ABSTRACT
Most organizations control the traffic that crosses into and out of their networks to prevent attacks against their computer systems and to conform with various policy choices.
Network packet filtering and inspection are means to control access to networks and systems. The concept consists of determining whether a packet is allowed to enter or exit a network by comparing the packet’s payload data and/or some fields’ value located in the packet’s header to predefined values. Packet filtering and inspection technology is found in operating systems, firewalls, intrusion detection and prevention systems, and as a security feature of most routers and of some advanced switches.
