AWS Shield DDoS

AWS Shield is the DDoS (Distributed Denial of Service) protection service. DDoS attacks flood your application with traffic to make it unavailable. Attackers send millions of requests/second from botnets, hoping to overwhelm your servers. Shield mitigates these attacks automatically. Two tiers: Shield Standard (automatic, free protection on CloudFront, Route53, ELB for layer 3/4 attacks) and Shield Advanced (managed service, layer 7 application attack protection, 24/7 DDoS Response Team, $3k/month).