With IPHost Network Monitor you can run simple snmp requests against a D-Link device in your network.
swSystemUpTime
Switch System Up Time
1.3.6.1.4.1.171.12.10.10.2
The time (in second) since the network management portion of the system was last re-initialized. It is the same as sysUptime.
Back to DLINK-TIME-MIB MIB page.
IPHost Network monitor allows you to monitor swSystemUpTime 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.