With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
stpxRSTPPortRoleTable
stpx RSTP Port Role Table
1.3.6.1.4.1.9.9.82.1.12.2
A table containing a list of the bridge ports for a particular Spanning Tree instance. This table is only instantiated when the stpxSpanningTreeType is mst(4) or rapidPvstPlus(5).
Back to CISCO-STP-EXTENSIONS-MIB MIB page.
IPHost Network monitor allows you to monitor stpxRSTPPortRoleTable on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco multiplexers right now.