Snort is an open source network intrusion detection and prevention
system. It is capable of performing real-time traffic analysis,
alerting, blocking and packet logging on IP networks. It utilizes
a combination of protocol analysis and pattern matching in order to
detect a anomalies, misuse and attacks.

Snort uses a flexible rules language to describe activity that can
be considered malicious or anomalous as well as an analysis engine
that incorporates a modular plugin architecture. Snort is capable
of detecting and responding in real-time, sending alerts, performing
session sniping, logging packets, or dropping sessions/packets when
deployed in-line.

Snort has three primary functional modes.  It can be used as a packet
sniffer like tcpdump(1), a packet logger (useful for network traffic
debugging, etc), or as a full blown network intrusion detection and
prevention system.

For more information about running Snort on Slackware, please see
README.SLACKWARE.