Worked on enhancing BPF NAT reliability in the cilium repositories, focusing on critical bug fixes for ICMP error handling and TCP checksum correctness. Addressed issues in derailed/cilium by ensuring ICMP error packets included sufficient L4 header data for accurate TCP checksum calculations, following RFC 4884, and added tests for RFC 1191-conformant packets to improve coverage. In DataDog/cilium, corrected inner packet L4 checksum detection and aligned test context length with kernel behavior, reducing edge-case failures. Utilized C programming, BPF, and network programming expertise to deliver more accurate and stable packet processing, with changes supported by comprehensive test updates and clear commit history.