A Python-based multi-threaded TCP port scanner built for internal network auditing in system. Developed as a University Coursework Project.

Group 12 — Python Programming: Network Programming Design, 2026

What does this tool do?

This tool scans a target IP address or a range of IP addresses and checks which TCP ports are open. Open ports reveal which services are running on a system(Computer/Laptops), which is useful for security auditing.

For example:

• Port 22 being open means SSH is running.
• Port 80 means a web server is running.
• Port 443 means HTTPS is running.

Requirements:

• Python 3.10 or Higher.
• No extra libraries needed - Uses Python inbuilt libraries only.

How to Install?

git clone https://github.com/mihithammi/Network-Scanner-Project.git
cd Network-Scanner-Project

How to use?

Run the scanner from the terminal:

python scanner.py <target> [options]

Options:

Option	What it does	Default
target	IP address or subnet to scan	required
-p	Ports to scan	1-1024
-t	Number of threads	100
--timeout	Seconds to wait per port	1.0

Example:

• Scan one IP on default ports:

python scanner.py 192.168.1.1

• Scan specific ports only:

python scanner.py 192.168.1.1 -p 22,80,443

• Scan a full subnet fast:

python scanner.py 192.168.1.0/24 -p 1-1024 -t 200 --timeout 0.5

• Scan your own computer (safe for testing):

python scanner.py 127.0.0.1 -p 1-1024

How the code works:

This scanner is built in four phases as required by the assignment.

Phase 1 - Core Networking The 'scan_port()' function uses Python's socket module to make a TCP connection attempt. If the connection returns 0, the port is open.

Phase 2 - Subnet Parsing The 'get_hosts()' function uses Python's ipaddress module to expand a CIDR subnet like 192.168.1.0/24 into a list of 254 individual IP addresses.

Phase 3 - Multi-threading The 'run_scan()' function uses ThreadPoolExecutor to scan many ports at the same time instead of one by one. This make the scanner much faster.

Phase 4 - CLI Interface The argphase module provides a professional command-line interface where users can set the target,ports,threads and timeout without editing the code.

Important legal notice

Only scan networkds and computers that you own or have written permission to scan. Unauthorised scanning may be illegal. This tool is for authorised internal auditing and education only.

Troubleshooting

Problem: "python is not recognized" Solution: Python is not added to PATH. Reinstall Python and tick "Add Python to PATH" during setup.

Problem: Scanner shows nothing, no error Solution: Check the last two lines of scanner.py are: if name == "main": main() These lines must have no extra spaces at the start.

Problem: "git is not recognized" Solution: Git is not installed. Download from git-scm.com and install with default options. Problem: Push rejected on git push Solution: Use your Personal Access Token as the password, not your real GitHub password. (I have update this part in organized way. Now i need commit details to it)

Testing The tool was tested in the following scenarios:

Test 1 — Local machine scan: python scanner.py 127.0.0.1 -p 1-1024 Result: Scanner ran successfully with progress bar displayed. Open ports were highlighted in green with service names shown.

Test 2 — Specific ports scan: python scanner.py 127.0.0.1 -p 22,80,443,8080 -t 100 Result: Only the specified ports were checked. Scan completed faster due to fewer ports.

Test 3 — Help menu: python scanner.py --help Result: All available options displayed correctly.

Authors

Group 12

• COHNDNE251F-17
• COHNDNE251F-30
• COHNDNE251F-42
• COHNDNE251F-46