERS2 Online Instructor
www.tinyurl.com/ciers2online

> -----Original Message-----
> From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of
> emir d souza
> Sent: Thursday, September 09, 2010 12:09 AM
> To: Cisco certification
> Subject: Merging MSTP and PVST regions
>
> Hi all,
>
> I've got a CatOS switch running PVST and I need to connect a new
> switch
> running MSTP (one link only) . I don't want the new switch to take over
> as
> root and cause an STP reconvergence (root bridge election) throughout
> the
> whole network.. Any advise?
>
> CAToS
> -----------
> set spantree priority 24576 1,3,5
>
>
>
> New Switch
> -----------------
> spanning-tree mode mst
> spanning-tree portfast bpduguard default
> spanning-tree etherchannel guard misconfig
> spanning-tree extend system-id
> !
> spanning-tree mst configuration
> name CISCO
> revision 1
> instance 1 vlan 1-4094
> !
> spanning-tree mst 0-1 priority 0
> !
>
>
> Thanks
>
>
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Received on Thu Sep 09 2010 - 15:23:55 ART