Network Scanner (FastAPI + React)

• FastAPI backend with a WebSocket endpoint that streams scan results as they arrive — no polling, no page refresh.
• Concurrent port scanner using ThreadPoolExecutor: scans all top ports across a subnet in parallel, then aggregates results per host.
• Service detection table covering 100+ well-known ports (HTTP, SSH, RDP, MSSQL, Redis, MongoDB, Docker, K8s API…).
• Risk classification (high / medium / low) per open port based on a curated RISK_MAP (Telnet, RDP, Metasploit listener, exposed databases…).
• CORS-enabled REST API alongside the WebSocket endpoint for easy integration with any frontend.
• React/Vite frontend with live-updating host cards, port badges colour-coded by risk, and scan progress indicator.

Transport

WebSocket (FastAPI + uvicorn) — real-time streaming

Concurrency

ThreadPoolExecutor — parallel port probing per host

Port coverage

100+ known services mapped in KNOWN_SERVICES dict

Risk levels

high / medium / low per port (Telnet, RDP, exposed DBs…)

Stack

Python 3, FastAPI, uvicorn, websockets · React 18, Vite

1. 1
   Host discovery

   The backend resolves the local subnet and pings each IP to build a list of live hosts.
2. 2
   Concurrent port scan

   For each live host, a ThreadPoolExecutor probes the TOP_PORTS list concurrently, collecting open ports and their service names.
3. 3
   Risk classification

   Each open port is looked up in RISK_MAP and tagged high / medium / low based on known exposure risk.
4. 4
   WebSocket streaming

   Results are pushed to the frontend in real time as each host finishes scanning — no need to wait for the full scan to complete.
5. 5
   React UI rendering

# Backend
pip install fastapi uvicorn websockets
python backend.py

# Frontend (separate terminal)
cd scanner-ui
npm install && npm run dev