sniffer.py

Capture packets for default protocols (ICMP, TCP, UDP)

$ sniffer.py

$ sniffer.py [protocol1] [protocol2]

$ sniffer.py tcp

python sniffer.py [interface]

interface
    The network interface to listen on (e.g., eth0, wlan0). If not specified, the script might attempt to automatically determine an interface or prompt the user.

sniffer.py is a Python script designed to capture and analyze network packets. It leverages the socket module to create a raw socket, allowing it to intercept network traffic directly from a specified network interface. The script is commonly used for security auditing, network troubleshooting, and educational purposes to understand network protocols and data flow. It can capture packets traversing the network interface, extract header information (like source/destination IP addresses, ports, protocol types), and potentially the data payload itself. The output is typically displayed on the console. Ethical considerations and legal compliance are paramount when using network sniffers. It is essential to have explicit permission before capturing traffic on any network you do not own or administer.

Requires root privileges to create raw sockets. Capturing packets on a busy network can generate a large volume of data. Interpreting packet data requires knowledge of network protocols. Some traffic may be encrypted (HTTPS, SSH), making payload analysis difficult without appropriate decryption keys. Sniffing network traffic without proper authorization is illegal and unethical.

When running sniffer.py, be aware of the security implications. The script itself could be a potential vulnerability if not written securely. Carefully review the code and any dependencies. Also, the captured packet data should be handled securely to avoid unauthorized access or disclosure.

sudo python sniffer.py eth0
This command starts the sniffer on the eth0 interface.

Python sniffers are popular because of the flexibility of the language and its cross-platform compatibility. Simple sniffer scripts have been used for educational purposes and basic network diagnostics for many years. More advanced Python packet analysis tools exist as well.

tcpdump(1), wireshark(1), tshark(1)