NTP Time Sync Monitoring Specified NTP Source In Windows with Nagios

NTP stands for Network Time Protocol, Used to sync all the servers time exact as main time server. All the servers time should be in equal if not they we may see problems in synchronization of Active Directories / User access. So CRITICAL part is if we miss time sync with actual NTP server then we may get lot many errors in environment, even we can’t analyze logs based on time stamp. Here in this article we are going to talk about NTP time sync Monitoring Specified NTP source in Windows using Nagios Server.

Windows time sync monitoring plugin is available in Nagios Exchange Just Download

NTP Time Sync Monitoring Configuration in Nagios Core / Nagios XI

This plugin works for windows only. After downloading the plugin just login to your Nagios client machine and paste the plugin in path as mentioned below

We have to Edit NSC.ini configuration File to add external commands

un-comment below configuration line to allow arguments from Nagios Server

;# COMMAND ARGUMENT PROCESSING
;  This option determines whether or not the NRPE daemon will allow clients to specify arguments to commands that are executed.
allow_arguments=1

Add External scripts as shown below

[External Scripts]
;check_es_long=scripts\long.bat
;check_es_ok=scripts\ok.bat
;check_es_nok=scripts\nok.bat
;check_vbs_sample=cscript.exe //T:30 //NoLogo scripts\check_vb.vbs
;check_powershell_warn=cmd /c echo scripts\powershell.ps1 | powershell.exe -command -
check_windows_time=scripts\check_windows_time.bat time.windows.com 30 10

Then un-comment CheckExternalScripts.dll entry or else you may receive UNKNOWN: No handler for that command” error

; Script to check external scripts and/or internal aliases.
CheckExternalScripts.dll

Save Configuration file and restart NsClient++ Service

Before going back to your Nagios Server just execute and check whether .bat script is working or not

Nagios Core Procedure

Now go back to your Nagios Server. manually call windows command using check_nrpe plugin if it is working fine then go ahead and write command in commands.cfg file.

[root@Ark-NagiosServ ~]# cd /usr/local/nagios/libexec/

[root@Ark-NagiosServ libexec]# ./check_nrpe -H 192.168.2.10 -p 5666 -c check_windows_time 3 1
OK: Time is +00.5859296s from time.windows.com|'Offset'=00s;30;10;0

Edit commands.cfg file and add below command OR custom command as you like

define command {
       command_name                             check_time
       command_line                             $USER1$/check_nrpe -H $HOSTADDRESS$ -t 30 -c $ARG1$ $ARG2$ $ARG3$
}

Open Host configuration file and add service definition 

define service {
        host_name                       windows-ad.arkit.co.in
        service_description             Time Check
        check_command                   check_time!check_windows_time!30!10!!!!!
        max_check_attempts              5
        check_interval                  5
        retry_interval                  1
        check_period                    xi_timeperiod_24x7
        notification_interval           0
        notification_period             xi_timeperiod_24x7
        notifications_enabled           1
        contacts                        nagiosadmin
        contact_groups                  Windowsadmins
        }

Save config file and restart Nagios Service.

That’s it NTP time sync monitoring is in place. It will send you an alert when NTP is not in sync for 30 seconds.

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