Linux Firewalls: Attack Detection and Response with iptables, psad, and fwsnort

Security information of all kinds, notices and alerts, whitepapers, tutorials, and so on can be found in the following sources:

BugTraq: http://www.securityfocus.com/archive/1

CERT Coordination Center: http://www.cert.org/

CIAC (Computer Incident Advisory Capability): http://www.ciac.org/ciac/

Freshmeat: http://www.freshmeat.net/

Geektools: http://www.geektools.com/

Internet Engineering Task Force (IETF): http://www.ietf.org/

Packet Storm: http://packetstormsecurity.org/

RFC Editor: http://www.rfc-editor.org/

SANS Institute: http://www.sans.org/

Security Focus: http://www.securityfocus.com/