Unanswered Question
May 13th, 2009

hello all,

how multiple vlans BPDU can carry by the single vlan.

does MST tag the BPDU.

if there is any clue please,

I have this problem too.
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Laurent Aubert Wed, 05/13/2009 - 07:37


The STP information for each instance are carried over a M-Record payload which is inserted in the IST BPDU (one M-record per instance). The IST is your global STP instance for your region which can interact with other MST regions

To be sure there is consistency on all switches of the same region regarding the VLAN-instance mapping table, a global hash value representing this table is also added to the BPDU.

This way, you don't need one BPDU per instance.



ramesh.karki Wed, 05/13/2009 - 21:12

Hi Laaubert,

Thanks for the response, exactily what my problem is MSTP BPDU is not passing using CX-600 HUAWEI MPLS switch. but there is no issue when I run PVST+ on the Cisco switches The Per VLAN BPDU is passed to the switches connected to another MPLS switch.



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