Perform the following procedure to display the MSTP, CIST port, and MSTI port information maintained by every port of the common spanning tree.
show spanning-tree mstp port role [{sub-port]][,...][slot/all][all]}]

Note
If your platform supports channelization and the port is channelized, you must also specify the sub-port in the format slot/port/sub-port.
Display the MSTP port information:
Switch:1>
show spanning-tree mstp port role 1/3
============================================================================
CIST Port Roles and States
============================================================================
Port-Index Port-Role Port-State PortSTPStatus PortOperStatus
----------------------------------------------------------------------------
1/3 Disabled Discarding Enabled Disabled