Portkey is a port-knocking daemon. It allows you to put a simple combination lock on your TCP services and grant access to a port once a client has supplied the correct combination. The combination is supplied by attempting to connect to a specific sequence of closed TCP ports within a configured time period. Access is later revoked after a suitable timeout period.
DMAring demonstrates a novel generic network interface card driver architecture which works in hybrid interrupt-polling mode to deliver superior real-time performance on Linux, Red Hat Linux, or Linux-RTAI-LXRT (a real-time co-kernel for Linux with user level extension). Existing Linux drivers saturate the CPU at a much lower packet rate than the maximum possible wire line packet rate, but this driver allows vanilla network cards to be used for high speed packet capturing.