Mst with multiple region

want to know how mst with multiple region operate and connect to external non-mst region with an example .

from the perspective of non mst (like pvst,rstp,stp) do all region look like a single switch or a group of switches .

Hello Binish

To start off with, I suggest you take a look at the following two lessons which deal with MST and its interoperability with other STP regions and protocols.

If you have any further questions or more specific questions, let us know!

I hope this has been helpful!

Laz