When SSH Key based authentication is being used, each time the a user logs in and authentication is performed using the SSH key pair, the following symptoms maybe observed:

• Following messages are seen in /var/log/ns.log

Mar 12 12:16:48 <local0.info> 10.10.10.10 03/12/2019:12:16:48 GMT NetScaler 0-PPE-2 : default AAA Message 15216765 0 : "rba authentication : user username response_len-183 cmdPolicyLen-175, partitionLen-0 PromptLen-8 timeout 805309968 authPolicyLen-0 authActionLen-0 ssh_pubkey_len-0"
Mar 12 12:16:48 <local0.info> 10.10.10.10 03/12/2019:12:16:48 GMT NetScaler 0-PPE-3 : default SNMP TRAP_SENT 14274904 0 : netScalerLoginFailure (nsUserName = "username", nsPartitionName = default)

• The following SNMP Trap is sent out by NetScaler:

12:16:48.124104 IP 10.10.10.10.3000 > 10.10.10.11.162:  C="4snmp2nms" V2Trap(128)  .1.3.6.1.2.1.1.3.0=136126 .1.3.6.1.6.3.1.1.4.1.0=.1.3.6.1.4.1.5951.1.1.0.55 .1.3.6.1.4.1.5951.4.1.10.2.4.0="username" .1.3.6.1.4.1.5951.4.1.10.2.23.0=127.0.0.1 .1.3.6.1.4.1.5951.4.1.1.2.0=10.91.31.177

• These messages will also appear in the NetScaler MAS (assuming that MAS is deployed and has been configured to recieve SNMP traps and syslog data from NetScaler)

Problem Cause

The root cause of this issue is in the platform software.