Getting Started

After setup, logs that would typically appear in /var/log/messages will be forwarded to the Nagios Log Server R2, allowing centralized monitoring and alerting.

Automatic Setup Using a Script

The easiest way to configure log forwarding is by using the provided script. This method requires rsyslog to be installed on your CentOS 10 machine.

Steps to Run the Script

Download the script from the Nagios Log Server R2:

curl -sS -O http://192.168.1.49/nagioslogserver/scripts/setup-linux.sh

curl -sS -O http://192.168.1.49/nagioslogserver/scripts/setup-linux.sh

Execute the script to configure rsyslog:

sudo bash setup-linux.sh -s 192.168.1.49 -p 5544

sudo bash setup-linux.sh -s 192.168.1.49 -p 5544

Replace 192.168.1.49 with your Nagios Log Server R2’s IP address.

The -p 5544 option specifies the port for log transmission.

Receiving Logs in Log Server

On your Log Servers GUI, click Add Log Source.

Click Linux.

Now type in your machine’s IP address to see if you are receiving logs. If it’s working, it will confirm that logs are being received.

Conclusion

Whether using the automatic script or manual setup, forwarding logs from CentOS 10 to Nagios Log Server R2 ensures centralized log management for better monitoring and alerting. Use the method that best fits your deployment needs.

Prerequisites

• A system running CentOS Stream 10
• Root or sudo privileges
• Internet connectivity to download necessary packages

Step 1: Update Your System

Before installing NCPA, update your system to ensure all packages are up to date.

sudo yum update -y

sudo yum update -y

Then navigate to the /tmp directory

cd /tmp

cd /tmp

Step 2: Enable the Nagios Repository

To install NCPA, you need to add the Nagios repository.

sudo rpm -Uvh https://repo.nagios.com/nagios/9/nagios-repo-9-2.el9.noarch.rpm

sudo rpm -Uvh https://repo.nagios.com/nagios/9/nagios-repo-9-2.el9.noarch.rpm

After adding the repository, update your system again:

sudo yum update -y

sudo yum update -y

Step 3: Install NCPA

Download and install the latest version of NCPA for CentOS Stream 10 (which aligns with EL9 packages):

sudo yum install ncpa -y

sudo yum install ncpa -y

This will install the NCPA agent along with its dependencies.

Step 4: Configure NCPA

Once installed, update the configuration file to set the authentication token. Open the NCPA configuration file:

sudo nano /usr/local/ncpa/etc/ncpa.cfg

sudo nano /usr/local/ncpa/etc/ncpa.cfg

Locate the following section and change mytoken to a secure token of your choice:

[api]
community_string = <your-secure-token>

[api]
community_string = <your-secure-token>

Save the file and exit the editor.

Step 5: Start and Enable the NCPA Service

Start the NCPA listener service and enable it to start on boot:

sudo systemctl start ncpa_listener
sudo systemctl enable ncpa_listener

sudo systemctl start ncpa_listener
sudo systemctl enable ncpa_listener

Verify that the service is running:

sudo systemctl status ncpa_listener

sudo systemctl status ncpa_listener

Step 6: Open Firewall Ports for NCPA

If your system has a firewall enabled, open the necessary port (default: 5693) to allow incoming connections:

sudo firewall-cmd --permanent --add-port=5693/tcp
sudo firewall-cmd --reload

sudo firewall-cmd --permanent --add-port=5693/tcp
sudo firewall-cmd --reload

Step 7: Verify NCPA Installation

Test if NCPA is running correctly by accessing its web interface. Open a browser and navigate to:

https://<server-ip>:5693

https://<server-ip>:5693

Log in using the authentication token you set earlier.

Monitoring With Nagios XI

Now that you have configured NCPA, monitoring with Nagios XI will be easy! Navigate to the Nagios web GUI and click Run a Wizard.

Click the NCPA wizard.

Enter the IP Address of your machine. You can leave the Port as default. Then pick the Token that you set earlier. Click Next, and Finish with Defaults.

Conclusion

You have successfully installed and configured the Nagios Cross-Platform Agent (NCPA) on CentOS Stream 10. Your system can now be monitored using Nagios XI, providing detailed insights into system performance and resource usage.

Prerequisites

Before proceeding, ensure you have:

• A CentOS Stream 10 system with root or sudo access
• An active internet connection to download packages
• A Nagios XI Server

Step 1: Install SNMP

The first step is to install the SNMP packages on your CentOS system. The SNMP software includes net-snmp and net-snmp-utils.

sudo dnf install -y net-snmp net-snmp-utils

sudo dnf install -y net-snmp net-snmp-utils

This command installs the SNMP service and utilities required to manage and interact with SNMP on your system.

Step 2: Enable + Start SNMP

After installation, enable the SNMP service to ensure it starts on boot:

sudo systemctl enable snmpd
sudo systemctl start snmpd

sudo systemctl enable snmpd
sudo systemctl start snmpd

This ensures that the SNMP service will automatically start when your system boots, keeping it available for monitoring.

Step 3: Check SNMP Status

Verify that the SNMP service is running correctly:

sudo systemctl status snmpd

sudo systemctl status snmpd

This command checks the current status of the SNMP service to ensure it is active and running without errors.

Step 4: Configure SNMP

To modify SNMP settings, edit the configuration file:

sudo nano /etc/snmp/snmpd.conf

sudo nano /etc/snmp/snmpd.conf

Find and modify the community string under the com2sec section:

com2sec readonly default YourCommunityString

com2sec readonly default YourCommunityString

Replace YourCommunityString with a secure string for authentication. Save the file and restart SNMP:

sudo systemctl restart snmpd

sudo systemctl restart snmpd

Step 5: Test Connection from Localhost

To ensure SNMP is working correctly, test it locally using the snmpwalk command:

snmpwalk -v2c -c YourCommunityString localhost

snmpwalk -v2c -c YourCommunityString localhost

This command queries the SNMP service on your local machine. The -v2c option specifies the SNMP version, and -c YourCommunityString is the community string used for authentication.

Step 6: Open Firewall for SNMP

If you want to allow SNMP traffic from remote machines, open the firewall to allow SNMP traffic:

sudo firewall-cmd --permanent --add-port=161/udp
sudo firewall-cmd --reload

sudo firewall-cmd --permanent --add-port=161/udp
sudo firewall-cmd --reload

This command opens port 161 (the default SNMP port) for UDP traffic, allowing SNMP queries from remote systems.

Step 7: Test SNMP from a Remote System

Finally, to ensure SNMP is accessible remotely, test it from another system using snmpwalk:

snmpwalk -v2c -c YourCommunityString <server-ip>

snmpwalk -v2c -c YourCommunityString <server-ip>

Replace <server-ip> with the IP address of your CentOS server. If SNMP is correctly configured, you will receive SNMP data from the remote server.

Monitoring with Nagios XI

On Nagios XI navigate to Run a Wizard and click on the SNMP wizard

Add your Host Name and type in the SNMP Community string that you created.

Pick the SNMP Services that you want to monitor and then click Next and Finish with Defaults.

Conclusion

You have successfully installed and configured SNMP on CentOS Stream 10. This setup allows your server to be monitored remotely, enhancing network management capabilities. You also configured SNMP monitoring with Nagios XI, which provides a powerful interface for tracking system performance and network activity. By adding your SNMP-enabled server to Nagios XI, you can gain deeper insights into system health, set up alerts, and optimize network monitoring for better performance.