ipchains
From Wikipedia, the free encyclopedia
ipchains is a free software based firewall for Linux. It is a rewrite of Linux's previous IPv4 firewalling code, ipfwadm. In Linux 2.2, ipchains is required to administer the IP packet filters. ipchains was written because the older IPv4 firewall code used in Linux 2.0 did not work with IP fragments and didn't allow for specification of protocols other than TCP, UDP, and ICMP.
ipchains is superseded by iptables in Linux 2.4 and above.

