Directed by security policies, a FortiGate unit screens network traffic from the IP layer up through the application layer of the TCP/IP stack. This chapter provides a general, high‑level description of what happens to a packet as it travels through a FortiGate unit running FortiOS 5.2.x.
This FortiOS Handbook chapter contains the following sections:
Packet flow describes the life of a packet as it passes through a FortiGate unit
Comparison of inspection types shows how different security functions map to different inspection types.