With IPHost Network Monitor you can run simple snmp requests against a D-Link device in your network.
swAuthBackendAuthFails
Switch Authentication Backend Authentication Fails
1.3.6.1.4.1.171.12.3.6.3.1.18
Counts the number of times that the state machine receives an EAP-Failure message from the Authentication Server (i.e., aFail becomes TRUE, causing a transition from RESPONSE to FAIL). Indicates that the Supplicant has not authenticated to the Authentication Server.
Back to DLINK-AUTH-MIB MIB page.
IPHost Network monitor allows you to monitor swAuthBackendAuthFails 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.