Snort is a network intrusion detection and prevention system. It is the most widely deployed technology of its kind in the world. It performs detection using a variety of methods including rules-based detection, anomaly detection, and heuristic analysis of network traffic. Its rules language is open source and available to the public as well.
Astaro Security Gateway (formerly Astaro Security Linux) is an all-in-one network security gateway that includes a firewall, intrusion protection, antivirus, spam protection, URL filtering, and a VPN gateway. Features include a modern packet filter, intrusion detection and prevention, portscan detection, application control, content filtering, virus detection for email and Web traffic, profile handling, L2TP, IPSec, SSL, and PPTP VPN tunneling, spam blocking, proxies for HTTPS, HTTP, FTP, POP3, SMTP, DNS, VoIP, SOCKS, and Ident, logging, and reporting. It supports Ethernet, VLAN, PPP, PPPoE, PPPoA, Cable Modem, IPv6, QoS, Link Aggregation, and WAN-Uplink-Load balancing in routing, and bridge mode. The WebAdmin GUI, Install Wizard, Change Tracking, Printable Configuration, and Up2Date service make it easy to install, manage, and maintain.
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.
GKrellM is a GTK-based stacked monitor program that charts SMP CPUs, disks, load, active net interfaces, and internet connections. There are also builtin monitors for memory and swap, file systems with mount/umount feature, mailbox checking including POP3 and IMAP, clock/calendar, laptop battery, sensors (temperatures, voltages, and fans), and uptime. It has LEDs for the net monitors and an on/off button and online timer for PPP. There is a GUI popup for configuration, plugin extensions can be installed, and many themes are available. It also features a client/server monitoring capability.
Tor is a network of virtual tunnels that allows people and groups to improve their privacy and security on the Internet. It also enables software developers to create new communication tools with built-in privacy features. It provides the foundation for a range of applications that allow organizations and individuals to share information over public networks without compromising their privacy. Individuals can use it to keep remote Websites from tracking them and their family members. They can also use it to connect to resources such as news sites or instant messaging services that are blocked by their local Internet service providers (ISPs).
DansGuardian is a Web content filtering proxy that uses Squid to do all the fetching. It filters using multiple methods including, but not limited to, phrase matching, file extension matching, MIME type matching, PICS filtering, and URL/domain blocking. It has the ability to switch off filtering by certain criteria including username, domain name, source IP, etc. The configurable logging produces a log in an easy to read format. It has the option to only log text-based pages, thus significantly reducing redundant information (such as every image on a page).
BalanceNG is a modern, IPv6 capable software IP load balancing solution. It is small, fast, and easy to use and set up. It offers session persistence, different distribution methods (Round Robin, Random, Weighted Random, Least Session, Least Bandwidth, Hash, Agent, and Randomized Agent) and a customizable UDP health check agent in source code. It supports VRRP to set up high availability configurations on multiple nodes. It supports SNMP, integrating the BALANCENG-MIB with Net-SNMPD. It implements a very fast in-memory IP-to-location database, allowing powerful location-based server load-balancing.
HAproxy is a high-performance and highly-robust TCP and HTTP load balancer which provides cookie-based persistence, content-based switching, SSL off-loading, advanced traffic regulation with surge protection, automatic failover, run-time regex-based header control, Web-based reporting and management interface, advanced logging to help trouble-shooting buggy applications and/or networks, and a few other features. Its own event-driven state machine achieves 100,000 connections per second and surpasses GigaEthernet on modern hardware, even with tens of thousands of simultaneous connections.
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.