Which mode in terraform WAF policy is primarily concerned with blocking traffic?

The mode in a Terraform Web Application Firewall (WAF) policy that is primarily focused on blocking traffic is the prevention mode. When a WAF is configured in prevention mode, it actively filters and blocks potentially harmful requests before they reach the web application. This is a critical feature in protecting applications from various types of attacks, such as SQL injection, cross-site scripting (XSS), and other malicious activities.

In this mode, the WAF doesn't just alert or log suspicious activity; it takes action by denying the traffic that meets certain attack criteria defined in its ruleset. This proactive approach is essential for maintaining the security posture of web applications, especially in environments where sensitive data is handled or where compliance with security regulations is necessary.

Overall, prevention mode serves as a defensive layer, reducing the risk of exploitations and ensuring that applications can operate securely. The other modes, while useful for monitoring and warning purposes, do not actively block traffic, which is the primary function of prevention mode.