fwknop implements an authorization scheme called Single Packet Authorization that requires only a single encrypted packet to communicate various pieces of information, including desired access through an iptables, ipfw, or pf firewall policy and/or specific commands to execute on the target system. The main application of this program is to protect services such as SSH with an additional layer of security in order to make the exploitation of vulnerabilities much more difficult. The authorization server works by passively monitoring authorization packets via libpcap. Also supported is a robust port knocking implementation based around iptables log messages.
ips-qos is a flexible firewall and traffic shaping tool. It was formerly offered as installers for the popular Linux distributions. The current version is available under Debian GNU/Linux. It was intended to give administrators more control over a shared Internet connection. It includes ips, a flexible and easy-to-use configurable firewall with the ability to control access to the Internet (or selected services) from a LAN. It also includes qos, a traffic shaping tool that measures and controls the traffic load for every computer in a LAN.
fwsnort translates snort rules into an equivalent iptables ruleset. By making use of the iptables string match module, fwsnort can detect application layer signatures which exist in many snort rules. fwsnort adds a --hex-string option to iptables, which allows snort rules that contain hex characters to be input directly into iptables rulesets without modification. In addition, fwsnort makes use of the IPTables::Parse Perl module in order to (optionally) restrict the snort rule translation to only those rules that specify traffic that could potentially be allowed through an existing iptables policy.
Endian Firewall is an all-in-on Linux security distribution that turns any system into a full-featured security appliance. It features a stateful packet inspection firewall, application-level proxies for various protocols (HTTP, POP3, SMTP), anti-virus support, virus and spam filtering for email traffic (POP and SMTP), content filtering of Web traffic, and a "hassle free" VPN system based on OpenVPN.
360-FAAR (Firewall Analysis Audit and Repair) is an offline, command line, Perl firewall policy manipulation tool to filter, compare to logs, merge, translate, and output firewall commands for new policies, in Checkpoint dbedit, Cisco ASA, or ScreenOS commands. It is all contained in one file. It can read policy and logs for: Checkpoint FW1 (in odumper.csv / logexport format), Netscreen ScreenOS (in get config / syslog format), and Cisco ASA (show run / syslog format). It uses both inclusive and exclusive CIDR and text filters, permitting you to split large policies into smaller ones for virutalization at the same time as removing unused connectivity. It supports policy to log association, object translation, rulebase reordering and simplification, rule moves, and duplicate matching automatically. It allows you to seamlessly move rules to where you need them. 'print' mode creates a spreadsheet for your audit needs with one command.
PHREL is a per host rate limiter. It will track the rate of incoming traffic on a server and insert a chain into iptables when a configured threshold is crossed. The inserted chain may either rate limit or block the offending host for a period of time. The inserted chain is automatically removed when the offending host's traffic levels return to normal. PHREL is particularly well suited to protecting nameservers (DNS) from random hosts that flood requests, and to preventing SSH brute force login attempts.
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.
conntrack-tools is a set of userspace tools for Linux that allow system administrators to interact with the Connection Tracking System, the module which provides stateful packet inspection for iptables. It includes the userspace daemon conntrackd and the commandline interface conntrack.