Network Settings for Security
This is a Sun document that describes what many of the most common TCP and UDP network security vulnerabilities exist, as well as how to reduce their threat.
Discover How To Secure My Network HOWTOs
Snort
A one-of-a-kind content-based IDS tool that generates alerts to syslog and/or text files. Comes with more than 1100 attack signatures.
RFC2267: Defeating IP Spoofing
RFC 2267, "Network Ingress Filtering: Defeating Denial of Service Attacks Which Employ IP Source Address Spoofing" by Paul Ferguson and Daniel Senie details methods for filtering spoofed packets on your network
IPTraf
IPTraf is a console-based network statistics utility for Linux. It gathers a variety of figures such as TCP connection packet and byte counts, interface statistics and activity indicators, TCP/UDP traffic breakdowns, and LAN station packet and byte c
Secure Shell
SSH is a powerful, yet easy-to-use application that uses strong cryptography for protecting all transmitted confidential data, including passwords, binary files, and administrative commands.
