MSTP configuration help

[bobbydazzler]

Hello,

I have a question regarding MSTP implementation. We are in the migration process to replace a standalone 6509 by two Nexus 9K switches.
We used to have MSTP running between the 6509 (root) site A and the nexus SFP site B. All others switches are in pvst. We have dedicated fibers connecting the switches with different vlan for each client. I was using MSTP in order to do that, but there might be a better solution ?

Attached is the layer 2 topology of the current situation, partly migrated some fibers to the Nexus and mstp in a messy state. I would like to migrate the final fibers of client C (in green) to the top Nexus and switch on the link between the 6509 and the Nexus (link in blue).

Could I configure MSTP only between the Nexus SFP of site A/B ? And keep the 6509 in pvst ? Which one of the Nexus should be root ?

Looking forward to any advice.

[paul driver · Accepted solution]

Hello
Based on your topology, as stated site B C9K1 would be the most applicable for the CIST root running MST
see attached file for possible solution.

[MHM Cisco World]

MHM

[paul driver]

Hello
not sure i follow this - We do not see dual stp domains ( pvst/rstp & mst) and any related boundary ports showing the interconnections between different stp domains ?