Author Note: this is a post by long-time Linux kernel networking developer and creator of the Cilium project, Thomas Graf
The Linux kernel community recently announced bpfilter, which will replace the long-standing in-kernel implementation of iptables with high-performance network filtering powered by Linux BPF, all while guaranteeing a non-disruptive transition for Linux users.
From humble roots as the packet filtering capability underlying popular tools like tcpdump and Wireshark, BPF has grown into a rich framework to extend the capabilities of Linux in a highly flexible manner without sacrificing key properties like performance and safety. This powerful combination has led forward-leaning users of Linux kernel technology like Google, Facebook, andNetflix to choose BPF for use cases ranging from network security and load-balancing to performance monitoring and troubleshooting. Brendan Gregg of Netflix first called BPF Superpowers for Linux. This post will cover how these “superpowers” render long-standing kernel sub-systems like iptables redundant while simultaneous enabling new in-kernel use cases that few would have previously imagined were possible….
Over the years, iptables has been a blessing and a curse: a blessing for its flexibility and quick fixes. A curse during times debugging a 5K rules iptables setup in an environment where multiple system components are fighting over who gets to install what iptables rules.