Note: Ubuntu 14.04 LTS reached end-of-life on April 25, 2019, and is unsupported. Its outdated packages (e.g., `rsyslog 7.4.4`) may not fully support modern features or security standards required by Nagios Log Server 2024R2. Use this guide for legacy systems only; upgrading to a supported Ubuntu version (e.g., 22.04 LTS) is strongly recommended.

Prerequisites

Before proceeding, ensure you have the following:

• Access to a Nagios Log Server instance (recommended latest stable release).
• An Ubuntu 14 system.
• Root or sudo privileges on your Ubuntu machine.
• Network connectivity between Ubuntu and Nagios Log Server (verify firewall settings).

Video Tutorial

For a visual walkthrough, watch this detailed step-by-step guide:

Step 1: Add a New Log Source in Nagios Log Server

1. Login to Nagios Log Server:
   • Open your web browser and navigate to your Nagios Log Server instance.
   • Log in with your administrator credentials.
2. Navigate to Log Source Setup:
   • On the Home page, locate the + Linux button at the bottom right corner.

• Alternatively, click + Add Log Source in the navigation bar and select Linux.

Step 2: Configuring the Linux Log Source

1. Download and Run the Setup Script

• The Linux Source Setup page provides a pre-configured command.
• Copy the command and paste it into the Ubuntu terminal.

If curl is not installed, install it first:

sudo apt update && sudo apt install -y curl

Then, execute the following command to download and run the setup script:

curl -sS -O http://your-nagios-log-server-address/nagioslogserver/scripts/setup-linux.sh
sudo bash setup-linux.sh -s your-nagios-log-server-address -p 5544

Replace your-nagios-log-server-address with the actual IP address or hostname of your Nagios Log Server.

• The -s flag specifies the Nagios Log Server address.
• The -p 5544 specifies the port for log transmission (default is 5544).

2. Verify the Script Execution

After running the script, you should see a confirmation message:

Detected rsyslog 7.4.4
Detected rsyslog work directory /var/spool/rsyslog
Destination Log Server: 192.168.0.65:5544
Creating /etc/rsyslog.d/99-nagioslogserver.conf...
getenforce command not found, assuming SELinux is disabled.
rsyslog configuration check passed.
Restarting rsyslog service with 'service'..  
Okay.
rsyslog is running with the new configuration.
Visit your Nagios Log Server dashboard to verify that logs are being received.

• If you encounter any errors, check the script logs.
• Ensure that the Nagios Log Server is reachable and that port 5544 is open.

Step 3: Confirming Log Reception

1. Navigate to Dashboards in Nagios Log Server:
   • Go to the Dashboards section.
   • Perform a query using the IP address of the Ubuntu machine to confirm logs are being received.
2. Send a Test Log Entry:

logger "This is a test log entry"

3. Refresh the Nagios Log Server dashboard:
   • If successful, you should see the test log entry listed in the dashboard.

Step 4: Accessing the Setup Script on Nagios Log Server

The setup script is located on the Nagios Log Server instance at:

/var/www/html/nagioslogserver/www/scripts/setup-linux.sh

You can access it directly via a browser or SSH if you need to make manual adjustments.

Step 5: Adding More Log Sources

Use the + Add Log Source button to configure additional sources, such as:

• Windows event logs
• Application logs
• Archived log files

Some log sources offer both scripted and manual setup options.

• The manual method provides more customization by allowing direct configuration file edits.

Troubleshooting Tips

1. Check rsyslog Status

Ensure that rsyslog is installed and running:

systemctl status rsyslog

If the service is not running, start it:

sudo systemctl start rsyslog

2. Verify Network Connectivity

Ensure that the Ubuntu machine can communicate with Nagios Log Server on port 5544.

• Check for network restrictions such as firewalls or proxy settings.

3. Check Firewall Settings

If you’re using ufw on Ubuntu, allow traffic on port 5544:

sudo ufw allow 5544/tcp

Also, check if there are any firewall rules on the Nagios Log Server that might block incoming log data.

4. Review Log Files

If the above steps don’t resolve the issue, review the log files:

• On Ubuntu: sudo cat /var/log/syslog | grep rsyslog
• On Nagios Log Server: tail -f /var/log/logserver/nagios.log

Conclusion

By following this guide, you have successfully configured your Ubuntu 14 machine to send logs to Nagios Log Server 2024R2 for centralized monitoring. This setup allows you to efficiently monitor system logs and gain insights into potential issues in real-time.

You can now extend your log monitoring capabilities by:

• Adding other sources
• Fine-tuning your configurations
• Creating alerts for critical log events

For troubleshooting or further assistance, visit the Nagios Knowledgebase or check the Nagios Support Forums.

Prerequisites

Before beginning the installation, ensure the following requirements are met:

• An Ubuntu 14.04 LTS system (64-bit recommended).
• sudo or root privileges.
• A stable internet connection for package downloads.

Verify your Ubuntu version by running the command:

lsb_release -a

lsb_release -a

Example Output:

Distributor ID: Ubuntu  
Description:    Ubuntu 14.04 LTS  
Release:        14.04  
Codename:       trusty  

Distributor ID: Ubuntu  
Description:    Ubuntu 14.04 LTS  
Release:        14.04  
Codename:       trusty  

Step 1: Download the NCPA Package

To download the latest NCPA package for your Ubuntu system, open a terminal and run:

wget https://assets.nagios.com/downloads/ncpa/ncpa-latest-trusty.amd64.deb

wget https://assets.nagios.com/downloads/ncpa/ncpa-latest-trusty.amd64.deb

Step 2: Install the NCPA Package

Once the package is downloaded, install it using the following command:

sudo dpkg -i ncpa-latest-trusty.amd64.deb

sudo dpkg -i ncpa-latest-trusty.amd64.deb

If you encounter dependency errors, resolve them by running:

sudo apt-get install -f

sudo apt-get install -f

Step 3: Configure NCPA

After installation, configure NCPA by editing the configuration file to set your API token:

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

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

Locate the line:

community_string = mytoken

community_string = mytoken

Replace mytoken with a secure API token of your choice. Save the file (CTRL + X, then Y and Enter).

Step 4: Restart NCPA Service

To apply the changes, restart the NCPA service:

sudo service ncpa restart

sudo service ncpa restart

Step 5: Configure Firewall (if enabled)

If you have a firewall enabled on your system, you will need to allow traffic on port 5693, which is used by NCPA.

For Ubuntu 14.04, configure UFW (Uncomplicated Firewall) as follows:

sudo ufw allow 5693/tcp
sudo ufw reload

sudo ufw allow 5693/tcp
sudo ufw reload

Troubleshooting: Firewall Not Enabled

If the firewall is inactive, enable it:

sudo ufw enable
sudo ufw reload

sudo ufw enable
sudo ufw reload

Step 6: Test NCPA Installation

Open a web browser and navigate to:

https://<NCPA_IP_Address>:5693/

https://<NCPA_IP_Address>:5693/

Bypass the security warning due to self-signed certificates by clicking Advanced and selecting Proceed.

On the NCPA login page, enter the API token you configured earlier and click Log In. Upon successful login, you will be directed to the NCPA Dashboard.

Step 7: Configure Nagios XI (Optional)

To monitor the Ubuntu server using Nagios XI and the NCPA agent:

1. Navigate to the Nagios XI dashboard.

2. Open the NCPA wizard by selecting Configure > Configuration Wizards > NCPA.

3. Enter the required details, including the IP address of the server and the API token you configured during NCPA setup.

4. Complete the wizard setup and apply configuration changes.

Verifying Monitoring Setup

After completing the wizard, Nagios XI should display the monitored host and its services. Navigate to the Service Status page to confirm that the system is being monitored.

For more detailed instructions, refer to the Nagios XI Documentation.

Troubleshooting Common Issues

1. Installation Fails with Dependencies
   • Symptom: dpkg -i errors out.
   • Fix: Run sudo apt-get install -f or manually install missing packages (e.g., sudo apt-get install python).
2. Service Won’t Start
   • Symptom: systemctl status ncpa_listener shows failed.
   • Fix: Check logs (sudo journalctl -u ncpa_listener or /var/log/syslog), verify ncpa.cfg syntax.
3. Web Interface Unreachable
   • Symptom: Browser times out at https://<IP>:5693/.
   • Fix: Ensure the service is running (sudo systemctl status ncpa_listener), port 5693 is open (sudo ufw status), and the IP is correct.”

Conclusion

You’ve installed and configured NCPA on Ubuntu 14.04 LTS, enabling system monitoring with optional Nagios XI integration. Due to Ubuntu 14.04’s EOL status, consider migrating to a supported OS for long-term security. For help, consult the Nagios Support Forum or  Nagios Knowledge Base.

This guide will walk you through the step-by-step installation and configuration of SNMP on Ubuntu 14.04 LTS, enabling seamless integration with Nagios XI. We’ll cover both SNMP v2c (widely used but less secure) and SNMP v3 (which includes authentication and encryption for enhanced security), ensuring you have the right setup for your monitoring needs.

Important Note: Ubuntu 14.04 LTS reached end-of-life in April 2019 (standard support) and April 2022 (Extended Security Maintenance). For production environments, consider upgrading to a supported version like Ubuntu 22.04 LTS or 24.04 LTS. This guide is provided for legacy systems or educational purposes.

Prerequisites

Before proceeding, ensure the following:

• You have administrative or sudo privileges on the Ubuntu machine.
• You are using Ubuntu 14.04 LTS.
• Nagios XI is installed and accessible, with the SNMP Wizard enabled.

Step 1: Install SNMP Packages

To install SNMP and the necessary libraries, log in to your Ubuntu machine and execute the following commands:

sudo apt-get update
sudo apt-get install snmpd libsnmp-dev -y

sudo apt-get update
sudo apt-get install snmpd libsnmp-dev -y

This updates your package list and installs:

• libsnmp-dev (SNMP development libraries for querying SNMP devices)
• snmpd (the SNMP daemon for handling SNMP requests)

Step 2: Configure SNMP

SNMP v2c Configuration

To configure SNMP v2c, first, create a backup of the existing configuration:

sudo cp /etc/snmp/snmpd.conf /etc/snmp/snmpd.conf.bak

sudo cp /etc/snmp/snmpd.conf /etc/snmp/snmpd.conf.bak

Now, edit the SNMP configuration file:

sudo nano /etc/snmp/snmpd.conf

sudo nano /etc/snmp/snmpd.conf

Find and modify the following line to define the community string and allow access from your Nagios XI server (replace Str0ngC0mmunity with your desired community string and 10.25.5.12 with your Nagios XI server’s IP address):

rocommunity Str0ngC0mmunity 10.25.5.12

rocommunity Str0ngC0mmunity 10.25.5.12

Save the file and restart the SNMP service:

sudo service snmpd restart

sudo service snmpd restart

SNMP v3 Configuration (Optional, More Secure)

To configure SNMP v3, create an SNMP user with authentication and encryption:

sudo net-snmp-config --create-snmpv3-user -ro -a SHA -A Str0ng@uth3ntic@ti0n -x AES -X Str0ngPriv@cy nagios

sudo net-snmp-config --create-snmpv3-user -ro -a SHA -A Str0ng@uth3ntic@ti0n -x AES -X Str0ngPriv@cy nagios

• -a SHA → Specifies SHA for authentication (use MD5 if needed, but it’s less secure)
• -x AES → Enables AES encryption (alternatively, use DES for lower security)

Restart the SNMP service:

sudo service snmpd restart

sudo service snmpd restart

Step 3: Configure Firewall Rules

If ufw (Uncomplicated Firewall) is enabled, allow SNMP traffic:

sudo ufw allow snmp
sudo ufw reload

sudo ufw allow snmp
sudo ufw reload

For better security, allow SNMP traffic only from the Nagios XI server:

sudo ufw allow from 10.25.5.0/24 to any port 161 proto udp
sudo ufw reload

sudo ufw allow from 10.25.5.0/24 to any port 161 proto udp
sudo ufw reload

Step 4: Enable SNMP Service on Boot

To ensure SNMP starts automatically on system boot, run:

sudo update-rc.d snmpd defaults

sudo update-rc.d snmpd defaults

Step 5: Test SNMP Communication

On your Nagios XI server, test SNMP connectivity using the following commands.

For SNMP v2c:

snmpwalk -v2c -c Str0ngC0mmunity 10.25.5.12

snmpwalk -v2c -c Str0ngC0mmunity 10.25.5.12

For SNMP v3:

snmpwalk -v3 -u nagios -l authPriv -a SHA -A Str0ng@uth3ntic@ti0n -x AES -X Str0ngPriv@cy 10.25.5.12

snmpwalk -v3 -u nagios -l authPriv -a SHA -A Str0ng@uth3ntic@ti0n -x AES -X Str0ngPriv@cy 10.25.5.12

Expected Output (Example)

iso.3.6.1.2.1.1.1.0 = STRING: "Linux myserver 3.13.0-32-generic"
iso.3.6.1.2.1.1.3.0 = Timeticks: (100032) 0:16:40.32

iso.3.6.1.2.1.1.1.0 = STRING: "Linux myserver 3.13.0-32-generic"
iso.3.6.1.2.1.1.3.0 = Timeticks: (100032) 0:16:40.32

Troubleshooting Steps

If SNMP does not return data:

1. Verify SNMP Service is Running:

sudo service snmpd status

sudo service snmpd status

2. Check Listening Ports:

netstat -tulnp | grep snmp

netstat -tulnp | grep snmp

3. Ensure Firewall Allows Traffic:

sudo ufw status

sudo ufw status

4. Check SNMP Logs for Errors:

sudo tail -20 /var/log/syslog

sudo tail -20 /var/log/syslog

5. Test Local SNMP Response:

snmpwalk -v2c -c Str0ngC0mmunity -O e 127.0.0.1

snmpwalk -v2c -c Str0ngC0mmunity -O e 127.0.0.1

Step 6: Add Ubuntu Host to Nagios XI

1. In Nagios XI, go to Configure > Run a configuring wizard.

2. Select the Linux SNMP Wizard.

3. Enter the Ubuntu machine’s IP (e.g., 10.25.5.12) and SNMP credentials (v2c community string or v3 details).

4. Click Next, choose metrics to monitor (e.g., CPU, memory, disk), and apply the configuration.

5. Verify data collection in Nagios XI’s dashboard

Common Issues & Fixes

• Host appears “Down” in Nagios XI:
  • Check SNMP configuration and firewall rules.
• Incorrect SNMP credentials error:
  • Verify the community string (SNMP v2c) or authentication details (SNMP v3).
• No data returned in snmpwalk:
  • Ensure snmpd is running and listening on port 161.

Conclusion

You’ve now configured SNMP on Ubuntu 14.04 for monitoring with Nagios XI. For optimal security and support, consider migrating to a current Ubuntu LTS release. To customize monitoring further, explore Nagios XI’s advanced options or visit the Nagios Support Forum or the Nagios Knowledgebase.