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How To Monitor Windows Server with Nagios XI and SNMP

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Picture of Salamon Anzel
Salamon Anzel

Monitoring Windows Server with Nagios XI using SNMP (Simple Network Management Protocol) provides a powerful and efficient way to track system performance, detect issues, and ensure uptime. SNMP allows Nagios XI to collect critical metrics such as CPU usage, memory utilization, disk space, and network activity from Windows servers in real time. By configuring SNMP on Windows Server and integrating it with Nagios XI, administrators can proactively monitor server health, set up alerts for potential problems, and optimize resource management. This guide will walk you through the step-by-step process of setting up SNMP on Windows Server and configuring Nagios XI to monitor essential system metrics effectively.


SNMP vs NCPA

FeatureSNMP (Simple Network Management Protocol)NCPA (Nagios Cross-Platform Agent)
TypeAgentless ProtocolAgent-Based
Data CollectedBasic metrics (CPU, Memory, Disk, Network)Detailed system metrics, logs and custom scripts
SecurityLess Secure (Uses Community strings)More Secure (Token-based authentication and API)
CustomizationLimited (Relies on predefined OIDs)Highly Customizable (API & scripting support)
Real-Time MonitoringSupports polling, but limited real-time eventsReal-time data collection & active monitoring
Best Use CaseSimple network-wide monitoringDeep monitoring of Windows & Linux systems

Summary:

  • Use SNMP if you need basic monitoring without installing an agent.
  • Use NCPA if you need in-depth Windows monitoring with strong Nagios integration.

For information on NCPA and Windows Server. See How To Monitor Windows Server with Nagios XI and NCPA


Step 1: Install SNMP on Windows Server

Method 1: Install SNMP via PowerShell

For a quicker installation, use PowerShell:

Open PowerShell as Administrator.

1. Run the following command:

Add-WindowsFeature SNMP-Service


To install SNMP Tools (optional):

Add-WindowsFeature RSAT-SNMP

2. Verify installation with:

Get-WindowsFeature | Where-Object { $_.Name -like "*SNMP*" }

Method 2: Install SNMP via Server Manager

1. Click on Start, then open Server Manager.

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Windows Start Button
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Server Manager

2. Click Add Roles and Features.

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Add roles and features

3. For Installation Type, choose Role-based or feature-based installation → Click Next.

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Installation Type

4. For Destination Server, choose your server → Click Next.

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Server Selection

5. Skip the Roles Section, Click Next (SNMP is a feature, not a role).

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Server Roles

6. In Features, scroll down to SNMP Service. Check the box for SNMP Service.

(Optional) Select SNMP Tools if you want SNMP utilities for management.

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Features

7. Confirm Installation, click Next, then Install.

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Confirmation

Wait for the installation to complete.

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Installation in progress
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Installation complete

8. Verify Installation

Click on Start, then open the Services App.

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Windows Start button
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Services App

Look for SNMP Service in the list.

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SNMP Service Running

If not running, right-click SNMP Service → Click Start.

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Start SNMP Service

Step 3: Configure Windows Server SNMP

Right-click on SNMP Service and select Properties, then the Security tab:

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SNMP Service Properties

Click Add under Accepted community names

In the Community Name field, enter nagios (or your preferred community string).

Select Read-Only for minimal access (or Read-Write if needed).

Click OK to save the community string.

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Adding Accepted community names

Under “Accept SNMP packets from these hosts”, click Add.

Enter the IP Address of the Nagios XI server.

Click Add to save the IP entry.

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Adding Accepted SNMP Host

Click Apply, then OK

Right-click SNMP Service → Click Restart.

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Restart SNMP Service

Step 4: Configure Nagios XI to Monitor Windows Server via SNMP

1. Log into Nagios XI.

2. Go to Configure → Configuration Wizards.

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Nagios XI Configuration Wizard

3. Select Windows SNMP

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Windows SNMP button

4. Enter Windows Server SNMP Details

IP Address: The IP of your Windows Server.

Operating System: If you’re Windows Server is higher then 2019, then select Windows Server 2019

SNMP Version: Select SNMP v2c (or v3 if configured).

Port: Leave as 161 (default).

SNMP Community String: The same string configured on Windows (e.g., nagios or public).

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How To Monitor Windows Server with Nagios XI and SNMP 34

Click Next.

5. Enter SNMP Monitoring Details

Choose the metrics you want to monitor, such as:

CPU Usage

Memory Usage

Disk Usage

Network Interface Traffic

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Monitoring details

Click Next.

6. Configure the Monitoring Settings:

The default is set to monitor every 5 minutes. When there is potential problem, it will recheck every one minute up to 5 times before sending a notification.

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Monitoring settings

Click Next

7. Configure the Notification Settings:

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notification settings

Click Next

8. Add your Windows Server to any Host Groups, Service Groups, or Parent Host

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Host Groups, Service Groups, or Parent Host

Click Next.

10. Click Finish & Apply to apply configuration.

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final settings
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successful install

Step 4: Verify Monitoring

1. Navigate to Views > Host Detail > Select your Windows Server

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Views > Host Detail

2. Confirm your windows machine and the services you’ve selected are being monitored:

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3. Verify Monitoring
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How To Monitor Windows Server with Nagios XI and SNMP 35

Troubleshooting

Confirm SNMP firewall port 161 is open

Confirm SNMP Firewall is open on the Windows Server by running the below command in Powershell:

Get-NetFirewallRule | Where-Object { $_.Name -eq "SNMP-In-UDP" } | 
Select-Object Name, DisplayName, @{Name="LocalPort";Expression={(Get-NetFirewallPortFilter -AssociatedNetFirewallRule $_.Name).LocalPort}}, Enabled, Direction, Action

Confirm that the Enabled is True and Action is Allowed

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Get-NetFirewallRule output

If it’s closed, you can enable it by running:

New-NetFirewallRule -DisplayName "Allow SNMP" -Direction Inbound -Protocol UDP -LocalPort 161 -Action Allow

You can also confirm in the Windows Defender Firewall with Advanced Security Setting here:

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Firewall Rule UI

Wizard detected that server does not have snmpwalk permission

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snmpwalk alert

This alert can occur when changes are made the SNMP Service Properties on the Windows Server and a restart of the SNMP service was never performed.

Restart the SNMP Service on the Windows server to see if the issue still occurs.

Please know alerts like this won’t stop a successful configuration.


If you have additional questions or other support-related questions, please visit Nagios Support. The Nagios Support Knowledgebase is also a great support resource.