Snort is a libpcap-based packet sniffer/logger which can be used as a lightweight network intrusion detection system. It features rules based logging and can perform content searching/matching in addition to being used to detect a variety of attacks and probes, such as buffer overflows, stealth port scans, CGI attacks, SMB probes, and much more. Snort has a real-time alerting capabilty, with alerts being sent to syslog, a seperate "alert" file, or as WinPopup messages via Samba's smbclient.
d1197a62590c2b6dfc978fd3c4cf1e82d8e2fbbbd35a5c0f1887101311459725