With IPHost Network Monitor you can run simple snmp requests against a D-Link device in your network.
swMacBasedAuthMaxUser
sw Mac Based Authorization Max User
This object indicates the maximum number of authorized client(s) on the whole device. Note: The maximum number of the authorized client(s) range is (0..N). The value N means the maximum number. This is determined by the project itself. When 0 is set, the maximum number of authorized clients is unlimited.
Back to Mac-Based-Authentication-MIB MIB page.
IPHost Network monitor allows you to monitor swMacBasedAuthMaxUser 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.