Port Scanning is one of the most commonly carried out process amongst Hackers. This text written by Ankit Fadia explains how a port scanner can deduce whether a particular port on a remote system is closed or open. This paper describes the most commonly used port scanning techniques (tcp connect, SYN scan, FIN scan, Xmas/Null scan, UDP port scan).

The purpose of this paper is to explain IP-spoofing to the masses. IP-spoofing is complex technical attack that is made up of several components. In this paper, daemon9 details the attack, including examples and relevant operating system and networking information.

Passive Fingerprinting is a stealth method that can be used to get information about a remote computer. This article written by Lance Spitzner shows a way to determine the operating system and other characteristics of a remote host using nothing more than sniffer traces. Though not 100% accurate, this method can get surprisingly good results.

This paper written by the ADM Crew describes a way to guess DNS ID. This method is based on a vulnerability on DNS Protocol. This technique allows an attacker to spoof DNS answer, and could be used for traffic redirection, man-in-the-middle attacks...