IPFilter (commonly referred to as ipf) is an open-source software package that provides firewall services and network address translation (NAT) for many Unix-like operating systems. It was created and is maintained by developer Darren Reed. IPFilter supports both IPv4 and IPv6 protocols and operates as a stateful firewall.
Overview
IPFilter is a TCP/IP packet filter suitable for use in a firewall environment. It can be installed as a runtime-loadable kernel module or directly incorporated into the operating system kernel, depending on the specifics of each system. The software's documentation recommends the module approach when possible.
Supported Operating Systems
IPFilter is delivered with or available on the following operating systems:
- FreeBSD
- NetBSD
- Solaris (versions 10 through 11.3)
- illumos (including OpenIndiana)
- HP-UX
- Linux
History
IPFilter was originally part of OpenBSD, but it was removed by Theo de Raadt in May 2001 due to licensing concerns. It was subsequently replaced in OpenBSD by PF (Packet Filter), which was developed by OpenBSD's own developers.
DragonFly BSD removed its support for IPFilter in May 2011.
Oracle Solaris imported the PF firewall from OpenBSD in the 11.3 release and removed IPFilter in the 11.4 release.
Licensing
- Before versions 4.1.35 and 5.1.1: IPFilter License (BSD-like)
- Since versions 4.1.35 and 5.1.1: GNU General Public License v2 (GPLv2)
The author later also licensed version 5.1.2 under the previous BSD-like license for use in the FreeBSD project.
Technical Details
| Attribute | Detail |
|---|---|
| Developer | Darren Reed |
| Stable release | 5.1.2 (22 July 2012) |
| Operating system | FreeBSD, NetBSD, Solaris, illumos (OpenIndiana), Linux, HP-UX |
| Type | Packet filtering / Firewall |
| Website | www.phildev.net/ipf/ |
Related Usage
The term "IPFilter" is also used in other contexts, notably:
- IPFilter Updater — a free, open-source utility for Windows that downloads and updates blocklists for BitTorrent clients such as uTorrent, BitTorrent, and qBittorrent.
- IP filtering — a general network security technique that decides whether to allow or deny traffic based on source or destination IP addresses, operating at Layer 3 of the OSI model.
