We have a couple of time servers (Time1 & Time2). I was testing notifications and I DO NOT receive an email notification when I unplug the enet cable in either Time1 or Time2. They do show down in the PRTG console. I DO receive an email notification when I do a Simulate Error test for Time1, Time2. I added the Ping sensor to Time 1 & Time2 and did receive the email notification that it was both down and back up.

Is this expected behavior? I'm just wondering if the SNTP sensor only sends a notification if the time if off and not if the device is down.

Thank you.

Article Comments

Hello,
The SNTP sensor tries to get a valid time stamp from the server up to three times per sensor scan. If this isn't working, it will then report an error. The ping sensor will report an error as soon as the target device is not reachable anymore.


Nov, 2022 - Permalink

Thank you for the reply. I am trying to figure out then why this sensor is not sending an e-mail when I unplug the unit but does when I do a simulate error. I know that alerting is working because I do receive the e-mail for the ping test which has the same alerting setup. Are there some more detailed logs that I can review to troubleshoot this as well as possibly turning up debugging that I can review. Thank you for your assistance.


Nov, 2022 - Permalink

Is the sensor in error state after unplugging the unit? If you want us to take a closer look, feel free to send us screenshots of the sensor (overview, log, notification triggers) and the issue you are referring to per mail at support@paessler.com.


Nov, 2022 - Permalink

Yes the sensor shows in an error state when the unit is unplugged. I had a ticket opened but we were unable to figure out the issue. Screen shots are in that ticket. Thanks.


Nov, 2022 - Permalink

According to your screenshots, the sensor is in "down" state for less than 600 seconds. however you configured "when sensor state is down for at least 600 seconds,..." as notification trigger. Therefore no e-mail will be send.

In order to receive notifications, you need to adjust your notification triggers accordingly.


Nov, 2022 - Permalink

Thanks but I did another test on 10/12/22 and Time2 was down at 7:35am and back up at 1:43pm (over 6 hours). I had included those screen shots in the ticket. The logs show that The target Server did not return a valid time error every 4 minutes but I never received an e-mail. Thank you.


Nov, 2022 - Permalink

Please note that the sensor was not down from 7:35am until 1:43PM as it was in unknown state in between. "unknown" is not the same as "down". Also have a look here: https://www.paessler.com/manuals/prtg/sensor_states. Your current notification triggers will only send a notification if the sensor stays in down state for more than 600 seconds.


Nov, 2022 - Permalink

Thank you for that detail, I will test it when I am in the office again next week by changing the sensor state. I do have a question just so I can understand what I am looking at.

During the extended test I was seeing 2 status messages every 4 minutes sent at the same time:

  1. Status - Down - The target server did not return a valid time
  2. Status - Unknown - No data since xx/xx/xx

How come the sensor was not picking up the Status - Down? Thank you.


Nov, 2022 - Permalink