After six months running XDP eBPF programs on production Linux edge servers, the results are clear: packet filter throughput jumped from under 1 Mpps with iptables to over 14 Mpps on a single CPU core, with p99 latency under 3 microseconds. This guide covers how XDP compares to iptables and DPDK, its real-world tradeoffs, and a full implementation of a dynamic blocklist filter and Layer 4 load balancer using eBPF maps.