FortiGate Firewall Flow Mode vs Proxy Mode



flowbase :
faster, but less secure

proxy :
slower, but more secure (as the name suggest, the flow is proxied, like this the client isn' t directly connected to the server, and the fortigate has the entire file to do the security scan)

For best performance, use the same mode for all your scan (AS, IPS, AV, ...).

In general flow based solution is faster, but provides a smaller feature set than proxy.