View the MSTP port information 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 [slot/port[/sub-port][-slot/port[/sub-port]][,...]]

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.
View the MSTP port information:
============================================================================
                           CIST Port Roles and States
============================================================================
Port-Index  Port-Role    Port-State   PortSTPStatus  PortOperStatus
----------------------------------------------------------------------------
1/3         Disabled    Discarding      Enabled        Disabled