Linux IP Firewalling Chains, normally called ipchains, is

free software Free software, libre software, libreware sometimes known as freedom-respecting software is computer software distributed open-source license, under terms that allow users to run the software for any purpose as well as to study, change, distribut ...

to control the packet filter or firewall capabilities in the 2.2 series of

Linux kernel The Linux kernel is a Free and open-source software, free and open source Unix-like kernel (operating system), kernel that is used in many computer systems worldwide. The kernel was created by Linus Torvalds in 1991 and was soon adopted as the k ...

s. It superseded ipfirewall (managed by ipfwadm command), but was replaced by iptables in the 2.4 series. Unlike iptables, ipchains is stateless.

History

It is a rewrite of Linux's previous

IPv4 Internet Protocol version 4 (IPv4) is the first version of the Internet Protocol (IP) as a standalone specification. It is one of the core protocols of standards-based internetworking methods in the Internet and other packet-switched networks. ...

firewall, ipfirewall. This newer ipchains was required to manage the packet filter in

s starting with version 2.1.102 (which was a 2.2 development release). Patches are also available to add ipchains to 2.0 and earlier 2.1 series kernels. Improvements include larger maxima for packet

counting Counting is the process of determining the number of elements of a finite set of objects; that is, determining the size of a set. The traditional way of counting consists of continually increasing a (mental or spoken) counter by a unit for ever ...

, filtering for fragmented packets and a wider range of

protocols Protocol may refer to: Sociology and politics * Protocol (politics), a formal agreement between nation states * Protocol (diplomacy), the etiquette of diplomacy and affairs of state * Etiquette, a code of personal behavior Science and technology ...

, and the ability to match packets based on the inverse of a rule. The ipchains suite also included some shell scripts for easier maintenance and to emulate the behavior of the old ipfwadm command. The ipchains software was superseded by the iptables system in

2.4 and above, which was in turn superseded by the nftables system in 2014.

References

External links

* IPChains HOWTO
on TLDP
an

{{Linux kernel Discontinued software Firewall software Free network-related software Free security software Free software programmed in C Linux kernel features Linux security software