The DDoS That Knocked Spamhaus Offline (And How We Mitigated It)
Mar 20, 2013Matthew Prince
Summary
This post details Cloudflare's mitigation of a massive 75Gbps Layer 3 DDoS attack against Spamhaus, highlighting the use of DNS reflection and ACK reflection techniques by attackers. It showcases how Cloudflare's Anycast network effectively dilutes and absorbs such large-scale attacks, preventing them from reaching the customer's servers. The post also emphasizes the importance of educating network operators to close vulnerabilities like open DNS resolvers, which are a major source of these attacks.
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