With IPHost Network Monitor you can run simple snmp requests against a D-Link device in your network.
swL2StpPortTable
Switch L2 Stp Port Table
1.3.6.1.4.1.171.11.70.5.2.16.4
A table that contains port-specific information for the Spanning Tree Protocol.
Back to DES3018-L2MGMT-MIB MIB page.
IPHost Network monitor allows you to monitor swL2StpPortTable on D-Link device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring D-Link switches right now.