With IPHost Network Monitor you can run simple snmp requests against a D-Link device in your network.
swDHCPServerBindingLifeTime
Switch DHCP Server Binding Life Time
1.3.6.1.4.1.171.12.38.3.4.1.6
The life time of the binding entry in seconds. The value '-1' means an infinite life time.
Back to DHCP-Server-MIB MIB page.
IPHost Network monitor allows you to monitor swDHCPServerBindingLifeTime 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 WiFi routers right now.