What is the difference between volumetric and application-layer DDoS attacks and what defense mechanisms are suitable for each?

Volumetric DDoS attacks aim to overwhelm the network bandwidth with a massive flood of traffic. Defense mechanisms include traffic scrubbing, rate limiting, and CDNs. Application-layer DDoS attacks target specific application vulnerabilities, such as HTTP flood attacks or slowloris attacks. Defense mechanisms here involve behavioral analysis, challenge-response systems, and web application firewalls (WAFs). The choice of defense mechanism depends on the type of attack. Volumetric attacks require bandwidth absorption, while application-layer attacks demand targeted filtering and application-specific protection.