Symptoms

Existing SNMPv3 monitoring fails with an 'Unknown user name', and SNMPv3 Traps are not sent. $ snmpget -v 3 -l authpriv -a SHA -A secretauth -x AES -X secretpriv -u snmp_svc idrac.example.com .1.3.6.1.4.1.674.10892.5.1.1.8.0 snmpget: Unknown user name

Cause

iDRAC firmware version 7.20.30.00 introduced SHA384/SHA512 hash attributes for local iDRAC user accounts. For existing iDRAC user accounts these new hash attributes value is null. The iDRAC event manager does not add the usmUser entries to SNMP configuration when the SHA384/SHA512 keys are null.

Resolution

This issue is fixed in the iDRAC9 firmware release 7.20.30.50. This firmware removes the event manager check for the new SHA384/SHA512 hash attributes to add user entries to the SNMP configuration. Workarounds Scenario 1: Upgrade scenario + For users created on or before 7.20.10.50 then upgraded to 7.20.30.50 SNMPv3 continues to work.+ For users created on or before 7.20.10.50 then upgraded to 7.20.30.00 SNMPv3 stops working. Workaround for 7.20.30.00 is to update the existing users password to restore functionality. Scenario 2: Downgrade Scenario + For users created on 7.20.30.00 or higher and then downgraded, SNMPv3 continues working IF "Enable Passphrase" was configured to legacy basic Auth/Priv options. All other scenarios stop working on downgrade. Workaround is to set Enable Passphrase and configure to supported Auth/Priv Type - Authentication Type (SHA|MD5) and Privacy Type (AES|DES). 

Support Cases