Hi Gavin

Here's some screenshots of what works for me... Dell R710 and R720 servers with recent iDRAC software - 1.96 on the one I just looked at.

ipmitool needs to specifically told to use "User" level privileges, it will default to "Administrator".

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​[user@observium01 ~]$ ipmitool -I lanplus -H 10.x.xx.xxx -U observium -P %{PASSWORD}% sensor
Set Session Privilege Level to ADMINISTRATOR failed: Unknown (0x81)
Error: Unable to establish IPMI v2 / RMCP+ session
Set Session Privilege Level to ADMINISTRATOR failed: Unknown (0x81)
Error: Unable to establish IPMI v2 / RMCP+ session
Set Session Privilege Level to ADMINISTRATOR failed: Unknown (0x81)
Error: Unable to establish IPMI v2 / RMCP+ session
Get Device ID command failed
Unable to open SDR for reading
[user@observium01 ~]$ ipmitool -L user -I lanplus -H 10.x.xx.xxx -U observium -P %{PASSWORD}% sensor
Temp             | na         |            | na    | na        | na        | na        | na        | na        | na
Temp             | na         |            | na    | na        | na        | na        | na        | na        | na
Temp             | na         |            | na    | na        | na        | na        | na        | na        | na
Temp             | na         |            | na    | na        | na        | na        | na        | na        | na
Ambient Temp     | 21.000     | degrees C  | ok    | na        | 3.000     | 8.000     | 42.000    | 47.000    | na
Planar Temp      | na         |            | na    | na        | 3.000     | 8.000     | 92.000    | 97.000    | na