  The human body has a very effective Immune system used to protect the body
from dangerous foreign pathogens. This paper aims at studying the immunology
and understanding how it works, it also shaded light on the usage of the
immunology principles in the computer network security. It also suggested a new
network security model which detects attacks that invades the LANs. This study
based on human immune system (IS). This model help protecting the datalink
layer by suggesting solution to detect the foreign frames in computer network
traffic. In this model, the frame format is changed in a way that prevents the
sender from sending his MAC address, and he send a unique identifier (ID)
instead. Moreover, a special network switch will replace the sender ID with the
corresponding MAC address and forward the packets to their right destination.
