Netfilter is a part of the technology included in the open-source Linux operating system. Within all of the free software in this operating system, Netfilter is a resource for controlling packets of data and overall network communications. It also represents the part of Linux that programmers use to build firewalls, which provide Internet security for computer networks.
Ipchains and iptables, an older technology, have now been replaced by Netfilter. These kinds of programs previously helped to filter data packets, which are individual bits of a larger Internet or network communication. With Netfilter, programmers can handle packets in different ways, for the purposes of directing network traffic or monitoring network communications. This free network related software gives individual programmers more power to create network oversight programs that serve their individual needs, without buying standardized firewall solutions and installing them in a system.
Netfilter is part of a GPL, or General Public License, category of technology,. This means that instead of being copyright protected for exclusive use, the makers of this technology used other legal means to ensure its free proliferation and use. This kind of software is an example of how public use technologies are rivaling those that are made by individual companies and copyrighted for exclusive sale and use.
One of the things that Netfilter does is filtering packets into different “sessions.” This will show users exactly how smaller packets were part of a larger set of communications within a network or over the Internet. Unlike some Internet “firewall” technologies that are made to secure communications, these free programs promote programmers “building” their own firewalls out of existing technology.
Since Netfilter is part of a “free” software movement, the program is more flexible than copyrighted and vendor-distributed firewall programs. The GPL category of software is an integral part of what is known as the “open source” movement, where a community of programmers distribute software for free use and even alteration. Linux and similar technologies provide a new kind of competition to companies that previously enjoyed more dominance over software distribution. Over time, commonly held skepticisms toward open source software, including concerns about accessibility and user-friendly interfaces, are giving way to programs like Netfilter that offer the prospect of saving money while increasing user-based customization of software.