With IPHost Network Monitor you can run simple snmp requests against a D-Link device in your network.
swL2TrunkIndex
Switch L2 Trunk Index
1.3.6.1.4.1.171.11.70.5.2.9.3.1.1
The index number of the logical port trunk group. The trunk group number depends on the existence of unit and module.
Back to DGS3200-L2MGMT-MIB MIB page.
IPHost Network monitor allows you to monitor swL2TrunkIndex 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 access points right now.