netfilter/iptables project homepage - The netfilter.org project Overview & Contact Data

The netfilter.org project serves as the main homepage for the netfilter and iptables ecosystem, a community-driven free and open source software effort that provides packet filtering software for Linux kernels from 2.4.x onward. The site documents the project’s role in the Linux network stack, where netfilter hooks allow kernel modules to register callback functions at defined points in packet processing. Through this framework, developers and administrators can implement stateless and stateful firewall rules, network address and port translation, packet logging, userspace queueing, and header mangling. The project is commonly associated with iptables, the long-standing firewalling tool, and nftables, its successor, which offers a more flexible ruleset model, transactional kernel updates, maps, sets, ingress and egress hooks, flowtables, and scripting support. The website functions as a practical hub for Linux network engineers, system administrators, firewall developers, and kernel contributors. It provides access to downloads, source repositories, mailing lists, bug tracking, patch review, workshop materials, and project documentation. Readers can follow release news for nftables, iptables, libnftnl, libnfnetlink, libnetfilter_conntrack, conntrack-tools, ipset, ulogd, and related libraries. The project also explains licensing under GPL-2.0 and compatible terms, helping users understand the legal basis for the kernel components and userspace utilities it maintains. What makes netfilter.org notable is its long-standing position in Linux networking. It supports the creation of internet firewalls, high-availability firewall clusters, NAT and masquerading setups, transparent proxies, and policy routing when used with tc and iproute2. The site also highlights how nftables consolidates previously fragmented tools such as iptables, ip6tables, arptables, ebtables, and ipset into a consistent syntax, while keeping the project open through public lists, documentation, and community collaboration.