Ipchains
Encyclopedia
Linux IP Firewalling Chains, normally called ipchains, is free software
to control the packet filter/firewall capabilities in the 2.2 series of Linux kernel
s. It superseded ipfwadm, but was replaced by iptables
in the 2.4 series. Unlike iptables, ipchains is stateless.
It is a rewrite of Linux's previous IPv4
firewall, ipfwadm. This newer ipchains was required to manage the packet filter in Linux kernel
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 maximums for packet counting
, filtering for fragmented packets
and a wider range of protocols, 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The ipchains software was superseded by the iptables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 Linux kernel
2.4 and above.
Free software
Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...
to control the packet filter/firewall capabilities in the 2.2 series of Linux kernel
Linux kernel
The Linux kernel is an operating system kernel used by the Linux family of Unix-like operating systems. It is one of the most prominent examples of free and open source software....
s. It superseded ipfwadm, but was replaced by iptables
Iptables
iptables is a user space application program that allows a system administrator to configure the tables provided by the Linux kernel firewall and the chains and rules it stores...
in the 2.4 series. Unlike iptables, ipchains is stateless.
It is a rewrite of Linux's previous IPv4
IPv4
Internet Protocol version 4 is the fourth revision in the development of the Internet Protocol and the first version of the protocol to be widely deployed. Together with IPv6, it is at the core of standards-based internetworking methods of the Internet...
firewall, ipfwadm. This newer ipchains was required to manage the packet filter in Linux kernel
Linux kernel
The Linux kernel is an operating system kernel used by the Linux family of Unix-like operating systems. It is one of the most prominent examples of free and open source software....
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 maximums for packet counting
Counting
Counting is the action of finding the number of elements of a finite set of objects. The traditional way of counting consists of continually increasing a counter by a unit for every element of the set, in some order, while marking those elements to avoid visiting the same element more than once,...
, filtering for fragmented packets
IP fragmentation
The Internet Protocol implements datagram fragmentation, so that packets may be formed that can pass through a link with a smaller maximum transmission unit than the original datagram size....
and a wider range of protocols, 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
Iptables
iptables is a user space application program that allows a system administrator to configure the tables provided by the Linux kernel firewall and the chains and rules it stores...
system in Linux kernel
Linux kernel
The Linux kernel is an operating system kernel used by the Linux family of Unix-like operating systems. It is one of the most prominent examples of free and open source software....
2.4 and above.
External links
- IPChains HOWTO: on TDLP and on FAQs.org