Which practice is NOT a preparation step for handling web application security incidents?

Creating a blacklist of all legitimate IP addresses and protocols is not a practical or effective preparation step for handling web application security incidents. Blacklisting is generally reactive and can lead to operational issues, such as inadvertently blocking legitimate users.

In contrast, the other practices listed are critical components of proactive incident preparation. Analyzing past incidents provides valuable insights that can help in mitigating future threats. Regular security training for staff ensures that all employees are aware of the latest security risks and protocols, fostering a culture of security within the organization. Establishing a communication plan for incident response is essential for coordinating actions during an incident and ensuring that all stakeholders are informed and involved as appropriate. These steps collectively contribute to a more robust security posture, enabling a quicker and more effective response to incidents when they occur.