Monitor Windows Server with Nagios XI and SNMP

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

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.

2. Click Add Roles and Features.

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

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

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

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.

7. Confirm Installation, click Next, then Install.

Wait for the installation to complete.

8. Verify Installation

Click on Start, then open the Services App.

Look for SNMP Service in the list.

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

Step 3: Configure Windows Server SNMP

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

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.

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.

Click Apply, then OK

Right-click SNMP Service → Click Restart.

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

1. Log into Nagios XI.

2. Go to Configure → Configuration Wizards.

3. Select Windows SNMP

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).

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

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.

Click Next

7. Configure the Notification Settings:

Click Next

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

Click Next.

10. Click Finish & Apply to apply configuration.

Step 4: Verify Monitoring

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

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

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

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:

Wizard detected that server does not have snmpwalk permission

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.