Knocker is asimple and easyto use TCPsecurity portscanner writtenin C to analyzehosts and allof thedifferentservicesstarted onthem. It isavailable forLinux, FreeBSD,HP-UX, andWindows9x/2000/NTand it islicensed underthe GNU GeneralPublic LicenseGPL
IPFire is aLinux firewalldistributionthat is builtfrom source andcomes with lotsof additionalfeatures. It iseasy to set upand administer.It features afirewall withstatefulinspection, acontentfilteringengine, trafficcontrol (QoS),VPN technology,and a lot oflogging.
Dowse is atransparentproxyfacilitatingthe awarenessof ingoing andoutgoingconnections,from, to, andwithin a localarea network. Dowse providesa central pointof soft controlfor all localtraffic: fromARP traffic(layer 2) toTCP/IP (layers3 and 4) aswell asapplicationspace, bychaining afirewall setupto a trasparentproxy setup. Acore featurefor Dowse isthat of hidingall thecomplexity ofsuch a setup.