Configure SNMP Alerting with Prometheus Alertmanager

Set up comprehensive SNMP monitoring with Prometheus exporters and create intelligent alerting rules in Alertmanager to proactively monitor network devices, interfaces, and performance metrics.

Prerequisites

Existing Prometheus installation
Network devices with SNMP enabled
Basic understanding of SNMP protocol
Email server for notifications

What this solves

SNMP monitoring provides deep visibility into network devices like switches, routers, and firewalls, but raw SNMP data becomes useful only when paired with intelligent alerting. This tutorial shows you how to configure Prometheus SNMP exporters to collect metrics from network devices and create sophisticated alerting rules in Alertmanager that trigger on specific conditions like interface downtime, high bandwidth utilization, or device failures.

Step-by-step configuration

Install Prometheus SNMP exporter

Download and install the SNMP exporter that translates SNMP queries into Prometheus metrics.

sudo apt update
wget https://github.com/prometheus/snmp_exporter/releases/download/v0.25.0/snmp_exporter-0.25.0.linux-amd64.tar.gz
tar xzf snmp_exporter-0.25.0.linux-amd64.tar.gz
sudo mv snmp_exporter-0.25.0.linux-amd64/snmp_exporter /usr/local/bin/
sudo chmod +x /usr/local/bin/snmp_exporter

sudo dnf update -y
wget https://github.com/prometheus/snmp_exporter/releases/download/v0.25.0/snmp_exporter-0.25.0.linux-amd64.tar.gz
tar xzf snmp_exporter-0.25.0.linux-amd64.tar.gz
sudo mv snmp_exporter-0.25.0.linux-amd64/snmp_exporter /usr/local/bin/
sudo chmod +x /usr/local/bin/snmp_exporter

Create SNMP exporter user and directories

Set up a dedicated user and directory structure for the SNMP exporter with proper security isolation.

sudo useradd --system --no-create-home --shell /bin/false snmp_exporter
sudo mkdir -p /etc/snmp_exporter /var/lib/snmp_exporter
sudo chown snmp_exporter:snmp_exporter /var/lib/snmp_exporter

Download SNMP exporter configuration

Get the default SNMP configuration file that includes MIB definitions for common network devices.

sudo wget https://raw.githubusercontent.com/prometheus/snmp_exporter/main/snmp.yml -O /etc/snmp_exporter/snmp.yml
sudo chown snmp_exporter:snmp_exporter /etc/snmp_exporter/snmp.yml

Create SNMP exporter systemd service

Configure the SNMP exporter to run as a system service with automatic restart capabilities.

[Unit]
Description=Prometheus SNMP Exporter
Documentation=https://github.com/prometheus/snmp_exporter
Wants=network-online.target
After=network-online.target

[Service]
Type=simple
User=snmp_exporter
Group=snmp_exporter
ExecReload=/bin/kill -HUP $MAINPID
ExecStart=/usr/local/bin/snmp_exporter \
  --config.file=/etc/snmp_exporter/snmp.yml \
  --web.listen-address=0.0.0.0:9116

SyslogIdentifier=snmp_exporter
Restart=always
RestartSec=1
StartLimitInterval=0

[Install]
WantedBy=multi-user.target

Enable and start SNMP exporter

Start the service and enable it to run at boot time.

sudo systemctl daemon-reload
sudo systemctl enable --now snmp_exporter
sudo systemctl status snmp_exporter

Configure Prometheus to scrape SNMP metrics

Add SNMP scraping configuration to your existing Prometheus setup. This example targets a Cisco switch and monitors critical interfaces.

global:
  scrape_interval: 15s
  evaluation_interval: 15s

rule_files:
  - "snmp_alerts.yml"

alerting:
  alertmanagers:
    - static_configs:
        - targets:
          - localhost:9093

scrape_configs:
  - job_name: 'snmp'
    static_configs:
      - targets:
        - 192.168.1.10  # Cisco switch IP
        - 192.168.1.11  # Router IP
    metrics_path: /snmp
    params:
      module: [if_mib]  # Use interface MIB module
    relabel_configs:
      - source_labels: [__address__]
        target_label: __param_target
      - source_labels: [__param_target]
        target_label: instance
      - target_label: __address__
        replacement: localhost:9116

Create advanced SNMP alerting rules

Define comprehensive alerting rules that monitor interface status, bandwidth utilization, and device availability.

groups:
name: snmp_network_alerts  rules:
  - alert: NetworkInterfaceDown
    expr: ifOperStatus{job="snmp"} == 2
    for: 2m
    labels:
      severity: critical
      service: network
    annotations:
      summary: "Network interface {{ $labels.ifDescr }} is down on {{ $labels.instance }}"
      description: "Interface {{ $labels.ifDescr }} on device {{ $labels.instance }} has been down for more than 2 minutes. Current status: {{ $value }}"

  - alert: HighBandwidthUtilization
    expr: |
      (
        rate(ifHCInOctets{job="snmp"}[5m]) * 8
        + rate(ifHCOutOctets{job="snmp"}[5m]) * 8
      ) / ifHighSpeed{job="snmp"} * 100 > 80
    for: 5m
    labels:
      severity: warning
      service: network
    annotations:
      summary: "High bandwidth utilization on {{ $labels.ifDescr }} ({{ $labels.instance }})"
      description: "Interface {{ $labels.ifDescr }} on {{ $labels.instance }} is experiencing {{ $value | humanize }}% bandwidth utilization for more than 5 minutes."

  - alert: SNMPDeviceUnreachable
    expr: up{job="snmp"} == 0
    for: 3m
    labels:
      severity: critical
      service: network
    annotations:
      summary: "SNMP device {{ $labels.instance }} is unreachable"
      description: "Cannot reach SNMP device {{ $labels.instance }} for more than 3 minutes. Check network connectivity and device status."

  - alert: InterfaceErrorRateHigh
    expr: |
      (
        rate(ifInErrors{job="snmp"}[5m])
        + rate(ifOutErrors{job="snmp"}[5m])
      ) / (
        rate(ifInUcastPkts{job="snmp"}[5m])
        + rate(ifOutUcastPkts{job="snmp"}[5m])
      ) * 100 > 1
    for: 10m
    labels:
      severity: warning
      service: network
    annotations:
      summary: "High error rate on interface {{ $labels.ifDescr }} ({{ $labels.instance }})"
      description: "Interface {{ $labels.ifDescr }} on {{ $labels.instance }} has an error rate of {{ $value | humanize }}% for more than 10 minutes."

  - alert: DeviceMemoryUtilizationHigh
    expr: |
      (ciscoMemoryPoolUsed{job="snmp"} / (ciscoMemoryPoolUsed{job="snmp"} + ciscoMemoryPoolFree{job="snmp"})) * 100 > 85
    for: 15m
    labels:
      severity: warning
      service: network
    annotations:
      summary: "High memory utilization on {{ $labels.instance }}"
      description: "Device {{ $labels.instance }} memory pool {{ $labels.ciscoMemoryPoolName }} is at {{ $value | humanize }}% utilization."

  - alert: DeviceCPUUtilizationHigh
    expr: ciscoCPUBusyPercentage{job="snmp"} > 80
    for: 10m
    labels:
      severity: warning
      service: network
    annotations:
      summary: "High CPU utilization on {{ $labels.instance }}"
      description: "CPU utilization on {{ $labels.instance }} has been above 80% for more than 10 minutes. Current value: {{ $value }}%"

Install and configure Alertmanager

Set up Alertmanager to handle alert routing, grouping, and notifications for SNMP alerts.

wget https://github.com/prometheus/alertmanager/releases/download/v0.27.0/alertmanager-0.27.0.linux-amd64.tar.gz
tar xzf alertmanager-0.27.0.linux-amd64.tar.gz
sudo mv alertmanager-0.27.0.linux-amd64/alertmanager /usr/local/bin/
sudo mv alertmanager-0.27.0.linux-amd64/amtool /usr/local/bin/
sudo chmod +x /usr/local/bin/alertmanager /usr/local/bin/amtool

wget https://github.com/prometheus/alertmanager/releases/download/v0.27.0/alertmanager-0.27.0.linux-amd64.tar.gz
tar xzf alertmanager-0.27.0.linux-amd64.tar.gz
sudo mv alertmanager-0.27.0.linux-amd64/alertmanager /usr/local/bin/
sudo mv alertmanager-0.27.0.linux-amd64/amtool /usr/local/bin/
sudo chmod +x /usr/local/bin/alertmanager /usr/local/bin/amtool

Create Alertmanager user and directories

Set up the necessary user account and directory structure for Alertmanager.

sudo useradd --system --no-create-home --shell /bin/false alertmanager
sudo mkdir -p /etc/alertmanager /var/lib/alertmanager
sudo chown alertmanager:alertmanager /etc/alertmanager /var/lib/alertmanager

Configure Alertmanager for SNMP alerts

Create an Alertmanager configuration that routes SNMP alerts based on severity and service type with intelligent grouping and notification channels.

global:
  smtp_smarthost: 'localhost:587'
  smtp_from: 'alertmanager@example.com'
  smtp_auth_username: 'alertmanager@example.com'
  smtp_auth_password: 'your_email_password'

route:
  group_by: ['alertname', 'instance', 'severity']
  group_wait: 10s
  group_interval: 10s
  repeat_interval: 1h
  receiver: 'network-team'
  routes:
  - match:
      service: network
      severity: critical
    receiver: 'critical-network-alerts'
    group_wait: 5s
    repeat_interval: 15m
  - match:
      service: network
      severity: warning
    receiver: 'network-warnings'
    group_interval: 5m
    repeat_interval: 2h

receivers:
name: 'network-team'  email_configs:
  - to: 'network-team@example.com'
    subject: 'Network Alert: {{ range .Alerts }}{{ .Annotations.summary }}{{ end }}'
    body: |
      {{ range .Alerts }}
      Alert: {{ .Annotations.summary }}
      Description: {{ .Annotations.description }}
      Device: {{ .Labels.instance }}
      Severity: {{ .Labels.severity }}
      Started: {{ .StartsAt }}
      {{ end }}

name: 'critical-network-alerts'  email_configs:
  - to: 'network-oncall@example.com'
    subject: 'CRITICAL Network Alert: {{ range .Alerts }}{{ .Annotations.summary }}{{ end }}'
    body: |
      CRITICAL NETWORK ALERT
      
      {{ range .Alerts }}
      Alert: {{ .Annotations.summary }}
      Description: {{ .Annotations.description }}
      Device: {{ .Labels.instance }}
      Interface: {{ .Labels.ifDescr }}
      Started: {{ .StartsAt }}
      
      This requires immediate attention.
      {{ end }}
  webhook_configs:
  - url: 'https://hooks.slack.com/services/YOUR/SLACK/WEBHOOK'
    send_resolved: true
    title: 'Critical Network Alert'
    text: '{{ range .Alerts }}{{ .Annotations.summary }}\n{{ .Annotations.description }}{{ end }}'

name: 'network-warnings'  email_configs:
  - to: 'network-team@example.com'
    subject: 'Network Warning: {{ range .Alerts }}{{ .Annotations.summary }}{{ end }}'
    body: |
      Network Warning Alert
      
      {{ range .Alerts }}
      Alert: {{ .Annotations.summary }}
      Description: {{ .Annotations.description }}
      Device: {{ .Labels.instance }}
      Severity: {{ .Labels.severity }}
      Started: {{ .StartsAt }}
      {{ end }}

inhibit_rules:
source_match:    severity: 'critical'
  target_match:
    severity: 'warning'
  equal: ['instance', 'service']

Create Alertmanager systemd service

Configure Alertmanager to run as a system service with proper security settings.

[Unit]
Description=Alertmanager
Documentation=https://prometheus.io/docs/alerting/alertmanager/
Wants=network-online.target
After=network-online.target

[Service]
Type=simple
User=alertmanager
Group=alertmanager
ExecReload=/bin/kill -HUP $MAINPID
ExecStart=/usr/local/bin/alertmanager \
  --config.file=/etc/alertmanager/alertmanager.yml \
  --storage.path=/var/lib/alertmanager/ \
  --web.listen-address=0.0.0.0:9093 \
  --web.external-url=http://localhost:9093 \
  --cluster.listen-address=0.0.0.0:9094

SyslogIdentifier=alertmanager
Restart=always
RestartSec=1
StartLimitInterval=0

[Install]
WantedBy=multi-user.target

Configure firewall rules for SNMP monitoring

Open necessary ports for SNMP exporter and Alertmanager while maintaining security.

sudo ufw allow 9116/tcp comment 'SNMP Exporter'
sudo ufw allow 9093/tcp comment 'Alertmanager'
sudo ufw allow from 192.168.1.0/24 to any port 161 proto udp comment 'SNMP queries'

sudo firewall-cmd --permanent --add-port=9116/tcp
sudo firewall-cmd --permanent --add-port=9093/tcp
sudo firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="192.168.1.0/24" port protocol="udp" port="161" accept'
sudo firewall-cmd --reload

Set up custom SNMP community configuration

Create a secure SNMP v3 configuration for enhanced security. Replace with SNMPv2c only if your devices don't support v3.

modules:
  if_mib_v3:
    walk:
    - 1.3.6.1.2.1.2.2.1.1     # ifIndex
    - 1.3.6.1.2.1.2.2.1.2     # ifDescr
    - 1.3.6.1.2.1.2.2.1.8     # ifOperStatus
    - 1.3.6.1.2.1.2.2.1.10    # ifInOctets
    - 1.3.6.1.2.1.2.2.1.16    # ifOutOctets
    - 1.3.6.1.2.1.31.1.1.1.6  # ifHCInOctets
    - 1.3.6.1.2.1.31.1.1.1.10 # ifHCOutOctets
    - 1.3.6.1.2.1.31.1.1.1.15 # ifHighSpeed
    auth:
      security_level: authPriv
      username: snmpuser
      password: YourAuthPassword123!
      auth_protocol: SHA
      priv_protocol: AES
      priv_password: YourPrivPassword456!

Start and enable all services

Start Alertmanager and restart Prometheus to load the new configuration.

sudo systemctl enable --now alertmanager
sudo systemctl restart prometheus
sudo systemctl status alertmanager prometheus snmp_exporter

Verify your setup

Test that SNMP metrics are being collected and alerts can be triggered properly.

# Check SNMP exporter metrics
curl -s "http://localhost:9116/snmp?module=if_mib&target=192.168.1.10" | grep ifOperStatus

Verify Alertmanager is receiving alerts
curl -s http://localhost:9093/api/v1/alerts | jq '.data[] | {"alertname": .labels.alertname, "status": .status.state}'

Test alert rule syntax
sudo promtool check rules /etc/prometheus/snmp_alerts.yml

Check if Prometheus can reach targets
curl -s http://localhost:9090/api/v1/targets | jq '.data.activeTargets[] | {"job": .labels.job, "health": .health, "target": .scrapeUrl}'

Test Alertmanager configuration
sudo amtool config show --alertmanager.url=http://localhost:9093

Note: Replace 192.168.1.10 with your actual network device IP. If using SNMPv3, update the Prometheus scraping configuration to include auth parameters.

Common issues

Symptom	Cause	Fix
No SNMP metrics appearing	SNMP community string mismatch	Verify `snmp.yml` community settings match device configuration
Alerts not triggering	Prometheus not loading rules	Check `sudo promtool check rules /etc/prometheus/snmp_alerts.yml`
Devices showing as down	Firewall blocking SNMP traffic	Ensure UDP port 161 is accessible between Prometheus and devices
Email notifications not sent	SMTP configuration incorrect	Test with `sudo amtool config show` and verify SMTP settings
High bandwidth alerts false positive	Interface speed not detected properly	Check `ifHighSpeed` OID is supported and returning correct values
SNMPv3 authentication fails	User not configured on device	Configure SNMPv3 user on network device with matching credentials

Next steps

Configure custom SNMP MIBs for vendor-specific monitoring to monitor device-specific metrics
Configure advanced Grafana dashboards and alerting to visualize SNMP metrics
Implement SNMP trap monitoring and alerting system for real-time event processing
Setup Prometheus Blackbox Exporter for endpoint monitoring to complement SNMP with synthetic monitoring
Configure Prometheus federation for multi-site SNMP monitoring for enterprise deployments

Running this in production?

Want this handled for you? Running this at scale adds a second layer of work: capacity planning, failover drills, cost control, and on-call. See how we run infrastructure like this for European teams.

Automated install script

Run this to automate the entire setup

install.sh

#!/usr/bin/env bash

set -euo pipefail

# SNMP Exporter Installation Script
# Configures Prometheus SNMP exporter for network monitoring

# Color codes
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
NC='\033[0m'

SNMP_VERSION="0.25.0"
PROMETHEUS_USER="snmp_exporter"
SNMP_PORT="9116"
CONFIG_DIR="/etc/snmp_exporter"
DATA_DIR="/var/lib/snmp_exporter"
PROMETHEUS_CONFIG="/etc/prometheus/prometheus.yml"
ALERTS_CONFIG="/etc/prometheus/snmp_alerts.yml"

# Cleanup function
cleanup() {
    echo -e "${RED}[ERROR] Installation failed. Cleaning up...${NC}"
    systemctl stop snmp_exporter 2>/dev/null || true
    systemctl disable snmp_exporter 2>/dev/null || true
    rm -f /etc/systemd/system/snmp_exporter.service
    rm -rf "$CONFIG_DIR" "$DATA_DIR"
    userdel "$PROMETHEUS_USER" 2>/dev/null || true
    rm -f /usr/local/bin/snmp_exporter
    exit 1
}

trap cleanup ERR

usage() {
    echo "Usage: $0 [SNMP_TARGET_IP] [SNMP_TARGET_IP2] ..."
    echo "Example: $0 192.168.1.10 192.168.1.11"
    echo "If no IPs provided, will use example IPs in configuration"
    exit 1
}

print_step() {
    echo -e "${GREEN}[$1] $2${NC}"
}

print_warning() {
    echo -e "${YELLOW}[WARNING] $1${NC}"
}

print_error() {
    echo -e "${RED}[ERROR] $1${NC}"
}

# Check if running as root
check_root() {
    if [[ $EUID -eq 0 ]]; then
        print_error "This script should not be run as root. Run as sudo user instead."
        exit 1
    fi
    
    if ! sudo -n true 2>/dev/null; then
        print_error "This script requires sudo privileges"
        exit 1
    fi
}

# Detect distribution
detect_distro() {
    if [ -f /etc/os-release ]; then
        . /etc/os-release
        case "$ID" in
            ubuntu|debian)
                PKG_MGR="apt"
                PKG_UPDATE="apt update"
                PKG_INSTALL="apt install -y"
                FIREWALL_CMD="ufw"
                ;;
            almalinux|rocky|centos|rhel|ol|fedora)
                PKG_MGR="dnf"
                PKG_UPDATE="dnf update -y"
                PKG_INSTALL="dnf install -y"
                FIREWALL_CMD="firewall-cmd"
                ;;
            amzn)
                PKG_MGR="yum"
                PKG_UPDATE="yum update -y"
                PKG_INSTALL="yum install -y"
                FIREWALL_CMD="firewall-cmd"
                ;;
            *)
                print_error "Unsupported distribution: $ID"
                exit 1
                ;;
        esac
    else
        print_error "Cannot detect distribution"
        exit 1
    fi
}

# Install prerequisites
install_prerequisites() {
    print_step "1/8" "Installing prerequisites"
    
    sudo $PKG_UPDATE
    sudo $PKG_INSTALL wget curl tar systemd
    
    if [[ "$PKG_MGR" == "dnf" ]] || [[ "$PKG_MGR" == "yum" ]]; then
        sudo $PKG_INSTALL firewalld
        sudo systemctl enable --now firewalld
    fi
}

# Download and install SNMP exporter
install_snmp_exporter() {
    print_step "2/8" "Downloading and installing SNMP exporter v$SNMP_VERSION"
    
    cd /tmp
    wget "https://github.com/prometheus/snmp_exporter/releases/download/v${SNMP_VERSION}/snmp_exporter-${SNMP_VERSION}.linux-amd64.tar.gz"
    tar xzf "snmp_exporter-${SNMP_VERSION}.linux-amd64.tar.gz"
    
    sudo mv "snmp_exporter-${SNMP_VERSION}.linux-amd64/snmp_exporter" /usr/local/bin/
    sudo chmod 755 /usr/local/bin/snmp_exporter
    
    rm -rf "snmp_exporter-${SNMP_VERSION}.linux-amd64" "snmp_exporter-${SNMP_VERSION}.linux-amd64.tar.gz"
}

# Create user and directories
create_user_dirs() {
    print_step "3/8" "Creating user and directories"
    
    sudo useradd --system --no-create-home --shell /bin/false "$PROMETHEUS_USER" 2>/dev/null || true
    sudo mkdir -p "$CONFIG_DIR" "$DATA_DIR"
    sudo chown "$PROMETHEUS_USER:$PROMETHEUS_USER" "$DATA_DIR"
    sudo chmod 755 "$CONFIG_DIR" "$DATA_DIR"
}

# Download SNMP configuration
download_snmp_config() {
    print_step "4/8" "Downloading SNMP configuration"
    
    sudo wget https://raw.githubusercontent.com/prometheus/snmp_exporter/main/snmp.yml -O "$CONFIG_DIR/snmp.yml"
    sudo chown "$PROMETHEUS_USER:$PROMETHEUS_USER" "$CONFIG_DIR/snmp.yml"
    sudo chmod 644 "$CONFIG_DIR/snmp.yml"
}

# Create systemd service
create_systemd_service() {
    print_step "5/8" "Creating systemd service"
    
    sudo tee /etc/systemd/system/snmp_exporter.service > /dev/null <<EOF
[Unit]
Description=Prometheus SNMP Exporter
Documentation=https://github.com/prometheus/snmp_exporter
Wants=network-online.target
After=network-online.target

[Service]
Type=simple
User=$PROMETHEUS_USER
Group=$PROMETHEUS_USER
ExecReload=/bin/kill -HUP \$MAINPID
ExecStart=/usr/local/bin/snmp_exporter \\
  --config.file=$CONFIG_DIR/snmp.yml \\
  --web.listen-address=0.0.0.0:$SNMP_PORT

SyslogIdentifier=snmp_exporter
Restart=always
RestartSec=1
StartLimitInterval=0

[Install]
WantedBy=multi-user.target
EOF
    
    sudo chmod 644 /etc/systemd/system/snmp_exporter.service
    sudo systemctl daemon-reload
    sudo systemctl enable snmp_exporter
}

# Configure firewall
configure_firewall() {
    print_step "6/8" "Configuring firewall"
    
    case "$FIREWALL_CMD" in
        "ufw")
            if systemctl is-active --quiet ufw; then
                sudo ufw allow "$SNMP_PORT/tcp" comment "SNMP Exporter"
            fi
            ;;
        "firewall-cmd")
            if systemctl is-active --quiet firewalld; then
                sudo firewall-cmd --permanent --add-port="$SNMP_PORT/tcp"
                sudo firewall-cmd --reload
            fi
            ;;
    esac
}

# Create Prometheus configuration
create_prometheus_config() {
    print_step "7/8" "Creating Prometheus and alerting configuration"
    
    # Build targets array from command line arguments
    local targets=""
    if [ $# -gt 0 ]; then
        for ip in "$@"; do
            targets+="        - $ip  # Network device\n"
        done
    else
        targets="        - 192.168.1.10  # Cisco switch IP\n        - 192.168.1.11  # Router IP"
    fi
    
    # Create Prometheus configuration directory if it doesn't exist
    if [ ! -d "/etc/prometheus" ]; then
        sudo mkdir -p /etc/prometheus
        print_warning "Created /etc/prometheus directory. Make sure to integrate with existing Prometheus setup."
    fi
    
    # Create example Prometheus configuration
    sudo tee "$PROMETHEUS_CONFIG.snmp_example" > /dev/null <<EOF
# Add this to your existing prometheus.yml
global:
  scrape_interval: 15s
  evaluation_interval: 15s

rule_files:
  - "snmp_alerts.yml"

alerting:
  alertmanagers:
    - static_configs:
        - targets:
          - localhost:9093

scrape_configs:
  - job_name: 'snmp'
    static_configs:
      - targets:
$(echo -e "$targets")
    metrics_path: /snmp
    params:
      module: [if_mib]
    relabel_configs:
      - source_labels: [__address__]
        target_label: __param_target
      - source_labels: [__param_target]
        target_label: instance
      - target_label: __address__
        replacement: localhost:$SNMP_PORT
EOF
    
    # Create alerting rules
    sudo tee "$ALERTS_CONFIG" > /dev/null <<EOF
groups:
- name: snmp_network_alerts
  rules:
  - alert: NetworkInterfaceDown
    expr: ifOperStatus{job="snmp"} == 2
    for: 2m
    labels:
      severity: critical
      service: network
    annotations:
      summary: "Network interface {{ \$labels.ifDescr }} is down"
      description: "Interface {{ \$labels.ifDescr }} on {{ \$labels.instance }} has been down for more than 2 minutes"

  - alert: HighInterfaceUtilization
    expr: (rate(ifInOctets{job="snmp"}[5m]) + rate(ifOutOctets{job="snmp"}[5m])) * 8 / ifSpeed * 100 > 85
    for: 5m
    labels:
      severity: warning
      service: network
    annotations:
      summary: "High bandwidth utilization on {{ \$labels.ifDescr }}"
      description: "Interface {{ \$labels.ifDescr }} on {{ \$labels.instance }} is {{ \$value }}% utilized"

  - alert: SNMPDeviceDown
    expr: up{job="snmp"} == 0
    for: 1m
    labels:
      severity: critical
      service: network
    annotations:
      summary: "SNMP device {{ \$labels.instance }} is unreachable"
      description: "SNMP device {{ \$labels.instance }} has been unreachable for more than 1 minute"
EOF
    
    sudo chmod 644 "$PROMETHEUS_CONFIG.snmp_example" "$ALERTS_CONFIG"
}

# Start service and verify
start_and_verify() {
    print_step "8/8" "Starting service and verifying installation"
    
    sudo systemctl start snmp_exporter
    sleep 3
    
    if ! systemctl is-active --quiet snmp_exporter; then
        print_error "SNMP exporter failed to start"
        sudo journalctl -u snmp_exporter --no-pager -l
        exit 1
    fi
    
    # Test the exporter endpoint
    if curl -s "http://localhost:$SNMP_PORT/metrics" > /dev/null; then
        echo -e "${GREEN}✓ SNMP exporter is running and responding${NC}"
    else
        print_error "SNMP exporter is not responding on port $SNMP_PORT"
        exit 1
    fi
    
    echo -e "${GREEN}✓ SNMP exporter installation completed successfully${NC}"
    echo
    echo "Next steps:"
    echo "1. Review and integrate $PROMETHEUS_CONFIG.snmp_example into your Prometheus configuration"
    echo "2. Update the target IPs in the configuration to match your network devices"
    echo "3. Configure SNMP community strings on your network devices"
    echo "4. Restart Prometheus to apply the new configuration"
    echo "5. Configure Alertmanager for notification delivery"
    echo
    echo "Service status: systemctl status snmp_exporter"
    echo "Logs: journalctl -u snmp_exporter -f"
    echo "Metrics endpoint: http://localhost:$SNMP_PORT/metrics"
}

main() {
    echo "SNMP Exporter Installation Script"
    echo "================================="
    
    check_root
    detect_distro
    
    install_prerequisites
    install_snmp_exporter
    create_user_dirs
    download_snmp_config
    create_systemd_service
    configure_firewall
    create_prometheus_config "$@"
    start_and_verify
}

main "$@"

Review the script before running. Execute with: bash install.sh

#snmp #prometheus #alertmanager #network-monitoring #snmp-exporter

Configure advanced SNMP alerting with Prometheus Alertmanager for network monitoring