With IPHost Network Monitor you can run simple snmp requests against a D-Link device in your network.
swL2TrunkMasterPort
Switch L2 Trunk Master Port
1.3.6.1.4.1.171.11.70.5.2.9.3.1.3
The object indicates the master port number of the port trunk entry. When using Port Trunk, you cannot configure the other ports of the group except the master port. Their configuration must be same as the master port (e.g. speed, duplex, enabled/disabled, flow control, and so on).
Back to DGS3200-L2MGMT-MIB MIB page.
IPHost Network monitor allows you to monitor swL2TrunkMasterPort 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.