Aldo’s NET Monitor: Complete Setup & Troubleshooting Guide
Overview
Aldo’s NET Monitor is a lightweight network monitoring tool designed to track device availability, basic performance metrics (latency, uptime), and simple alerts for small-to-medium networks. It supports ICMP/ping checks, HTTP(S) endpoint checks, and email/SMS notifications.
Prerequisites
- A machine (Windows, macOS, or Linux) with network access to monitored devices
- Administrative privileges to install software and configure firewall rules
- SMTP credentials (for email alerts) or an SMS gateway/API key (for SMS)
- Ports allowed: ICMP for ping checks; outbound TCP ⁄443 for web checks; outbound SMTP/API ports for notifications
Installation (assume Linux server)
- Update packages:
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sudo apt update && sudo apt upgrade -y - Install dependencies (example):
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sudo apt install -y python3 python3-venv python3-pip git - Clone and set up:
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git clone https://example.com/aldos-net-monitor.git cd aldos-net-monitor python3 -m venv venv source venv/bin/activate pip install -r requirements.txt - Create a systemd service (/etc/systemd/system/aldos-net-monitor.service):
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[Unit] Description=Aldo’s NET Monitor After=network.target[Service] User=monitor WorkingDirectory=/home/monitor/aldos-net-monitor ExecStart=/home/monitor/aldos-net-monitor/venv/bin/python run_monitor.py Restart=on-failure[Install] WantedBy=multi-user.target
- Start and enable:
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sudo systemctl daemon-reload sudo systemctl enable –now aldos-net-monitor
Basic Configuration
- config.yml (example):
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probes: - name: “Office Router”type: ping host: 192.168.1.1 interval: 60- name: “Web Server” type: http url: https://example.com/health
interval: 30 notifications: email: smtp_server: smtp.example.com port: 587 username: [email protected] password: “securepassword” from: [email protected] to: [email protected]
- name: “Web Server” type: http url: https://example.com/health
- Place config.yml next to runmonitor.py or point via CLI flag.
Common Troubleshooting
Service won’t start
- Check logs:
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sudo journalctl -u aldos-net-monitor -f - Common causes:
- Virtualenv path mismatch in systemd ExecStart
- Missing dependencies — run
pip install -r requirements.txt - Permission errors — ensure service user owns files
Probes show “unreachable” or false negatives
- Verify network connectivity from the monitor host:
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ping -c 4 192.168.1.1 curl -I https://example.com/health - Ensure firewalls permit ICMP and required ports.
- Increase probe timeout and retries in config for flaky links.
No email/SMS alerts
- Test SMTP from host:
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swaks –to [email protected] –from [email protected] –server smtp.example.com:587 –auth LOGIN –auth-user [email protected] –auth-password “securepassword” - Check API credentials and rate limits for SMS gateway.
- Confirm notification subsystem enabled in config and not muted.
High CPU or memory usage
- Reduce probe frequency or spread probes across multiple monitoring instances.
- Check for memory leaks in long-running Python processes; restart service as temporary mitigation.
Best Practices
- Keep monitor host on a reliable power/network source or use a secondary monitor instance.
- Monitor the monitor: create an external ping or synthetic check from a different network.
- Use grouped alerting thresholds (e.g., 2 consecutive failures before alert) to reduce noise.
- Secure credentials with environment variables or a secrets manager instead of plaintext config.
- Rotate notification credentials and enforce least privilege.
Quick Recovery Commands
- Restart service:
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sudo systemctl restart aldos-net-monitor - View last 200 log lines:
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sudo journalctl -u aldos-net-monitor -n 200 - Validate config (if tool provides parse flag):
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./run_monitor.py –validate-config config.yml
When to Seek Further Help
- Persistent false positives across multiple monitor hosts — possible network segmentation or asymmetrical routing.
- Data corruption or missing historical metrics — check storage backend and disk health.
- Complex integrations (LDAP, advanced alerting) — contact vendor support or consult detailed docs.
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