eBPF/XDP Packet Filtering Offers High-Speed DDoS Mitigation for Linux Servers

A technical guide published on DEV Community by Zyekh Abdul Qadir Jailani on August 4, 2026, details how eBPF and XDP technologies can be used to defend Linux servers against volumetric DDoS attacks. Traditional Linux network processing allocates a kernel socket buffer for every incoming packet, which becomes a bottleneck under high-volume floods reaching tens of millions of packets per second. XDP addresses this by executing eBPF bytecode directly inside the network driver's receive buffer, allowing malicious packets to be dropped before any memory allocation occurs. The approach uses BPF hash maps to maintain dynamic IP blocklists and can process over 10 million packets per second on standard server hardware. The guide also covers compiling XDP programs in C using Clang/LLVM and verifying high-throughput performance through benchmarking.