fwlogwatch is a packet filter and firewall log analyzer with support for Linux ipchains, Linux netfilter/iptables, Solaris/BSD/HP-UX/IRIX ipfilter, Cisco IOS, Cisco PIX/ASA, Netscreen, Elsa Lancom router, and Snort IDS log files. It can output its summaries in text and HTML and has a lot of options. fwlogwatch also features a realtime anomaly response capability with a Web interface.
Firewall is a set of scripts (firewall, fwup, and fwdown) that implement an ipchains firewall and various forms of network address and port translation. All you have to do is read the policy file and edit it to reflect your topology and filtering policy. It supports many different types of network topology (single host, traditional forwarding, masquerading, port forwarding, alias port forwarding and NAT), up to 10 untrusted interfaces each with their own policy, and over 50 network applications. It also supports centralised administration of multiple remote firewalls (meta-firewall).
Gibraltar is a Debian GNU/Linux-based router/firewall distribution, fully workable from a bootable, live CD-ROM. Log files can be stored on a hard disk, and configuration data is stored on a USB mass storage media or a floppy disk and kept on a RAM disk during run-time. Due to its Debian base, a vast manifold of firewalling, routing, and proxy packages is available. It comes with an intuitive, easy to use Web administration interface and support, and is free to use for home users.
IP Filter is a TCP/IP packet filter suitable for use in a firewall environment. To use, it can either be run as a loadable kernel module (recommended) or incorporated into your kernel. Scripts are provided to install and patch system files as required. IP Filter also supports transparent proxying via packet forwarding, including round-robin forwarding to achieve load-balanced proxy.
The IPchains Firewalling Module, part of the RockSolid Linux Distribution, allows you to easily maintain a firewall based on ipchains with the Webmin look and feel. It has three modes: Newbie (select one of five security levels), Template (define from a table with protocols and directions what should be allowed to pass your firewall), and Expert (have the real ipchains experience by having every parameter under control by editing a script file which has all ipchains rules). Nearly all of the ipchains options are supported.
iptables is built on top of netfilter, the packet alteration framework for Linux 2.4.x and 2.6.x. It is a major rewrite of its predecessor ipchains, and is used to control packet filtering, Network Address Translation (masquerading, portforwarding, transparent proxying), and special effects such as packet mangling.