snmpdf failed with "snmpdf: Authentication failure (incorrect password, community or key)" after restarting snmpd configured with SNMPv3

Issue

• SNMPv3 user is configured on the SNMP agent (snmpd).

# cat /etc/snmp/snmpd.conf| grep testadm
iquerySecName testadm
agentSecName testadm
rouser testadm
# cat /var/lib/net-snmp/snmpd.conf | grep testadm
createUser testadm SHA <Password> AES <Password>

NOTE: is replaced into any prefer password.

• After starting snmpd, snmpdf command still works. ~/.snmp/snmp.conf has the following information.

defVersion 3
defSecurityLevel authPriv
defSecurityName testadm
defPassphrase <Password>
defAuthType SHA
defPrivType AES

NOTE: is replaced into any prefer password.

• snmpd stopped once, add the following line into /etc/snmp/snmpd.conf.

defaultMonitors yes

• Start snmpd, and snmpdf didn't work with the following error.

Description              size (kB)            Used       Available Used%
No log handling enabled - turning on stderr logging
snmpdf: Authentication failure (incorrect password, community or key)