Defending the Internet: How Cloudflare blocked a monumental 7.3 Tbps DDoS attack

This post details the autonomous mitigation of a record-breaking 7.3 Tbps DDoS attack, highlighting the scale of the attack (37.4 terabytes in 45 seconds) and its multi-vector nature, primarily UDP floods with smaller percentages of QOTD, Echo, NTP, Mirai UDP, Portmap, and RIPv1 reflection/amplification attacks. It provides detailed breakdowns of each attack vector, including how they work, how to prevent becoming a reflection/amplification participant, and how to defend against them. The post also analyzes the attack origins, noting the significant contributions from Brazil and Vietnam, and the involvement of over 122,000 source IP addresses across 5,433 Autonomous Systems.