IP Spoofing: An Introduction

IP spoofing is one of the most common forms of on-line camouflage. In IP spoofing, an attacker gains unauthorized access to a computer or a network by making it appear that a malicious message has come from a trusted machine by "spoofing" the IP address of that machine. This paper examines the concepts of IP spoofing: why it is possible, how it works, what it is used for and how to defend against it.