snoop (software)

Snoop is a network analysis tool, also known as a packet sniffer, available on Solaris and other Unix-like operating systems. It allows users with appropriate privileges (typically root or membership in a specific group) to capture and analyze network traffic transmitted to or from a system.

Functionality

Snoop's primary function is to passively intercept and record network packets passing through a network interface. This captured data can then be analyzed to diagnose network problems, monitor network performance, detect security vulnerabilities, and understand network communication patterns. Snoop provides a command-line interface to initiate the capture process, specify filtering criteria to limit the capture to specific traffic (e.g., based on source/destination IP addresses, ports, or protocols), and display the captured packets in human-readable format.

Features

Key features of Snoop include:

• Packet Capture: Ability to capture raw network packets from a specified network interface.
• Filtering: Allows users to define filters to capture only packets that match specific criteria. This reduces the amount of irrelevant data captured and simplifies analysis. Filters can be based on IP addresses, port numbers, protocol types, and other packet header fields.
• Protocol Decoding: Snoop can decode common network protocols, such as TCP, UDP, IP, ICMP, DNS, and HTTP, presenting the captured data in a more understandable format. This makes it easier to identify the contents and purpose of each packet.
• Display Options: Provides various options for displaying the captured packets, including summary views and detailed packet information.
• Saving and Loading Captures: Snoop allows users to save captured packets to a file for later analysis. Captured files can also be loaded for offline viewing.
• Command-Line Interface: The tool is primarily accessed via the command line, allowing for scripting and automation of network analysis tasks.

Security Considerations

Because Snoop captures network traffic, it can potentially expose sensitive data, such as passwords, confidential documents, and other private information. Therefore, it's critical to use Snoop responsibly and ethically. Access to Snoop should be restricted to authorized personnel only, and captures should be stored securely to prevent unauthorized access. Capturing traffic without proper authorization is illegal in many jurisdictions.

Alternatives

While Snoop is a standard tool on Solaris systems, other packet sniffers are available for various operating systems, including:

• tcpdump/libpcap (cross-platform)
• Wireshark (cross-platform)
• Microsoft Network Monitor (Windows)

These alternative tools often provide similar functionality and may offer a more user-friendly graphical interface.