With IPHost Network Monitor you can run simple snmp requests against a D-Link device in your network.
swMacAuthStatsTable
Switch Mac Authentication Stats Table
1.3.6.1.4.1.171.12.3.6.2
A table that contains the statistics objects for the Authenticator PAE associated with each Mac address. An entry appears in this table for each Mac that may authenticate access to itself.
Back to DLINK-AUTH-MIB MIB page.
IPHost Network monitor allows you to monitor swMacAuthStatsTable 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.