How to Monitor Proxmox VE with PRTG using SNMP

Read more about dedicated sensors using PowerShell for VM/LXC monitoring here

Part 1: Install and Configure SNMP on Proxmox
Part 2: Configure PRTG to Monitor Proxmox
Part 3: Special Considerations for PRTG Running as a Proxmox VM

This guide explains how to configure Proxmox to be monitored by PRTG Network Monitor using SNMP (while running within a VM in Proxmox). It covers SNMP installation, configuration, and firewall rules required for successful monitoring.

Prerequisites

Proxmox VE server (this guide uses IP 10.0.0.1 as an example)
PRTG Network Monitor server (this guide uses IP 10.0.0.40 as an example)
SSH access to your Proxmox host
Administrative access to PRTG

Note: Replace the IP addresses in this guide with your actual Proxmox and PRTG server IPs, in case of Remote Probes use the Remote Probe’s IP address.

Part 1: Install and Configure SNMP on Proxmox

Step 1: Install SNMP daemon

Connect to your Proxmox server via SSH (or use the build-in “Shell” Button in the GUI from your node) and run:

apt-get update
apt-get install snmpd

Step 2: Backup the original configuration

cp /etc/snmp/snmpd.conf /etc/snmp/snmpd.conf.backup

Step 3: Configure SNMP

Edit the SNMP configuration file:

nano /etc/snmp/snmpd.conf

Delete all existing content or and replace with / modify your original:

# System Information
sysLocation    Your Location Here
sysContact     Your Name <your@email.com>
sysServices    72

# Agent Operating Mode
master  agentx
agentaddress udp:161

# Access Control
view   allview    included   .1

rocommunity  public 10.0.0.40 -V allview
rocommunity  public 127.0.0.1 -V allview

Important configuration notes:

agentaddress udp:161 – SNMP listens on all interfaces on port 161
rocommunity public 10.0.0.40 -V allview – Allows your PRTG server read-only access to all SNMP data
rocommunity public 127.0.0.1 -V allview – Allows local testing
If your sensor is running on a Remote Probe, you need to adjust the IP from the PRTG Server to the PRTG Remote Probe Server.

Save and exit:

Press Ctrl+O to save
Press Enter to confirm
Press Ctrl+X to exit

Step 4: Restart and enable SNMP

systemctl restart snmpd
systemctl enable snmpd

Step 5: Verify SNMP is running

systemctl status snmpd

You should see “active (running)” in the output.

(Optional) Step 6: Test SNMP locally

Install SNMP utilities for testing:

apt-get install snmp

Test the SNMP connection:

snmpwalk -v2c -c public 127.0.0.1 .1.3.6.1.2.1.1

You should see system information including your hostname and location.

Part 2: Configure PRTG to Monitor Proxmox

Step 1: Add Proxmox as a device

Log in to your PRTG web interface
Navigate to Devices → Add Device
Enter the following:
- Device Name: Your Proxmox hostname (e.g., Proxmox-S01)
- IP Address/DNS Name: 10.0.0.1 (your Proxmox IP)
Click OK

Step 2: Configure SNMP settings

Go to the device settings
Under SNMP Settings, configure:
- SNMP Version: v2c
- Community String: public
Save the settings

Step 3: Add sensors

Option A: Auto-Discovery

Right-click on the device
Select Auto-Discovery
PRTG will automatically find available SNMP sensors

Option B: Manual sensor addition

Right-click on the device
Select Add Sensor
Search for SNMP Library
Select Basic Linux Library (UCD-SNMP and LM-SENSORS MIB)

Recommended sensors

After discovery or manual addition, you should have sensors for:

SNMP CPU Load – Monitor processor usage
SNMP Memory v2 – Track RAM utilization
SNMP Disk Free v2 – Monitor storage capacity
SNMP Traffic v2 – Track bandwidth on network interfaces
SNMP Uptime v2 – Monitor system availability

Part 3: Special Considerations for PRTG Running as a Proxmox VM

If your PRTG server runs as a VM on the same Proxmox host you want to monitor, additional firewall configuration may be required.

If you have the Proxmox firewall enabled, you need to allow SNMP and ICMP traffic from your PRTG server.

Step 1: Check firewall status

pve-firewall status

If the firewall is disabled, you can skip to Part 3.

Step 2: Configure host firewall rules

more info in Step 4

Edit the host firewall configuration:

nano /etc/pve/nodes/YOUR_NODE_NAME/host.fw

Replace YOUR_NODE_NAME with your actual Proxmox node name (e.g., S01).

Add the following rules under [RULES]:

[RULES]

IN ACCEPT -source 10.0.0.40 -p udp -dport 161 -log nolog
IN ACCEPT -source 10.0.0.40 -p icmp -log nolog
IN ACCEPT -source 10.0.0.0/24 -p tcp -dport 8006 -log nolog
IN ACCEPT -source 10.0.0.0/24 -p tcp -dport 22 -log nolog

Rule explanations:

UDP 161 – Allows SNMP traffic from PRTG
ICMP – Allows ping from PRTG (for connectivity checks)
TCP 8006 – Allows Proxmox Web UI access from your network
TCP 22 – Allows SSH access from your network

Save and exit (Ctrl+O, Enter, Ctrl+X).

Step 3: Reload the firewall

pve-firewall reload

Troubleshooting

SNMP connection timeout

Verify SNMP is running on Proxmox CLI: systemctl status snmpd
Check SNMP is listening on Proxmox CLI: ss -ulnp | grep 161
Test locally on Proxmox CLI: snmpwalk -v2c -c public 127.0.0.1 .1.3.6.1.2.1.1
Use the free Paessler PRTG SNMP Tester for troubleshooting from PRTG Server. (Manual)

Security Recommendations

Change the community string – Replace public with a unique, complex string in both the Proxmox SNMP config and PRTG device settings
Restrict access by IP – Only allow your PRTG server’s IP address in the SNMP configuration
Consider SNMPv3 – For enhanced security, consider using SNMPv3 with authentication and encryption
Limit firewall rules – Only open the ports that are absolutely necessary

Quick Reference

Files to configure:

SNMP configuration: /etc/snmp/snmpd.conf
Host firewall: /etc/pve/nodes/NODENAME/host.fw
Cluster firewall: /etc/pve/firewall/cluster.fw

Key commands:

Restart SNMP: systemctl restart snmpd
Check SNMP status: systemctl status snmpd
Reload firewall: pve-firewall reload
Stop firewall (testing): pve-firewall stop
Start firewall: pve-firewall start

PRTG sensor to use: SNMP Library → Basic Linux Library