Dell OpenManage Support
For Dell OpenManage support you will need to install Dell OpenManage (yeah - really :)) (minimum 5.1) onto the device you want to monitor. Ensure that net-snmp is using srvadmin, you should see something similar to:
master agentx view all included .1 access notConfigGroup "" any noauth exact all none none smuxpeer .188.8.131.52.4.1.674.10892.1
service snmpd restart
Ensure that srvadmin is started, this is usually done by executing:
Once this has been done, add the device to LibreNMS as normal and you will start to receive Temperatures and Fanspeed data.
Download OpenManage from Dell's support page Link and install OpenManage on your windows server. Make sure you have SNMP setup and running on your windows server.