A network analyzer (also called a protocol analyzer or packet analyzer) is a combination of hardware and programming, or in some cases a stand-alone hardware device, that can be installed in a computer or network to enhance protection against malicious activity. Network analyzers can supplement firewalls, anti-virus programs, and spyware detection programs.

Network analyzers can:
• Provide detailed statistics for current and recent activity on the network.
• Test anti-malware programs and pin point potential vulnerabilities
• Detect unusual levels of network traffic.
• Detect unusual packet characteristics.
• Identify packet sources or destinations.
• Configure alarms for defined threats.
• Search for specific data strings in packets.
• Monitor bandwidth utilization as a function of time.
• Create application-specific plug-ins.
• Display all statistics on a user-friendly control panel.

Network analyzers are not intended to replace firewalls, anti-virus programs, or spyware detection programs. However, the use of a network analyzer in addition to other countermeasures can minimize the probability that an attack will occur, and can facilitate rapid response in the event an attack begins.