net-scan

NetScan

A lightweight web-based TCP port scanner built with Python, Flask, HTML, CSS, and JavaScript.

What it does

Enter an IPv4 address and NetScan checks a focused list of common TCP ports, then displays which ports are open and the commonly associated service.

Features

• IPv4 validation
• TCP connect scanning
• Common port/service identification
• Clean cybersecurity dashboard
• JSON API
• Responsive frontend
• Educational authorization notice

Run locally

git clone https://github.com/btwsalts/net-scan.git
cd net-scan
python3 -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt
python3 app.py

Open http://127.0.0.1:5000.

Ports checked

21, 22, 23, 25, 53, 80, 110, 139, 143, 443, 445, 3306, 3389, 5432, 5900, 8080.

Architecture

Browser → Flask API → Python TCP scanner → Target → JSON results → Browser

Security note

Only scan systems you own or have explicit permission to test. This project is intended for learning, home labs, and authorized security testing.

Limitations

• IPv4 targets only.
• The initial release checks a predefined list of common ports.
• A closed result means the TCP connection attempt did not succeed; it does not prove that a service is absent.
• Results can be affected by firewalls, filtering, routing, and network conditions.

Future improvements

• Custom port ranges
• Concurrent scanning
• Scan history
• Exportable reports
• More service detection
• Authentication for hosted deployments
• Rate limiting and audit logging