What can John the Ripper be used for?

John the Ripper is a widely recognized password-cracking software tool that is specifically designed to identify weak passwords by using various techniques, including brute force and dictionary attacks. It is particularly effective at cracking passwords stored in different formats, such as those found in Windows systems. The importance of password security cannot be overstated, as weak passwords can provide easy access to unauthorized users, leading to potential security breaches.

The other options focus on tasks that are outside the primary capabilities of John the Ripper. Filing security reports and monitoring network traffic require different tools and strategies relevant to security information and event management or network analysis. Similarly, testing firewall configurations is a specific task that would involve other software solutions designed to assess and validate firewall settings. Thus, John the Ripper is designated for password cracking, making it a unique tool primarily used for that purpose.