“A spoofing attack involves forging one’s source IP address.
It is the act of using one machine to impersonate another. Most of
the applications and tools in Unix systems, including Linux, rely
on source IP address authentication, and many developers have used
host-based access controls to secure their networks. The source IP
address is a unique identifier, but it is not a reliable one.
It can easily be spoofed.”
“To understand the spoofing process, I will begin by explaining
the TCP and IP authentication process. Then I will discuss how an
attacker can spoof your network.”
“TCP uses sequence numbers. When a virtual circuit establishes
between two hosts, TCP assigns each packet a number as an
identifying index. Both hosts use this number for error-checking
and reporting.”