fli4l is a single-floppy Linux-based ISDN/DSL/ethernet-router. It features configuration with some simple ASCII-files and several possible connection-flavors (in/out/callback, raw IP/PPP, PPPoE).
A portsentry clone written in java designed to run on any platform. You be able to give CLI for blocking access after detection (ie. shell, cmd, bat, etc..), Customizable for all ports on UDP,TCP