Monitoring Clear Linux with SNMP in Nagios XI: A Step-by-Step Guide

Clear Linux, developed by Intel, is a high-performance, stateless Linux distribution optimized for Intel hardware. Although not based on traditional RPM or DEB systems, Clear Linux supports standard tools like net-snmp, making it possible to monitor using SNMP. This guide shows how to install, configure, and integrate SNMP with Nagios XI for agentless monitoring of your Clear Linux system.

Prerequisites

Before you begin:

• A Clear Linux system updated with sudo swupd update
• Sudo or root access on the Clear Linux system
• Nagios XI installed and reachable
• Network connectivity between Clear Linux and Nagios XI (UDP port 161 open)

Step 1: Install SNMP Tools on Clear Linux

Clear Linux doesn’t include SNMP utilities by default. Install them:

sudo swupd bundle-add net-tools
sudo swupd bundle-add sysadmin-basic

Then install SNMP manually:

sudo swupd bundle-add package-utils
curl -O https://download-ib01.fedoraproject.org/pub/epel/7/x86_64/Packages/n/net-snmp-5.7.2-49.el7.x86_64.rpm
rpm2cpio net-snmp-5.7.2-49.el7.x86_64.rpm | cpio -idmv
sudo cp -r ./usr/* /usr/

Note: Use the latest compatible SNMP RPM or build from source if preferred.

Step 2: Configure SNMP

SNMP v2c Configuration

1. Create a new config file:

sudo mkdir -p /etc/snmp
echo 'rocommunity Str0ngC0mmunity 10.25.5.12' | sudo tee /etc/snmp/snmpd.conf

2. Start SNMP (foreground):

sudo /usr/sbin/snmpd -f -Lo

To run it as a background process, remove -f.

SNMP v3 Configuration (Optional)

SNMP v3 requires a more complex setup. Use net-snmp utilities to create a user:

sudo net-snmp-create-v3-user -ro -a SHA -A Str0ng@uth3ntic@ti0n -x AES -X Str0ngPriv@cy nagios

This may require additional scripting or compiling from source.

Step 3: Open the SNMP Port (UDP 161)

Clear Linux typically uses iptables. Allow SNMP traffic:

sudo iptables -I INPUT -p udp --dport 161 -j ACCEPT
sudo iptables-save > /etc/iptables/rules.v4

Verify:

sudo iptables -L -n | grep 161

Step 4: Test SNMP Communication

From your Nagios XI server:

SNMP v2c:

snmpwalk -v2c -c Str0ngC0mmunity <clearlinux-ip>

SNMP v3:

snmpwalk -v3 -u nagios -l authPriv -a SHA -A Str0ng@uth3ntic@ti0n -x AES -X Str0ngPriv@cy <clearlinux-ip>

Expected Output:

iso.3.6.1.2.1.1.1.0 = STRING: "Linux clearlinux ..."

Step 5: Add Host in Nagios XI Using SNMP Wizard

1. Log into Nagios XI
2. Navigate to Configure > Run a configuring wizard
3. Select Linux SNMP
4. Enter the Clear Linux IP and SNMP credentials
5. Choose metrics (CPU, memory, disk, etc.)
6. Apply and save configuration

Troubleshooting Tips

• SNMP Daemon Not Running: ps aux | grep snmpd
• Firewall Blocking Traffic: Ensure port 161 is open and rules are persistent
• Permission Issues: Verify snmpd.conf is readable and SNMP is correctly installed

Conclusion

Clear Linux can be monitored via SNMP with a few workarounds despite its stateless design. Once configured, Nagios XI provides deep insight into your system using lightweight, agentless checks.

Resources:

• Nagios SNMP Guide
• Net-SNMP Docs
• Nagios Knowledgebase