With IPHost Network Monitor you can run simple snmp requests against a D-Link device in your network.
swUnitMaxSupportedUnits
Switch Unit Max Supported Units
1.3.6.1.4.1.171.12.11.1.9.2
The maximum number of units that are supported in the system.
Back to EQUIPMENT-MIB MIB page.
IPHost Network monitor allows you to monitor swUnitMaxSupportedUnits 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.