With IPHost Network Monitor you can run simple snmp requests against a D-Link device in your network.
swL2StpPortRole
Switch L2 Stp Port Role
1.3.6.1.4.1.171.11.70.5.2.16.4.1.4
When the port Enable state is enabled, the port's current port role as defined by application of the Spanning Tree Protocol. If the Port Enable state is disabled, the the port role will be nonstp(7). If the port is in loop-back status, the port role will be loopback(8)
Back to DES3018-L2MGMT-MIB MIB page.
IPHost Network monitor allows you to monitor swL2StpPortRole 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 routers right now.