-

How to Add Windows Host to Nagios Monitoring Server

We will firstly setup the client machine & then will make changes to nagios server. For adding a windows host for monitoring on Nagios, we will need a software called NSClient++. We can download it from https://sourceforge.net/projects/nscplus/files/latest/download, once downloaded we will start the setup by double clicking the downloaded .msi file.

1- Hit ‘Next’ on the first screen, once the installation starts

2- Now, accept the license agreement & hit ‘Next’

3- On the next screen, click on ‘Typical’

4- Leave the following screen as it is & hit ‘Next’

5- Here on this screen, enter the IP address of Nagios server (for us it’s 192.168.0.20) & press ‘Next’

6- Click on ‘Install’ & wait for the installation to complete. Once its complete, hit ‘Finish’

Changes on Nagios server

Once the settings on the client side are complete, we need to make changes to configuration file of nagios. Open the file /usr/local/nagios/etc/nagios.cfg

[root@linuxtechi ~]# vi /usr/local/nagios/etc/nagios.cfg

Uncomment the following line

cfg_file=/usr/local/nagios/etc/objects/windows.cfg

Save file and exit. Next open the file /usr/local/nagios/etc/objects/windows.cfg

[root@linuxtechi ~]# vi /usr/local/nagios/etc/objects/windows.cfg

This file contains a host definition which can be used as a reference to create the host definition for our window client machine. Edit the hostname & IP address to match your own windows machine, below the host definition are some Service Definitions, here we can add more services definition. Make sure that hostname is changed to your windows client name in all the services. Once done making changes, save file & exit.

Now restart your nagios server & check if the windows host has been added or not to nagios for monitoring, by browsing to ‘HOSTS‘ under current status.

Our host has been successfully added to nagios for monitoring. Similarly we can add more servers in nagios for monitoring & once any service is affected, nagios will show the status on web console & will also send an alert notification to email the address mentioned in contacts.cfg file.

     ###############################################################

To monitor Windows Machines you will need to follow several steps and they are:

• Install NSClient++ addon on the Windows Machine.

• Configure Nagios Server for monitoring Windows Machine.

• Add new host and service definitions for Windows machine monitoring.

• Restart the Nagios Service.

To make this guide simple and easier, a few of configuration already done for you in the Nagios installation.

• A check_nt command definition already added to the command.cfg file. This definition command is used by check_nt plugin to monitor Windows services.

• A windows-server host template already created in the templates.cfg file. This template allows you to add new Windows host definitions.

The above two files “command.cfg” and “templates.cfg” files can be found at /usr/local/nagios/etc/objects/directory. You can modify and add your own definitions that suits your requirement. But, I’d recommend you to follow the instructions described in this article and you will be successfully monitoring your windows host in less than 20 minutes.

Step 1: Installing NSClient++ Agent on Windows Machine

Please use the below instructions to install NSClient++ Agent on the Remote Windows Host. First download the latest stable version NSClient++ 0.3.1 addon source files, which can be found at below link.

• http://sourceforge.net/projects/nscplus/

Once you’ve downloaded latest stable version, unzip the NSClient++ files into a new C:\NSClient++ directory.

Now open a MS-DOS command prompt from the Start Screen –> Run –> type ‘cmd‘ and press enter and change to the C:\NSClient++ directory.

C:\NSClient++

Next, register the NSClient++ service on the system with the following command.

nsclient++ /install

Finally, install the NSClient++ systray with the following command.

nsclient++ SysTray

Open the Windows Services Manager and right click on NSClient go to Properties and then ‘Log On‘ tab and click the check box that says “Allow service to interact with the desktop“. If it isn’t already allowed, please check the box to allow it to.

Install NSClient++

Open NSC.INI file located at C:\NSClient++ directory and uncomment all the modules defined in the “modules” section, except for CheckWMI.dll and RemoteConfiguration.dll.

[modules] ;# NSCLIENT++ MODULES ;# A list with DLLs to load at startup. ;  You will need to enable some of these for NSClient++ to work. ; ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ; *                                                               * ; * N O T I C E ! ! ! - Y O U   H A V E   T O   E D I T   T H I S * ; *                                                               * ; ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! FileLogger.dll CheckSystem.dll CheckDisk.dll NSClientListener.dll NRPEListener.dll SysTray.dll CheckEventLog.dll CheckHelpers.dll ;CheckWMI.dll ; ; RemoteConfiguration IS AN EXTREM EARLY IDEA SO DONT USE FOR PRODUCTION ENVIROMNEMTS! ;RemoteConfiguration.dll ; NSCA Agent is a new beta module use with care! ;NSCAAgent.dll ; LUA script module used to write your own "check deamon" (sort of) early beta. ;LUAScript.dll ; Script to check external scripts and/or internal aliases, early beta. ;CheckExternalScripts.dll ; Check other hosts through NRPE extreme beta and probably a bit dangerous! :) ;NRPEClient.dll

Uncomment the “allowed_hosts” in the “Settings” section and define the IP address of your Nagios Monitoring Server or leave it blank to allow any hosts to connect.

[Settings] ;# ALLOWED HOST ADDRESSES ;  This is a comma-delimited list of IP address of hosts that are allowed to talk to the all daemons. ;  If leave this blank anyone can access the deamon remotly (NSClient still requires a valid password). ;  The syntax is host or ip/mask so 192.168.0.0/24 will allow anyone on that subnet access allowed_hosts=172.16.27.41

Uncomment the “port” in the “NSClient” section and set to default port ‘12489‘. Make sure to open ‘12489‘ port on Windows Firewall.

[NSClient] ;# NSCLIENT PORT NUMBER ;  This is the port the NSClientListener.dll will listen to. port=12489

Finally start the NSClient++ service with the following command.

nsclient++ /start

If your properly installed and configured, you should see a new icon in the system tray in yellow circle with a black ‘M‘ inside.

Step 2: Configuring Nagios Server and Add Windows Hosts

Now Login into Nagios Server and add some object definitions in Nagios configuration files to monitor new Windows machine. Open windows.cfg file for editing with Vi editor.

[root@tecmint]# vi /usr/local/nagios/etc/objects/windows.cfg

A sample Windows host definition already defined for the Windows machine, you can simply change the host definition like host_name, alias, and address fields to appropriate values of your Windows machine.

############################################################################### ############################################################################### # # HOST DEFINITIONS # ############################################################################### ############################################################################### # Define a host for the Windows machine we'll be monitoring # Change the host_name, alias, and address to fit your situation define host{ use             windows-server  ; Inherit default values from a template host_name       winserver       ; The name we're giving to this host alias           My Windows Server       ; A longer name associated with the host address         172.31.41.53    ; IP address of the host }

Following services are already added and enabled in windows.cfg file. If you wish to add some more other service definitions that needs to be monitored, you can simple add those definitions to same configuration file. Make sure to change the host_name for these all services with host_name defined in the above step.

define service{ use generic-service host_name winserver service_description NSClient++ Version check_command check_nt!CLIENTVERSION } Add the following service definition to monitor the uptime of the Windows server. define service{ use generic-service host_name winserver service_description Uptime check_command check_nt!UPTIME } Add the following service definition to monitor the CPU utilization on the Windows server and generate a CRITICAL alert if the 5-minute CPU load is 90% or more or a WARNING alert if the 5-minute load is 80% or greater. define service{ use generic-service host_name winserver service_description CPU Load check_command check_nt!CPULOAD!-l 5,80,90 } Add the following service definition to monitor memory usage on the Windows server and generate a CRITICAL alert if memory usage is 90% or more or a WARNING alert if memory usage is 80% or greater. define service{ use generic-service host_name winserver service_description Memory Usage check_command check_nt!MEMUSE!-w 80 -c 90 } Add the following service definition to monitor usage of the C:\ drive on the Windows server and generate a CRITICAL alert if disk usage is 90% or more or a WARNING alert if disk usage is 80% or greater. define service{ use generic-service host_name winserver service_description C:\ Drive Space check_command check_nt!USEDDISKSPACE!-l c -w 80 -c 90 } Add the following service definition to monitor the W3SVC service state on the Windows machine and generate a CRITICAL alert if the service is stopped. define service{ use generic-service host_name winserver service_description W3SVC check_command check_nt!SERVICESTATE!-d SHOWALL -l W3SVC } Add the following service definition to monitor the Explorer.exe process on the Windows machine and generate a CRITICAL alert if the process is not running. define service{ use generic-service host_name winserver service_description Explorer check_command check_nt!PROCSTATE!-d SHOWALL -l Explorer.exe }

Lastly, uncomment the windows.cfg file in /usr/local/nagios/etc/nagios.cfg.

[root@tecmint]# vi /usr/local/nagios/etc/nagios.cfg

# Definitions for monitoring a Windows machine cfg_file=/usr/local/nagios/etc/objects/windows.cfg

Finally, verify the Nagios configuration files for any erros.

[root@tecmint]# /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg

Total Warnings: 0 Total Errors:   0 Things look okay - No serious problems were detected during the pre-flight check

If the verification process throws any error messages, fix those errors until the verification process completes without any error messages. Once’ you fix those errors, restart the Nagios service.

[root@tecmint]# service nagios restart Running configuration check...done. Stopping nagios: done. Starting nagios: done.

That’s it. Now go to Nagios Monitoring Web interface at “http://Your-server-IP-address/nagios” or “http://FQDN/nagios” and Provide the username “nagiosadmin” and password. Check that the Remote Windows Host was added and is being monitored.

Nagios Monitor Windows Host

That’s it! for now, in my up-coming article I will show you how to add Printer and Switches to Nagios Monitoring Server. If you’re having any difficulties while adding Windows host to Nagios. Please do comment your queries via comment section, till then stay tuned to Tecmint.com for more such kind of valuable articles.

-