Changing the FortiGate’s inspection mode to flow or proxy
You can select flow or proxy mode from the System Information dashboard widget to control your FortiGate’s security profile inspection mode. Having control over flow and proxy mode is helpful if you want to be sure that only flow inspection mode is used (and that proxy inspection mode is not used). As well, switching to flow inspection mode also turns off the explicit web proxy and the explicit FTP proxy, making sure that no proxying can occur.
In most cases proxy mode (the default) is preferred because more security profile features are available and more configuration options for these individual features are available. Some implementations; however, may require all security profile scanning to only use flow mode. In this case, you can set your FortiGate to flow mode knowing
that proxy mode inspection will not be used.
If you select flow-based to use external servers for FortiWeb and FortiMail you must use the CLI to set a Web Application Firewall profile or Anti-Spam profile to external mode and add the Web Application Firewall profile or Anti-Spam profile to a firewall policy.