With IPHost Network Monitor you can run simple snmp requests against a D-Link device in your network.
swPortMirrorTargetPort
Switch Port Mirror Target Port
1.3.6.1.4.1.171.11.70.5.2.6.4
This object indicates switch which port will sniff another port. A trunk port member cannot be configured as a target Snooping port. The port number is the sequential (logical) number which is also applied to bridge MIB, etc.
Back to DES3010FL-L2MGMT-MIB MIB page.
IPHost Network monitor allows you to monitor swPortMirrorTargetPort 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.