With IPHost Network Monitor you can run simple snmp requests against a D-Link device in your network.
agentLoginUserName
agent Login User Name
1.3.6.1.4.1.171.12.1.7.2.1.8
This object is the name of the user login which failed.
Back to AGENT-GENERAL-MIB MIB page.
IPHost Network monitor allows you to monitor agentLoginUserName 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 switches right now.