We have a network that is running MSTP as spanning tree protocol.
Since it doesn't use different instances for VLAN and we're introducing new 5710 switches as core we want to use RSTP.
The core switches are, at the moment, 2 5406ZL configured with MSTP with a single instance. Connected to them there are several kind of different switches all configured with MSTP
As we introduced the new 5710 IRF stack as core, connected to the 5406, we configured it with RSTP and all was running fine.
We configured the 5710 as root primary.
Then we started changing the 5406 from MSTP to RSTP using the command
spanning-tree mode RSTP.
After that all seemed to work properly but we found that the 5406 still acts as root for all the vlan ( show spanning-tree ) except for vlan 1.
we also found that it seems the 5710 runs instance 0 while 5406 use instance 1, but RSTP shouldn't have different instances.
Can anyone explain how is that and how to fix it ?
thanks