title: snmp v3 traps not working when configuring same user with different authentication type
body: <p>I am using Linux based snmp (net-snmp) in my Linux device. To receive snmp trap on Linux host machine, I have configured snmptrapd in /etc/snmp/snmptrapd.conf file as below (After stopping snmpd daemon)</p>
  
  <pre><code>createUser user MD5 "password123" DES "encrypt123"
  
  authuser log user authPriv
  </code></pre>
  
  <p>Above configuration allow me to receive snmp trap on Linux host machine when I execute below command from my Linux device</p>
  
  <pre><code>snmptrap -Ci -v3 -u user -a MD5 -A password123 -x DES -X encrypt123 -l authPriv 10.103.0.110 '' Test-MIB::statusChangeNotification Test-MIB::statusChangeAlarm s 'status change'
  </code></pre>
  
  <p>Now if I execute above snmptrap command with same user and SHA/DES configuration (as below) then in that case snmptrap command is failing with "snmpinform: Authentication failure (incorrect password, community or key)" error message. (snmptrapd is stopped and started after SHA/DES configuration as above.)</p>
  
  <pre><code>snmptrap -Ci -v3 -u user -a SHA -A password123 -x DES -X encrypt123 -l authPriv 10.103.0.110 '' Test-MIB::statusChangeNotification Test-MIB::statusChangeAlarm s 'status change'
  </code></pre>
  
  <p>Can anybody suggest possible reason behind this error?
  Does snmptap command maintain usmUser table which not allow same user entry with different authentication type?
  Is there any way to reset usmUser table?
  Is there any additional configuration required?</p>