Symptom

NTP Sync Failure Alarms with more than 2 NTP Servers Configured. When we check show ntp status its normal. Checking syslogs we see that NTP is switches from one ntp to another. No Root Dispersion delay is observed.

Conditions

If you have more than NTP server chorny can switch from one NTP to another one triggering alarm "NTP not synced" .

Workaround

To confirm this check alarms.log get the timestamp of the alarm and then compare with linux messages log. You should be able to see how ISE jumps from one NTP to another one. This is not impacting as ISE never lose NTP connectivity. to overcome this situation ISE 3.1, 3.0p4 and 2.7p5 includes two extra commands on the CLI. You have to: configure the main NTP server as trust using the command: ise(config)#ntp server trust configure the reselectdistance with command: ise(config)#ntp reselectdistance 2 however this still not fixes the issue

Further Problem Description