In 2017 IPv4 and IPv6 flow offload infrastructure was added, allowing a speedup of software flow table forwarding and hardware offload support. The connection tracking and NAT subsystems are more general and more powerful than the rudimentary versions within ipchains and ipfwadm. Each connects to the Netfilter hooks at different points to access packets.

Whereas ipchains and ipfwadm combine packet filtering and NAT (particularly three specific kinds of NAT, called masquerading, port forwarding, and redirection), Netfilter separates packet operations into multiple parts, described below. Both ipchains and ipfwadm alter the networking code so they can manipulate packets, as Linux kernel lacked a general packets control framework until the introduction of Netfilter. Prior to iptables, the predominant software packages for creating Linux firewalls were ipchains in Linux kernel 2.2.x and ipfwadm in Linux kernel 2.0.x, which in turn was based on BSD's ipfw. In September 2007 Patrick McHardy, who led development for past years, was elected as new chairman of the coreteam. In April 2004, following a crack-down by the project on those distributing the project's software embedded in routers without complying with the GPL, a German court granted Welte an historic injunction against Sitecom Germany, which refused to follow the GPL's terms (see GPL-related disputes). In August 2003 Harald Welte became chairman of the coreteam.

The software they produced (called netfilter hereafter) uses the GNU General Public License (GPL) license, and in March 2000 it was merged into version 2.4.x of the Linux kernel mainline.

As the project grew, he founded the Netfilter Core Team (or simply coreteam) in 1999. Rusty Russell started the netfilter/iptables project in 1998 he had also authored the project's predecessor, ipchains.

Relation of (some of) the different Netfilter components

Fortigate vm license file crack