Building an eBPF/XDP L2 Direct Server Return Load Balancer from Scratch Coding Lab Now Available (opens in new tab)

Last week, we’ve built an eBPF/XDP NAT-based Layer 4 load balancer. It was a fun project on its own, and it touched several core eBPF concepts: using maps for connection tracking, the bpf_fib_lookup helper, and hashing to select backend servers.