firewall -- SooSet

This is a filtering tool for a linux-based bridging firewall.

Linux IP Firewalling Chains, normally called ipchains, is free software to control the packet filter/firewall capabilities in the 2.2 series of Linux kernels.

GPL- firewall- filter

iptables 1.4.6

iptables is the userspace command line program used to configure the Linux 2.4.x and 2.6.x IPv4 packet filtering ruleset. It is targeted towards system administrators.

BSD- firewall- filter

dante 1.2.0

Dante is a circuit-level firewall/proxy that can be used to provide convenient and secure network connectivity to a wide range of hosts while requiring only the server Dante runs on to have external network connectivity.

GPL- sock- firewall- qos

firestarter 1.0.3

Firestarter is an Open Source visual firewall program.

GPL- firewall- security

campagnol 0.3.3

Campagnol is a distributed IP-based VPN software able to open new connections through NATs or firewalls without any configuration.

GPL- vpn- nat- firewall- networking

proxyknife 1.7

which is a program mainly used to validate free proxies for the users behind firewall.

GPL- firewall- proxy