Network Scanner

Discover and identify devices on local or remote networks using nmap. Gathers IP addresses, hostnames (via reverse DNS), MAC addresses, and vendor identification.

Safety First: Includes built-in protection against accidentally scanning public IP ranges or networks without proper private routing — preventing abuse reports from hosting providers.

Requirements

```
nmap
```
- Network scanning (
```
apt install nmap
```
or
```
brew install nmap
```
)
```
dig
```
- DNS lookups (usually pre-installed)
```
sudo
```
access recommended for MAC address discovery

Quick Start

# Auto-detect and scan current network
python3 scripts/scan.py
Scan a specific CIDR
python3 scripts/scan.py 192.168.1.0/24
Scan with custom DNS server for reverse lookups
python3 scripts/scan.py 192.168.1.0/24 --dns 192.168.1.1
Output as JSON

python3 scripts/scan.py --json

Configuration

Configure named networks in

~/.config/network-scanner/networks.json

{
  "networks": {
    "home": {
      "cidr": "192.168.1.0/24",
      "dns": "192.168.1.1",
      "description": "Home Network"
    },
    "office": {
      "cidr": "10.0.0.0/24",
      "dns": "10.0.0.1",
      "description": "Office Network"
    }
  },
  "blocklist": [
    {
      "cidr": "10.99.0.0/24",
      "reason": "No private route from this host"
    }
  ]
}

Then scan by name:

python3 scripts/scan.py home
python3 scripts/scan.py office --json

Safety Features

The scanner includes multiple safety checks to prevent accidental abuse:

Blocklist — Networks in the
```
blocklist
```
config array are always blocked
Public IP check — Scanning public (non-RFC1918) IP ranges is blocked
Route verification — For ad-hoc CIDRs, verifies the route uses private gateways

Trusted networks (configured in

networks.json

) skip route verification since you've explicitly approved them.

# Blocked - public IP range
$ python3 scripts/scan.py 8.8.8.0/24
❌ BLOCKED: Target 8.8.8.0/24 is a PUBLIC IP range
Blocked - in blocklist
$ python3 scripts/scan.py 10.99.0.0/24
❌ BLOCKED: 10.99.0.0/24 is blocklisted
Allowed - configured trusted network
$ python3 scripts/scan.py home
✓ Scanning 192.168.1.0/24...

Commands

# Create example config
python3 scripts/scan.py --init-config
List configured networks
python3 scripts/scan.py --list
Scan without sudo (may miss MAC addresses)

python3 scripts/scan.py home --no-sudo

Output Formats

Markdown (default):

### Home Network
*Last scan: 2026-01-28 00:10*























IP Name MAC Vendor
192.168.1.1 router.local AA:BB:CC:DD:EE:FF Ubiquiti
192.168.1.100 nas.local 11:22:33:44:55:66 Synology

2 devices found

JSON (--json):

{
  "network": "Home Network",
  "cidr": "192.168.1.0/24",
  "devices": [
    {
      "ip": "192.168.1.1",
      "hostname": "router.local",
      "mac": "AA:BB:CC:DD:EE:FF",
      "vendor": "Ubiquiti"
    }
  ],
  "scanned_at": "2026-01-28T00:10:00",
  "device_count": 2
}

Use Cases

Device inventory: Keep track of all devices on your network
Security audits: Identify unknown devices
Documentation: Generate network maps for documentation
Automation: Integrate with home automation to detect device presence

Tips

Use
```
sudo
```
for accurate MAC address detection (nmap needs privileges for ARP)
Configure your local DNS server for better hostname resolution
Add configured networks to skip route verification on every scan
Add networks you can't reach privately to the blocklist to prevent accidents
Extend
```
MAC_VENDORS
```
in the script for better device identification

Network Scanner

AI Skill Market Insights

Be Part of the 0+ Developer Community

Network Scanner

Requirements

Quick Start

Scan a specific CIDR

Scan with custom DNS server for reverse lookups

Output as JSON

Configuration

Safety Features

Blocked - in blocklist

Allowed - configured trusted network

Commands

List configured networks

Scan without sudo (may miss MAC addresses)

Output Formats

Use Cases

Tips

Quick Start

Manual Installation

TEAR & SHARE

Tags

Check Security

Check Privacy

Check Aws Security

Skill Vetter

ClawDefender - OpenClaw Security - Prompt injection, rogue skills etc

Channels

Learn

Compare

Company

IP	Name	MAC	Vendor
192.168.1.1	router.local	AA:BB:CC:DD:EE:FF	Ubiquiti
192.168.1.100	nas.local	11:22:33:44:55:66	Synology