A real-time, command-line network packet analyzer built using Python and Scapy
Works seamlessly on Linux, Windows, and macOS with admin/root permissions.

Packet Sniffer CLI is a Python-based command-line tool that captures and analyzes live network packets.
It provides detailed protocol information, supports filters, and can save logs and PCAP files for later analysis in Wireshark.

✅ Live real-time packet capture using Scapy
✅ Decode TCP, UDP, ICMP, ARP, and DNS
✅ Display source/destination IPs, ports, and payload size
✅ Save results in:

• Human-readable logs → logs/captured.log
• PCAP format → captures/capture.pcap (for Wireshark)
  ✅ Apply filters:
• by protocol (tcp, udp, icmp, arp, dns)
• by IP address
• by port number
  ✅ Cross-platform: Linux, Windows, macOS
  ✅ Auto-creates required directories (logs/, captures/)
  ✅ Error-safe and permission-aware

packet-sniffer/
│
├── sniffer.py                     # Main entry point – CLI & packet capture
├── packet_parser.py               # Decodes and extracts packet details
├── filters.py                     # Filtering logic (protocol/IP/port)
├── logger.py                      # Logs and PCAP saving
├── utils.py                       # Helper functions (timestamp, admin check)
│
├── requirements.txt               # Dependencies
├── README.md                      # Project documentation
├── LICENSE                        # MIT License
├── .gitignore
├── .gitattributes
│
├── captures/                      # Auto-created; stores PCAP files
└── logs/                          # Auto-created; stores log files

git clone https://github.com/mantrapatil03/packet-sniffer.git
cd packet-sniffer

pip install -r requirements.txt

sudo python3 sniffer.py

Run Command Prompt or PowerShell as Administrator:

python sniffer.py

Examples

# Capture only TCP packets
sudo python3 sniffer.py --protocol tcp

# Capture packets from specific IP
sudo python3 sniffer.py --ip 192.168.1.10

# Capture packets for port 80 (HTTP)
sudo python3 sniffer.py --port 80

Output Files

• Logs

Human-readable output

logs/captured.log

• PCAP

Raw packet data (open in Wireshark)

captures/capture.pcap

Filters can be combined, e.g.

sudo python3 sniffer.py --protocol tcp --port 443

Permission Denied → Use sudo or Administrator privileges

No Packets Captured → Try specifying a network interface:

sudo python3 sniffer.py --iface eth0

List interfaces:

python3 - <<EOF
from scapy.all import get_if_list
print(get_if_list())
EOF

PCAP Not Saving → Ensure captures/ and logs/ exist (auto-created). Check file permissions.

Windows Note: Scapy requires Npcap — install it from https://npcap.com

Main Modules

• Adding New Protocol Decoders

1. Edit packet_parser.py
2. Add new parsing logic for your protocol (e.g., HTTP)
3. Update CLI filter options if needed

Contributions are welcome!

If you’d like to improve or extend this tool:

• 1️⃣ Fork the repo
• 2️⃣ Create a feature branch
• 3️⃣ Write clean, well-documented code
• 4️⃣ Submit a pull request

For major changes, open an issue first.

Mantra Patil

✉️ techmantrapatil@gmail.com

Made with ❤️ & Python by Mantra Patil

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