From Application Load Balancer access logs, a security engineer observes excessive requests from a single IP address. How can the engineer throttle requests from that IP without completely blocking it?

AWS WAF (Web Application Firewall) with a rate-based rule is the most effective solution. A rate-based rule allows you to specify a threshold for the number of requests allowed from a single IP address within a five-minute period. If the request rate exceeds this threshold, subsequent requests from that IP can be blocked or throttled for a configurable duration, without completely denying all access. An Application Load Balancer rule cannot directly throttle requests based on rate; it primarily routes traffic. AWS Shield primarily provides DDoS protection and does not offer granular, IP-based rate limiting for specific application traffic. Amazon Route 53 GeoLocation routing directs traffic based on the user's geographic location, not on request rates from a specific IP.