Which IDS should I use?

Runs on TCP and UDP sockets to detect port scans against your system.
PortSentry is configurable to run on multiple sockets at the same time so you only need to start one copy to cover dozens of tripwired services.
PortSentry will react to a port scan attempt by blocking the host in real-time.

Runs on TCP and UDP sockets to detect port scans against your system.