Look at the below guide and understand the Limitations :
Thank you for sharing document
I just want to what is the meaning of highlighted text below
"The ML Series supports per-VLAN rapid spanning tree (PVRST) and a maximum of 255 rapid
I found some info regarding details in Cisco 6500 and Cisco 4500, where can i find these info for other switch modules.....3850 and 2960X
the key to achieve scalability when the number of Vlans is greater then 128 is to move to spanning-tree mode mst as noted by Joseph.
With MST you can provision how the IEEE whole range of Vlans 1-4094.
(Please note that modern SVL uses Vlan 4094 on the SVL link) is mapped to few MST instances even before you create the Vlan.
Because MST consider two switches to be in the same MST region if they agree on the following parameters:
MST region name ( up to 32 characters is a string)
MST revision number
Vlans to MST mapping.
Actually only the IST instance 0 BPDUs are sent out with additional sections for each MST instance.
In the BPDUs an MD5 checksum of the Vlans to MST instances mapping is actually sent.
So MST requires a different approach: when you need to create a new Vlan you need to keep an unused Vlan from the subset of Vlans that are mapped to the MST instance that has the desired topology ( root bridge and so on).
So you first choice the topology the new Vlan should have and then you can pick a Vlan-id in the correct sub-set.
Changing the Vlans to MST mapping causes the MST region to be partitioned.
To be noted VTP version 3 has a feature that allows to carry the Vlans to MST mapping that is very interesting and handy.
This is likely the reason why modern access switches have not improved the number of RSTP instances
Hope to help