With IPHost Network Monitor you can run simple snmp requests against a D-Link device in your network.
swL2PTPortIndex
Switch L2 PT Port Index
1.3.6.1.4.1.171.12.93.1.2.1.1
This object indicates the port number.
Back to L2PROTOCOL-TUNNEL-MIB MIB page.
IPHost Network monitor allows you to monitor swL2PTPortIndex 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.