How To Perform UDP Port Sacnning Using Python

How to Perform UDP Port Scanning Using Python
UDP port scanning is a technique used to discover open UDP ports on a target system. Unlike TCP scanning, which relies on three-way handshakes, UDP scanning involves sending UDP packets to specific ports and analyzing the responses.

1. Prerequisites
Before starting, ensure you have Python installed. You also need the socket and time modules (both included in Python by default).

2. Creating a Simple UDP Scanner
We will use the socket library to send UDP packets and detect open ports based on responses or timeouts.

3. Explanation
A UDP socket is created using socket.AF_INET and socket.SOCK_DGRAM.
An empty UDP packet is sent to the target port.
If a response is received, the port is considered open.
If no response is received after a timeout, the port is open or filtered (some firewalls drop UDP packets without responding).
The recvfrom() method waits for a response but times out if none is received.
4. Notes & Limitations
Many UDP services do not respond even if the port is open, so detecting open ports is less reliable than TCP scanning.
Firewalls and IDS (Intrusion Detection Systems) can detect UDP scans and block them.
Running scans on unauthorized networks can be illegal—always obtain permission before scanning.