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 7 machine.

Steps to Run the Script:

1. Ensure Rsyslog is Installed:

sudo yum install rsyslog -y
sudo systemctl enable --now rsyslog

sudo yum install rsyslog -y
sudo systemctl enable --now rsyslog

2. 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

3. 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.

Manual Setup Using Rsyslog Configuration

If you prefer manual setup or need more control over configurations, follow these steps:

1. Edit Rsyslog Configuration:

<code>sudo nano /etc/rsyslog.d/99-nagios.conf

<code>sudo nano /etc/rsyslog.d/99-nagios.conf

2. Add the following configuration:

*.* @@192.168.1.49:5544

*.* @@192.168.1.49:5544

• Replace 192.168.1.49 with the IP address of your Nagios Log Server R2.
• The @@ symbol indicates TCP transmission; use @ for UDP if needed.

3. Restart Rsyslog to Apply Changes:

sudo systemctl restart rsyslog<br>

sudo systemctl restart rsyslog<br>

4. Check Status to Ensure it’s Running:

sudo systemctl status rsyslog<br>

sudo systemctl status rsyslog<br>

Receiving Logs in Log Server

On your Log Server’s GUI, click Add Log Source.

Click Linux.

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

Conclusion

Whether using the automatic script or manual setup, forwarding logs from CentOS 7 to Nagios Log Server R2 ensures centralized log management for better monitoring and alerting. Use the method that best fits your deployment needs.

Step 1: Add the Nagios Repository

First, add the Nagios repository to your system to access the NCPA package:

sudo rpm -Uvh https://repo.nagios.com/nagios/7/nagios-repo-7-4.el7.noarch.rpm

sudo rpm -Uvh https://repo.nagios.com/nagios/7/nagios-repo-7-4.el7.noarch.rpm

Step 2: Install NCPA

Once the repository is added, install NCPA with:

sudo yum install ncpa -y

sudo yum install ncpa -y

Step 3: Start and Enable NCPA Services

After installation, start and enable the NCPA services to run at boot:

sudo systemctl enable ncpa
sudo systemctl start ncpa

sudo systemctl enable ncpa
sudo systemctl start ncpa

Step 4: Configure NCPA

The main configuration file for NCPA is located at:

/etc/ncpa/ncpa.cfg

/etc/ncpa/ncpa.cfg

Before making changes, back up the original file:

sudo cp /etc/ncpa/ncpa.cfg /etc/ncpa/ncpa.cfg.bak

sudo cp /etc/ncpa/ncpa.cfg /etc/ncpa/ncpa.cfg.bak

Now, edit the configuration file:

sudo nano /etc/ncpa/ncpa.cfg

sudo nano /etc/ncpa/ncpa.cfg

Locate the [api] section and update the community_string value:

[api]
community_string = YourCommunity

[api]
community_string = YourCommunity

Save and exit the file, then restart the NCPA services:

sudo systemctl restart ncpa_listener
sudo systemctl restart ncpa_passive

sudo systemctl restart ncpa_listener
sudo systemctl restart ncpa_passive

Step 5: Adjust Firewall Rules

To allow NCPA traffic, open the necessary ports:

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 6: Verify NCPA Functionality

To check if NCPA is running correctly, open a web browser and navigate to:

https://<server-ip>:5693

https://<server-ip>:5693

Log in using the community string configured earlier. If you see the NCPA web interface, the agent is working correctly.

Monitoring with Nagios

On your Nagios web GUI, click Run a wizard and find the NCPA wizard.

Type in the Address of your machine running NCPA. You can leave the Port as default. Enter the Token that you created earlier and click Next, and Finish with Defaults.

Conclusion

You have successfully installed and configured the Nagios Cross Platform Agent (NCPA) on CentOS 7. This setup allows Nagios to monitor the server efficiently, providing real-time insights into system performance and resource utilization. By integrating NCPA with Nagios, you enhance your network monitoring capabilities, ensuring proactive management of system health and performance.

Step 1: Install SNMP and Utilities

CentOS 7 uses yum as the default package manager. Install SNMP packages with:

sudo yum install net-snmp net-snmp-utils -y

sudo yum install net-snmp net-snmp-utils -y

Step 2: Start and Enable the SNMP Service

Once installed, start and enable the SNMP service so that it runs at boot:

sudo systemctl enable snmpd
sudo systemctl start snmpd

sudo systemctl enable snmpd
sudo systemctl start snmpd

Step 3: Configure SNMP

The main configuration file for SNMP is located at:

/etc/snmp/snmpd.conf

/etc/snmp/snmpd.conf

Before making changes, back up the original file:

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 configuration file:

sudo nano /etc/snmp/snmpd.conf

sudo nano /etc/snmp/snmpd.conf

Modify or add the following lines to set up SNMPv2c with a community string (replace YourCommunity with a strong name):

com2sec readonly  default  YourCommunity
group   MyROGroup v2c        readonly
view    all    included   .1
access  MyROGroup ""      any       noauth    exact  all    none   none
syslocation "Data Center"
syscontact "Admin <admin@example.com>"

com2sec readonly  default  YourCommunity
group   MyROGroup v2c        readonly
view    all    included   .1
access  MyROGroup ""      any       noauth    exact  all    none   none
syslocation "Data Center"
syscontact "Admin <admin@example.com>"

Save and exit the file, then restart the SNMP service:

sudo systemctl restart snmpd

Step 4: Adjust Firewall Rules

To allow SNMP traffic, open the necessary UDP port (161):

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

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

Step 5: Verify SNMP Functionality

Test if SNMP is working correctly with:

snmpwalk -v2c -c YourCommunity -O e 127.0.0.1

snmpwalk -v2c -c YourCommunity -O e 127.0.0.1

If you see output with system information, SNMP is working correctly.

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 7 server. If SNMP is correctly configured, you will receive SNMP data from the remote server.

Monitoring with Nagios XI

In 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 7. 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.