Fast IP Monitor

A high-performance PowerShell script that monitors IP address ranges for connectivity changes in real-time. Designed for network administrators who need immediate notifications when devices come online or go offline.

✨ Key Features

• ⚡ Ultra-fast parallel scanning - Monitor 254 IPs in ~2-3 seconds
• 🎯 Real-time change detection - Instant notifications when devices change state
• 🔍 Smart verification - Reduces false positives from network fluctuations
• 🖥️ Cross-platform - Works on PowerShell 5.1+ and PowerShell 7+
• 📱 Clean output - Shows only what matters: state changes
• ⚙️ Configurable - Adjust timeout, scan interval, and thread count

🚀 Quick Start

# Download and run
.\ip-monitor.ps1

# Enter IP range when prompted
Enter IP range: 192.168.1.1-254

# Monitor output
Ready. UP: 12, DOWN: 242 (scan: 2.1s)
....
[15:30:15] 192.168.1.100 changed from DOWN to UP
....

📋 Requirements

• Windows/Linux/macOS with PowerShell 5.1 or later
• Network access to target IP ranges
• ICMP ping enabled on target devices (or network path)

🔧 Usage

Basic Usage

.\ip-monitor.ps1

With Custom Parameters

# Fast scanning (3-second intervals, 400ms timeout)
.\ip-monitor.ps1 -ScanInterval 3 -PingTimeout 400 -ThrottleLimit 100

# Conservative scanning (10-second intervals, 2-second timeout)  
.\ip-monitor.ps1 -ScanInterval 10 -PingTimeout 2000 -ThrottleLimit 30

Supported IP Range Formats

192.168.1.1-254                    # Short format (recommended)
192.168.1.1-192.168.1.254         # Full format
10.0.0.1-10.0.0.100               # Any valid range
172.16.0.1-172.16.0.50            # Partial ranges

⚙️ Parameters

Parameter	Default	Description
ScanInterval	5	Seconds between scans
PingTimeout	600	Ping timeout in milliseconds
ThrottleLimit	80	Number of parallel ping threads

Parameter Examples

# Ultra-fast mode
.\ip-monitor.ps1 -ScanInterval 2 -PingTimeout 300 -ThrottleLimit 120

# Balanced mode (default)
.\ip-monitor.ps1 -ScanInterval 5 -PingTimeout 600 -ThrottleLimit 80

# Slow/reliable mode  
.\ip-monitor.ps1 -ScanInterval 15 -PingTimeout 3000 -ThrottleLimit 40

📊 Performance Guide

Scan Time Estimates

IP Count	Typical Scan Time	Recommended Settings
1-50 IPs	0.5-1 seconds	Default settings
51-100 IPs	1-2 seconds	Default settings
101-254 IPs	2-4 seconds	Default or faster timeout
255+ IPs	4+ seconds	Increase ThrottleLimit to 100+

Optimization Tips

• Faster detection: Lower PingTimeout (300-500ms)
• More reliable: Higher PingTimeout (1000-2000ms)
• Larger ranges: Increase ThrottleLimit (100-150)
• Older systems: Decrease ThrottleLimit (30-50)

🎯 Use Cases

Network Administration

# Monitor server farm
.\ip-monitor.ps1
Enter IP range: 10.0.1.1-100

# Watch for new devices on DHCP range  
.\ip-monitor.ps1 -ScanInterval 3
Enter IP range: 192.168.1.100-200

Security Monitoring

# Detect unauthorized devices
.\ip-monitor.ps1 -ScanInterval 10
Enter IP range: 192.168.1.1-254

Infrastructure Health

# Monitor critical infrastructure
.\ip-monitor.ps1 -PingTimeout 1000 -ScanInterval 30
Enter IP range: 10.0.0.1-50

📝 Sample Output

Fast Ping Monitor (Timeout: 600ms, Threads: 80)
Enter IP range (e.g. 192.168.0.1-254): 192.168.1.1-254
Monitoring 254 IPs every 5s. Press Ctrl+C to stop.

Ready. UP: 25, DOWN: 229 (scan: 2.3s)
............................
[14:25:33] 192.168.1.101 changed from DOWN to UP
.................
[14:26:15] 192.168.1.200 changed from UP to DOWN
[14:26:15] 192.168.1.201 changed from UP to DOWN
....................

Legend:

• ... = No changes detected (normal operation)
• Green text = Device came online (DOWN → UP)
• Red text = Device went offline (UP → DOWN)

🔧 Troubleshooting

Common Issues

"No changes detected but I know devices are changing"

• Increase PingTimeout (devices may be slow to respond)
• Decrease ScanInterval for faster detection
• Check if ICMP ping is blocked by firewalls

"Too many false positives"

• Increase PingTimeout for more reliable detection
• Increase ScanInterval to reduce network load
• Network may have intermittent connectivity issues

"Script is too slow"

• Decrease PingTimeout (600ms → 400ms)
• Increase ThrottleLimit (80 → 120)
• Use smaller IP ranges for testing

"High CPU usage"

• Decrease ThrottleLimit (80 → 50)
• Increase ScanInterval (5 → 10 seconds)
• Update to PowerShell 7+ for better performance

Performance Optimization

# For PowerShell 7+ (fastest)
.\ip-monitor.ps1 -ThrottleLimit 120 -PingTimeout 400

# For PowerShell 5.1 (compatible)  
.\ip-monitor.ps1 -ThrottleLimit 60 -PingTimeout 800

# For slow networks
.\ip-monitor.ps1 -PingTimeout 2000 -ScanInterval 10

🚨 Limitations

• ICMP dependency: Requires ping (ICMP) to be enabled on target devices
• Firewall limitations: May not detect devices with strict firewall rules
• Network load: High-frequency scanning can generate significant network traffic
• Windows Defender: May trigger network scanning alerts on some systems

📄 License

This project is released under the MIT License. Feel free to use, modify, and distribute.

🤝 Contributing

Contributions are welcome! Please feel free to submit issues, feature requests, or pull requests.

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💡 Pro Tip: Start with default settings and adjust parameters based on your network's behavior and performance requirements.