# Network Connectivity Monitor

A Python-based network monitoring tool designed to diagnose connectivity issues on your OPNsense/TP-Link network infrastructure.

## Monitored Devices

- **10.0.0.254** - OPNsense Firewall
- **10.0.0.253** - TP-Link AX5400 (253)
- **10.0.0.252** - TP-Link Device (252)
- **10.0.0.55** - DNS/Other Service

## Features

- ✅ Real-time connectivity monitoring with live status updates
- 📊 Detailed statistics including success rates and failure patterns
- 🔍 Automatic failure incident detection and grouping
- 📈 Final comprehensive report with health assessment
- ⏱️ Configurable monitoring duration and ping intervals
- 🛑 Graceful interrupt handling (Ctrl+C for early stop)

## Requirements

- Python 3.6+
- Unix-like system with `ping` command
- No external Python dependencies required!

## Usage

### Quick Start

```bash
# Make the script executable
chmod +x network_monitor.py

# Run with default settings (1 hour monitoring)
./network_monitor.py
```

Or run directly with Python:

```bash
python3 network_monitor.py
```

### Configuration

Edit the following constants at the top of the script to customize:

```python
MONITOR_IPS = {
    "10.0.0.254": "OPNsense Firewall",
    "10.0.0.253": "TP-Link AX5400 (253)",
    "10.0.0.252": "TP-Link Device (252)",
    "10.0.0.55": "DNS/Other Service"
}

PING_INTERVAL = 5       # seconds between ping checks
MONITOR_DURATION = 3600 # 1 hour in seconds
PING_TIMEOUT = 2        # seconds to wait for ping response
PING_COUNT = 1          # number of pings per check
```

### Example Output

**Live Status Screen:**
```
================================================================================
Network Connectivity Monitor - 2026-01-07 17:15:30
================================================================================

Monitoring Duration: 45s / 3600s (1.3%)
Next check in: 5s

--------------------------------------------------------------------------------
IP Address      Device                    Status     Success Rate   
--------------------------------------------------------------------------------
10.0.0.254      OPNsense Firewall         🟢 UP      100.00% (9/9)
10.0.0.253      TP-Link AX5400 (253)      🟢 UP      100.00% (9/9)
10.0.0.252      TP-Link Device (252)      🔴 DOWN    88.89% (8/9)
10.0.0.55       DNS/Other Service         🟢 UP      100.00% (9/9)
--------------------------------------------------------------------------------

⚠️  CURRENT ISSUES:
   • 10.0.0.252 (TP-Link Device (252)): 1 consecutive failures
```

**Final Report:**
```
================================================================================
FINAL MONITORING REPORT
================================================================================
Start Time: 2026-01-07 17:14:45
End Time:   2026-01-07 18:14:45
Duration:   3600 seconds
================================================================================

DEVICE SUMMARY:
--------------------------------------------------------------------------------
IP Address      Device                    Success Rate    Total Failures 
--------------------------------------------------------------------------------
10.0.0.254      OPNsense Firewall         ✅ 100.00%                 0
10.0.0.253      TP-Link AX5400 (253)      ✅ 100.00%                 0
10.0.0.252      TP-Link Device (252)      ⚠️  98.61%                10
10.0.0.55       DNS/Other Service         ✅ 100.00%                 0
--------------------------------------------------------------------------------

DETAILED STATISTICS:
================================================================================

TP-Link Device (252) (10.0.0.252):
  Total Checks:              720
  Successful:                710 (98.61%)
  Failed:                    10 (1.39%)
  Max Consecutive Failures:  3
  First Failure:             17:25:10
  Last Failure:              17:42:35
  Failure Incidents:         2

  Failure Timeline:
    Incident 1: 17:25:10 - 17:25:20 (3 failures, 10s)
    Incident 2: 17:42:25 - 17:42:35 (7 failures, 10s)

================================================================================

OVERALL ASSESSMENT:
⚠️  ISSUE ISOLATED: Only TP-Link Device (252) (10.0.0.252) had connectivity issues.
   This suggests a device-specific problem rather than network-wide issue.
================================================================================
```

## Use Cases

### Diagnosing DHCP Issues
This tool was originally created to diagnose DHCP renewal loop problems causing high CPU usage on TP-Link routers. Run it before and after applying fixes to verify improvement.

### Network Stability Testing
Monitor your network infrastructure during configuration changes, firmware updates, or after new device installations to ensure stability.

### Intermittent Connection Troubleshooting
Identify patterns in connectivity issues that might not be immediately obvious. The incident grouping helps distinguish between temporary blips and recurring problems.

## Tips

- **Short Duration Test**: For quick diagnostics, edit `MONITOR_DURATION` to 300 (5 minutes)
- **Faster Checks**: Reduce `PING_INTERVAL` to 1 or 2 seconds for more granular data
- **Save Results**: Redirect output to a file: `./network_monitor.py > results.txt`
- **Background Running**: Use `nohup ./network_monitor.py &` to run in background

## Troubleshooting

**Permission Denied:**
```bash
chmod +x network_monitor.py
```

**Python Not Found:**
```bash
# Use python instead of python3
python network_monitor.py
```

**No Ping Command:**
This script requires the standard Unix `ping` utility. It should be available by default on Linux, macOS, and WSL.

## License

This script is provided as-is for network diagnostics. Feel free to modify and adapt for your specific needs!

## Related Issues

This tool helps diagnose the TP-Link AX5400 DHCP renewal loop issue documented in the OPNsense troubleshooting session.