IPFire is a Linux firewall distribution that is built from source and comes with lots of additional features. It is easy to set up and administer. It features a firewall with stateful inspection, a content filtering engine, traffic control (QoS), VPN technology, and a lot of logging.
homeLANsecurity is a series of shell scripts for loading iptables firewall rules. The goal of these scripts is to provide an easy to manage framework for standard iptables rule sets. The scripts are well documented and are easily edited. It is primarily designed to operate on home or small office gateway Linux system, but the scripts can be easily adapted to protect an individual Linux server or workstation. homeLANsecurity's command set is written to support loading, clearing, saving, restoring, testing, and displaying of iptables rules. The configuration supports NAT, port forwarding of common services, TOS packet mangling, OpenVPN, Squid transparent proxy, IP address banning, adaptive banning, and connection tuning. Custom iptables rules are easily inserted without any editing of the scripts themselves.
Webfwlog is a Web-based firewall log reporting and analysis tool. It allows users to design reports to use on logged firewall data in whatever configuration they desire. Included are sample reports as a starting point. Reports can be sorted with a single click, or "drilled-down" all the way to the packet level, and saved for later use. Supported log formats are netfilter, ipfilter, ipfw, ipchains, and Windows XP. Netfilter support includes ulogd MySQL or PostgreSQL database logs using the iptables ULOG target.
sshdfilter automatically blocks ssh brute force attacks by reading sshd log output in real time and adding iptables rules based on authentication failures. Block rules are created by logging on with an invalid user name, or wrongly guessing the password for an existing account. Block rules are removed after a week to maintain a small list of blocks. It also comes with a LogWatch filter.
DeleGate is a multi-purpose application level gateway or proxy server that mediates communication of various protocols, applying cache and conversion for mediated data, controlling access from clients, and routing toward servers. It translates protocols between clients and servers, converting between IPv4 and IPv6, applying SSL (TLS) to arbitrary protocols, merging several servers into a single server view with aliasing and filtering. It can be used as a simple origin server for some protocols (HTTP, FTP, and NNTP).
Vyatta is a Linux-based routing and security distribution. It is meant to deliver a flexible, affordable alternative to Cisco 1800 through 7200 series routers. Vyatta is also a great virtual router, virtual firewall, virtual security solution for VMware, Xen, XenServer, and KVM virtualization projects.
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.
Nagios is a host, service, and network monitoring system that will watch your network and alert you to problems before your clients or end-users do. The system runs checks on hosts and services that you specify using plugins that return status information to Nagios. When problems are encountered, the system will send notifications to system administrators so that they can take action on the problem. The JumpBox for Nagios gives you a head start to using the system. It eliminates the complexity involved in getting the application installed, and allows you to focus on the configuration for your specific environment. Since Nagios is based on plugins, depending on what you want to do this will vary in complexity.
OpenVPN is a robust and highly configurable VPN (Virtual Private Network) daemon which can be used to securely link two or more private networks using an encrypted tunnel over the Internet. OpenVPN's principal strengths include wide cross-platform portability, excellent stability, support for dynamic IP addresses and NAT, adaptive link compression, single TCP/UDP port usage, a modular design that offloads most crypto tasks to the OpenSSL library, and relatively easy installation that in most cases doesn't require a special kernel module.